hi all,
ok - i've finally had some time to catch up on some chase reports (sorry for the delay - you'll see from the reports we have covered a few miles lately...hehe).
Michael - we did just that yesterday - after the Thursday show in western Kansas, we didn't chase y'day and went to Greensburg to catch up with some friends to see how they were doing after the tornado from May 4th last year (more on this later...an amazing day) and then we headed south and east to Tulsa.
We are going to target central eastern Arkansas today - it will be my first proper warm-front chase so interested to see how it goes. SPC are about to update their convective outlook - wouldn't surprise me to see a HIGH risk pop out for that area.
Ok - back to the reports...refer to the following posts
.
Macca
Posted on: 10 May 2008, 10:16:46 PM
Day 7
We drove down to south west Texas in the hope that something would kick off on the mountains and move NE towards us. Shear was ok (20-25knts at 850mb from the SE and 30-35knts from the SW at 500mb) and moisture was returning along the Rio Grande but lack of upper level support surpressed convection until very late. We waited in Odessa and storms bubbled away on the mountains all afternoon but died each time they moved off. At 6pm we called it a day as we needed to be up in southern Kansas for a better chance of storms the next day. Of course 1.5 hours drive into our venture northwards, storms moved off the ranges towards Odessa (although they didn't make it to there until nearly 1am). The storm/s were severe warned in the early evening (8:30pm) so our target wasn't overly bad. Just a few small things didn't come to the party in terms of the weather.
There was a general consensus amongst the group that the far south west of Texas is an interesting place that we would be happy not to visit again for a while.
I think the highlight of this day was on our way S along I-20. A large 4WD overtook us doing about 85mh (in a 70 zone) and shortly after a highway patrol car coming the other way slowed, drove across the median (the grass...not a turning point) and FLEW past us (easily near 100mph) and pulled this 4WD over. As he stopped behind her, he threw his door open, jumped out and pointed viciously at another car behind us and ordered it to pull over too!!! Unbelievable! The car he pointed at slammed on its brakes and pulled over in front of the first car. It was fairly exciting to say the least!
Anyways...so no action this day.
Posted on: 10 May 2008, 10:18:29 PM
Day 8
So after leaving Odessa the night before, we headed N to Lubbock for the night. From there, we headed N through the Tx panhandle, targeting the Oklahoma panhandle (Guymon - Boise City) where two outflow boundaries looked collide later in the afternoon. In addition to this, a weak dryline was developing along the mountains over eastern New Mexico. DP's were forecast to get into the mid-high 50's with a mid level shortwave trough forecast to move through the area in the late afternoon. This area is quite elevated (around 1000m ASL) so mid 50's DP's aren't too bad. Low level winds were forecast to be 25-30knts from the S and upper level winds were forecast to be in the 40-45knt vicinity. As we cruised N, a cluster of storms developed over the Colorado/Texas/Oklahoma border area and moved slowly ENE. We jumped on the southern side of these N of Boise City, however, with daytime heating, moisture levels had dropped over the panhandle region into the high 40's so the storms were quite high based. We played around on some dirt roads as we jogged east and south and east again with the storms and eventually the storms moved into some slightly better moisture over south eastern Kansas. The storms were primarily outflow dominant but one developed a weak wall cloud and the storm was warned for hail and damaging winds. Another storm further NE of this one produced hail in Garden City up to the size of softballs (!!).
We played with this storm in south west Kansas and the Oklahoma panhandle until just on dark before dropping south to Perryton. Storms had developed along the dryline in eastern New Mexico and had developed into an MCS and we were anticipating some lightning action from these storms later in the evening. So we got a hotel room, dumped our luggage and headed S from Perryton where we intercepted a more isolated storm N of the MCS coming up from the SW but it was raining well ahead of it making lightning photography difficult. To alleviate this problem, we headed west through the storm which had some heavy rain and hail to 1-1.5cm, and then stopped and photographed it from the back, out of the rain. The only problem was that the cell died just as it passed over us so we were only left with anvil crawlers. Some of us managed to catch a few but the show only lasted about 15 minutes so we headed back to Perryton for the night since the MCS was just a mess of rain and was moving east quite a distance to our south.
