Hi all,
Chase reports from our last two chase days in Texas (Tues/Wed last week):
13th May 2008
We started the day in Oklahoma City knowing that we wanted to head S. Our target from the nightly check of the models was southern Oklahoma near Waurika - the cap was strong but was expected to break down the dryline from OKC to the red river (Tx/Ok border). However, a check of the models in the morning revealed precip breaking out down towards Abilene in northern Texas where the low level winds backed to the ESE in response to an approaching upper level feature. This had our interest so we headed S to Wichita Falls (S of Waurika) and decided to re-check data from here to ensure we didn't blow off our initial target too early. The day was to hold quite some promise with CAPE approaching 4000j/kg in the forecasts and relatively strong mid-level shear (50-60knts). Big hailers were on the cards but tornado potential was low-ish due to sluggish (slack) low level winds of only about 10knts.
We got to Wichita Falls and crossed to the western side of the dryline in the process. We sat in Wichita Falls for a few hours watching and waiting. There was some cirrus aloft which was preventing significant heating at this stage and the dryline had stalled about 10 miles to our east. As the cirrus cleared, strong heating and increasing low level winds saw convergence along the dryline improve and TCu started to bubble nicely along the dryline just east of Wichita Falls. We headed east about 20 miles to sit just near this TCu but after about half an hour, it didn't get any better (it actually got worse). We noticed that some weak cells had popped up along the dryline further S where the models were indicating backed surface flow N of Abilene. We packed our things and booked it south.
We headed S to Graham and then west to intercept the southern portion of the now line of storms which had developed in this region (WRF model nailed it perfectly - it could've been GFS but I can't remember). As we neared, it looked nice with an inflow band but we could tell without even getting out of the car that the inflow was not great at the surface (less than 10 knts).
We found a good vantage point on the side of the road and stopped to watch as this cell produced an OK wall cloud to our SW and moved slowly towards us. There must've been a decent updraft going up to our near west under a half-decent looking base as it soon unloaded and pushed out a strong burst of outflow. There was some intense motion above us as the outflow pushed overhead and CG's started pounding down around us. We moved east to stay ahead of it and pulled over just near some high tension power lines. We were here for about 15 minutes watching the nice gust front push out with nice whale-jaw look to it. More CG's rained down around us then suddenly....SNAPCRACKBOOOM!!!!!!!! WHOA!!!! I asked Andrej is he was OK as I swear it had hit the fence he was standing/leaning on but he was fine - it had hit the high tension lines just 50m from us. Both Brad and I had our video camera's running at the time but neither of us caught the actual bolt but we have the flash, the snap and the crack - its quite nice
. I think the Sheriff who was parked up the road from us was somewhat amused (as he cleaned his own underwear) as we all grabbed our cameras and tripods and bolted (pun intended) back to the car.
We headed east again as the precip reached us with more CG's hammering down around us. We made it back to Graham and headed SE but then decided to head NE as the storm was seemingly going ENE and a SE road option wasn't going to suit. After 10 minutes, we decided the storm looked like crap so we dumped it for some new development to the far SW (just N of Abilene) in the hope it would provide a nice lightning show just after sunset. UNfortunately this didn't quite come off and the storm decayed quite quickly after sunset.
We ended up staying the night in Breckenridge (no...not the Colorado version) which was a good thing as we got up the next morning and discovered a flat tyre (tire as they spell it here).
14th May 2008.
So we checked the models for this day during our stay in Breckenridge and decided we had two options to play. The area around Abilene (just to our S) was looking OK in terms of shear (30knts from SE at 850 and 50-60knts from the W at 500) but instability was somewhat in question as a result of an overnight MCS which grazed the area. The question was whether the atmosphere would recover enough in time to get instability sufficient for supercells (this did eventually occur thanks to the strong upper trough coming into the region and rapidly dragging moisture and thus instability back north during the day). The other option was to boot south to near San Angelo into the untapped air which hadn't been overturned by the overnight MCS and play with the dryline bulge and east-west aligned boundary which was drapped across this area in conjunction with the strong instability developing (CAPE of around 3500-4000 and LI's of around -10 to -11). This sounded too good to refuse for us so after we had our tyre fixed we bootd south. A third (early) target was over far eastern New Mexico in the upslope easterly flow which saw DP's of 55-60f heading up the hills into eastern New Mexico into the region where the upper trough was having an early influence. Storms went up in this area by lunchtime and were severe warned. I know a few chasers targeted this area but it failed to produce even with the strongly backed surface flow. THe cap was a little weak in this area which saw quite a lot of convection firing and probably spoiling the party.
