Topic: Rain event SE Qld and NE NSW: 19 - 25 August 2007

[Steven]

After think the worst is over, Weatherzone reports that recent yet sharp drops in air pressure suggest a new low may be developing off the coast, certainly the case, since 11am a rainband set in from the NE, and so far we scored 34mm of rain, conditions are deteriorate once again, wind is increasing and it just looks miserable. The good thing though, the rain has put an extra months supply of water to our local dams, and a few weeks for Brisbane dams.

[Steven]

Getting a LOT of rain accompanied by strong winds and unbelievably thunder and lightning!, now we are up to 47mm at Maroochydore, and going up fast! The rainband has spread out to the Brisbane dams so I would imagine them getting at least 30-40mm out of that, Brisbane is starting to get some of that rain.

EDIT: Now 50.4mm of rain, and a loud crash of thunder!

[Michael Bath]

Great to see the Sunshine Coast getting some great falls out of this prolonged weather system. How much rain have you had now Steven ?

[Michael Bath]

Been some MASSIVE falls overnight:
http://www.bom.gov.au/cgi-bin/wrap_fwo.pl?IDQ60361.html

Some stations in the Noosa area have had over 600mm in less than 24 hours. Some rivers are now in major flood as you would expect.

[Michael Bath]

713mm at Rainbow beach, 706mm at Coops Corners, and 689mm at Mt Bilewilam and Noosa had 419mm to 9am today. Incredible totals.

Quite a similar setup to the Gold Coast floods of 30th June 2005 with a near stationary trough line allowing massive convection to train over the same area for many, many hours.

Current VIS shows another low has developed to the northeast of all the current action.

[Macca]

WHOA WHOA AND MORE WHOA!!!!

Rainbow Beach (approx. 200km N of Brisbane) has had 713mm in the 24hrs to 9am, closely followed up by Coops Corner which finished the 24hrs period with 706mm and Mt Bilewilam which finished with 689mm.  And by finished, I merely mean the 24 hour period...the rain is still pouring down over that area and looks to continue for at least another few hours.  

Coops Corner has now had 847mm for the event and I would be surprised if they don't kick over to 1000mm by close of business today.  The first rainfall for this event fell on the 19th of August with totals on that day and up to and including this morning's reading as follows (at Coops Corner)...4mm, 33mm, 1mm, 36mm, 67mm, 713mm (!!!)...and more today.

Major flood warnings are in place in the area (not surprisingly).

Brisbane's catchments have received some good steady rain over the duration of this event too with the upper reaches of the Stanley River (which flows into Somerset Dam) scoring 225mm for the event, however, it tapered off quite a bit with the main dam (Wivenhoe) recieving 95mm for the event so far.  Certainly nothing to scoff at - with any luck we'll get another 10-15mm over the dam today with a further 40-50mm over the upper reaches of the Stanley River and we could see a boost to Brisbane's water supply by 3-5% as the water runs in over the next week.

Macca

[Jimmy Deguara]

As you can see Michael, the balance can be made up given such an extended dry period during a period of so called La Nina. It has to give eventually and it did!

Massive falls - I was wandering why you kept messaging me last night - I thought it was a case of 300m fall of rain - but that's doubled!

Not bad I must say - keep us posted.

Regards,

Jimmy Deguara

[Macca]

Post on weatherzone from Blair Trewin (BOM Statistician) indicates that the previous record for a 24hr period rainfall for August in Australia is 464mm at Mourilyan Harbour on 31/8/1998.  If the 713mm verifies (officially), it will be a new August record...and by quite a long way!

Macca

[Macca]

I'm going to head up into the affected area tomorrow to get some photos.  Will try and get them online by Sunday night to show.

Macca

[Steven]

Never seen anything like this since we moved on the Sunshine Coast in December 1998, all I can say that this is incredible. Totals this morning are flabbergasting, 310mm (thats in one day!!!) for Tewantin, and 192mm for Maroochydore, this is by far huge totals, luckily we haven't flooded due to higher ground but I am pretty sure that if I went around low ground places theres should be flooding. Still raining here, might even break the 300mm mark ourselves this month.