Posted on: 10 May 2008, 10:18:59 PM
Day 9
The overnight MCS had pushed out an outflow boundary well to the S of the Texas panhandle (and we were in the far north of the Texas panhandle) so we had a relatively early start to the day which saw us heading S. The upper low which had been sitting off the coast of California for a few days ejecting out shortwave troughs was now forecast to start moving towards the plains and with it came some better shear. The dryline was forecast to sharpen over eastern New Mexico and the associated low level jet was forecast to increase to 30-40knts by the afternoon from the S. A mid-level jet was forecast to arrive over the Texas panhandle by late afternoon bringing 50-60knt WSW'lys with an 80knt jet aloft. There was nice moisture to the S of the outflow boundary over south central Texas so we had to be south of that but further west where storms were likely to initiate, the moisture wasn't as nice. DP's were in the mid-50's with surface temps pushing into the mid 80's. So what we needed was storms to develop on the dryline and move eastwards into the more juicy airmass.
SPC had a 10% chance of tornadoes for the area we were targeting (the area around Lamesa - south of Lubbock). As we drove south through Lubbock, it started drizzling - classic stuff. But shortly after, we crossed the outflow boundary (which had similar characteristics to a warm front by this stage) and the sky cleared to reveal some nice cumulus. We stopped for data in Brownfield along with the DOW and convoy (per my post on the day) and noticed two areas of interest. One on the New Mexico/Texas border south of Hobbs and another further south near Midland/Odessa. Storms had already developed SW of Midland/Odessa and were looking nice on radar and an area of enhanced cumulus were bubbling into a small storm out near Hobbs. We dropped a little further SW to Seagraves to get closer to the Hobbs action where we waited for a little while and watched. A line of rapidly developing TCu to our S and SE had us interested as did the severe warned storms which were now heading NE out of Midland heading to the area S of Lamesa so we headed east to keep both as options. The developing TCu became storms quickly and were warned for hail and winds shortly after as we drifted just south of them. We stopped between Seagraves and Welch where the inflow into these storms had picked up considerably. Dust-filled southerly winds were racing into these storms at about 35-40knts - it was incredible. A left mover emerged out of the complex of storms to our SW (the Midland stuff) with a solid base on the nothern side. This soon put out one of the strongest downbursts I have seen with a massive blast out outflow which raced north and probably smashed Seagraves (i'll have to check the SPC storm reports for wind reports from this cell as it was VERY intense looking at it from a distance (of 5km or so)).
The base of this left mover and the other cells to our north had merged into one BIG nasty base with solid rain cores on both sides and was moving ENE. We jogged eastwards to Welch whilst being blasted by the insane inflow winds. Along this east-west road, a large 4WD towing a caravan had been blown off the road by the inflow winds with the caravan lying on its side (oops). It was raining from the anvil on us nearly the whole time since our earlier stop east of seagraves and the storms didn't seem to like this much. We had some interesting moments as the core of the now merged beast got VERY close to us as we had to take a north, then west, then north, then east detour to stay on sealed roads. Some smallish hail (2cm or so) and some pretty hefty wind gusts smacked us before we were able to go futher east. After the merger between the two storms we witnessed a brief wall cloud which wrapped up and looked quite nice (from near Welch) but after this, we followed this now crappy looking complex to Tahoka as it moved at about 35mph to the NE but it was outflow dominant. We persisted with it figuring that the insane inflow and the fact that it was moving into an area with better moisture that it would eventually get better.
Finally between Tahoka and Spur a new bunch of storms went up on the southern edge of the complex (just to our SW). We raced east to Post and then south east. We were now off the flatest of the flat lands and were getting into the "hill country" of Texas which is covered with smaller trees/bushes and small hills and is kinda swampy (not ideal for chasing). We managed to find a decent view SE of Post and these storms had developed into a HP monster!! Over the next hour or so we watched this beautiful striated storm moved across in front of us and blast us with outflow (the storm was moving ENE and our road went SE with no other options for 30km so we let it go). The sun then poked through under the storm and lit it up in spectacular fashion. We eventually dropped S to Jayton and then east to near Aspermont where we finally had a road option northwards. It was now dark but we were intent on getting some lightning so we booked it north and managed to intercept the storm again just S of Guthrie (Texas). We got some nice CG's from this cell but it moved off to the east. More storms had developed to our SW so we waited for these cells and scored some great lightning!!
Eventually we called it a night (after midnight) and headed N to Childress for the night. We were subject to storms/lightning for the next 3 or so hours although I think we all fell asleep before the storms finished.
It was quite an eventful day but again no tornadoes. If moisture had been better and the upper level flow had been more SW'ly I think we would've been in business but the high bases and the anvil seeding of the updrafts seemed to be the telling factors this day.
