Australian Weather Mailing List Archives: Tuesday, 2 November 1999

From Subject -------------------------------------------------------------------------------------- 001 Paul Mossman [paulmoss at tpgi.com.au] Re: John from Brisbanes Post about Frigs etc 002 "Leslie R. Lemon" [lrlemon at compuserve.com] Re Doppler effect and strong winds conning the 003 John Woodbridge [jrw at pixelcom.net] RE: Hail, Gales, and a CG from Brisbane S'ly Storms 004 "Mark Hardy" [mhardy at magna.com.au] Re Doppler effect and strong winds conning the radar?? 005 "Leslie R. Lemon" [lrlemon at compuserve.com] Re Doppler effect and strong winds conning the 006 Paul_Mossman at agd.nsw.gov.au Re Doppler effect and strong winds conning the radar?? 007 "Halden Boyd" [haldenboyd at hotmail.com] Re Doppler effect thanks Leslie 008 Anthony Cornelius [cyclone at flatrate.net.au] Re Doppler effect and strong winds conning the radar?? 009 "Leslie R. Lemon" [lrlemon at compuserve.com] Re Doppler effect and strong winds conning the 010 "Dane Newman" [dpn at bigpond.com] Possible storms later in the week 011 "Leslie R. Lemon" [lrlemon at compuserve.com] Re Doppler effect thanks Leslie 012 Michael Scollay [michael.scollay at telstra.com. Dry Winds and Allergy... 013 Lindsay [writer at lisp.com.au] Dry Winds and Allergy... 014 Paul_Mossman at agd.nsw.gov.au Dry Winds and Allergy... 015 Jimmy Deguara [jdeguara at ihug.com.au] elcome Leslie 016 "Ben Tichborne" [tich at netaccess.co.nz] Dry Winds and Allergy... 017 "Ben Tichborne" [tich at netaccess.co.nz] Re Doppler effect and strong winds conning the radar?? 018 Jimmy Deguara [jdeguara at ihug.com.au] NSW ASWA meeting 6th November 019 Jimmy Deguara [jdeguara at ihug.com.au] More on the ASWA meeting 020 Jimmy Deguara [jdeguara at ihug.com.au] Please support the ASWA newsletter 021 Jimmy Deguara [jdeguara at ihug.com.au] Re: uk.sci.weather 022 Anthony Cornelius [cyclone at flatrate.net.au] [Fwd: Reminder Notice of ASWA Meeting] 023 "Michael Thompson" [michaelt at ozemail.com.au] Entry Level SLR cameras getting cheap ! 024 "Michael Thompson" [michaelt at ozemail.com.au] Dry Winds and Allergy... 025 "Michael Thompson" [michaelt at ozemail.com.au] Re Doppler effect and strong winds conning the radar?? -------------------------------------------------------------------------------------- 001 Date: Tue, 02 Nov 1999 00:16:49 +1100 From: Paul Mossman [paulmoss at tpgi.com.au] X-Mailer: Mozilla 4.08 [en] (Win98; I) To: aussie-weather at world.std.com Subject: aus-wx: Re: John from Brisbanes Post about Frigs etc Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Nature is such a complicated machine we dont know much about - but it does seem to have "in built" weather forecasting More examples: 1. Ants scurrying around before rain. 2. The "storm" bird - never ceases to amaze me......nearly 100% accuracy! And its widespread 3. Certain Frogs "croak" during periods of high humidity before & after rain 4. Cows lying down on the grass anyone else come up with any "natural" weather tools? Paul (maybe we can keep a log of some sorts of Australian weather tools!). +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 002 Date: Mon, 1 Nov 1999 10:41:28 -0500 From: "Leslie R. Lemon" [lrlemon at compuserve.com] Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? To: "INTERNET:aussie-weather at world.std.com" [aussie-weather at world.std.com] X-MIME-Autoconverted: from quoted-printable to 8bit by europe.std.com id KAA02957 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Halden: >However, there was not much of a show on the Grafton local >radar....could this be because the rain was moving away from it that the >Doppler effect could have "fooled" the radar??? >I would be interested in your comments. I have recently joined this group. As my signature entry testifies, I am a long time (30 years) radar, severe storms, and research meteorologist. My research and that of two colleagues at the US National Severe Storms laboratory in Norman, OK, lead to the NEXRAD program. I joined industry and designed and developed much of the WSR-88D (NEXRAD) system. This very brief background is supplied in order to comment on your question. I believe the radar you question is a conventional and not a Doppler weather radar. However, in either case the "Doppler effect" is not responsible for what you describe. Due to the fact that I have not seen the radar images you speak of nor do I know the geography of the area (I am in the states) or the radar type, all I can do is speculate. Perhaps I should not even do that. But I will venture a guess or two. First, the radar you speak of is probably a C-band (~ 5 cm wavelength) radar which is prone to "attenuate" due to rain and/or hail falling on the radome of the radar, if it is raining at the radar site. Additionally, intervening rain and/or especially hail between the radar and the storm you speak of would also seriously attenuate the radar returns from the storm in question making it appear to be significantly weaker than it would otherwise appear. Attenuation, of course, speaks of radar signal depletion due to absorption of the microwave energy transmitted by the radar. If the Grafton local radar you speak of is an X-band (~ 3 cm wavelength) the attenuation is even a factor of 10 worse than C-band radars! And C-band radars are a factor of 10 worse than the S-band (10 cm) network weather radars such as NEXRAD. Thus, attenuation is a likely suspect for the problem you mention. However, it could be that the storm is "on top" of the radar and therefore the radar could not obtain a good view of the storm, in any case, in addition to the attenuation. Another factor, could be that the calibration (one might refer to this as the "tuning accuracy") of the radar might be poor. There are a few other possibilities such as beam blockage, but I will not go into those here. I hope this response is not too technical nor too elementary for you or for the group. I must also again say that I am so unfamiliar with the area or the radar in question, I may have responded incorrectly. If so, please forgive me and my ignorance. Finally, since I joined this group I have been impressed with the knowledge and enthusiasm of its members; you all are to be congratulated on both. Thank you for permitting me to attempt to contribute something of possible value. Les ************************ Leslie R. Lemon Radar, Severe Storms, & Research Meteorologist Phone: 816-373-3533 E-Mail: lrlemon at compuserve.