4/24/07 FCST: KS/OK/TX/MO/NE/IA/IL

[Brian Stertz]

The 18z GFS had a very favorable looking setup for C/S Kansas and N.Oklahoma with a decent sfc low near Meade KS and what looked to be a double point near Med. Lodge KS area. The 500mb low was near DDC and there was a very nice lobe encroaching the dryline. Nice theta ridge poking up towards NW Oklahoma and SC Kansas...lots of shear too...especially across SC Kansas and NW/NC Oklahoma along/north of US 412/Cimarron Tpk.. Looks promising if the GFS solution is close to reality.

 

[Jeff Snyder]

We're still a little ways out, so I won't make much of a forecast yet... I will say that I can put pretty good odds on the setup (dryline, jet axis, etc) being west of the current progs. There's been a known bias for years that the models tend to bring troughs out of the southwestern US too quickly. Indeed, we've seen this time and time again this year -- the NCEP models have consistently been too far east / too fast with upperlevel troughs (and, thus, surface features that are a reflection of forcing from said troughs), particularly beyond 36 hours. It could be a heck of a spring for those in the western / High Plains at this pace! One of those years, so far, I wish that I lived in AMA or DDC...

 

[SteveCarter]

I also hate to even address something THIS far out, but......there is a lot to think about next week. This system seems to be a closed L, and should be a LOT better, and easier to chase. Moisture definately not a problem, and it APPEARS that this could be a rather deep low, so...with all that in mind, thinking perhaps cOK Tuesday, maybe AR/LA border Wed, and scAL Thu, then home to South Carolina. The thing(s) that stands out with this system is the MUCH slower movement than previous systems, the abundant WARM MOISTURE, and the vertical shear forecast for this. Not saying this will be a "super outbreak", but it will be one of the best shots so far this year..IMHO.

 

[Ray Walker]

4/24/07 Fcst: KS / OK / TX

I think this day could be the bigest out of them all for the comming up week. Strong instability, capes AOA 2500, strong shear, and the dryline FINALLY MOVING INTO OKLAHOMA LOL!!!!!!!!!! Dewpoints should be in the low to mid 60's by tuesday also.

 

[Kenny Drake]

NAM and GFS have already begun to slow this system down considerably. NAM has the 500mb low much farther west yielding a slower surface solution. GFS has also begun to slow it down, but not as considerably as the NAM. ECMWF has been in general agreement with the NAM, and given that models have been overspeeding most of these systems I think this will be more of a western OK event spreading eastwards. Normally I'm not really a fan of stacked lows because the largescale 500mb divergence over and ahead of the dryline will likely lead to widespread cloud-cover. However, the April 13th event in Texas (very similar) shows that even great chase days come with widespread cloud-cover (and May 3rd for that matter.) After todays event there should be no disruption of the Gulf so 60+Td's are almost a given at this point. At this point it is difficult to narrow down some possible target zones, but going off Sfc obs I would either target the warm front across northern portions of OK or the dryline near Wichita Falls. Both locations have nicely backed winds making up for the not so veered (with height) winds from 700 to 500mb due to the stacked nature of the low.

Of course, I have class and possibly a quiz from 4:30-5:45 on Tuesday. If things stay far enough west than maybe I can grab a cell after class/quiz. This possible event is still a few days out so I will not get too excited (or dissapointed) about it until tomorrow evening.

 

[Brian McKibben]

The 12Z WRF has a pretty good setup on the DL bulge near Childress. However, with the event still several days away the model runs will certainly change. Currently it looks like the Tds will make it to the lower 60s. This will aid in a narrow corridor of near 3000 j/kg of SBCAPE. Also, it looks like the surface winds ahead of the dryline will back to SE. The 0-1 km shear looks to be pretty good. We shall see how this pans out.

BMac

 

[Brandon Clement]

The latest SREF run is getting me pretty excited. If I had to pick a target it would be Altus, Ok where there is a 3k cape bullseye, 0-1 is 200, 0-3 is 300, dewpoints are 65 and temp is 73. It looks as though storms will be discrete. It does not look like an "all world" setup but IMO it looks like a very solid chase day. Still a ways out but as of now it looks like a great day setting up.

 

[Mark Farnik]

The newest Day 3 outlook has a Moderate Risk area outlined over south central KS/central OK/northcentral TX! The SPC's gotta be extremely certain of a significant outbreak to issue a Day 3 Moderate Risk.
The latest NAM and GFS paint some pretty impressive parameters in a north/south corridor from roughly Medicine Lodge, KS to Wichita Falls, TX. Given these facts, unless the setup does a complete 180, there's almost no doubt in my mind that this will be a High Risk day and quite possibly a signficant tornado outbreak across the Central and Southern Plains. The overall setup bears a certain eerie resemblance to April 26, 1991... and we all know what went down that day.