Posted on: 10 May 2008, 10:19:33 PM
Day 10
After a mere 5 hours (or so) sleep, we were up again to play another dynamic day. The upper low was now moving rapidly eastwards and in response, a surface low was developing just as rapidly over the eastern Texas panhandle/south west Oklahoma. The system was nearly stacked (meaning that the surface low was sitting very close to the upper low) but it seemed as though it would allow a narrow corridor of instability to develop ahead of the dryline in an area of strong shear. 500mb winds were forecast to reach 80-90knts from the SW and the LLJ was forecast to get to around 50knts from the S. The axis of instability east ofthe dryline looked to sit somewhere around Gainesville - Sherman (this was our target) in north central Texas and with the shear, storms would rapidly move NE. SPC had a moderate risk out for north eastern Texas with 15% hatched area for tornadoes!
The dryline passed over us at about 9:30am in Childress with another storm and some heavy rain. We headed east and overtook the dryline near Vernon. We stopped in Henrietta for some data and saw the DOW + convoy again and after getting data, we continued on to Gainesville where we again encountered chaser convergence with the DOW + convoy.
I'll keep this fairly brief. A storm developed on the dryline in far northern Texas WNW of Gainesville and produced golf-ball hail but was never warned for anything more than hail and winds. We watched this from a distance but it looked multicellular with the strong shear seemingly preventing it from maintaining a single updraft. I think quite a few chasers went after this. We were also keeping an eye on a weak storm passing over Dallas. We headed east to Sherman so we could keep both storms as an option and shortly after, the Dallas storm went from nothing to tornado warned as it intensified rapidly and showed a hook echo on radar. We went for it and core punched about 10km N of the main action and encountered some more strong winds and hail to about 2cm. As we broke through to the south eastern side, it was evident that this cell had gusted out and undercut the wall cloud. We watched as this cell raced off to the NE and waited for the final line of storms to come through along the dryline. This didn't take long given the strength of the shear but this storm had also gusted out. It was quite photogenic in the late afternoon light thou.
Again no tornadoes with a few things just not coming together again. The best storm was in an area of higher instability (the one WNW of Gainesville) but the shear was too linear and the area where the shear was better, the instability was lacking.
Posted on: 10 May 2008, 10:20:30 PM
Day 11
WOW. Not sure how to even start typing about this day. Lets start with the set up. SPC's Day 2 outlook was showing a 15% chance of severe storms over western Kansas with hail and damaging winds the main threats as moisture was expected to be an issue. In its 7am outlook, SPC noted that shear was sufficient for high-based supercells with hail up to golf balls possible in stronger storms but did not have any percentage for tornadoes.
We started the day in Ardmore, Oklahoma and as Friday wasn't expected to deliver any storms, we thought we'd go for the chance of some nice structure and a lightning show in Kansas before heading back east for Saturday (which was looking potent). We needed to be on the ball in the morning as we had a 7 hour drive ahead of us to our target area (Dodge City). The various models were in consensus (for the first time in AGES) that a dryline bulge would set up over south western Kansas in response to an approaching upper level shortwave trough. The models didn't really seem to correctly guage the strenth of the upper trough and also the quality of the moisture return. We were a little surprised to see DP's in the Oklahoma panhandle and south western Kansas to be in the mid-50's after the significant weather events of the previous day (perhaps a sign of real May moisture coming).
By early afternoon, DP's were into the high 50's over south western Kansas and CAPE was getting up above 2000j/kg with LI's of -8. This was quite a bit higher than forecast with the models going for 1000-1500j/kg and -5 to -6 LI's. By this stage, SPC had upgraded the tornado chances to 2% given the slightly higher DP's. A storm fired north of the dryline bulge north west of Scott City and before it had even reached the higher end of the reflectivities it was tornado warned. We later learned that it spawned a few landspouts in its early stages (conditions early on were classic for landspouts). At this stage we were in Woodward in north western Oklahoma and were probably 240km away at a guess. We continued on our trip towards Dodge City as there was a chance convection could fire further S along the dryline closer to our location.
Over the next hour or so the storm clearly tapped into better moisture and intensified rapidly and was again tornado warned as it passed just S of Scott City. Intersetingly enough, it was crawling along at no more than 15-2omph. Low level winds were forecast to be about 30-35knts from the SSE and with the upper level shortwave coming through, the mid level flow was supposed to be 50-60knts from the west so shear was definitely nice. We caught distant glimpses fo the anvil and dropped west to be near the dryline in case something went up further south but after reaching Meade in southern Kansas with a clear view of the dryline, we could see that this was going to be the southern most storm. It was on - we raced northwards and watched updrafts explode up the back end. In its 4pm update, SPC had upgraded to a 5% risk of tornadoes in the area of this storm!
