4/13/07 FCST: TX / OK / AR / MO / IL / TN

[Michael O'Keeffe]

The latest GFS shows a very strong low to eject out of the high plains into SE Kansas on Friday April 13th. Deep moisture and shear will contribute to very favorable conditions for possibly strong tornadic supercells across the S Plains into the Mid-Mississippi Valley. The area most at risk seems to be N TX/far E OK/most of MO/AR/W.KY/W.TN/W.IL

 

[Ray Walker]

This system continues to look more and more interesting. The system for tuesday looks weaker than earlier proged, which means the gulf should be primed for strong moisture advection into the southern plains. The stage looks to be set for a potentially dangerous severe weather episode across the eastern 2/3 to 1/2 of Oklahoma, most of north and central texas on east into Arkansas, louisiana, and parts of MO. The models are showing the main action to be across eastern portions of the area, however I dont think the dryline will make it as far east as the models are showing.

 

[Jim Bishop]

Friday looks like a big severe weather outbreak from Northeast Texas/Eastern Oklahoma to Arkansas and Missouri. Moisture return may have been an issue a couple days ago. But both the GFS & European models show a great return flow off the Gulf by Thursday.

 

[Chris C Sanner]

NWSFO OUN is still saying that the dryline won't be as far east as what the models are saying which I think will be the case. Remember March 28th? Up until the day of the event we were still looking at a dryline in the E. Texas Panhandle and the dryline ended up in the Western Texas Panhandle. The chaseability of the setup is a bit in question to me too as the storms could be hauling in less than favorable chase terrain. If things verify though "somewhere" across the plains then that area looks to have a pretty long day ahead of it in terms of severe weather.

 

[Brian Stertz]

4/13/07 FCST: AR/OK/TX/MO/MS/LA/TN/KY/IL

Depending on which model one buys in to...Friday should be a pretty active and potentially significant severe wx day. The Euro tracks a surface low out of EC/SE Oklahoma into N. Arkansas during the day. It appears that the shear should be good to excellent for some strong and possibly intense tornadic supercells, particularly across N/C Arkansas along the warm front and vicinity of the surface low. It looks like mid 60 Td's will be in place along/north of the warm front, with upper 60's and possibly even lower 70 Td's across N. Louisiana, S.Arkansas, and W/S Mississippi. Now all that remains a quandry is timing of the wave(s). Also, will have to see if N.Texas/SE Oklahoma may also be a play on the dryline. Not too excited to see all the veered low level winds there, but if timing is slower, this may also be an area to keep an eye on.

 

[Brandon Sullivan]

Im buying into this system... I like the tilt of the low.. Looks stronger and stronger each run.. Really thought the 4-8 would be further north, but it doesnt matter.. I really like the system.. Hope I get the new laptop before then!

 

[SteveCarter]

I'm starting to buy into this now as well. Had a day there where it seemed like the mositure would never make it up there, but it DOES appear it will. This has the potential to be a big event. We're ending up with to many threads dealing with the same storm, and same areas tho. Thinking maybe we need to add AL/MS/KY into this. What days will it be? Friday, maybe even Saturday into Sunday before it's all over.

 

[Brandon Sullivan]

Ya, we do have lots of threads.. A quick look at the 12z GFS, stille shows a nice setup.. Shear is looking pretty impressive with this system, aong with CAPE of around 1700 J/KG area wide.. Even with the further south track, nearly the entire area is "warm sectored" due to the negative tilt... I wont even try to get too specific with a target until wed.. when we have SWODY 3

 

[matt patterson]

Wow....The GFS is really kicking this system out very quickly as compared to previous runs... while the EC is lagging behind..... If the current run were to verify then i think one could write all of ok/ks/tx out of the mix. The NCEP says that they prefer the EC in their diagnostic discussion released at 1:20 CDT today....

I hope the models will have a better hold on things one way or another in the next 24 to 36 hrs......

 

[Jim Bishop]

Well the EC is more concistent compared to the GFS, so maybe that's why NCEP preferes it. It is interesting that the GFS has a more northern track with the low than the EC. In the past I've seen the EC have the further north track in most cases, and usually the verification is somehwere in-between, but closer to the EC solution.

In any case I do hope the EC is correct, because it would give me a much better chance of chasing given the more southern storm track and slower ejection of the trough.

 

[Brett Adair]

Looking like a big time, long lived severe weather outbreak to come. Excessive instability and gulf moisture looks to come back into the picture with a strong upper level system coming across the midwest. This looks to set the stage for a diffluent pattern across the southern plains/Gulf coast into the midsouth for an outbreak of severe storms Friday through Sunday.

 

[Kevin Crawmer]

After a brief look at the ECMWF and GFS I believe the best area at the moment looks to be in SE KS and southern MO. Dewpoints look to soar to around 60 as far north as Columbia, MO to St. Louis to around Springfield, IL into norhtern KY. The center of the low looks to be somewhere in central KS or at the MO/KS stateline at 00z Sat. Given the varying speeds of the models, an exact location will be tough to pick until 24 hrs out or less. I have a hunch that the models may continue to trend north putting the bullseye on NE OK, SE KS into the ozarks and points southward. It will be interesting to see if the surging dewpoints play out....I would love to be able to see some action up my way (St. Louis area)...I'm always up for a post-work chase.

 

[Travis Carlson]

I agree with the models possibly pushing the track of this system farther north in the upcoming runs. This is usually the case for developing mid-latitude systems in April. Current model guidance is taking the track through central Illinois or a little south of there. Also I believe the system may trend to slow down. We'll have to keep this in mind as well. We get a better update tomorrow, but all in all looks like a severe wx outbreak either way you cut it with a north or south track. I would not be surprised to actually see some decent snow totals as well in MN or WI out of this especially with a farther north track and if enough cold air is in place as well. Also have to keep an eye on that as well. Looks like an impressive system either way with a variety of weather for sure. Maybe another weekend chase?

 

[Brandon Sullivan]

Just took a look at the 18Z gfs.. It has the system south again.. .. With the main CAPE and QPF over SW MO and TX OK... New 00z WRF out soon..


EDIT: 00z WRF shows a still southern track, and not so much of a negative tilt.. Im still interested though.. Hopefully SWODY 4-8 will tell more tommorow!

 

[Gabe Garfield]

The 00Z NAM is showing a slower wave than the 12Z GFS had progged. If this trend continues (which, given the usual GFS bias, it probably will), I would expect the I35 corridor could become a potential play.

For comparison:
12Z GFS http://weather.ou.edu/~garfield/images/gfs12z.gif

00Z NAM http://weather.ou.edu/~garfield/images/nam00z.gif

EDIT:
It looks like the 00Z GFS continues with a fairly progressive wave (contrary to the 00Z NAM sol'n). Also, looks like the GFS is a bit more bullish with Tds on Thursday than the NAM.

Gabe