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 003 From: John Woodbridge [jrw at pixelcom.net] To: "'aussie-weather at world.std.com'" [aussie-weather at world.std.com] Subject: RE: aus-wx: RE: Hail, Gales, and a CG from Brisbane S'ly Storms Date: Tue, 2 Nov 1999 02:57:45 -0000 Organization: Pixel Components Pty Ltd X-Mailer: Microsoft Internet E-mail/MAPI - 8.0.0.4211 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Anthony/James, I think the wind action must have been local, mainly to the coast & largely associated with a small squall line which moved in, early afternoon. I got a very average photo of stuff falling from clouds. Not a lot of wind at Sumner, certainly not a gale, I would say 50km/hr tops. No rain all day, except for a very light pricking drizzle that set in around 5:00pm. Bit better story at Mt. Crosby, with 5.0mm falling mid-afternoon to add to the 25mm overnight stuff. No evidence of strong wind however. John. >snip To Anthony and List: Gusty SE Change through the Western suburbs at about 1:20, with light rain starting at 2:30 with a period of heavy for about 10 minutes after that. The wind was savage at times just before the downpour. I did hear a report on 4BC that there was hail reported at Kenmore, however most places it would of been none or too small to recognise. Michael Hi all! An interesting, yet rather unusual and short "chase" around my area today. I was hoping for some cells to occur right on the front, but it wasn't looking too promising, with a lot of 'muck' cloud around this morning. However, I was watching a large Cu/congestus that was dumping very heavy rain near James Chambers' house. About 10 minutes later, I looked outside again to notice that it had now developed into a Cb, it wasn't very strong, certainly not much height, but some fairly crisp updrafts. This prompted me to go down to my "spotting" place. I was dismayed as I was putting on my shoes, that the S'ly suddenly picked up, very soon it was reaching well in excess of gale force. Lots of small branches down here, and leaves everywhere. I quickly sped out of the garage, afraid that it'd collapse before I could even get a good view of it. My AC had broken, so I had wound all the windows down (it was still fairly warm), only to try and wind them all up in a hurry, as further gales buffeted the car in the local streets, and leaves/twigs were blowing everywhere - even into the car! I was happy to see more development to my north, but was unable to follow this up any further. I continued down Belmont and Meadlowlands Rd, to a small park at the back of Carina. The winds were still very strong, still buffeting the car. The development then began to take on an explosive look, with an updraft to my ENE taking on for a very short period of time, a nuclear bomb look (of course, as soon as I got to my advantage point, this was nowhere as good - I was unable to stop along Meadowlands Rd, as there's no shoulder). At the carpark/park it was still blowing about a 20kn S'ly, it began to get very cold, I was shivering (only had t-shirt/shorts) probably was about 23C or so by now! To my amazement, I saw a CG to my S - this prompted me to turn on the radio. When I entered the carpark, there was no one there, so I pointed the car south (so I could sit down and watch the development if I got too lazy), however when I got back in the car to put the radio on and adjust the AM radio, I still had my leg out of the car - a bit of a mistake! Another very strong gust came through, probably in excess of 45-50kn, it slammed the car door on my leg, and then I heard a large crack, I wasn't sure what it was, but I suspect it was a tree going down (a rather bushy/tree area on the northern side of the carpark). None-the-less, I stayed at the carpark, watching a large "roll" (not really a foot, but when the rain is just being blown well ahead of the cell in one big mass). I also noticed some light, white streaks to my W - I still stayed at the carpark, as I was fairly safe, the only trees were to my N, and the wind was a strong S'ly. Very soon, it began to drizzle, I estimated the storm to be at least 7-10km though. It gradually got heavier, until I got back in the car and waited for a while...until the drops got very large. I thought it'd be high time to get out of there...it's about a 300m drive-way into the carpark...I was going out at about 15km/h, when suddenly it POURED, it was also accompanied by yet another burst of gales and hail!!! Only pea size, but it made a loud 'pint' on the car roof. Even though I was driving slowly (15km/h), I was driving towards the S, I had to have the windscrean wipers on full to see the road (or driveway), this only lasted for about one minute though! By the time I got back on the road, it was well and truly over, with only moderate rain. I wound the window down...brrrr!!! It was ICY, now about 19/20C. At the moment, there's a conglomeration of cells over western Brisbane, similar to one ones I saw, I wouldn't be surprised to hear of more hail and gales. Any other interesting reports Brisbanites? Certainly not what one would expect in Brisbane on the 1st of November, but it was better than fine weather! +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 004 X-Mailer: Microsoft Outlook Express Macintosh Edition - 4.5 (0410) Date: Tue, 02 Nov 1999 07:29:16 +1100 Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? From: "Mark Hardy" [mhardy at magna.com.au] To: aussie-weather at world.std.com Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Morning all, Leslie's mail prompted me to remember that the Bureau have some excellent web pages describing all their radar sites in detail. It also provides some excellent insight into interpreting radar images. For those of you that have not read this, I would suggest it is a must if you even only occasionally use the BoM's radar images. This explanation can be found at: http://www.bom.gov.au/reguser/by_prod/radar/radarexp.shtml Mark -- _____________________________________________________ Mark Hardy. The Weather Company Pty. Ltd. Level 2, 7 West Street, North Sydney 2060 Ph (02) 9955 7704. Fax (02) 9955 1536. Mobile 0414 642 739 email: mhardy at theweather.com.au _____________________________________________________ ---------- >From: "Leslie R. Lemon" >To: "INTERNET:aussie-weather at world.std.com" >Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? >Date: Tue, 2 Nov 1999 2:41 AM > > Halden: > >>However, there was not much of a show on the Grafton local >>radar....could this be because the rain was moving away from it that the >>Doppler effect could have "fooled" the radar??? >>I would be interested in your comments. > > I have recently joined this group. As my signature entry testifies, I am a > long time (30 years) radar, severe storms, and research meteorologist. My > research and that of two colleagues at the US National Severe Storms > laboratory in Norman, OK, lead to the NEXRAD program. I joined industry > and designed and developed much of the WSR-88D (NEXRAD) system. This very > brief background is supplied in order to comment on your question. > > I believe the radar you question is a conventional and not a Doppler > weather radar. However, in either case the "Doppler effect" is not > responsible for what you describe. Due to the fact that I have not seen > the radar images you speak of nor do I know the geography of the area (I am > in the states) or the radar type, all I can do is speculate. Perhaps I > should not even do that. But I will venture a guess or two. > > First, the radar you speak of is probably a C-band (~ 5 cm wavelength) > radar which is prone to "attenuate" due to rain and/or hail falling on the > radome of the radar, if it is raining at the radar site. Additionally, > intervening rain and/or especially hail between the radar and the storm you > speak of would also seriously attenuate the radar returns from the storm in > question making it appear to be significantly weaker than it would > otherwise