7/19/06 NOW: MN / IA / WI / IL

[Mike Hollingshead]

CU field finally becoming more aggitated in nw IA along that outflow boundary.

 

[Scott Lincoln]

yeah i know it is normal to hear that, but KLOT and KDVN or KILX rarely says weak rotation is detected, i always see "severe thunderstorms can and occasionally do produce tornadoes" so i pieced together the report i heard from moline to the storm moving thru the county, hmmm must have misinterpreted the statement then
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I will tell you though, it does look like its more than just weak rotation on radar right now. Got a couplet at 5000ft where the inflow of the storm is on radar, Marshal County Illinois, near Henry.

 

[Danny Neal]

SPC shifted the mod risk further south thru central illinois, before looked like chicagos northern suburbs were gona get it now it looks like the focus tonight will be well south of the metro, although the northern end of the MCS is looking to flare up again west/northwest of chicago

I will tell you though, it does look like its more than just weak rotation on radar right now. Got a couplet at 5000ft where the inflow of the storm is on radar, Marshal County Illinois, near Henry.
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yeah im listening to spotters right now they claim to have saw a brief lowering before the rain obstructed the view of the spotter .........looks like east side of peoria-metamora-eureka-roanoke area may be in the path

 

[David Draun]

Some new storms are trying to get going west of Dekalb, IL. Radar imagery indicates new development, but it appears to not be holding together very well at this time.

 

[Mike Hollingshead]

MD out for nw IA now

 

[Danny Neal]

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR PEORIA...NORTHWESTERN WOODFORD AND MARSHALL COUNTIES...

DAMAGING WINDS WILL MOVE INTO THE PEORIA METROPOLITAN AREA.


This goes along with my theory in the "chasing hot spots" thread, if you want severe weather in illinois head to around peoria, it never fails haha, they confirmed 75 mph winds in moline that blew glass out of houses blew the roof off of several buildings and knocked hundreds of trees down, waiting for round 2 to flare up later today

 

[Dan Robinson]

Decided to chase lightning in IN/IL today, currently in Dayton OH for a quick data stop. Good news is that I won't have as far of a drive to find storms, but I don't like the massive stratiform precip area and its huge cloud canopy. Where did that come from :angry: I think anything east of this stuff is out of luck for strong storms later tonight. I hate to say it, but this afternoon's grunge is all places like Chicago and points north and west will see. Even with the strong shortwave, the boundary layer in these places is getting no sun and plenty of precip to keep it cool.

 

[nickgrillo]

Holy cow... You rarely see these kind of CAPE profiles Check out the RUC forecast sounding for 21z at Fort Dodge IA (just west of the nw-se oriented warm front). I can't recall the last time I've seen >9000 CAPE... Latest RUC mesoanalysis shows 5000-7000 MLCAPE with the largest values near I-80. Normalized CAPE peaks near I-35 in central IA (corresponding to the 'fat' CAPE profiles, suggesting extreme parcel accelerations). The RUC forecast soundings for Mason City IA (along I-35 in northcentral IA) and Fort Dodge show incredibley extreme instability, and weakened CINH, and negligable by 21z. With +55kts of 0-6km shear and pronounced boundary layer veering (leading to the large and cyclonically curved hodographs and strong low-level SRH). Deep convection that initiates in this environment should immediately take on supercell charactoristics and will most certainly be capable of producing extremely large hail (i.e. >4" inches in diameter) and likely a few tornadoes given the strong low-level shear and low LCLs.

I'm pretty stuck on the area just west of I-35 in northwest/northcentral IA as well... Current RUC/SPC mesoanalysis shows CINH weakening (given the persistant diabatic heating across much of the region through the afternoon) and LFC heights lowering. I think initiation is possible closer to I-35 within the next couple of hours (i.e. 5-6pm) as the inversion continues to erode (evident on the RUC forecast soundings, owed primarily due to the deepening of the moist BL).

 

[Danny Neal]

TORNADO WARNING FOR...
EASTERN FULTON COUNTY IN WEST CENTRAL ILLINOIS...

* UNTIL 430 PM CDT.

* AT 359 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO 3 MILES
EAST OF CANTON MOVING SOUTHEAST AT 20 MPH.

the warning text says very high winds along with the storms and brief tornadoes anywhere along the line, i know the area there is near the illinois river and alot of forest preserves so i expect at the very least for there to be a lot of tree damage

 

[Jeff Snyder]

The environment across northern IA certainly looks juicy. This is just about as unstable as we see in the U.S. (with sbCAPE approaching and exceeding 7000 j/kg in places), owing largely to very high low-level theta-e beneath steep mid-level lapse rates. The backed surface low invof and to the cool-side of the OFB currently set in a NW-SE fashion (see DMX radar) is providing seasonably strong low-level shear profiles in the extremely unstable environment. I agree that we may see rapid supercell development within the next couple of hours.

A storm has developed in ne NE (in se Knox co.), with further development to the southwest. I'd like to see more boundary layer Cu east-northeast of this area (namely, in nw IA) before I get too confident in impending initiation in the "moist sector" (environment w of OFB is drier and hotter owing to stronger mixing through the past several hours, resulting in temps in the 100-106F range and dewpoints in the mid-60s).

 

[Danny Neal]

weather radio just went off saying about cancellation of the watch for all of the northern illinois counties except the counties around chicago i find that interesting i know somehting can develop in 5 mins but alot of the spotter networks are saying tonight the severe weather from iowa is gona follow the same path thru central illinois due to the lack of sunshine and dynamics around chicago and pts north, although right now the temperature is 88 degrees with thick cloud cover....we shall see at the very least this area needs rain

 

[Andrew Pritchard]

ILX issued a blanket warning for 10 counties. Strongest winds are moving right for Lincoln in Logan and McLean county. New tornado warning for Mason County as well.

 

[David Draun]

Precip is starting to clear out in SE WI and N IL. I would not rule out the threat of storms anywhere in this airmass. One problem though, the cap has definitely strengthened especially to the north of the southbound MCS. LOT AFD still calling for strong storms overnight, especially from late-evening on.

 

[Andrew Pritchard]

I wouldnt expect to see anything north of this MCS until the Iowa stuff makes its way into the state tonite. The airmass north of it is capped and the air has been contaminated so the odds of new development up there are real slim at this point.

70-90 mph winds being reported now from the MCS near Mason County. 3.75" hail also being indicated by radar.

 

[Danny Neal]

i agree, im not sure that even the mcs later tonight will make it into ne ill and s wis, they just cancelled for all of ne illinois, looks like another bust but stranger things have happened, well keep an eye to the sky