05/07/05: TALK: Southern/Central Plains

[nickgrillo]

Here's a talk thread for the 7th...

It appears that SUN will be holding more widespread action then SAT will, but SAT still appears quite favorable for severe weather across W OK/TX/KS. I see a problem with moisture, but as someone said earlier in the FCST thread, supercells can EASILY form in 60F dew points. I'm currently liking W OK...

 

[Scott Lincoln]

I dont know if I would call it "quite favorable" at this time. The latest model runs I analyzed today have a nice dry line from central Nebraska into the western panhandle of Texas. Forecast temperatures of at least 80F are located ahead of this boundary. Surface winds from the south, possibly a slight backing of the winds ahead of the dry line.
The main problem isn't so much with moisture or WAA advection on this one, its the shear. I could see some multi-cell clusters or a squall line from this setup, but the chance for tornadoes would not be very high. The upper-air winds at 250mb are forecast to be SW and even SSW along the dryline. The best chance for rotating storms would probably be closer to Texas, according to the latest model data, but this will probably change at least slightly.
Until we get a bit closer to Saturday, I wouldn't say much more than a chance of severe weather at this time.

 

[nickgrillo]

I'm currently thinking W OK for SAT... And may I add that this next week could be an extremely active week. Severe thunderstorms are possible everyday (on the southern/central plains) starting Thursday and continuing into the next week...

 

[B Ozanne]

Amarillo NWS is backing off a little on their POP's for T-storms. They are thinking less moisture. Any thoughts on this? Maybe chances are shifting a little farther north.

I was hoping to at least got onto some convection on Friday, even if it isn't severe. I still like Saturday for some more significant weather, and I'm not dissapointed by the way the weather looks after that.

 

[Mike Johnston]

Just from looking at the latest dewpoint forecasts, looks like Friday should still be fairly marginal. After Friday - dewpoints and therefore potential for instability generally increase across the plains - but convergence line may well already be E of Amarillo by then. Note the OKC long term HWO speaks of an increasing potential for severe over the weekend.

 

[Ben Prusia]

I am thinking the same as Mike, GFS shows the dryline a little more east, near the OK/TX border, it may be hard for east TX Pan. to get some storms. It looks like west OK's turn!

 

[Jason Montano]

It looks as though things are finally setting up for the 7th and 8th. I was waiting for a good couple of days to begin my chase vacation and here they are. I am heading out later tonight from Northern Virginia (NOVA) and heading to the Central/Southern Plains. I hope to get out to NW KS for Friday and then play it from there for Saturday. As of now I am thinking W. OK or maybe the TX panhandle for the best setup Saturday. I have been planning like crazy and believe I have dotted every "j" and crossed every capital "I".

I can't wait to get out there yet again. If ya see me around on the plains come say hi, I am driving the black "honda" with three antennas on the trunk and the wifi antenna on the roof. Good luck everyone.

 

[Jason Boggs]

Boy, I can't wait to get out there and do some chasing myself. Saturday does look like a pretty descent day to be out and about. After the 5 inches of snow we had on May 2nd, I will be happy to see some storms. Looks like the eastern TX panhandle has the best opportunity for severe wx on Saturday.
Good luck to everyone!

 

[Ben Prusia]

The strong upper level system up in ND/SD/MN sure looks tempting to me, only if the upper level winds were better, but I am watching both of the setups. Since I'll be out on Friday, I'll have to make a crucial decision, head N to MN/ND/SD or south to OK/TX...

EDIT: Or as the SPC Day 3 looks, stay here in KS...

 

[J Holder]

Originally posted by nickgrillo
Here's a talk thread for the 7th...

It appears that SUN will be holding more widespread action then SAT will, but SAT still appears quite favorable for severe weather across W OK/TX/KS. I see a problem with moisture, but as someone said earlier in the FCST thread, supercells can EASILY form in 60F dew points. I'm currently liking W OK...