When we were about 50mi N of San Angelo the first storm of the day (in our target area) popped up and within half an hour it was severe warned as it headed towards the southern part of San Angelo. We dropped south on the western side of San Angleo and we got a nice view of the base here. It looked very nice (see pics). As we dropped further S and the storm neared, we placed ourselves just east of the base. What a sight!! We were sitting in the vault and the view was incredible (see pics). The only problem we had with this cell was that it looked like it was weakening a little and this may've been due to the new cell which developed to the S of this one. All we could see was the precip on the northern side but it was looking nice on radar. We decided to blow off the first storm (which was still looking nice) and head for the southern most storm but our road options were limited. THis meant we had to drive either a long way south and then east or head south east on an unsealed road. We took the unsealed option to keep us relatively close to the cell. What an option this turned out to be. As the storm pulled away to the east and we headed south east, we got an AWESOME view of the back end of this storm. It looked like a bomb had gone off with the updraft EXPLODING in the highly unstable air. It made for some awesome photos (see pics). We couldn't stop for timelapse video given the relatively fast motion of the storms (35-40mph). We eventually made it back onto the sealed road as this storm went tornado warned and was also warned for hail larger than baseballs - she was a BEAST! The Threatnet was indicating storm tops of 55-60,000ft and from what we saw, this was looking pretty much on the money! We were now gaining on the cell but the downwind precip filled with golfball and larger hail was moving ESE with the main updraft moving SE towards Eden. We were hoping to head N from Menard to Eden but we weren't going to make it in time without risking getting pounded by some massive hail.
We kept heading E (and then ENE) towards Brady whilst watching this beast just a few miles off to our north. It was very photogenic but was definitely a HP monster. As we neared Brady, we realised we needed fuel. FOrtunately the gas station was on the south western edge of town right near our next south east road option. We raced into the gas station, fueled up and as we were doing so, took turns in racing back out to the main road on foot to take photos of the FAST approaching, green, hail-filled monster! It was spectacular but the locals didn't seem to realise the impending doom their town was about to face. THey just casually filled up their gas tanks and wandered around as if it was any other day. I'm not sure why the sirens never went off in Brady - perhaps it was because the large hook was going just north of town. Anyway - as we pulled out of the gas station the outflow blasted us and a few drops of precip started to fall. A wall of white and green was JUST there! We scooted south east JUST ahead of it only to hear on the weather radio minutes later than baseball hail was reported on the northern side of Brady with winds in excess of 70mph!! I'm sure the locals weren't so complacent by this stage.
Just taking a step back, as we drove towards Brady from Menard, we watched as another cell exploded to our SSE (about 40mi away). This thing was incredible to watch and kept my attention whilst the others had the view out the other side of the car of the massive HP beast to the north. The southern cell split and we then watched the left split move almost due N towards Brady but then fizzle out and die as it got close (we were a little concerned it may kill the storm we were chasing).
After we left Brady to be smashed by the HP, we headed south east to get ahead of the storm to get photos of this fairly awesome gust front. We stopped about 20mi down the road and got some nice pics but the radar was indicating this storm was looking fairly outflow dominated (even thou it was still tornado warned, a lot of these warnings appeared to be mostly from either rain-wrapped wall clouds or from significant outflow). A decision was reached to keep heading SE to Llano to intercept the southern storm which was still looking fairly impressive. No more than a few minutes after this decision, the storm was tornado warned with spotters reporting funnel clouds. We had to go about 35mi to Llano and the storm had about 20mi to get to Llano - we beat it but we took the core punch route (a very well calculated, relatively risk-free one). We encountered some torrential rain and small (2-3cm) hail but popped out of the precip about 4mi N of Llano (heading S) and the view to our west was incredible!! The base was HUGE and there was great separation between the precip and the updraft. We managed to get to the southern side of Llano and set up for about 15 minutes as we watched two areas of strong rotation approach Llano (not sure why the sirens didn't go off here either). Inflow into this storm was WARM and very moist and was much better than the previous day - it looked to be about 25-30knts. CG's were raining out of the vault and the structure was quite amazing. Eventually we were forced to move as precip hit our location. Unfortunately the storm was moving into an area with some terrible road options and terrible terrain (the hill country) but we had to make do.
We had to push a long way SE before we got another decent view but with the storm speed it was oK as it gave us plenty of time to watch as the storm approached out location. We were now well S of LLano and the storm was still going strong - not quite HP yet. It had an awesome wall cloud as we stopped and a nice inflow band extending off to the ESE (which actually marked the E-W aligned boundary that we found out the storm was riding along. SPC had mtioned in a mesoscale discussion that this storm (and another up near Abilene) had the most potential to produce tornadoes given their proximity to east-west aligned boundaries. Several other chasers were on this storm also and passed us at this location. We watched from this hilltop for quite a while as the storm passed across our path to the north. As it did this, a second wall cloud developed and the wall cloud in the notch of the developing HP was really cranking with rotation. We had to move from here as the storm moved behind a hill so we dropped south again but with still very few road options and darkness approaching we headed well south and east to Marble Falls.
