4/21/07 FCST: OK / KS / TX / NE

[Billy Griffin]

Models now showing a possible severe weather event for this upcoming weekend. All are surprisingly consistent in pointing out Saturday as a potential widespread event over the central / southern Plains, although locations tend to differ slightly (no big surprise).

I don't think the GOF will be shut down too long this time, and with plenty of time to recover, by the time this weekend rolls around, this could be a good chase day for most everyone! It certainly bears watching nevertheless.

 

[Michael O'Keeffe]

I think this day may have potential only if we can get the Gulf to bring back the moisture after this recent cold spell I feel it will be tough for the tds to reach anything significant, but I do see at least low 60s across much of the S Plains. I agree that will may see an active severe weather day across the plains from NE into TX. If this pans out, then I'm there!

 

[SteveCarter]

I'm not sure why I'm even posting this far in advance...WAY to early to start this thread, but......this set-up has the potential to be a pretty big event. Moisture? Don't see any problems with that...at all. But...still to early to know anything yet. I'll post about Wednesday or Thursday.

 

[Billy Griffin]

The reason I have had my eye on this one is I'm seeing an all-too-familiar pattern setting up over the Gulf of Alaska. Ridging over the Pacific NW has held the past couple of days and shows a breakdown by mid-week, allowing quite a trough to dig in.

You're right - way too early to start trying to pinpoint things, and I was reluctant to even start this thread, but it should make for some good conversation/forecasts until the event arrives. The long wave trough should establish itself over the western US by mid-week. But at this point, I'm relatively confident we're looking at a significant event for the period of Friday through Sunday of this next week for the central and southern Plains.

Being in Seattle one day, Norman the next, throughout the week, it helps in seeing this pattern evolve, and kinda fun too!

 

[Brian Stertz]

Both Sat. and Sun look interesting...if the ext. model trends are correct...Sat. should be the dryline setup day from W/C Kansas southward into W.Oklahoma and the Texas Panhandle/Caprock areas. Sunday should be the more widespread event (NC/NE Kansas, E.Nebraska, W.Iowa) as the fairly deep surface low takes off to the northeast from NC Kansas Sunday afternoon to NC Iowa by early Monday morning. I am sure more changes are forthcoming with respect to this system's ejection, but at this point this is how things were shaping up. Moisture does not appear to be a problem as there should be a good sustained southerly flow off the Gulf developing by Friday and continuing into the weekend. Cap may be of a problem for Saturday though...unless there can be some minor wave getting kicked out ahead of the main wave which will be about to turn the corner by late Saturday to lift out towards the Plains and MO Valley.

 

[Angie Norris]

I'm not impressed yet...I'm seeing very slow progression of that trough, looks like the becoming typical overnight convective event Saturday night into Sunday. It's all wishcasting at this point...we've got 5 days of runs to go. Worth keeping an eye on, though.

 

[Ray Walker]

I'm just glad to see that the models are starting to show moisture return sticking around for a while after this front moves through the plains tuesday. It looks like a steady SW to westerly flow across the plains from friday all the way into next week and beyond. All I know is that there should be at least one pretty nice setup between friday 4/20/07 and wednesday 4/25/07.
Hopefully Oklahoma will see a good chase day soon.

 

[Jeff Miller]

If the pattern verifies, I am believing Sunday, not Saturday, will be the severe day for the Plains. Certainly a long way out, and just beyond the available forecast discussion guidelines for this thread (Day 8), but I too will be keeping a close eye out on the models.

If it verifies for this next Sunday, I will be chasing. I'll be watching this closely all week. Glad we have something to concentrate on as we head into the heart of the chase season.

 

[Brandon Sullivan]

I dont see moisture as a problem.. Even the timing looks favorable at this time... While we all know things will change, it looks nice.. Two shortwaves to move across central IL on Sunday Afternoon and Evening.. This would provide a nice cap breaker and focus point.. I am going to be watching this system!

 

[Kenny Drake]

What i've noticed recently has been the GFS slowing this system down considerably. The 12Z GFS run sfc forecast for Friday basically looks like the current (00Z) GFS run for Saturday. I also don't think we will see a surface low tracking over the Rockies as the landscape would not support it. If the current GFS verifies on general location the best dynamics appear to be near the warm front in NC KS/SC NE near the 500mb jet max exit region. It will be interesting to see if the GFS progged 60F Tds can make it to the KS/NE border in time. Farther south, higher temps and less cloud-cover would likely present an LCL and capping problem given low 60Tds to the coast. However, I find it hard to believe mid 60Tds would not find there way into Oklahoma. I guess this is highly contingent on the characteristics and location of the air mass that will be advected in behind the system pushing through the southern plains on Tuesday.

I probably went into way too much detail with this forecast because im sure the models will change significantly before this weekend. However, its still good to do these forecasts just to get it into your head in case of a future system that verifies very similar to what the current model is forecasting.

 

[Billy Griffin]

SPC and local AFDs for the region still painting an ominous forecast for this upcoming weekend! Interesting wording by SPC for this far out also!

 

[nickgrillo]

Nice looking day progged by the models... Strong surface cyclogenesis with robust boundary layer moisture being advected northward into much of the warm sector, which will yield plenty of instability for severe storms. Nice shear throughout all of the troposphere with strong low-level veering, which should yield strong boundary layer SRH supportive of tornadic supercells. Too bad I won't be able to chase until the first week of May...

 

[Donald Giuliano]

Though I'm not usually one to get too excited about systems 5 days out, the strong agreement between the GFS, ECMWF, Canadian, and even NOGAPS (geez, been awhile since I checked that one) has really caught my attention. They all seem to be pointing towards a likely outbreak in western NE/KS/OK/TX, and on a Saturday no less. 40-50kt 850mb winds out of the south over a large area with good moisture return and a jet nose rounding the base of the trough and coming over a strong dryline? Count me in! If this verifies we could easily see a repeat of March 28, except with more daylight (sweet!).

 

[Chris Wilburn]

Just like Donald said above I don't think moisture will be a problem. I too noticed the 40-50kt 850mb winds that should draw up enough moisture. Directional shear as well as speed shear look very good. I will leave it at that for now, but agree with the mentioned targets of western Nebraska/Kansas/Oklahoma and the Texas panhandle. Low 60 td's somewhere along the dryline would be very nice. That combined with nice directional and speed shear could yield a very nice chase day on Saturday.

 

[Ray Walker]

This system looks very interesting, but of more importance is the weather pattern change. Starting around Thursday Moisture return will comince across the plains. With 60's dewpoints all the way into Nebraska by Saturday. This sytstem looks like a classic, eastern TX panhandle, Western Oklahoma isolated supercell event. This event sure does look good right now but alot could change. Also I really like the 997mb low that the GFS is showing in NE colorado by saturday afternoon.