Cut y'all a deal... Keep the weather in OK and TX for the weekend and send it up to KS next week. I've got a turkey hunt with friends I haven't seen in 3 years and I'm not missing it!


JH

 

[Nic Wilson]

From the new SPC 3-Day outlook...

Originally posted by Broyles of SPC


NAM AND GFS SHOW A DISTURBANCE MOVING ACROSS OK AND KS BY EARLY EVENING WITH FORECAST SOUNDINGS SHOWING 0-6 KM SHEAR VALUES OF 35 TO 45 KT. THIS SHOULD BE MORE THAN SUFFICIENT FOR SUPERCELLS. AN UPGRADE TO MODERATE RISK MAY BECOME NECESSARY IN LATER OUTLOOKS

Glad I'm not the only one liking the set-up for Saturday. I believe that this is the only possibility for tornadic supercells during the entire weekend with this first trof. The low-level shear in SD in vicinity of the surface low should be sufficient, but one has to think the the Td's are being overdone in that area. Shear will be in place across the Plains on Saturday before the forcing goes linear on Sunday. Td's won't need to be too incredible to get some High Plains tornadoes out in Western OK and KS. It is reassuring that the NAM and GFS are in sync now as well, the 84-hour NAM isn't even worth looking at with its awful performance.

That being said next weeks system looks to be much more potent and could be the major outbreak of the severe season. Time to get back to work on a 25 page paer so I can get some chasing done in the midst of OU finals week!

 

[nickgrillo]

I'm a little bit baffled with the SPC's decision to include the area with some of the best tornado potential in a 15% risk. I really can't see any justification for this...

I agree that the upper level winds are a bit weak, but are more then sufficant enough to support supercells/tornadoes (especially across NW OK/SW-SC KS). I sure hope they decide to upgrade by the 1730...

 

[Kurt Hulst]

25% and hatched doesnt always mean tornadoes, it can also spell slop and disorginization. And large HP sups. But farther south in SC KS and N OK things look to be more discrete and isolated. Thats good, I would rather chase an isolated cell than a cell that keeps merging with other storms in its area. And SPC has there reasons for painting it that way but im sure things will definetly change by 1730. I did notice how early that posted Day two last night as well. Came out the same time Day 1 did and day one came out 15 minutes early. Was it rushed?

 

[Jim Bishop]

Originally posted by nickgrillo
I'm a little bit baffled with the SPC's decision to include the area with some of the best tornado potential in a 15% risk. I really can't see any justification for this...

I agree that the upper level winds are a bit weak, but are more then sufficant enough to support supercells/tornadoes (especially across NW OK/SW-SC KS). I sure hope they decide to upgrade by the 1730...

Yeah, I was surprised when I did not see a moderate risk, actually. Well, it looks good enough for me to drive up to northwest OK from Houston!

 

[Karen Politte]

What are other's thoughts on the ETA's very aggressive progged moisture recovery for this Saturday's timeframe?

Today's 12Z May 06 ETA run forecasts a "dry hole" (due to overnight precip/MCS?) to move from central TX to around the SPS area by 1200UTC Saturday morning - with this area containing sub-50oF dewpoints. It THEN progs a VERY rapid turnaround in the afternoon bringing 60s across the board all the way through SPS, western OK, and up into South Dakota!!! By 00Z Sunday it plays around with 65oF dewpoints near SPS, too.

How realistic does the list think this is?? I don't quite know where it's getting it's moisture from - especially from taking a look at the current surface pattern and noting that there are NO 60-anything degree Tds onshore ANYWHERE in Texas, and also looking at buoy data and seeing that the highest dewpoint locatable in the Gulf is 63.0oF at Scenic-Route Station 42020 in the north-western Gulf.

I am wondering just *how* we are going to realize these ETA-progged 60-65oF dewpoints on Saturday evening from San Angelo to Fargo.

:?

I'm not being pessimistic - goodness only knows I want this higher-moisture resolution to verify......because I will, barring unforeseen circumstances like grungefest - be out there.

KR