appear. Attenuation, of course, speaks of radar signal depletion > due to absorption of the microwave energy transmitted by the radar. If the > Grafton local radar you speak of is an X-band (~ 3 cm wavelength) the > attenuation is even a factor of 10 worse than C-band radars! And C-band > radars are a factor of 10 worse than the S-band (10 cm) network weather > radars such as NEXRAD. Thus, attenuation is a likely suspect for the > problem you mention. However, it could be that the storm is "on top" of > the radar and therefore the radar could not obtain a good view of the > storm, in any case, in addition to the attenuation. Another factor, could > be that the calibration (one might refer to this as the "tuning accuracy") > of the radar might be poor. > > There are a few other possibilities such as beam blockage, but I will not > go into those here. I hope this response is not too technical nor too > elementary for you or for the group. I must also again say that I am so > unfamiliar with the area or the radar in question, I may have responded > incorrectly. If so, please forgive me and my ignorance. > > Finally, since I joined this group I have been impressed with the knowledge > and enthusiasm of its members; you all are to be congratulated on both. > Thank you for permitting me to attempt to contribute something of possible > value. > > Les > > ************************ > Leslie R. Lemon > Radar, Severe Storms, & Research Meteorologist > Phone: 816-373-3533 > E-Mail: lrlemon at compuserve.com > > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 005 Date: Mon, 1 Nov 1999 16:01:03 -0500 From: "Leslie R. Lemon" [lrlemon at compuserve.com] Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? To: "INTERNET:aussie-weather at world.std.com" [aussie-weather at world.std.com] Cc: "Leslie R. Lemon" <102177.2336 at compuserve.com> X-MIME-Autoconverted: from quoted-printable to 8bit by europe.std.com id QAA04198 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Thanks very much for this! I was unaware of its existence, obviously. Les +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 006 From: Paul_Mossman at agd.nsw.gov.au X-Lotus-FromDomain: NSW_AG To: aussie-weather at world.std.com Date: Tue, 2 Nov 1999 08:57:06 +1000 Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Leslie Welcome!! All I can say is WOW - you are most welcome on this list! The wealth of knowledge that you can add would be fascinating & very informative! Keep it up! Paul Mossman +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 007 X-Originating-IP: [203.2.218.1] From: "Halden Boyd" [haldenboyd at hotmail.com] To: aussie-weather at world.std.com Subject: Re: aus-wx: Re Doppler effect thanks Leslie Date: Mon, 01 Nov 1999 15:09:53 PST Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Thanks Leslie very much for the information....at the time there was a pretty heavy rain band over the radar some 100kms to the south, so what you describe is probably what was happening. Thanks once again...Halden >From: "Leslie R. Lemon" >Reply-To: aussie-weather at world.std.com >To: "INTERNET:aussie-weather at world.std.com" >Subject: Re: aus-wx: Re Doppler effect and strong winds conning the >radar?? >Date: Mon, 1 Nov 1999 10:41:28 -0500 > >Halden: > > >However, there was not much of a show on the Grafton local > >radar....could this be because the rain was moving away from it that the > >Doppler effect could have "fooled" the radar??? > >I would be interested in your comments. > >I have recently joined this group. As my signature entry testifies, I am a >long time (30 years) radar, severe storms, and research meteorologist. My >research and that of two colleagues at the US National Severe Storms >laboratory in Norman, OK, lead to the NEXRAD program. I joined industry >and designed and developed much of the WSR-88D (NEXRAD) system. This very >brief background is supplied in order to comment on your question. > >I believe the radar you question is a conventional and not a Doppler >weather radar. However, in either case the "Doppler effect" is not >responsible for what you describe. Due to the fact that I have not seen >the radar images you speak of nor do I know the geography of the area (I am >in the states) or the radar type, all I can do is speculate. Perhaps I >should not even do that. But I will venture a guess or two. > >First, the radar you speak of is probably a C-band (~ 5 cm wavelength) >radar which is prone to "attenuate" due to rain and/or hail falling on the >radome of the radar, if it is raining at the radar site. Additionally, >intervening rain and/or especially hail between the radar and the storm you >speak of would also seriously attenuate the radar returns from the storm in >question making it appear to be significantly weaker than it would >otherwise appear. Attenuation, of course, speaks of radar signal depletion >due to absorption of the microwave energy transmitted by the radar. If the >Grafton local radar you speak of is an X-band (~ 3 cm wavelength) the >attenuation is even a factor of 10 worse than C-band radars! And C-band >radars are a factor of 10 worse than the S-band (10 cm) network weather >radars such as NEXRAD. Thus, attenuation is a likely suspect for the >problem you mention. However, it could be that the storm is "on top" of >the radar and therefore the radar could not obtain a good view of the >storm, in any case, in addition to the attenuation. Another factor, could >be that the calibration (one might refer to this as the "tuning accuracy") >of the radar might be poor. > >There are a few other possibilities such as beam blockage, but I will not >go into those here. I hope this response is not too technical nor too >elementary for you or for the group. I must also again say that I am so >unfamiliar with the area or the radar in question, I may have responded >incorrectly. If so, please forgive me and my ignorance. > >Finally, since I joined this group I have been impressed with the knowledge >and enthusiasm of its members; you all are to be congratulated on both. >Thank you for permitting me to attempt to contribute something of possible >value. > >Les > >************************ >Leslie R. Lemon >Radar, Severe Storms, & Research Meteorologist >Phone: 816-373-3533 >E-Mail: lrlemon at compuserve.com > > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ > ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 008 Date: Tue, 02 Nov 1999 09:07:28 +1000 From: Anthony Cornelius [cyclone at flatrate.net.au] X-Mailer: Mozilla 4.6 [en] (Win98; I) X-Accept-Language: en To: aussie-weather at world.std.com Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Leslie, Halden and all, Halden Boyd wrote: > > I was in Lismore today and it rained quite a bit. The wind was howling from > the south and the rain was coming down at about a 45 degree angle to the > ground. However, there was not much of a show on the Grafton local > radar....could this be because the rain was moving away from it that the > Doppler effect could have "fooled" the radar??? > I would be interested in your comments. I personally don't think it's quite the doppler effect, but I believe that it may be possible that the wind does have something to do with the way the radar was detecting the