Chase Log: April 25th, 2005
Click on any of the SPC products below (Convective Outlooks, Watches, or MCDs) to see the SPC's "Severe Thunderstorm Events" page pertaining to this event.
Total Distance: 440 miles
Target Area: Gainesville to Denton, TX
Chase Area: Sanger to Ladonia, TX
Maximum SPC Risk category: Moderate
Watches:
Tornado Watch 202, Severe Watches 201, 202, and 203
Mesoscale Discussions (MCDs): 682, 683, 684, 685, 686, 687, 688, and 689
Yet another chase with possible 'just in the nick of time' type of moisture. Low-level shear was forecast to be very strong in the warm sector, east of a dryline across western north Texas. With 200-300 0-1km SRH in place, we felt that the upper 50 dewpoints and resultant 1500 j/kg sbCAPE may have been enough to produce some nice tornadic supercell. Except for a couple of slightly tornadic supercells in the southern Dallas/Fort Worth Metroplex, the storms really weren't able to utilize the very strong low-level shear because of the poor instability in place.
Got down to Ardmore to look at data by about 2:30 or 2:45pm. Radar was showing some storms already forming west of Fort Worth, though we didn't want to try to intercept those given the fact that they'd be moving through the metroplex area during rush hour -- not fun. So, we meandered southward through Gainesville, watching for any other convection to fire. By now, surface dewpoints were up into the upper-50s, with CAPEs in the 1500 j/kg range. We watched a storm move across I35 between Denton and Gainesville, and we followed this storm eastward. The storm, despite looking pretty good on radar, looked very poor in person. The updraft appeared to be very elongated, and the base looked very stratiform. There was a 10-15 minute period where we saw a very nice RFD cycle and rapidly rotating wallcloud between Trenton and Randolph in Fannin County. The storm looked like it may produce a tornado at this time, though this wallcloud fell apart rather quickly, and the storm continued on with a poor visual appearance. We eventually gave up on the storm in Ladonia, to the south of Honey Grove. The storm was looking worse in time, and this was confirmed on radar.
We stopped in Bonham for some food, and I finally got to meet Dave Crowley and Justin Teague, whom I, in an almost eerie sense, tend to run into on the vast majority of my chases. In addition, we ran into Kenneth McCallister while just east of Sanger, TX. It was nice chasing with him as well!
Oddly enough, the best-looking storm we saw all day was near Sherman at about 8:00p-8:15p. The storm looked very stout, with an awesome, crisp updraft and backsheared anvil. There was a nice wallcloud present to the immediate east of Hwy 82 between Sherman and Gainesville as well. Since we had a lot of stuff to do (with the semester coming to a close soon), and the fact that the storm was in a similar environment to the very non-tornadic storm was had chased earlier, we left the storm after taking 10-15 minutes worth of pictures.
So, all in all, this was yet another disappointing chase. The area would have likely experienced a significant tornado outbreak had there been better, more typical late April moisture in place. Instead, we chased on yet another day that "could have been", had it not been for the persistent Gulf scouring. Ugh. What I wouldn't give for upper 60 dewpoints and >3000 CAPE...
04-25-2005 Chase Pictures
Click on any photo to see a larger version
