2014-04-26 FCST: KS OK TX

[Dan Robinson]

The RAP and HRRR are badly mixing out the moisture along the DL, while the 4KM WRF is staying true to the NAM/GFS and maintaining things until the upper support finally kicks things off at sunset. I still favor the central Nebraska target for the better low-level shear. However, I'm simply not as motivated to do the 10-hour drive for a nighttime tornado, given the marathon that may be needed for Sunday.

 

[Michael Thompson]

Target, Clinton, Okalhoma

Not much to add to what has already been said, but had to type up for an Aussi forum with a virtual chase target.The two big concerns are dewpoints and CAP strength. GFS appears to be overcooking dewpoints a little, 2-3C compared to other models. The surface low (lee cyclone) has not had enough time to advect the richer moisture too far north into the better shear. I think you will need to be position as far south along the dry line as possible without losing the shear.

The thermal trough is hanging way back on the Rockies still near sunset, so it may be too capped until after dark as that trough noses forwards. However I still think some isolated supercells should form along the dryline in Oklahoma and far northern Texas.

After dark things get interesting as dewpoints increase and surface temperatures cool, plus the upper level support strengthens, this could be interesting at 1-2am for certain Aussies at their chase base in Kansas, a nocturnal tornado is not out of reason.

My sunset target is Clinton, OK, it is as far south as I dare to go. I expect large hail, lovely high based supercell structure and lightning. There may be a surprise tornado near sunset if GFS optimism about dewpoints holds. Clinton also set ups good for the moderate risk day in Arkansas on Sunday.

Perhaps because I am a chase anything desperado (as most Aussie chasers are) I find it hard to understand why many USA chasers will stand down for Saturdays photogenic storms in reasonable chase topography, and chase a higher tornado risk further east on Sunday, but in thick forest and hills.

 

[James Gustina]

Not really sure if I even want to leave Norman for this one, the lack of a set tornado threat is what is making me hesitant. The trough is lagging pretty far behind with it's center onshore in south-central California. Moisture is still advecting north at a pretty good clip and some nice cloud cover will hopefully knock the sfc temps down later into the afternoon. I'd probably end up picking Gotebo or somewhere a little further north on the nose of where the best moisture is progged per the NAM and GFS. With any luck, spreads will stay down around 20F today and it'll take some time for the sun to really cook the prairie.

 

[Jared Orr]

Just made one of the most difficult decisions I've made in a long time:

SE Nebraska---
Pros: RAP showing isolated precip. Better terrain/reception than a lot of OK. Less chaser convergence. Chance to bag a tornado that most people miss. Lower cloud bases than Oklahoma. Great backed surface winds. Closer to home.

SW Oklahoma---
Pros: Better moisture (unlikely that moisture will advect to the degree than NAM is showing for Nebraska). Less conditional initiation (and earlier) due to stronger upper support, better moisture convergence, and surface temperatures. Better position for the southern target on Sunday. LP cells look cool.

I won't say which one I chose. This is a personal decision. You need to work this out in your own heart and mind.

 

[Mike Johnston]

Just FWIW, looks like actual moisture advection is proceeding a little quicker than the RUC is depicting. RUC shows 60 dewpoints barely reaching the Red River now and for the rest of the afternoon, whereas the Oklahoma mesonet indicates current mid-60's in that area, plus numerous > 60tds through central OK and even up to northern OK. Sure, there will be mixing out this afternoon, but at least the moisture advection looks a little ahead of schedule so far. RUC is trying to break out precip just ahead of the dry line around 00z, so still some chance for something to pop. Also, CIN may erode in N Central OK and S Central KS around 00z w/ >2,000 j/kg CAPE.

 

[Lance Maxwell]

I think we've decided to call it off today. That DFW sounding is putrid in terms of moisture and with the trough hanging so far west I don't see much of a tornado threat out there this evening before dark.

 

[Andrew Stoller]

I hope someone took the NE target; the HRRR has consistently shown a nice isolated discrete cell track across central NE with very strong directional shear/helicity/EHI. 73/50 temp/dewpoints currently in the area. HRRR only shows modest convection popping in north central TX for the southern target.

 

[JeremyS]

I am planning on going out mainly since I am so close. HRRR has been showing a cell or 2 for the past 4-5 runs so it's too hard not to bite on it. Shear will be great up this way as the LLJ starts to ramp up, warm front in the area, not as hot so hopefully as it starts to cool this evening and the dews come up even more there will be a chance of a tornado before dark and before the storms become elevated north of the warm front.

I hope someone took the NE target; the HRRR has consistently shown a nice isolated discrete cell track across central NE with very strong directional shear/helicity/EHI. 73/50 temp/dewpoints currently in the area. HRRR only shows modest convection popping in north central TX for the southern target.

 

[Matt Hunt]

I hope someone took the NE target; the HRRR has consistently shown a nice isolated discrete cell track across central NE with very strong directional shear/helicity/EHI. 73/50 temp/dewpoints currently in the area. HRRR only shows modest convection popping in north central TX for the southern target.

Looks like about 80/50 in the area now. Temps will likely outpace the dewpoints as daytime heating continues. I really liked the hodographs up there, but I was too concerned for inadequate moisture that far north, and still too big of a TDD.