rain. Although one would really need to know what the winds were around the radar level. It could be possible, that the wind would help in scattering the rain, ie, instead of the rain falling over a 10km^2 area, the wind pushes this and spreads it out, and spreads it over say a 15km^2 area. But one would imagine this to be more noticable at the ground, and not really at radar level. A few months ago, a similar thread came on the list, and I posted the following email, perhaps Leslie would be so kind as to tell me if I'm correct, or if I'm totally off. Email is below: Subject: aus-wx: Incoherrent radar observations vs rainfall totals. Date: Tue, 13 Apr 1999 21:30:54 +1000 Hi all, Ok - I'm going to try and attempt to give a better answer to Ben's question about colours on radar then I did before. I did a little research in the university library, and I found out some fairly interesting information, that I'm going to put forth here some opinions and idea's, I'd especially like it if some of our physicists here could comment :) Please note that there is a lot of concepts I still do not understand, and I've had to read over some of the information several times - for this reason, I've tried to make it "simpler" for all to understand by using basic English! (ie, my own words) and not because I do not believe people won't be able to understand the technical jargon, but rather because I'm sure many of you here do not want to be sitting here reading over this email 2-3 times to try and understand what I'm saying! Essentially, the question (how I personally interpreted it was) why does some areas under (for example) yellow intensity on one day, receive much more higher totals then another area on a completely different day (with different atmospheric conditions) which still showed a very similar radar reflectivity pattern. There are a plethora of variables that need to be taken into account, one of these was already brought up previously. That is wind speed, strong, squally winds often have a dramatic effect on the total of rainfall, as the rain gauge no long becomes a proper representative area (ie, it is now possibly too small to give an accurate measure of rainfall). Certainly, this could explain some instances, but have been a host of incidences that I know of where winds have only been generally light at the surface. Before we can continue, it is critical to note that only rain events and coastal showers will be used as examples (because these are the events that appear to be where radar 'underestimates.') Again, another important factor is the fact that 90-95% of coastal showers are intense, small droplets of rain. Thunderstorms, on the other hand generally have very large drops of rain (however there can be, and are at times exceptions to this.) Thunderstorms also tend to appear on radar, fairly representative of the actual rainfall received, coastal showers and rain events however do not. I have personally been in coastal showers that have had 100mm+/hr rainfall rates and have not shown well on radar (even what appears to be fairly widespread rates). Given this above information, lets look into how radar works. Radar works on a method of reflectivity, that is, it shoots a microwave beam out into the sky, and then measures the amount of reflectivity that is received, and thus corresponds to the different intensities of radar. So if no reflectivity is received, the radar/computer will read this as no precipitation. However, during this process of reflectivity, there are a myriad of variables that could possibly alter both the path of the microwaves to the precipitation and back to the radar dish. There are two main variables, the scattering of the radar beam by the droplets of rain, and the absorption of the radar beam by the rain droplets. The sum of both of these variables is referred to as the "attenuation." The attenuation is effected greatly by the intensity of rainfall, the greater the rainfall, the greater the attenuation. This is because the higher the intensity of rainfall, the larger the volume of water is, the more microwave energy is absorbed. This is the same for the scattering, however it could be slightly different. This is where my limited area of physics knowledge comes in, I cannot understand the equations given to explain some of the processes. So I'll be deducting a few hypotheses and making a few assumptions from here on. The scattering of microwave energy, is somewhat proportional to the volume of water precipitating. However, from what I could interpret from the information given, that this is also affected by the frequency of the drops, and the size of the drops. So here's a theory, that the scattering of microwave energy is proportional to the frequency of raindrops, and the size of raindrops. However, the frequency of rain drops would have the greater influence of the scattering, and thus the attenuation of a radar beam. The reason for this is because although a large raindrop, would 'catch' more radiation, a radar beam would not pass through many large raindrops, and thus the overall scattering effect would be reduced. However, with many small raindrops, the scattering effect would be magnified by many times as the radar beam would hit many more raindrops, each giving a degree of scattering. Lets assign some theoretical values for the scattering of radar beams, by raindrops (we'll ignore the absorption of the radar beam for the time being for ease of understanding.) Lets say that after passing through one, small raindrop, a beam loses 0.0001% of it's energy. As it passes through rain, it hits many of these raindrops, lets say 20 raindrops per meter x centimeter (again, another theoretical value) That is now 20,000 raindrops per kilometer For that kilometer, it has now lost 2% of it's total energy, for the next kilometer, it'll lose another 2% (ok, it won't lose 2%, because there's only 98% energy left, so it'll lose about ~1.96%, however for this example, 2% is close enough). A similar example could be used for less frequent, larger drops, however it won't hit as many larger drops, and thus, would could say that the scattering would be less (even though the drops are larger). Do you understand what I am saying here? That perhaps, the small drops are so intense and frequent, that the scattering of the radar beam is amplified many many times. And remember this, that not only does the radar beam have to pass through the precipitation, but any reflection has to additionally pass through any precipitation it had just passed through, and will get scattered once again! I have figures for theoretical values of the attenuation, if we use 10cm waves for our radar, and have a rainfall intensity of 16mm/hr there'll be a 0.01db/km loss (db is just another way of measuring rainfall from radar, it works on a logarithmic scale, and if you're wondering, yes the graph does compensate for the logarithmic scale). This is just one way, so if radar passes through 100km of precipitation (ie a rain event) you can expect to lose (0.01 X 100) X 2 = 2db of radar beam just due to the attenuation. These, however, are theoretical values, and take into account the average rain drop size/intensity, when clearly, this is often not the case. After all this, I