I can tell you Micheal, we just about soaked so much, it even humid in the house!!! all the run off is going downwards to the street but gutters are overflowing like crazy, it is just amazing, incredible, flabbergasting call whatever it is just crazy, hallelujah!!! By the way despite school being open, I'm not going today because of the extreme wetness around the place, might stay in and make myself a nice hot cup of soup.

[Steven]

By the way, were not the only ones with jaw dropping rainfall totals

713mm at Rainbow Beach to 9am this morning
706mm at Coops Corner to 9am this morning
689mm at Mt Bilewilam to 9am this morning

Those totals are very exciting yet concerning because of the extensive flooding, in fact Maroochy river has some major flooding breaking the 6m mark last night however most severely flooded places are north of the Sunshine Coast, Eumiundi is a worry as it is still rising at 6.4m, and some other moderately flooded places have rising flood waters too, but most flooding is beginning to fall now.

It reminds me alot of the Lismore floods of 2005, similar situation, but Sunshine Coast has quite a bit of terrain to worry about flooding, its only those who live in low lying areas that should watch out. The main rain has eased a little but it doesn't look like clearing until the weekend, so those totals might be bumped up still.  The wind has died off here as well, although there are some occasional gusts.

[Michael Bath]

This long-lasting event finally comes to a close. The cloud associated with the trough very quickly dissipated last night.   I've done up an interactive satellite loop from last Sunday to this morning (about 5.9mb)

http://australiasevereweather.com/storm_news/2007/satpics/20070819/satellite_loop_20070819.htm

Also, an MSL chart loop which shows just how persistent the east coast trough was. A couple of small lows formed within the trough on various days bringing the extreme rainfalls.

http://australiasevereweather.com/storm_news/2007/maps/20070815/msl_loop_20070815.htm

and the last of the rainfall maps for the 24 hours to 9am on 24th and 25th August





A couple of site near Noosa have cracked the 1000mm mark this week - extraordinary !

Station Name   24 hours to 9am - last 7 days   Since 9am
25 Aug
   19   20   21   22   23   24   25   
Noosa
Rainbow Beach SYN   9.2    22    0.6    12    30    713    154     
Coops Corner TM *   4.0    33    1.0    36    67    714    256     
Mt Bilewilam AL *   6.0    28    0.0    25    56    689    211     
Mount Elliot AL *   3.0    29    0.0    44    58    234    210     
Mount Wolvi AL *   0.0    31    0.0    60    100    245    202     
Black Pinch Road AL *   0.0    26    0.0    38    54    252    124     
Boreen Point AL *   0.0    27    0.0    62    53    336    173     
Lake Cooroibah AL *   1.0    29    0.0    49    43    276    154     
Lake Cooroibah   0.2    32    0.6    50    47    275    187     
Mount Tinbeerwah AL *   0.0    29    0.0    52    74    256    166     
Tewantin AWS *   0.0    36    0.4    56    46    310    191     
Tewantin AL *   0.0    37    0.0    49    32    312    185     
Noosa Heads AL *   1.0    41    0.0    73    50    419    219     

[Mike]

For all the bad things that may have occurred re rivers breaking their banks, this is just what that part of the country needed.  Ironic how weather patterns change so quickly after such a dry hot spell to bring relief to all those rural areas that so desperately needed it. fantastic to see and I'm sure the farmers are sitting on the porchy enjoying a beer watching this rain fall.

Mike

[Steven]

Went last night to the Maroochy river at about 8:55pm, it was on the verge of breaking on the road, it overflowed onto some areas, including a ramp (carpark near the edge of the water) the water blended in with the road as if the beach was on the road! thankfully it didn't rise any higher and subsided a bit today. Today it cleared up very quickly and by midday it was clear blue sky, a bit of a strange feeling after last seeing the sun on Tuesday. The rain also filled our dams up to 100% and are still coping with the tremendous water flow.





I took these two pictures from inside the car, we got out of there ASAP. Water rose quite quickly somehow when we were there as it was breaking its banks.

[Michael Bath]

Just found that the BoM have issued a detailed report on the Sunshine Coast rainfall event:

http://www.bom.gov.au/hydro/flood/qld/fld_reports/Sunshine_Coast_Floods_August_2007.pdf

MB