We somehow found the lookout of the year in Marble Falls on the southern side of town - it was deserted when we arrived (ti was a church carpark). It was an elevated position looking N towards the storm! A long inflow band extended off to the east (still) and had a heavy core. As it moved ESE, we noticed a low bowl-shaped wall cloud partially rain wrapped. As the storm continued ESE towards our location the light faded but we could still make out the wall cloud. Through the poor contrast we noticed a small funnel as the wall cloud wrapped more tightly. For about 10 seconds, this funnel appeared to condense most of the way to the ground (refer pics on my gallery). Shortly after, it lifed back up btu maintained a funnel shape for another minute or so before we lost it in the rain and poor contrast. A nice hook was showing up on radar in this location and the shear marker on the Threatnet indicated 115mBy this time, loads of other chasers had turned up at this location and the carpark was now packed with chase vehicles and tour groups. The storm moved over Marble Falls in the valley below us and soon smashed into our location and the chasers disperesed rapidly. The outflow from this monster was STRONG with gusts easily over 50mph (80km/h). As we raced south, the car was pushed around a bit but suddenly FWHOOOSHH...debris, gravel and other sh!t smashed into the side of the car as a gustnado slammed into us from the side and the car lurched off into the left lane. It only lasted about 1 second but it was STRONG. We estimate the winds were probably around 80mph (130km/h). We sustained a few minor scratches on the side of the car but otherwise escaped unscathed.
We again had very few decent road options and we decided to head into Austin and through to the eastern side of Austin to wait for the storm there. We didn't fancy trying to find somewhere IN Austin traffic to view the storm from. This gave us time to traverse Austin and get some food (quickly) and set up for the storm. It was still tornado warned (and had been for a long time now) yet apart from the possible tornado we had seen, no other tornado reports had been made. As the storm passed accross the northern part of Austin with a very nice hook echo, there were reports of brief touchdowns however I don't think any of these have yet been confirmed. It was now 10pm or so and this storm had been going since about 6pm and had ben tornado warned for the last 3 hours! We waited on the eastern side of Austin and positioned ourseleves just south of its path to get some lightning photos and keep an eye out for any base features. To keep it short, we didn't see much. THere were a few OK CG's but nothing special.
We let the storm slide off to the east but we had another line of storms in our sights to the west whih was about 50mi west of Austin. We cruised around, set up at a little clearing we found about 25mi NE of Austin and waited. We copped a glancing blow from another storm which developed ahead of the other line but this soon cleared off. The best area of this line of storms looked to pass a bit to our south so we dropped back south to near where we had had some dinner earlier in the evening (it was now well after 11pm). We set up near a carwash off the main road looking west towards Austin and it started. A barrage of CG's which lasted probably all of an hour (maybe more). One cell west of Austin was going nuts but was a little far away for photos but another cell along the line closer to us (just NE of Austin) was putting out some infrequent but very nice CG's. As this weakened and moved away to our NE the stuff west of Austin was starting to come into range. Two, three and at times four and even five CG's filled our frames (and we also missed countless bolts either watched through the viewfinder trying to re-focus on a different area or bolts hitting just off the side of the frame). Great hilarity was involved in this as we each called out as we viewed our photos with CG's off the side or watched them through the viewfinder. This went on for AGES as the storm got closer and closer. Eventually a HUGE duwnburst unloaded over Austin (and produced softball sized hail at 1am!!!) and another storm went up close to our location dropping CG"s no more than 2-5km away. THis made for even more great photos, again with 2 or more CG's filling our frames. This whole time we had remained precipitaiton free but finally it was upon us and we were forced to pack up and move. We headed east about 25 miles to get ahead of it in case it wanted to keep going. We set up again in a clearing and although the storm had weakened signifintly, it managed to punch out 2 more CG's for us. We eventually called it a night just after 2am and headed to Elgin (just east of Austin) for the night. We had been chasing storms from just north of San Angelo to east of Austin and had covered 480km in doing so and had been viewing the storms for just under 12 hours (both new records for me!). It was an amazing day with a bit of everything. Hail, base structure, updraft structure, wall clouds, possible tornadoes and finished off with some AWESOME lightning.
It was the last chase for a while as a ridge moved in and we did some touristy stuff. More on those things in a later post.
Macca & Crew.
(Oh - as noted, the pics from these two days are up on my gallery here...
http://macca.bsch.au.com/gallery2/v/USA2008/ ).
