04/24/04 FCST: MO/W IL

Matthew Havin

May possibly setup to be an active weather day Saturday in central MO/ W IL. Post your thoughts.......
 
DEEP
LAYER WIND FIELDS WOULD SUPPORT SUPERCELLS OR CELLS MERGING INTO
BOWING LINE SEGMENTS WITH GREATEST THREAT BEING WIND DAMAGE AND/OR
TORNADOES. WIND POTENTIAL MAY BE ENHANCED BY STRONG MID LEVEL DRY
INTRUSION ACROSS NWRN MO DURING THE AFTERNOON. IN ADDITION...NCEP
ETAKF POINT FCST SOUNDINGS INDICATE LARGE HODOGRAPHS AND LOW LFC
WILL EXIST NEAR WARM FRONT/TRIPLE POINT EXPECTED TO MOVE FROM CNTRL
MO AND INTO WRN IL DURING THE 18Z-00Z TIME FRAME. IF THIS
ENVIRONMENT CAN DEVELOP COINCIDENT WITH SURFACE-BASED STORMS...A
SMALL MDT RISK AREA MAY BE REQUIRED IN LATER OUTLOOKS.


Say my "Preliminary" target will be around Randolph Co. Perry Co. Illinois around 2:00pm. But this is a little far in advance. Will probably sww where the most daytime heating if any, occurs near this area.
 
This is rushed, found the time to do this in about 15 min before I go to bed, so add your input, say where I'm wrong, but don't be too cruel as I'm not at my best ;-)...

If the models are to be believed, tomorrow won't do much. However, if we get some insolation, that'll ratchet up instability and we could be in business for tornadic supercells. Everything else seems to be there. It's possible the precip is being overforecasted, the models might be experiencing some convective feedback with the copious moisture and lift. A midlevel dry intrusion, noticed by SPC, could make things interesting as well. However, there already is a sickening amount of nasty precip from Missouri to Mexico at about 2 AM (which could also retard northward advance of sfc WF). We'll see... Area would be ahead of deepening negatively-tilted low or somewhere along warm front from northern/central Missouri into west-central Illinois. There is good jet structure with the streak on the lee see of the trough, plenty of lift and moisture, nice LLJ and WAA, great directional shear and just enough but not too much speed shear. H500 subsidence between two jet streaks is possible, but the ETA might be out to lunch, and that should be compensated for by other lift (incl. some decent divergence at H250). GFS takes the low more south and more east, but overall, the progs remain show at least a shot at some convective bliss, if we can get sufficient insolation and instability. Since everything went right only last Tuesday and I can chase, I don't expect everything to go right this time.

Scott
 
Kinda my take as well, Im stickin to my guns with SW -W Illini line. Low track does seem more to south of St. Louis area. It all depends on cloud cover along & south of warm advection for sure
Kevin
 
Looking at an area from Falls City NE east into, dare I say, nw MO. Please god don't let this pan out into a chase. Please clouds, stay put...PLEASE! NW MO does not want me and I'm ok with that. Not a terrible little setup if clearing began really soon.

Edit:

Might have to revise this a bit nw of Falls City.

http://www.spc.ncep.noaa.gov/exper/mesoana.../s3_loops/pmsl/

That sfc low looks to want to lift nnw, which would be SWEET....given some clearing of course. Waving bye bye to nw MO, I hope.
 
NW Misery. We all say we won't do it, but then we end up there again eventually. As for me, resistance holds but could turn out to be futile. E KS/SE NE or NW MO :).

Scott
 
Haven't spent a lot of time on this, but here's a preliminary take on the situation. My target remains the four corners of NE KS, NW MO, SW IA and SE NE. Things that I'm concerned with - INSTABILITY. We have good wind environment and 0-1km shear, we have moisture ... but how will CAPE turn out? After reading the outlook language, I would think this will be our most important ingredient today. I'm having a hard time getting RUC2 to give me an idea of instability in the target area today (Skew-Ts that I pull up keep registering with 0 CAPE, which is no good), so I'm going to have to base this off of satellite.

Biggest concern: The grunge/cloud canopy ahead of this system is extensive. The canopy currently extends across the entire state of Iowa, the entire state of Missouri, and most all of Nebraska and Kansas, as well as eastern Oklahoma. The nearest break is currently situated over western Oklahoma just east of the panhandle. It's very hard to believe that the grunge will clear out in time to make way for really good instability to establish itself. Just how quickly will the warm sector be able to recover after the passage of the warm front. I guess we've seen it happen, but I have to wonder if this system really has the ability to swing hard enough to clear the warm sector sufficiently in time to build high instabilities.

I'm making room for a possible chase today, and like Mike and Scott, I'm hoping it's not around here, but would much rather NE KS or SE Nebraska. Target today will be the warm sector riding the warm front (wherever it ends up) tucked about 30-40 miles east of the surface low, most likely.
 
