Tuesday, May 31, 2016

5/28/2016 Snyder, TX Convection

Saturday was a fairly marginal setup for severe weather from an ingredients perspective, especially in regards to vertical wind shear. Late May dewpoints and some veering of the wind with height along a morning outflow boundary was able to create an environment at least supportive of widely scattered severe storms.  We watched a beautiful sunlit updraft tower from near Hermleigh, TX in front of a windmill farm and then moseyed northeast toward Snyder, TX where we were treated with a spectacular evening lightning show.

MISC: Overnighted in Snyder, TX  |  Walker's Birthday  |  Found neat hail divots in a field near Hermleigh, TX

Monday, May 30, 2016

5/27/2016 Leoti to Dighton, KS Supercells

We (Walker | Laura) opted for a less traditional target on Friday, in the bent back area north of the surface low. Several landspouts were noted, but we could not confirm any of these reports. Between Leoti (a popular place for supercells this year!) and Dighton, we did observed tight cyclonic rotation overhead.  This cell attempted, but failed, to produce a tornado. Overall, a great day that exceeded our expectations.

MISC: Overnighted in Garden City, KS, in the the brand new Heritage Inn (highly recommend).

View from our current home
Van is just a little dirty :-)

5/26/2016 LP Supercell from Tribune to Leoti, KS

Thursday featured an environment favoring left-splitting supercells, with several anticyclonic funnels noted on convection that formed in western KS. Overall, the day was a big "bust" from a forecast standpoint.  A "moderate" risk for severe weather was forecast, yet there were no tornadoes reported in the MDT risk area!  Early morning convection broke out and muddied up the atmosphere causing a significant decreasing risk for severe weather in the MDT risk area by late afternoon.  We slid west out of the MDT risk area toward Tribune, KS, where the atmosphere was still relatively pristine. A nice LP supercell formed near Tribune and tracked to Leoti, where we were treated with some beautiful skies.
1800Z weather balloon data from KDDC

Anticyclonic funnel cloud! 

5/25/2016 Enterprise to Chapman, KS Tornado

We (Laura and I) departed early 5/25 with sights on northeast Kansas for a mesoscale accident.  The 1300Z SPC outlook highlighted a "marginal" risk for severe storms in this area, but one has to keep in mind that these outlooks also must consider coverage of severe weather over an area (the outlook was upgraded to a "slight" risk at 1630Z).  The overall CAPE/Shear parameter space was favorable for supercells, it was just more of a question of exactly what the forcing mechanism would be.  Two potential target areas became clear by mid-afternoon.  One option emerged near El Dorado, KS, just east of dryline apex, and the other further northwest along an overnight east-west oriented outflow boundary / dryline intersection.  We met up with Walker and initially chose the El Dorado play, due to the slightly higher progged instability. As towers went up in this area, they were plagued by dry air entertainment, and it was clear that we needed more forcing. We bailed for the northwest play, and made it just in time for the Enterprise to Chapman EF4 tornado. Positioning on the northeast side of the hook (see velocity image below for position) made for some incredible views of the tornado as it moved east. An incredible mesoscale accident day! 

MISC: Overnighted in Junction City, KS.  Crossed the damage path (picture below) along I-70 heading westbound the next morning.  The tornado also damaged a section of railroad tracks outside of Chapman. Lesson learned to stick with gut and play stronger forcing/triple point in these scenarios. 

5/22/2016 Memphis, TX Supercell

5/22 was our last day out with College of DuPage Trip 2.  With high hopes for a good end to the trip, we set our sights on the eastern TX panhandle for supercell storms.  Our target storm near Memphis, TX had great rotation during its classic phase, but then morphed into a dangerous high-precipitation supercell with an embedded tornado.  Due to safety reasons, we pulled back further to the east to remain out of the dangerous areas of the supercell.  Not what we were hoping for (especially because a different storm to the north produced a much greater visibility tornado), but we did our best. 

MISC:  Overnighted in Moore, OK. 

Monday, May 23, 2016

5/21/2016 Leoti, KS Stationary Supercell

Saturday was a day that chasers dream for.  As a professor, it was a remarkable opportunity to teach students about storm structure as a majestic supercell sat nearly stationary for over three hours just north of our morning target of Leoti, KS.

We met up with the the Mississippi State and Western Kentucky field programs to launch a weather balloon from Garden City, KS (skew-T/log-P data attached below). The data showed weak upper-level winds, but surface and near-surface winds were anomalously strong.  

High based convection developed by mid-afternoon in steepening lapse rates along and just west of a N/S oriented dryline in western KS.  As this convection matured, it was able to anchor to a pseudo warm front on the edge of deeper moisture to the east.  Remarkably strong low-level winds were able to overcome the relatively weak deep-layer shear, and this resulted in stationary storm motions (a chaser's dream!; reminded me a little of the West Point/Dodge, NE supercell from June 2013). A couple of tight circulations were noted (see the timelapse below), along with intermittent touchdowns early in the evolution.  As the sun began to set, we were treated to mouth watering storm structure.  The students were amazed (as was the professor!).  This was likely a top-5 storm chase structure day for me.  Enjoy the pictures and timelapse below.

Launch photo courtesy of Trip 2 participant Rebecca Jacobson
19 UTC Skew-T/ Log-P data from our balloon launch


Photo by Trip 2 participant Alysa Pederson
Our position relative to the supercell

5/19/2016 Carlsbad Caverns

Thursday was a "down" day for storm chasing, as a strong high pressure system over the Great Lakes forced northerly surface winds (and COLD air!) into the Rio Grande Valley.  I took the group to Carlsbad Caverns National Park, where we explored the caverns.  The elevator out of the cavern was broken, so we had to hike our way back out!

MISC: Overnighted in Raton, NM.


Wednesday, May 18, 2016

5/16/2016 Texline Tornado

We awoke in Amarillo, TX, to thick fog, worried that the day was going to be hampered by lack of sunshine and instability.  After lunch in Dalhart, TX, we traveled northwest to Boise City, OK, where we launched a weather balloon from a park on the north side of town.  Balloon data showed that winds just off the surface were meager and that storms may have a difficult time having strong low-level mesocyclones.  Storms began to form as we were collecting data and we tracked them to the TX/NM border near Texline. Cool rear-flank air and lack of substantial moisture likely inhibited this from being a very good day.  Nevertheless, we did see a brief tornado on HWY 120, just south and east of Texline. There was no full condensation of the tornado, but it did have ground/dust circulation for 1-2 min. 

After the storms became shrouded in outflow, we dropped south of Stratford to near Marsh and let a big supercell cross the road north of us.  We went back to see how big the hail was, and found lots of baseball and tennis ball size hail. 

Overall, a great day!

MISC: Overnighted in Lubbock, TX.

Students helping set up for the balloon launch
Weather balloon launch data