07/13/04 NOW: MIDWEST/GREAT LAKES/OHIO VALLEY

[Robert Dewey]

NOW thread started at request... Supercell firing over IL right now, and more action likely later today...

 

[Joel Wright]

So far this is the only game in town. Nothing else of interest going on yet. The 5500 SBCAPE bullseye is over southeast IA but it's still very capped there.

I've noticed a weak appendage on the west side of the NW IL supercell.

 

[Larry J. Kosch]

Two watches posted

We have two watches posted this late a.m. today. NWS has issued a TORN watch for Northern half of IL and a SWW for the Upper Lake Michigan area between Wisconsin and Michigan.

NWS is showing a nice storm cell moving E-SE between Freeport and Sterling, IL. Looks like it may brush close to Chicago, Joliet and Gary if it holds its course.

[Automated by GetSmile]

 

[Zach Bailey]

looks like that cell has developed a meso per the latest velocity imagery and as said before looks to be developing a hook...expect a tornado warning any minute now...Northern IL, look out!

 

[Steve Fitzsimmons]

The way the weather has been this year, I wouldn't be surprised a bit if that storm created a tornado or two near Chicago. Here in Madison it is expected to hit 87, before the storms hit in the afternoon. The atmosphere has a full tank of gas to run on and this day is just starting.

:shock:

 

[rdale]

"looks to be developing a hook"

Only about 1/3rd - 50% at best of hook echoes result in a tornado - you need to be doing a mesoanalysis to find any sort of surface boundary to kick it into TOR mode unless the meso is REALLY turning.

- Rob

 

[Zach Bailey]

"looks to be developing a hook"

Only about 1/3rd - 50% at best of hook echoes result in a tornado - you need to be doing a mesoanalysis to find any sort of surface boundary to kick it into TOR mode unless the meso is REALLY turning.

- Rob

ah, well, if that's the case, then it might not produce a tornado. I just looked over the SPC's meso analysis for that region and that cell appears to be moving out of favorable sheer and convergence, so perhaps no tornadoes yet.

 

[Robert Dewey]

"looks to be developing a hook"

Only about 1/3rd - 50% at best of hook echoes result in a tornado - you need to be doing a mesoanalysis to find any sort of surface boundary to kick it into TOR mode unless the meso is REALLY turning.

- Rob

ah, well, if that's the case, then it might not produce a tornado. I just looked over the SPC's meso analysis for that region and that cell appears to be moving out of favorable sheer and convergence, so perhaps no tornadoes yet.

I would really be concerned with the damaging wind threat later today, maybe a couple isolated tornadoes at best, but the real threat will be widespread damaging winds. At least thats how it looks now...

 

[Joel Wright]

WOW!!

According to the SPC, cape has reached 7000 just southwest of the Quad Cities. LI are now down to -14 as well! *edit*ewpoints have pooled to near and just above 80 degrees right along the Mississippi River!!! Wow!!

New more agressive cumulus are developing in this area too.... :shock:

 

[Ben Prusia]

From the NWS Quad Cities:

AT 1241 PM CDT...TRAINED SPOTTERS REPORTED A TORNADO. THIS TORNADO
WAS LOCATED NEAR LA MOILLE...OR ABOUT 8 MILES WEST OF MENDOTA...
MOVING SOUTHEAST AT 30 MPH.

 

[Jacki Earnest]

WOW!!

According to the SPC, cape has reached 7000 just southwest of the Quad Cities. LI are now down to -14 as well! *edit*ewpoints have pooled to near and just above 80 degrees right along the Mississippi River!!! Wow!!

New more agressive cumulus are developing in this area too.... :shock:

Sure are! Just to the west of Davenport in Walcott, the cumulus are definitely firing up! Too bad I do not have a drop of gas.... why does this happen the day before payday? :lol:

 

[Robert Dewey]

WOW!!

According to the SPC, cape has reached 7000 just southwest of the Quad Cities. LI are now down to -14 as well! *edit*ewpoints have pooled to near and just above 80 degrees right along the Mississippi River!!! Wow!!

New more agressive cumulus are developing in this area too.... :shock:

ILX reporting 82F TD!! That is the highest TD I have every seen...

 

[rdale]

ILX sounding (18Z observed) has CAPE 6700, LI -16, WBZ 13K (probably why hail isn't too large) and 0-3km hel of 100 (but most in the lowest 1km!)

DVN LI was -17, CAPE 4600 but sounding was cut short. GRB 2400 / -7.

DTX was rather wimpy but it's not very humid there - I increase dew's to 70*F and got CAPE 3300 LI -9 (still no helicity.)

- Rob

 

[Steve Fitzsimmons]

Madison, WI in center of latest mesoscale discussion.

 

[Zach Bailey]

new MD out concerning storm genesis from outflow of current tornadic supercell over north-central IL.