 

[Mike Hollingshead]

New nam looks pretty sweet for sc KS south through OK then on east. One concern, timing a bit too fast/early? Cap's gone by 18z with a lot of lift over the area. I hope it can slow some. Would hate to see it go to hell by too much going too soon. What was that date last year in KS? March 30?

 

[Mikey Gribble]

All in all, it looks like a pretty good setup. I haven't been following model trends closely for this event since I was focused in on yesterday's forecast up until today. One thing that doesn't look good with the 12Z NAM is the 850mb elongated NE-SW low, which veers low-level winds. I'm not going to worry about that unless the 00Z is still showing the same thing. Storm motions are going to be nasty. I managed to pick up my 3rd ticket of the season yesterday, so I am going to need to ride shotgun on Tuesday with storm motions like that. It seems like it has been a weekly thing for me to send in petitions for an amendment to a nonmoving violation. Anyways, I am focusing in on southern Oklahoma at this point. Storms should be more discrete, the shear vector is more normal to the boundary, and low-level shear was better (on 00Z).

 

[Ben Prusia]

It is agreed that the setup looks very decent for all forms of severe weather. A concern that I am seeing from this system is the cap that is about all gone by mid afternoon. Speaking on just the 12Z NAM, there is a nicely formed dryline heading south from the low pressure near Wichita at 0Z. Looks like the Td's of 60-65+ aren't out of the question, along with the surface air temperatures only about 10 degrees higher should at least make for some better forecasted LCL levels on this system than previous systems. 0-3km forecasted Cape values are very high, forecasted storm motions look a little on the nasty side, but I am much in agreement with SPC's moderate risk area for all kinds of severe weather on Tuesday. I am more inclined for a KS target around Wichita-Medicine Lodge because its closer to me and the low pressure but I will hunt down a more precise target on later model runs.

 

[Michael O'Keeffe]

I'm pretty certain Tuesday will be a huge day from KS to TX. The latest WRF shows Tds to 68f!!!! near Pratt at 18z, CAPE to 35000j/kg will also be in place over this region! I agree this may be an early afternoon show, but I will most likely chase this event after yesterday's depressing bust. I expect storms to fire in the vicinity of Pratt-Medicine Lodge area and blast E to NE towards I-35 as the low moves east along with the dryline. Very concerned with how fast the low moves out. I think this day could be a big day across the Plains regardless.

 

[Brett Adair]

Hm....does look like a pretty classic OK/KS dryline situation. The SPC may go high risk on the day 2 for only the second time in history. This has me looking to possibly drive out there from Alabama around Monday or so..... I'll have to ponder over it for the next model run or two. Confidence is increasing though.

 

[mark plate]

I believe the nam/wrf and gfs are too far east late Tuesday. I prefer the ukmet given its far superior handling of systems in this part of the country the past couple years. At 00z Wed. (Tue. evening), the ukmet has a 999 mb sfc low centered between GLD and GCK with a warm front extending east from the low to near RSL to south of TOP. Dryline appears to extend se from the low to near Alva, OK and then south from there. 500 mb low center is about 60 miles north of Lamar, CO on the ukmet. The ukmet also suggests an old convective boundary from Monday night convection will extend from near Enid, OK to TUL to north of FSM.

Certainly looks like a major event Tuesday with several different boundaries around to locally enhance potential in their vicinities.

 

[Kenny Drake]

Well if things hold together I'll be skipping class on Tuesday. I dont have any Meteorology classes, only classes that satisfy generals. Okay now heres the meteorology:

NAM has actually sped the system up slightly since the 12Z run yesterday. Due to the speeding up of the system the NAM has slightly veered the surface winds ahead of the dryline in OK. However, directional shear is still there as 850mb winds are out of the SSW and 700 out of the WSW. Moisture will be abundant so that should not be a question at all. The primary factor in my opinion will be instability. Timing of the 500mb jet max will be crucial for destabilization. Given the dewpoints only a few hours of limited heating will be required to reach convective temperatures. From the looks I think there will be plenty of cloud-cover, however the large-scale upward forcing and convergence along the dryline will be more than adequate to fire convection. I will do a more complete forecast tomorrow as the questions of a two day out forecast are anwered... If the NAM verifies OKC could be in trouble, and I'd much more prefer the system to be slightly farther west because I'm not a fan of chasing in the middle of populated areas for multiple reasons.