am therefore proposing, that the small, intense droplets of rain, actually scatter the radar beam more then thought. Radar, should have built into it, a calculation that helps deal with the attenuation, however it cannot be feasibly changed for each rain event , and may in fact be programmed to most accurately calculate the major situations (ie thunderstorms). As a general rule, there are two types of precipitation that occur during coastal showers, the small intense drops (as mentioned before, these are the most frequent) and the larger, less intense drops (much less frequent). At times, there can be large, intense drops (ie the 110mm of rain that fell in two hours earlier this year from a very heavy 'shower.' Yet radar showed a general 10-20mm/hr with some 20-40mm/hr in the area - a far cry from the 55mm/hr expected! So what happened here? Well, as I just mentioned, the frequency of the drops and the size of the drops effect how rain drops are scattered. However, we also have to remember that this type of rainfall is analogous to storm rainfall (the large, intense drops of rain). This certainly complicated this for me, and literally 'blew' my theory apart. Especially since the heavy coastal showers are often about the same size of a thunderstorm. So I'm going to introduce another concept, one that I'm not too familiar with, so again, please bear with me! While talking to Jeff Callaghan (head of severe wx in QLD) he mentioned that some radar situations, do not show up particularly well on radar. Particularly, coastal squall line situations. The reason being the "salt nuclei" in the air, apparently this absorbs a lot of the radiation(?) If we go back to what I was saying and look at the keyword "coastal" in "coastal showers" one could certainly assume that the salt nuclei concentration would have to be fairly high (especially with an onshore wind) and could quite possibly absorb some of the microwave energy from the radar beam. Please note, that this is all just my deduction, and it's not all coming from written material, so don't take it as the actual truth. Because it's only my interpretation/opinions to try and answer, what I believe is, a very interesting question. Well, I certainly believe that I have put in my 2c in this subject, anyone else care to do the same? -- Anthony Cornelius Queensland Coordinator of the Australian Severe Weather Association (ASWA) (07) 3390 4812 14 Kinsella St Belmont, Brisbane QLD, 4153 Please report severe thunderstorms on our Queensland severe thunderstorm reporting line on (07) 3390 4218 or by going to our homepage at http://www.severeweather.asn.au +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 009 Date: Mon, 1 Nov 1999 18:24:09 -0500 From: "Leslie R. Lemon" [lrlemon at compuserve.com] Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? To: "INTERNET:aussie-weather at world.std.com" [aussie-weather at world.std.com] Cc: "Leslie R. Lemon" <102177.2336 at compuserve.com> X-MIME-Autoconverted: from quoted-printable to 8bit by europe.std.com id SAA29221 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Thank you very much for that vote of confidence. I appreciate very much the welcome! I hope I can help at times, please don't hesitate to ask specific questions and I will answer as I am able. Les ************************ Leslie R. Lemon Radar, Severe Storms, & Research Meteorologist Phone: 816-373-3533 E-Mail: lrlemon at compuserve.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 010 From: "Dane Newman" [dpn at bigpond.com] To: [aussie-weather at world.std.com] Subject: aus-wx: Possible storms later in the week Date: Tue, 2 Nov 1999 11:29:45 +1100 X-Mailer: Microsoft Outlook Express 4.72.3110.1 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com

Hi all, we had 68mm of rain here in Kilsyth for October Ave is 81mm. 2 thunderdays, 1 day of hail(small) and fogs on 2 days. Ave max was 20.2c ave min was 9.1c. Currently (11.20am) temp is 17c dew pt 6c Bar 1029S Wind light southerly Cloud 1 ockta Small Cu. Looks like a low pressure trough will start to affect weather over Victoria on Thursday or Friday. This trough should still be affecting Victoria on Saturday, instability with this trough should should see the development of isolated showers and thunderstorms over the state, slight chance tomorrow in western and northwestern districts and more likely Thursday to Saturday in most districts, lets hope so anyway. Dane (Kilsyth) Melbourne. BTW my tip for the cup is No 11 Streak I would back it though my horse racing skills are even worse than my weather forecasting skills.

011 Date: Mon, 1 Nov 1999 20:26:19 -0500 From: "Leslie R. Lemon" [lrlemon at compuserve.com] Subject: Re: aus-wx: Re Doppler effect thanks Leslie To: "INTERNET:aussie-weather at world.std.com" [aussie-weather at world.std.com] X-MIME-Autoconverted: from quoted-printable to 8bit by europe.std.com id UAA18245 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Halden and all: You are welcome. However, I did look up the Grafton local radar (as indicated by Mark Hardy, at: ) and found it, as I recall, to be a 74 S-band radar. Because it is an S-band radar, the attenuation should be on the order of 0.1 db per km (one way).....or only a minor attenuation except along the axis of the line itself. Thus, it may be necessary to consider some of the other possibilities I suggested. I guess the bottom line is that I would probably need to see the image and know more of the particulars to attempt to better answer the question. Sorry, I hope I have not confused the issue! Les ************************ Leslie R. Lemon Radar, Severe Storms, & Research Meteorologist Phone: 816-373-3533 E-Mail: lrlemon at compuserve.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 012 Date: Tue, 02 Nov 1999 13:06:56 +1100 From: Michael Scollay [michael.scollay at telstra.com.au] Organization: Telstra Strategy & Research X-Mailer: Mozilla 4.5 [en] (X11; I; SunOS 5.5.1 sun4m) X-Accept-Language: en To: aussie-weather at world.std.com Subject: Re: aus-wx: Dry Winds and Allergy... Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Michael Thompson wrote: > > I get Asthma, yet when I went to the US for 2 months back in 1985 > I never suffered once with it. Different allergens are responsible in different places and seasons. > I have heard a theory that Australian babies are simply not exposed > to enough ' normal ' germs and viruses. A too clean early childhood. > The result is the immune system says OK what do I do now, then starts > fighting things that are not really a threat such as pollens and dust > mites. There's also a study conducted soon after the Berlin Wall was brought down. West Berliners had many more asthma sufferers than East Berliners. Researchers put it down to West Berliners having "hyper-sensitised immune response". Their access to anti-biotics, an overly clean environment, an absence of childhood diseases etc. is believed to be partly responsible but I do not have the full report available to refer too. > Then there are Asthma sufferers that say thunderstorms send them > into an attack, now that is what I can unfortunate in the extreme. My previous post highlighted the results of research into this factor - apparently saturated pollen breaking down to smaller allegen particals that can penetrate deep with the lungs thereby causing asthma. Michael Scollay mailto:michael.scollay at telstra.com.au +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 013 Date: Mon, 01 Nov 1999 10:57:23 -0800 From: Lindsay [writer at lisp.com.au] X-Mailer: Mozilla 3.0 (Win16; I) To: aussie-weather at world.std.com Subject: Re: aus-wx: Dry Winds and Allergy... Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Nandina, Thanks for your info. I'm not sure if the easterlies would affect us too much as they are typically moist/cloud laden or misty around here. The North West winds seem to do it up here. Then again, maybe the easterlies up here do have a sinister impact on the sinuses. All i know is that it has been a bad year for allergy which is funny considering all the rain. Lindsay Pearce Nandina Morris wrote: > > G'day Lindsay > I have found winds from the east will generally produce sinus and hayfever problems, and have had many friends complain too, although they didn't realise the connection. Once I pointed it out, they kept a watch on things, and sure enough, it's the easterlies over spring/summer that do it. Don't know why. > PS your mails got thru! > Cheers, > > Nandina > nandina at alphalink.com.au > > ---------- > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 014 From: Paul_Mossman at agd.nsw.gov.au X-Lotus-FromDomain: NSW_AG To: aussie-weather at world.std.com Date: Tue, 2 Nov 1999 13:21:15 +1000 Subject: Re: aus-wx: Dry Winds and Allergy... Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi Lindsay, Nandina, Michael & allergy sufferers! I suffer most from the SW'ers....... everytime they arrive I just die! Go Tie the Knot!!!! Paul. Lindsay on 02/11/99 04:57:23 AM Please respond to aussie-weather at world.std.com To: aussie-weather at world.std.com cc: (bcc: Paul Mossman/LCO/NSW_AG) Subject: Re: aus-wx: Dry Winds and Allergy... Hi Nandina, Thanks for your info. I'm not sure if the easterlies would affect us too much as they are typically moist/cloud laden or misty around here. The North West winds seem to do it up here. Then again, maybe the easterlies up here do have a sinister impact on the sinuses. All i know is that it has been a bad year for allergy which is funny considering all the rain. Lindsay Pearce Nandina Morris wrote: > > G'day Lindsay > I have found winds from the east will generally produce sinus and hayfever problems, and have had many friends complain too, although they didn't realise the connection. Once I pointed it out, they kept a watch on things, and sure enough, it's the easterlies over spring/summer that do it. Don't know why. > PS your mails got thru! > Cheers, > > Nandina > nandina at alphalink.com.au > > ---------- > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 015 X-Sender: jdeguara at pop.ihug.com.au X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.58 Date: Tue, 02 Nov 1999 18:32:09 +1100 To: aussie-weather at world.std.com From: Jimmy Deguara [jdeguara at ihug.com.au] Subject: Re: aus-wx:Welcome Leslie Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Welcome to the list Leslie. It is a pleasure to get such professional information from experts in the US. The radar at Grafton is not Doppler. There is only a doppler in Darwin and recently one installed in Sydney. All other radars are of the type you specify - conventional radar. Jimmy Deguara At 10:41 1/11/99 -0500, you wrote: >Halden: > > >However, there was not much of a show on the Grafton local > >radar....could this be because the rain was moving away from it that the > >Doppler effect could have "fooled" the radar??? > >I would be interested in your comments. > >I have recently joined this group. As my signature entry testifies, I am a >long time (30 years) radar, severe storms, and research meteorologist. My >research and that of two colleagues at the US National Severe Storms >laboratory in Norman, OK, lead to the NEXRAD program. I joined industry >and designed and developed much of the WSR-88D (NEXRAD) system. This very >brief background is supplied in order to comment on your question. > >I believe the radar you question is a conventional and not a Doppler >weather radar. However, in either case the "Doppler effect" is not >responsible for what you describe. Due to the fact that I have not seen >the radar images you speak of nor do I know the geography of the area (I am >in the states) or the radar type, all I can do is speculate. Perhaps I >should not even do that. But I will venture a guess or two. > >First, the radar you speak of is probably a C-band (~ 5 cm wavelength) >radar which is prone to "attenuate" due to rain and/or hail falling on the >radome of the radar, if it is raining at the radar site. Additionally, >intervening rain and/or especially hail between the radar and the storm you >speak of would also seriously attenuate the radar returns from the storm in >question making it appear to be significantly weaker than it would >otherwise appear. Attenuation, of course, speaks of radar signal depletion >due to absorption of the microwave energy transmitted by the radar. If the >Grafton local radar you speak of is an X-band (~ 3 cm wavelength) the >attenuation is even a factor of 10 worse than C-band radars! And C-band >radars are a factor of 10 worse than the S-band (10 cm) network weather >radars such as NEXRAD. Thus, attenuation is a likely suspect for the >problem you mention. However, it could be that the storm is "on top" of >the radar and therefore the radar could not obtain a good view of the >storm, in any case, in addition to the attenuation. Another factor, could >be that the calibration (one might refer to this as the "tuning accuracy") >of the radar might be poor. > >There are a few other possibilities such as beam blockage, but I will not >go into those here. I hope this response is not too technical nor too >elementary for you or for the group. I must also again say that I am so >unfamiliar with the area or the radar in question, I may have responded >incorrectly. If so, please forgive me and my ignorance. > >Finally, since I joined this group I have been impressed with the knowledge >and enthusiasm of its members; you all are to be congratulated on both. >Thank you for permitting me to attempt to contribute something of possible >value. > >Les > >************************ >Leslie R. Lemon >Radar, Severe Storms, & Research Meteorologist >Phone: 816-373-3533 >E-Mail: lrlemon at compuserve.com > > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 016 From: "Ben Tichborne" [tich at netaccess.co.nz] To: [aussie-weather at world.std.com] Subject: Re: aus-wx: Dry Winds and Allergy... Date: Tue, 2 Nov 1999 21:14:43 +1300 X-Mailer: Microsoft Internet Mail 4.70.1161 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com I suffer from either dust or pollen allergies (I haven't had a full diagnosis), especially in the spring. Canterbury spring weather is often dominated by warm, dry northwesterly winds, so there's quite probably a connection. Ben Tichborne Christchurch NZ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 017 From: "Ben Tichborne" [tich at netaccess.co.nz] To: [aussie-weather at world.std.com] Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? Date: Tue, 2 Nov 1999 21:23:16 +1300 X-Mailer: Microsoft Internet Mail 4.70.1161 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com > PS It is blowing a gale here at Evans Head as I speak from the SSE....the US > Navy Mil weather IR Radar shows a deep welling from Antarctica over NZ and > through the Tasman Sea....the WSW upper airflow is spinning a low off the > coast here on the ground....very interesting > > Halden By "deep welling" do you mean a movement of air?. While there certainly has been a pulse of cool air over the South Island, I would hardly call it Antarctic in origin (it's down to about 9 C in Christchurch now in the evening). A lot cooler than yesterday though, when we had strong, warm northwesterlies. BTW a deep low from the North Tasman is expected in move down onto northern NZ from tomorrow - could be significant rain and wind there. Ben Tichborne Christchurch NZ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 018 X-Sender: jdeguara at pop.ihug.com.au X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.58 Date: Tue, 02 Nov 1999 19:58:33 +1100 To: aussie-weather at world.std.com From: Jimmy Deguara [jdeguara at ihug.com.au] Subject: aus-wx: NSW ASWA meeting 6th November Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com I am hoping this did get to people as I had problems sending e-mail at the time. Hi everyone in NSW or interstate travellers, Looks like we are heading for yet another NSW ASWA meeting. I must say we had fun at the last meeting: probably the best meeting so far besides the AGM. There were more than enough videos and still more to see. Well the date of the next meeting is Saturday 6th November again at Mario's house details below. The meeting starts around 5:30 - 6pm. The venue address is 90 Station St, Arncliffe. Nearest cross roads are Mitchell St. Station St runs away from the station and he is further up the road away from the railway station. I would suggest you try and pool each other to the meeting but there is ample parking in a quiet street. The meeting itself?? To be discussed is the End of Year Chase with forms supposed to be in to Matt by then (oops I haven't). Then I think we won't waste any time and watch the video from Matt and Daniel. They will of course give us a run down of what happened on that day of the chase in the Hunter!!! Please remember to bring along: -a chair to sit on -money for the pizza -some drinks and nibbles please -your stories, photos, laughs etc.... Come along for a fun night. If you haven't been and feel you are shy, you will blend in no time. trust me!!!! See you there. Jimmy Deguara +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 019 X-Sender: jdeguara at pop.ihug.com.au X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.58 Date: Tue, 02 Nov 1999 20:06:43 +1100 To: aussie-weather at world.std.com From: Jimmy Deguara [jdeguara at ihug.com.au] Subject: aus-wx: More on the ASWA meeting Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Sorry, this was meant to be covered in the previous meeting message. Paul Graham is preparing to talk about sounding interpretations for those people like myself who are amateurs. Do come along and bring your questions with you. And to also emphasise the message passed on by James Harris: the video footage is excellent and covers some of the most spectacular high contrast footage seen for some time. Please don't be the one to miss it!!! The footage includes recent chases and also spectacular footage of a change undercutting moist air over the northern suburbs. What a site to see!!! Don't forget - 6th November around 5pm onwards. Details in the previous message. Jimmy Deguara +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 020 X-Sender: jdeguara at pop.ihug.com.au X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.58 Date: Tue, 02 Nov 1999 20:16:29 +1100 To: aussie-weather at world.std.com From: Jimmy Deguara [jdeguara at ihug.com.au] Subject: aus-wx: Please support the ASWA newsletter Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com I know some people may like to downplay the ASWA newsletter and not use it, but please re-think this one. Not for my sake either. There are some ASWA members who are not on the list and would like to know what is going on - I suppose including the articles and stories of chases etc as well as meeting details and the what's on. One person that spoke to me recently stressed the importance of knowing what is going on. He is one of several of a growing list of people who need to keep up to date with the weather and should not be the forgotten ones. So if you have something positive to submit, please do and contact Kathryn Jolly who like others in ASWA has worked hard to put this together weekly although now it is fortnightly. Thanks members. Jimmy Deguara +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ Date: Tue, 02 Nov 1999 09:49:49 +0000 From: Les Crossan [les.crossan at virgin.net] 021 Organization: Personal - ICQ 17296776 - note all times in GMT X-Mailer: Mozilla 4.7 [en] (Win98; I) X-Accept-Language: en To: Chas & Helen Osborn [hosborn at tassie.net.au] aus-wx , Jane ONeill Subject: aus-wx: Re: uk.sci.weather Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Chas & Helen Osborn wrote: > Dear Les > > I seek your advice! I note that you use uk.sci.weather and reading > between the lines you understand computers. > Could say that - microsfot certified professional and all that!! > > dear list - > > I tried to hook up with uk.ski.weather Firstly - its uk.sci.weather! It's alive and well and the Virgin Net news server hosts it amongst others. ... but we don't get golfball hail, continuous lightning, supercells or 85mm./hr! Well not often, anyhow. Try this - If you use Netscape set up another user profile and for your newsgroup setup put in news.virgin.net then start the subscription process off. If you use IE then this cannot be done due to the universal inbox type thingy... + else + read this thread which I've also posted to aus.wx and ASWA Victoria Anywhere in Oz where you can subscribe to uk.sci.weather??? Les +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 022 Date: Tue, 02 Nov 1999 19:42:00 +1000 From: Anthony Cornelius [cyclone at flatrate.net.au] X-Mailer: Mozilla 4.6 [en] (Win98; I) X-Accept-Language: en To: Australian Weather Mailing List [aussie-weather at world.std.com] Subject: aus-wx: [Fwd: Reminder Notice of ASWA Meeting] Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Hi all, This is an email to any QLD, or NE NSW people who are interested in attending an Australian Severe Weather Association Meeting, this has been sent out to all of the members, but guests are most welcome, and are invited to attend! This is a quick reminder of the next QLD ASWA meeting, that will take place at 10am, this Saturday (6th of November). The address is: Unit 9/14 Argon St. Sumner It's sure to be another great meeting, with some footage of recent thunderstorms by James Chambers - and Michael Bath has some more storm chase footage to show us! Please bring all your photos, and any video footage that you have taken of any weather-related phenomena for all to enjoy. We'll be finalising the end of year chase - in fact, this Saturday will be the absolute