We continued north through Cimmaron and finally got a view of the base and updraft structure - it was AWESOME. The storm was still tornado warned for doppler-indicated rotation and had shear markers on the Threatnet with 103mph of shear. We dropped west a bit and then north and pulled up amongst a bunch of chasers just as the storm was pushing out a nice RFD. When we got out of the car, the inflow surprised us all. It was easily 40mph with gusts getting up over 50mph and it was from the SE! Trying to video and photograph in these conditions is difficult to say the least. Tripod footage is almost out of the question as the wind blows over even the sturdiest of tripods. The road network in this part of Kansas is incredible (if you are willing to drive on dirt/gravel roads) with a cross road every mile or so. We stayed at this location as long as possible but we had to move eventually when the storm put down another RFD to our direct north which surged southwards towards us - it was this downburst which started the storm's transition to HP. We, along with a bunch of other chasers, raced eastwards before we scattered in various directions - some went north (into it!), some went south and some went east. We stopped briefly for more photos before busting it south end east again.
The easiest way to put it from here is that we jogged east with the storm to Kalvesta and then to Jetmore stopping every 5-8 miles for photos and video at various locations. THe storm exhibited strong rotation for much of this time. During one of our southward jogs, an area of intense rotation developed about 1/2 to 1mi behind us - it was REALLY cranking - probably the strongest rotation I have ever seen without producing a tornado - if this thing had dropped one, it was going to be pretty close to us (within 1 mile!).
We stopped just west of Jetmore to take more pics and there was a HUGE hail-filled green RFD which had dumped down just to our west - it was RACING towards us. We later heard that tennis ball sized hail fell just east of Jetmore not long after we left. We copped a nice battering of 2-3cm hail with the odd 4cm stong thrown in and we left quite a way ahead of this nasty core. We had the choice of going S from Jetmore but we chose to go ENE. As this storm was now HP, we wanted to be able to see (be in) the notch as if any tornadoes were going to happen, it was going to be here in the notch. As we left Jetmore, we were battered with CRAZY inflow winds with branches coming off trees and sparking powerlines. It was incredible - dust was coming from everywhere into the storm. As we hooned ENE, a barrage of clear air CG's started to occur out in front of us - it was awesome to watch these bolts hit out ahead of us with clear blue sky in the background! We got out of the hail and got a way ahead of the beast and as we drove ENE towards Sanford the anvil crawler activity went nuts! Daylight crawlers every 4 seconds were ripping across the underside of the anvil. We stopped in Sanford where we watched the storm wrap up again. It came close to producing here again with tendrils of scud rotating around each other quite rapidly. We had parked beside some large pools of water from previous days storms and it wasn't long before the hail started again. We stayed here for nearly 10 minutes in sporadic 2-3cm hail watching the storm wrap and the hail splash into the water - it was AWESOME! Suddenly...BANG...BANG...the bigger stuff started. In amongst the 2-3cm stones was now the odd golf ball - and they were SOLID! The splashes in the water were now BIG and the stones were bouncing easily 8ft in the air. We finally had to move as we heard a report of the tennis ball hail and we didn't want to lose our windscreen! Inflow was the strongest it had been too at this time with gusts easily over 60mph!
As we dropped south for a little bit of safety, we saw a snapped power pole which had broken as a result of the inflow and we heard reports over the NOAA weather radio that more poles had been snapped and houses unroofed from the inflow winds! Over the next hour in the now fading light we watched this HP beast slide past us to the north as we dropped south and east and the warnings on this storm were downgraded to severe thunderstorm warnings. During these moves, we crossed over several of the tornado tracks from May 4th and 5th from 2007 which were still clearly visible. Another cell which had been tracking behind this one had now developed further to the SW and a line of storms had fired along the cold front west of these storms. We had made it nearly to Pratt when we decided to wait for this next line of storms which were looking intense on radar. This was confirmed when a nice area of rotation developed about 5mi to our west which we could only see in the 1-2 flashes/sec lightning. Shear markers popped up on the Threatnet of 115mph but we didn't see anything resembling a tornado. Again the hail started ahead of the main core (1-2cm) and we decided to head east into Pratt to watch as these storms as they moved into town - we had a 10mi eastward movement to make to do this. Well...lets just say the first 8 miles was pure excitement as hail pounded down heavier than it had all day
!!! It was only small(ish) 2-3cm but the entire road was covered making for interesting driving and the noise was deafening.
We made it to Pratt but the storm lost its grunt as it came in to Pratt and the hail had backed off to just heavy rain. We got ourselves a room and called it a day...but what a day! What a storm. The inflow into that storm was incredible - something I have never seen before. I mentioned in an earlier post that the inflow winds caused damage - these winds have been estimated by experienced chasers at 70-90mph!!
Anyway - I think I've gone on long enough.
