2/24/07 FCST: OH/KY/TN/IA/KS/MO/TX/LA/OK/IL/AR

[Michael O'Keeffe]

I agree with Mike on that one. I was also thinking about playing the TP or the dryline further south in southern Kansas. Maybe due to overnight convection we could see a few boundries come into play as well.

Still lots can change, but as of right now this is what I think is the best areas to setup. Man, if this really does pan out it should be pretty wild. I'm anxious to see the next model run.

 

[Justin Walker]

I see no reason to disagree with the last couple of points, except that it is 132 hrs out!! The forcing is extremely strong the closer you get to the jet max into southern KS and pts south and eastward. Plus there is not much veering with height, but there is a ton of speed shear. Not a big fan of that when hunting for tornadoes, too many indicators for squall line/wind event. The cap is stronger over ne KS and might keep things from going upscale quickly. However, many days out and many, many more runs to bring us all out of our winter hibernations. I will keep dreaming!

 

[Chris Wilburn]

Here are my thoughts on Saturday per tonights 00z run. 993mb surface low in northeast New Mexico at 12z deepening to 984mb by 00z. Very deep surface low and backed surface winds. Just like the post above the speed shear looks great, but one thing that jumped out a bit was the lack of ideal veering with height that I like for tornadic supercels. However, with such dynamics on board it may not mater. Mid to upper 50 dews should provide just enough moisture. Appears to be a closed 500mb low near the surface low that showed up one previous runs. That is all I will add for now as it is obviously still far out. Will be fun monitoring future runs associated with this system. I will be chasing as it looks to be relatively close to home.

 

[Jason McIntosh]

One thing we can all agree on at this point is that a big change is underway. The positive side of this is an early Spring chase season is looking likely. If you wanna forcast off the models 4-7 days out just look at the storm after this one. I think this will initially be a very dirty storm as it gains strength out of the central plains. Lots of cloud cover and low instability. Arkansas could possibly get a nice round on Saturday night if there is minimal cloud cover that day. Any big outbreaks of tornadoes, though possible, I feel will be unlikely with this system. Especially as it gets up here towards northern Illinois and southern Wisconsin. I feel all the snow pack that will be melting all week prior to this storm will over saturate the area with low level fog and clouds. So very little in the way of sunshine. If there is to be a big event for tornadoes or severe weather it will be along the Gulf Coast states where better instability should occur. One thing I remember about the March 12th storm of last year was the next day western WI was hit with a strong snowstorm. The flip side of this storm may be a more significant snowstorm/blizzard on Sunday in Wisconsin. No doubt as this weekend nears we will have a clearer picture of this potentially significant weather system. Get those cars, cameras, and weather radios ready!

 

[Paul Knightley]

Without wishing to trash the thread with extensive comparisons, could I just ask for opinions on whether this situation is anything like April 6th-8th last year please? I only ask as the deep southerly flow progged over eastern KS reminded me of Mike H's chase/tornado at Hanover, KS on the 6th.

 

[rdale]

Until we're in a timeframe where we have an actual idea of what's going to happen - it is useless to make comparisons... Right now there's still way too much wishcasting since we're so far away.

 

[Paul Knightley]

No wishcasting on my part, just a pertinent question on the possibilities! I wouldn't say it's useless making comparisons either, but don't wish to get into some big debate on it.

 

[Michael O'Keeffe]

Well the model has slowed down for good it seems as of right now. The future of this system is slowly becoming more clear as we get closer to the weekend (even though its only Tuesday).

The system should eject into the Plains around noontime Saturday. Due to a strong low-level jet, we will see suffient low-level moisture return into OK and KS by the afternoon. Storms should then erupt along the dryline and blast eastward. All of this along with strong vertical shear will be supportive of tornadic supercells, some of which could be strong. The supercells should move east throughout the afternoon and evening as the system moves east. The cells should converge into a squall soon after dark and bring damaging winds and heavy rains to the Mississippi River Valley.

Am thinking of targeting the I135 corridor between Newton and Salina which should be a bit closer to the TP which I like better because of a bit slower storm speeds.

 

[Jim Bishop]

I'm concerned about the intensity of the upper system itself. There is going to be so much lift from upper dynamics I'm afraid storms go up too early, too fast. Basically, I'm worried storms fire before the low level clouds can mix out. This of course can't be determined until the day of, but it's a concern nonetheless.

Asside from these usual uncertainties days before the event, it still looks like a big severe weather outbreak starting over Central or eastern Oklahoma/Kansas, and then blasting northeast or north-northeastward into Missouri/Arkansas. Whether it becomes more of a tornado event than a strong wind event remains to be seen. I'm betting on tornadoes followed by a damaging squall line. Either way I see no way around tornadoes occuring on Saturday.

 

[Mike Hollingshead]

http://grib2.wxcaster.com/wxcaster4/CONUS_GFS_1000-500_SLPPRPTHK_114HR.gif

Just for fun for those that might not look at the 6z gfs(I never do).

