2016-04-16 EVENT: KS/OK/TX

[Tom Dulong]

Thought I would start a thread, since I am not chasing today but plan to get out with the 10,000 other chasers tomorrow.

Here is the analog NAM forecast [http://www.eas.slu.edu/CIPS/ANALOG/DFHR.php?reg=SP&fhr=F036&rundt=2016041512] from the past (20090417/0000) that is the second-best match to what the 12Z NAM advertises for tomorrow evening [first image] and the actual severe weather reports for that day [second image]. I chose to not use the best analog, since the only tornado reports were from north central OK (does not make sense based on latest model forecasts). In the 20090417/0000 event, the surface dews ahead of the dry line were only in the mid 50s 12 hours prior but rose to lower 60s by storm initiation. Based on this, I would think there would be at least a 5 percent risk for tornadoes drawn in the SWO Day 1 for tomorrow.



I often use the Texas Tech 3-km WRF model. Here is what it shows for 21Z tomorrow (I have annotated its forecasts of various other parameters. My initial target would be somewhere east of LBB (Guthrie) by around 18Z. Initiation is forecast for 19Z-20Z.

 

[James Gustina]

Feeling overall pleased with the overnight progression of moisture and the synoptic setup for tomorrow. While a closed low like tomorrow isn't necessarily ideal, it doesn't look like the shear profiles have been affected too badly. Most models are still progging decent veering profiles, with a slight hint of VBV, in the eastern TX PH and SW OK tomorrow with upper-50s/low 60s dews overspreading the region. Storm modes may be a bit more messy than yesterday but setting up shop near the Prairie Dog Town Fork Red River in Armstrong County doesn't seem like a bad idea. Moisture is still advecting northward and I'm guessing we'll have the chance to squeak out a tornado or two before things get messy in the early evening and our heavy rain event gets going.

 

[Ethan Schisler]

Like yesterday, today will feature a threat for at least an isolated tornado or two in the Texas Panhandle perhaps up into the same area of Northwest Oklahoma as yesterday. I think there are several limiting factors though for today. For one, lapse rates (especially mid-levels) appear to be quite a bit less rigorous compared to yesterday (current values only around ~6C/KM). This creating a narrow corridor of instability values and H5 flow that is generally meridional, I think storm mode will be messier than yesterday as well. If I were chasing (which I'm not) I would probably set up somewhere just E of Amarillo in the Claude-Groom-Panhandle region right off I-40. Storm motion should be more northerly than easterly, which may assist in these storms not out-running the narrow corridor of instability instantly. Good luck to anyone out there today and be safe.