STORM2K

It appears another significant severe weather event/possible outbreak is beginning to unfold for the period Sunday through Tuesday from the Southern Plains into the Southeast, affecting many areas hit hard just a few days ago. The central focus could be a bit further north than the mid week system, as the low tracks further north. But, overall it looks very similar to this most recent event.

Strong negative tilt trough will be in place as a low pressure moves east across Northern KS into MO on Sunday. Thunderstorms will become widespread across KS/MO/OK/AR/TX/LA on Sunday afternoon and Sunday night as the atmosphere becomes moist and unstable. The best chances of Severe weather appears to be Eastern Oklahoma, Western Arkansas, Southwest Missouri and Southeast KS. Discrete supercell formation is initially likely before the development of a squalll line that sweeps across AR and MO overnight Sunday before dissipating by Monday Morning near the Mississippi River. Tornadoes will be possible at least initially, and could still occur with embedded supercells along the squall line due to helicity and shear that will remain. Very large hail is also likely and damaging winds will be a great threat once the squall line develops. Slight risk is already out and it should be a moderate on the day 2 outlook. Some are saying this will be the first high risk day of the year.

The system moves east Monday putting portions of MO/AR/KY/TN/MS/LA under the threat of more severe weather. Atmosphere will once again become warm, moist, and unstable and any sunshine that could occur or if a cap can suppress morning development, another outbreak situation could occur here. Again possibly early discrete supercell formation before a squall line, although I believe the supercell risk is slightly lower than on Sunday. Isolated tornadoes, hail, damaging winds are possible. This will put Brandon, MS among other hard hit communties from Wednesday in the risk area.

On Tuesday, the models decrease the strength of the system, but another round of severe storms is possible for TN/AL/GA/FL Panhandle. Most likely mode here is squall line with damaging winds. The threat here is much less than to the west, but should be monitored because it is several days out.

People in these areas should closely monitor future weather information about the possibility of more severe weather beginning Sunday into Tuesday. Further details on the exact threat and scope of the storm will be available later tonight and especially on Sunday.

SPC finally threw out the moderate on their second day two outlook at 1730z. Should have been done initially, but at least now its there. Still a big event shaping up with supercell development initially then quick organization into a squall line with damaging winds overnight from the Ozarks south into LA. Best tornado threat will be initially over Southeast OK and Northeast TX, and also near the low in Southeast KS.

Does anyone think the Day 3 outlook is way too small? Maybe I do because I really want severe weather in Memphis and we're barely in it, but the NAM has the highest instability well north into MO. The GFS is further south though. There is a "doughnut hole" between areas of higher instability right over us according to NAM, which I don't like. Maybe that will change.

Here comes severe weather season again. Nice analysis! I hope this year is more like last year for us than 2003.

wx247 wrote:Here comes severe weather season again. Nice analysis! I hope this year is more like last year for us than 2003.

Thanks. I also hope it is a similar season to 2003 as well. Your area is looking good for a squall line tomorrow with damaging winds. However, there will be some tornado potential even though shear becomes unidirectional and winds back. Could be some embedded supercells.

I am less and less confident about severe on Monday, large discrepancies on the models and between NWS offices themselves. Some go with the NAM taking the low across central MO, others the GFS which reforms the low in SE Arkansas taking it northeast. The GFS has had some convective feedback, so my bet is for the NAM at this point. The Jackson office is calling for a significant event Monday (they play up things frequently), Little Rock is pretty sure of some severe weather, Birmingham thinks there is some potential, but Memphis and Huntsville think there is little threat for severe.

This "doughnut hole" of instability which I described above still worries me and remains on the 18z. There could be some considerable cloudiness during the day which leads to the stability, with higher values on either side of the mid south. Certainly strange looking depiction on the models, but we shall see what happens.

Definitely going to be a busy day though for OK/TX/KS/MO/AR/LA. Still expecting supercell development along the dryline initially then quick transition to a squall line. Folks in this area keep a close eye on it.

Well they dropped the outlook to slgt now for the area. Modified 12z soundings only show MLCAPE values around 750-1000 J/KG. Will be interesting to see what happens now.

Yeah! I was really surprised to see that development. (or lack there-of!) I'm stuck at work all day, so I'll be watching it!

Same here OKwx. Stuck at work so will be watching the show from my desk. Intersting to see what happens now that the sun appears to be trying to peak out from underneath those clouds.

Man, it sure appears we're having a hard time clear out of these clouds in Norman!

Things are not looking quite as good now today either. Clouds are hanging tough and instability is having a tough time from forming. We should still see development of supercells, however it will probably be delayed until the upper air dynamics arrive, and that will make the supercelluar mode even briefer as they are quickly forced into a squall line. The squall line should move east into MO/AR overnight and weaken by the time it reaches Little Rock or so.

For monday, my confidence is once again increasing some, but still not completely sure as instability questions remain.How much the thunderstorms from tonight weaken will determine if there will be any morning rain and clouds. I believe its going to be there, but am hopeful for some clearing by late morning into afternoon. If that happens, Capes should easily reach 1000 j/g or more, Lis -3 or below. Decent SRH will be present and should be favorable for supercells, especially over Northwest MS, Sotuheast AR, and Northeast LA, where there is a hatched 25% slight risk. Another squall line is possible as the activity moves east of the MS river, before weakening when hitting AL and Middle TN.

SPC has thrown out the moderate for most of MS and eastern LA for Monday. A 35% and hatched area are present, a little displaced from each other, but covering most of MS, LA, and AR. Should see re-intensification of the line along with new development out ahead of it Monday afternoon near the MS River with supercell tornadoes possible, and strong tornadoes possible in the southern portion of the moderate. Isolated development on the backside of the line in AR/LA could create hail concerns.

SPC implies to me that here in Memphis its more of the hail concern behind the line, but I'm hoping that the line and anything ahead of it can make it this far north and west.

All right, we're finally getting a bit of clearing here in Norman...

OklahomaWeather wrote:All right, we're finally getting a bit of clearing here in Norman...

We shall see if it is too late... 24 hours ago, today looked like a big severe weather day. Now... it looks okay but not as impressive. Just shows you how quickly things can change.

Meso Disc just out for cent OK. Looks like things could get going in the next 1 to 2 hours. 30-40m area of clearing ahead of dryline may be enough to get things going. Temphs now in mid 60's and dew point has slowly risen over the last few hours to low 60's as well.

I've been watching the weather out over KS and NE. It is really active there right now.

Kristi

For Monday afternoon, from Iowa south through Louisiana seems to be the worst chance of svr wx. This will move east and expand northward as far as potions of Minnesota overnight Monday into Tuesday. Iowa, Illinois, Tennessee river valley, Mississippi will see svr thunderstorm, large hail, and tornados. This system is stronger then last week, but looses it's punch as it moves further east and southeast at this time.
NOGAPS:
https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... 2005041012

Well past 1hr 30min have been interesting in Norman. I was at Chilie with some friends so didn't get to watch all the tv coverage but some of my friends went outside and got a good look at wall clould that was over Norman just east of I-35. A friend who lives almost south of the OU campus said the wall cloud above him was definitely rotating. Man had the shear been better today Norman would've been in serious trouble.

TORNADO WARNING JUST WENT UP FOR S-ERN OK COUNTY (radar indicated). Same cell that came here through Norman. Doesn't surprise me that this storm may drop something