10/18/04 FCST: Midwest

Current SPC Day 3 is showing a slight risk area on Monday with a possible upgrade for the Ia/Ill/Mo/Ark eastward into IN/Oh/Ky area. Currently they are mentioning possibility of supercells and tornadoes for this late season setup.

What think ye ?
(S.E. Mo is my initial area of interest)

Also CPC is showing possible severe weather in S.Mo to N.E.Tex area on 10-21,22:
http://www.cpc.ncep.noaa.gov/products/expe...nt/threats.html

Jon Miller
 
Convective forecast today is for a possible outbreak of severe thunderstorms overall in Missouri, Iowa and Illinois...Instability will be moderate/strong and shear it's going to be very favorable for tornadic supercell:

Forecast can still change but according to me things at the end willl remain in this way.
 
Wow! That's promising. Even MY area is gonna be included. Looks like some lifting on a warm front could get interesting. Low-toppers, anyone? SLGT risk goes up to just S of Chicago. I also have thunderstorms forecast for my area on Thursday too. Could they be severe too? Here's to an active week everyone.
 
LOL! Here I am looking at the 21st and there are ops sooner? Well, anyway, Wednesday and Thursday look rather interesting as well. Just glanced at the new eta and I guess the area of nw MO might be interesting Monday. I think Wed and/or Thur should be better. Looks like a humdinger come Thursday.
 
Here comes October I guess. Wow. Looking at the 12Z today, I wish Monday's instability was better co-locateed with the helicity and deep layer shear. Seems like the theta-e doesn't quite get up into the ideal shear, but that's definitely subject to change. I'm not a huge fan of chasing Missouri so might wait for what looks like a more dynamic setup in bettter chase turf later in the week.
 
Certainly does look interesting, as this warm front/push of warm moist air may be setting the stage for something bigger and better mid to late next week. GFS has been very consistant with a very strong low between Wed-Fri timeframe next week for areas between the Southern Plains and the Midwest/Great Lakes, with possibly a classic fall "Lake induced bomb".
 
I agree with Mike and others that this potential on Monday may lead to an even greater potential later in the week.

I am hoping for something closer to OH/IN rather than MO AR but at least we will have something to watch on radar or perhaps a genuine chase.

For those wanting to investigate late fall outbreaks there is a good analysis of the nov 10, 2002 outbreak here.

http://mcc.sws.uiuc.edu/Nov10-02SvrWx/Nov1...10-02SvrWx.html

Tom
 
Originally posted by tom hanlon
...I am hoping for something closer to OH/IN rather than MO AR but at least we will have something to watch on radar or perhaps a genuine chase...

Tom

Same here, since I can't afford to be traveling too many miles... However, right now it looks like both of those areas may get into some action... So the best of both worlds I guess. I think if the current model trend continues, a thread for late next week may need to be started (actually, the past couple posts have strayed off topic)...
 
Looking at the 12z ETA, CAPE values look to be really high across central Missouri on Monday, particularly from Columbia, SEward. combine that with the 65+ degree dewpoint and the 70-75 degree temperatures that the model expects in the area, the area is going to have really soupy air to work with. Since I have a LAB in my intro Meteorology class tomorrow until 2:30 about winds, it's a no go for me. If I did go, target area would be somewhere like Rolla, SEward, but I don't like that area in MO anyway for chasing, too many hills and bad roads. I think any area south of Interstate 70 and east of US Highway 71 in Missouri is a good bet for seeing at least some severe weather tomorrow.
 
ETA - 7PM Mon showing best CAPE & LI's in s/se Mo. with 400-500 SRH in se Mo /s.ILL/w. Ky. Also 40-50 kt wind shear in thes area's. with 65 deg dew pt. and with a warm front draped over the area.- Poplar Bluff to Cape Girardeu to Paducah or there abouts would be my target area for now.

Jon Miller
 
Well it looks like there could be a decent setup for tommorow. Just finished doing anaylses of the 21z run and I really wish I could be down there for this one. Im a little concerned about intiation in the more favorable area of SC MO to the corridor of KY and IL. Not much for omega but with daytime heating there should still be a decent chance of intiation. If storms do develop tornadoes should certainly be possible. I think the most likely place for tornadogenesis is going to be the crossroads of MO, KY and IL.
 
Originally posted by Scott Olson
Just finished doing anaylses of the 21z run and I really wish I could be down there for this one.

Is this a local run of one of the models (ETA, WRF, etc)? The operational models are run at 0, 6, 12, and 18z... Just curious if you run the WS-ETA or WRF on your own computer. FWIW, I'm currently in the process of setting up my computer to run the WS-ETA, though I may look into the WRF instead...

EDIT: For whatever reason, I forgot to make any forecast-related comments on this original post to qualify it as Target-Area appropriate... Therefore, I will my take on this situation... From a shear-instability standpoint, the environment in southeastern MO and ne AR looks moderately favorable for tornadic supercells (instability isn't terribly impressive, but low-level shear looks quite nice). My only concern is convective initiation for surface-based parcels. The shortwave trough looks to pass through the region between 18z and 0z, presumably leaving the area in subsidence, or at least no significant UVVs (which shift east of the area by late afternoon). The surface front will be a source for surface convergence, but it, per the ETA at least, doesn't look to really take shape until after dark... So, I"m not entirely confident in the situation, but then again, I've only look at one model for about 15 minutes here, so take it for what it's worth...
 
Is this a local run of one of the models (ETA, WRF, etc)? The operational models are run at 0, 6, 12, and 18z... Just curious if you run the WS-ETA or WRF on your own computer. FWIW, I'm currently in the process of setting up my computer to run the WS-ETA, though I may look into the WRF instead...[/quote]

Yes this is a local WRF setup for off hour runs. I prefer WRF as I have had less problems with it.
 
Damage reported Near Little Rock

Tornados with damage and injuries reported 13 miles south of Little Rock already this morning. With sun out and heating up around Newport in NE AR now I think it will be quite a day later on this afternoon. I think I will hang around right here and wait for things to fire up.

NWS radar showing nice hook east of Little Rock ATT with counties warned.

Is anybody on this?
 
Chase target for today, October 18

Chase target: 30 mi south-east of Jefferson City, Mo.

Timing: 5 PM CDT.

Severe mode: isolated supercells with hail to golf ball size, and isolated tornadoes.

At 15Z, surface low pressure was located between ICT and CNU, with a warm front extending eastward along an AIZ-FAM line. This front will lift slowly northward during the day and will lie along I-70 by 00Z. To the south of this front, significant moisture return was underway, as evidenced by surface dewpoints in the mid- to upper-60’s, and 850 MB Td’s near 60F.

A 250 MB, 90 KT jet had moved into SRN AZ and SRN NM last night. In response to this, significant divergence in the left front quadrant of the jet was lifting into the forecast area this morning. An 850 MB jet of 50 KTS was also nosing into this area, resulting in a large area of elevated convection in ERN MO at this time. A negating factor today is the phasing of the shortwave energy, which will be lifting to the east of the target area by 00Z. Model guidance (RUC, UKMET, ETA, and GFS) are similar with handling of surface features, LLJ, and upper jet; as well as instability and lapse rates today. Clearing has taken place over SWRN MO, and decent destabilization will take place. A triple point at the warm front - weak dryline/trough line just east of the low should provide the focus for renewed convection in the 21Z-22Z timeline. An instability bullseye in ERN MO will exist by 20Z, with MLCAPE’s in excess of 2000 J/kG. Additionally, 0-3 km SRH’s around 200 m^2/s^2 will result from SRLY surface and veering SWRLY 850 MB winds.

bill schintler
 
Back
Top