Looks like I will be going to SE Nebraska. Still have concerns concerning grunge and wether or not we can clear skies enough with the drier air to allow sufficient heating. But with a 5% SPC tornado threat, and enough of a chance to go, Im going to give it a shot. Still trying to pin out what time I should get there. **If conditions change to the worse I will call this off.**
 
partly sunny being reported at Salina and Newton KS now...still a ways to go though to catch up with the big-time helicity that Mike just pointed out.

This will be a long-shot day for sure for the NE KS MO IA border region, but the shear and LCL heights are sure nice. Do any of you think Tuesday's IL debacle might be playing into the thinking at least a little bit?
 
Some decent clearing happening now in central to nc KS. Hopefully we can get this to quickly overspread the wf where the shear is located.

Edit:

Reality is starting to kick in. This is seeming more and more stupid. There that should jinx it the right way.
 
Thanks for bringing the thread back in harmony with the universe, Mike. To help do my part, I will say that this whole thing is just really falling apart.

Now ... having said that ... I'm starting to get more excited. After looking at those pretty helicities and the clearing in KS now (are pics ok in here? - if not, I'll be happy to remove -)

<img src=http://img47.photobucket.com/albums/v143/mikeperegrine/sat.jpg>

Wondering now about the exact path the low decides to take ... it keeps looking to me like it's going to cut straight through extreme NE KS/NW MO, but I'm HOPING it is just a bit further west.
 
SFC low over about Concordia right now 19z. Still drifting north. WF along the KS/NE border. Really could of used clearing earlier and further north...oh well.
 
My thoughts. I don't think we're gonna get enough heating in the area of enhanced helicity....so I'm gonna bug out on this one.

Now watch it all explode. If it does, thank me because I decided to stay home ;)
 
Continuing the Downplay...

Well, seeing as how things are continuing to look "crappy"...a few of us have decided to head west from Columbia to see if that dry slot can destabilize things up near MO/KS/NE border, where those high helicities are currently located. Hope to see a few of you out there today.


Marc D.
 
Glad to see all the negativity ... I'm convinced that there should be a negativity parameter with chasers ... the higher the negativity, the greater the likelihood of severe weather. Would go something like:

<100 = generally positive, SVR not so likely
101-299 = mildly negative ... SVR possible
300-499 = negative outlook ... SVR quite likely
>500 = highly negative ... look for SVR, tornadoes, hail - the works

hehe

This one would rate about 297, I'd say. Glad it's a backdoor chase, because it's not likely that I would drive ... BUT ... I have to say that the warm sector is clearing very nicely to the west ... we still have quite a while for this thing to move northward. I look for this to be a late afternoon chase with some cells that can hug the front.
 
http://www.wxcaster.com/CONUS_RUC_1000-500...PRPTHK_03HR.gif

My happy map for the moment ... RUC2 showing precip breaking out across target.

I needed to add one more parameter to the above list:

<50 = high risk day, chasers giddy - 0 risk of SVR

Just to bump us up a couple of notches on the negativity param., I'll add that it's still RAINING here right now ... yes ... DRIZZLE and rain under the grunge. (was supposed to have stopped at 1:00 p.m. and here it is 3:00 p.m.) ... there, that should be sufficient to put us over 300.
 
Well - this doesn't seem to be improving much. There's a line of weak convection ahead of the CF that has been struggling to develop. It's on the western side of the grunge in already cold air. Hopefully it falls apart quickly and doesn't provide any more rain-cooling. Destablization is looking more and more iffy ... dropped to 2% tor risk, now. Storm motion looks like it will again be parallel to the front if it can get off the ground, and will be moving fairly quickly if any of this early stuff is an indication.

According to outlook, anything that does manage to get going will be low-topped ... there may be a couple of minis yet, will have to wait and see. But losing what confidence had been there -
 
Went ahead and started a NOW thread, though confidence remains pretty low. First MD has been issued for target area for low topped supercells and weak tornadoes.
 
Squally activity moving towards Poplar Bluff MO. Some structure but nothing has got going to any measure. Some rapid development east of Hopkinsville KY. looked interesting. Just nothing im too interested in driving after...yet :?
Kevin
 
Just got back from SEMO area Ill make it short. 2 reports to WFO PAH. 2 very nice wall clouds and a funnel more than half way to ground near Grand tower near Carbondale IL.. Good chase day on that warm front. No touchdowns but near Ellsinore MO confirmed touchdowns. 6 or 8 injuries reported im sad to say but local & SPC with local tv did a great job during this event. Just wish we would have left about an hour earlier!! :oops:
Kevin
 
Today had a lot of things going for it, but there was just no adequate recovery. Even with the incipient clearing in KS, I decided a nogo a little before noon. I'm taking every weekend chance I can get, but the negatives seemed to point strongly to a nonevent. I didn't really seriously consider SE MO/S IL though it looked like there would a better shot at sups and there does appear to have been a few touchdowns.

Scott
 
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