last opportunity that members will be able to hand their chase forms in if they want to attend the chase. (If you only want to come for a day or two to meet everyone, then you don't need to fill out the form, but you MUST inform myself of when you're thinking of attending, so that we can expect you! There are plans of having a BBQ in NE NSW, details of this will be given out at the meeting.) After the meeting, I'll be express-posting the forms down to Matthew Smith, the chase coordinator - who has kindly allowed me to extend the date. More information of the QLD ASWA Christmas party will also be given out (this has been posted to you this evening). I'll also be starting off a new segment in our meetings, with an introduction on skew-ts, how to read them, and how to forecast off them. Also - I have the last remaining ASWA t-shirts! All future orders will have an additional cost of $5 for P & A attached to them, so if you want to buy ASWA t-shirts, now is the time to save some money! I have the following sizes/shirts left (you can email me and reserve them to be picked up at the meeting if you like, first in - first served). 1 X M T-shirt ($15) 1 X L T-shirt ($15) 2 X XL T-shirt ($15) 1 X XL Polo Shirt ($25) 1 X XXL Polo shirt ($25) All future orders made, will incur a P&A cost of $5 per order, so purchase them now! It'd be much appreciated if you could quickly reply to this email to inform that you're coming (if you haven't already), or phone me on (07) 3390 4812 - it helps us a great deal with organising this. Please bring $2 for a light lunch/afternoon tea. I look forward to seeing everyone there! Anthony Cornelius QLD ASWA Coordinator +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 023 From: "Michael Thompson" [michaelt at ozemail.com.au] To: [aussie-weather at world.std.com] Subject: aus-wx: Entry Level SLR cameras getting cheap ! Date: Tue, 2 Nov 1999 22:32:14 +1100 X-Mailer: Microsoft Outlook Express 5.00.2014.211 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com I have been looking at a few entry level SLR cameras over the last few days I am surprised how much you can get for your dollar these days. My Nikon FA and Nikkor 35-105mm lens is like carting a house brick around to and from work, so I was looking at a second camera and leave the Nikon for serious colour slide work. I though the group may be interested in the prices and specs of three what I see as very good SLR's Pentax MZ-50 with 28-80 Zoom $499 ( Can get $459 in Sydney ). Has fully auto, Aperture Priority, Shutter Priority or manual, plus some program modes. Faster flash syn speed compared to the Minolta. Like most of these cameras the lens is not particularly fast at F4.5, even my Nikkor 35-105mm is a couple of stops faster ( but also costs more then this whole kit ). There are several lens options with the MZ50 such as a faster and wider range Sigma zens for about $50 more. Minolta 404Si .$499. This one seems to have hit the shelves only 3-4 months ago. It really has my interest as it offers a lot for the money. Again the lens is a 28-80 zoom with F4.5 minimum F stop.( or do they say maximum ). Like the Pentax there is Aperture and shutter priority and manual, plus several program modes such as action, landscape, etc. Has two metering options, the normal pattern metering that's averages seven individual segments of the view ( in the middle ), or spot metering which is a storm chasers friend. By spot metering you can expose by pointing the camera exposure thingy at the exact spot you want to expose for, such as bright cloud. You can then lock the exposure and take the picture of the subject, even if you move. This helps sort those dark green grass vs white Cb towers photos, where the dark grass leads to overexposed clouds. Another nifty feature is exposure bracketing. You have just seen the tornado shot of your life and want to make certain that the exposure is correct, by using exposure bracketing the 404si will take three pics the middle will be at the metered exposure, the first half an exposure setting fast ( darker ), the last half an exposure setting fast ( lighter ). On the down side the flash syn speed is nothing to brag about. Canon 4000 EOS $369. Up you saw right a SLR under $400, in fact I saw it in Sydney for $339. That is retail, the duty free takes it below $300. I have not read any reviews yet and winder what the catch is, especially as it is combined with a Canon ( yes canon ) 28-80mm zoom. I think however it is really slow at F5. Don't know about what modes it does, but probably at least program. It also is manual !!! which is better for storm chasers who like to experiment. There is a shutter speed knob on top of the camera so I know it has B ( for lightning ) and a top of 1/2000 sec. It may be worth holding off for a few weeks as the sub $400 price may make some brands review there prices. Regards Michael Thompson http://thunder.simplenet.com +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 024 From: "Michael Thompson" [michaelt at ozemail.com.au] To: [aussie-weather at world.std.com] Subject: Re: aus-wx: Dry Winds and Allergy... Date: Tue, 2 Nov 1999 22:34:49 +1100 X-Mailer: Microsoft Outlook Express 5.00.2014.211 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Like Michael S, I also share Rye grass as a allergen, apparently it is a common one, so it could be suspect. Michael > I suffer from either dust or pollen allergies (I haven't had a full > diagnosis), especially in the spring. Canterbury spring weather is often > dominated by warm, dry northwesterly winds, so there's quite probably a > connection. > > Ben Tichborne > Christchurch > NZ > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------ 025 From: "Michael Thompson" [michaelt at ozemail.com.au] To: [aussie-weather at world.std.com] Subject: Re: aus-wx: Re Doppler effect and strong winds conning the radar?? Date: Tue, 2 Nov 1999 22:40:26 +1100 X-Mailer: Microsoft Outlook Express 5.00.2014.211 Sender: aussie-weather-approval at world.std.com Reply-To: aussie-weather at world.std.com Certainly the BOM GASP models have a very deep low moving SE over New Zealand. I would like to be around the west side of the north island for that one. Michael > By "deep welling" do you mean a movement of air?. While there certainly > has been a pulse of cool air over the South Island, I would hardly call it > Antarctic in origin (it's down to about 9 C in Christchurch now in the > evening). A lot cooler than yesterday though, when we had strong, warm > northwesterlies. > BTW a deep low from the North Tasman is expected in move down onto > northern NZ from tomorrow - could be significant rain and wind there. > > Ben Tichborne > Christchurch > NZ > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ > To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com > with "unsubscribe aussie-weather your_email_address" in the body of your > message. > -----------------------jacob at iinet.net.au------------------------------ > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe from aussie-weather send e-mail to:majordomo at world.std.com with "unsubscribe aussie-weather your_email_address" in the body of your message. -----------------------jacob at iinet.net.au------------------------------