 

[Karen Politte]

That's certainly a neato image there, MikeH. LOL.

Well - while the warm front's certainly a possible play up north into MO or wherever it ends up setting up, I think I'd rather stay closer to home for this Saturday. It will just not be worth my while to spend $$$$ on gas and leave in the dead of night to catch 60mph storms rocketing through the trees and hills at the warm front. If this scenario had the possibility of playing itself out in SErn KS or SWrn MO, I'd be interested - however it looks like it's going to be too early and too fast.

We will stay down close to home and in the nice, deep(ish) moisture. Maybe a jaunt west on I-40 to play with something in the daylight - although the atmosphere will have to tread the fine line of squall line vs. embedded supercells vs. discrete cells. Hell - after the past two months we have had here I will be quite happy to see lightning. And maybe a golfball or two.

I think my sentiments echo Jim Bishop's with some dashes of pessimism thrown in. The season is, after all, very very young. With all of the dynamics coming out into the Plains for Saturday's system - tornadoes look undeniable......somewhere. I just don't know if I want to be the one seeing them, trapped in a pac-man-style HP wrapping a hellish meso as it deforests part of the Ozarks. No thanks.

KL

 

[afischer]

Without wishing to trash the thread with extensive comparisons, could I just ask for opinions on whether this situation is anything like April 6th-8th last year please? I only ask as the deep southerly flow progged over eastern KS reminded me of Mike H's chase/tornado at Hanover, KS on the 6th.

Kind of a good point here. I'd say 500mb flow during the April 6 Salina to Hanover cyclic tornadic storm was from about 210 degrees. I personally was surprised that storm was able to remain discrete for as long as it did given the intense dynamics and rather meridional nature of the mid-level winds. The 2-8km shear vector did have some crossover with the dryline that day, but not a lot. I think strong isallobaric adjustments were creating some extremely favorable 0-1km SRH in the corridor where that storm was, which was never really sampled directly (though the TOP RAOB was kind of close)... this may have been a factor in its persistence.

Discrete tornadic supercells can and do occur with near-unidirectional deep southerly flow. 09/21/06 last year is a good example, but these storms were immediately in advance of a compact closed low with a well-timed dry slot wrapping in ahead of it.

Back to Saturday... I've been seeing a much more elongated vort max in the progs, with mid-level flow actually forecast to back with time on the "northern" end of things as the wave goes negative tilt. In that regard I believe it's a little different from April 6... and the progs spell more of a squall line/line segments to me.

I think we're all aware convective mode is hard to anticipate. Pattern recognition and drawing comparisions are still a good thing.

Edit: I actually like the looks of the 12Z GFS better, esp for cold core activity. The vort max is awfully elongated still, but the sfc and mid-level lows are in far closer proximity and it doesn't occlude as quickly. The prog looks very, very similar to the 11/27/05 event; like, nearly a mirror image. *Disclaimer: Surprise! it's still too early to tell.* lol.

 

[Brian Stertz]

Yeah right on Karen...60 mph brush hogs can be pretty scary blasting through the Ozarks. Just hoping that initial storm development can stay somewhat discrete on the very strong 700mb wave the 12z GFS has moving up across SE Kansas/NE Oklahoma by early afternoon. Also have the dryslot/triple point to consider as well across C/SC Kansas early on. Time to sift through all the data and find the nugget to make the ultimate decision of chase or no chase...where...and when !! It's a solid MDT risk setup. Just have to see if this parlays into chaseable supercells.

 

[Brandon Sullivan]

Well I am starting to lose excitement over this system.. Models continue the southern trend. As well as the slower trend.. The slower setup screws everything up for us! I think if I want to see something.. Looks like I will be bound to somewhere in MO... Well have to wait and see.. Also, models are turning down the amount of cape. So the system will have to get some severeity out of the shear and moisture.. Im bummed.. But im not turning my head yet!

 

[Bill Tabor]

Concerning the other thread - 'What day will be the first high risk of 2007?', I'd say that is likely Saturday Feb 24. Moisture will be the biggest factor in determining this. Biggest concern for me and good chasing in daylight OK/KS to MO are the current forecast dewpoints, the extra large amount of forcing, and the storm speeds.

The triple point area should be in 55 or less dewpoints and that is a bit lower than I prefer. As others stated the immense forcing can make the storms go early killing good discreet severe, and finally what ever does emerge will be that early season fasting moving crap with possible poor visibilities / overcast.

This setup in some ways reminds me of April 7th 2001 which I previously referred to in my wx-chase account as "A Shocking Good Time", but I believe dews were higher that day.

Another thought, the (should I say 'lying' - ) GFS is showing precip on Friday in OK. That area will have the better 60's dewpoints on Sat. If perhaps and outflow boundary did exist in OK and interacted with the shortwave.....

EDIT: Question - what snow cover like in KS / OK?