April 26, 2009

Statistics:

Initial Target: Woodward, OK
Departure: Weatherford, OK 10:00 am
Arrival: Westchester, IL 6:00 pm April 27
Intercepts: Roll, KS
Tornadoes: 0
Hail: Non-Severe (Pea Sized)
Wind: Non-Severe (not measured)
Features: RFB, Funnel
Miles: 1290

Summary:

Second day in two day run to Oklahoma.  High risk day featured strongly sheared dryline setup with weak cap favoring continuous thunderstorm development.  Left Weatherford heading north for unwarned storms.  Dropped south of Clinton to severe warned storm that became tornado warned after intercept.  Followed storm north of Clinton before it fell apart.  Left deteriorating storms for newly initiating dryline storms in southwest OK.  Dryline storms failed to materialize so intercepted tail end charlie of cold front storms.  Adjacent cell tornadoed before we arrived.  Noted RFB with condensation.  Brief funnel developed but missed photographing it.  Entire line of storms quickly gusted out without recovering.  Waning instability and lack of new initiation ended days opportunities.

Crew and Equipment:

Solo Chase.  Equipment: TH-F6A Tribander, and GPS/mobile data card equipped laptop.  Pictures by Skip Talbot and Brandon Sullivan.

Details:

The second day in a two day run looked to be a big one.  Wind shear levels were very impressive with 1km storm relative helicity values over 400.  Moisture had been advecting overnight and Cape was already over 3000 in the TX panhandle before noon.  Brandon, Mike, and I checked out of our hotel room at 11 am targeting Woodward for a 21z (4 pm) initiation.  Storms were forecasted to develop continuously across the region all day, but the parameters were maximized over Woodward at this time.
We left Weatherford at around 11 am and headed towards Clinton where we met up with Jesse Risley and co.  There were some sells firing north of town that we went after.  The storm we intercepted exhibited a high, rain filled base and failed to organize.  As the storm became choked by neighboring cells and failed to gain a warning, we left it and dropped south for a severe warned storm southwest of Clinton.  The roads prevented us from intercepting right away without core punching, so we pulled off onto a county gravel road and let the storm come to us.  The storms from the day before prevented us from using any roads that were not paved or well maintained gravel due to the possibility of getting stuck.  After a few minutes of watching a base hidden by the precipitation core, the storm picked up a tornado warning and we decided to move on it.  We dropped south on the gravel road before picking up a paved west option that would take us to the base.
The storm had a rain free (mostly) base, but there was not much structure otherwise.  Any supercell structure was hidden by low level clouds.
A brief wall cloud like lowering formed under the base, but it failed to organize much.

We followed the storm well north of Clinton before we finally gave up on it.  SPC upgraded to a high risk and issued PDS tornado watches due to the extreme shear and instability combination, which really got our hopes up.  We headed over to Watonga and then down south towards 40 to play new convection coming off the dryline.  We stopped for a leisurely lunch in Geary as storms on the cold front started to ramp up. 

Heading west on 40 it became apparent that the dryline storms were not going to materialize and our only play would be on the cold front in northwest Oklahoma.  En route a storm in the middle of the line put down three tornadoes.  It was really disappointing knowing we were missing the only show in town.  We turned north out of Sayre.  We knew we couldn't catch that storm so we plotted a course for Tail-End-Charlie.  The roads near the Canadian River are sparse and hilly so we had to stop 10 miles east of the base to watch the storm.
I pulled my camcorder off the tripod I had secured to my passenger seat in the van to shoot the base.  The battery died though as if it had never charged while connected to the outlet in the van.  While I was fiddling with that, a brief, but well defined rope funnel formed on the forward flank of the base.  I missed seeing it due to my fumbling and equipment issues, while the others in the caravan snagged photos of it.  It was the consolation prize of missing the tornadoes and I missed it.
Due to the large chaser convergence near Roll, I wound up getting split up from the caravan.  The cold front storms became outflow dominant and linear shortly afterwards anyway.  New convection failed to initiate due to lack of instability and the cold pool being put down by the cold front storms.  Despite the maintenance of the high risk and PDS tornado watches, I started heading for home.  I made one last intercept after dark on a severe warned cell near Cherokee, OK noting lots of lightning and a gust front but not much more.  I stopped for the night just across KS border, sleeping in the van, before making the long drive back to Illinois the next day.
Conclusion:

Sunday was a huge bust, personally and forecast wise.  The high risk failed to materialize with only three tornadoes coming out of the high risk area in Oklahoma.  The tornadoes that did form were gorgeous, however, and it really stung having driven all that way only to miss them due to bad positioning.  The storms in general across the region were grungy and poorly structured.  Missing the rope funnel our caravan saw only added insult to injury.  I left Oklahoma heart broken. 

 

Lessons Learned:

  • Don't abandon cold front storms in favor future storms that may never occur.