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

[mikegeukes]

Special Marine Warning issued by the NWS Grand Rapids office
http://kamala.cod.edu/offs/KGRR/0407132159.whus53.html

Expect some warnings to be issued soon,
probably first will be Oceana and Muskegon counties.

Going somewhere to chase in West Michigan.

Edit: Severe Thunderstorm Warning for Muskegon County
until 745 PM EDT

Mike

 

[Robert Dewey]

Latest mesoanalysis shows a mesoscale low developing across southern lake MI... With SFC winds backing to the SSW... This has increased 0-1KM helicities to >150m2/s2, but 0-3KM helicities are still lacking.

 

[mikegeukes]

Lake Michigan is up to its old tricks again, some of the storms have weaken, hoping when they interact with the land, they will intensify.

Mike

 

[Robert Dewey]

Lake Michigan is up to its old tricks again, some of the storms have weaken, hoping when they interact with the land, they will intensify.

Mike

Yeah... 22Z SFC temps across lake MI (from bouy data) indicates T of 71F and TD of 68F, with a SST of 68F.

Temps right along the shore of lake MI is 84F with TDs in the lower 70s.

 

[Jeff Snyder]

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
557 PM EST TUE JUL 13 2004

0555 PM BLIZZARD MARTINSVILLE 39.42N 86.42W
07/13/2004 MORGAN IN AMATEUR RADIO

30 INCH DIAMETER TREE DOWN LINCOLN STREET HILL.

-----> http://kamala.cod.edu/in/latest.nwus53.KIND.html


Jeez... I know this system is developing a decent cold pool, but man, that IS some cold air!

I'm not very optimistic that we're going to get derecho development in central/northern IL, central/northern IN and adjacent portions of OH, as forecast. The bow in southern IN/IL has greatly stabilized (both through local subsidence as well as surface cold pool / outflow) these areas, and thus I think it'll be hard to get damaging winds down to the surface later on with any storms that do form here. Likewise, much of western IN has felt the modifying effects of the MCS/bow echo complex. Places from se IA into western IL still look good to go, but initiation in this environment seems uncertain... It'll be interesting to see what may happen if convection can fire from the Quad Cities / DVN south into sw IL (west of the areas impacted by current/earlier system), as instability and shear strongly favorable severe storms... Low 90's and Td of upper 70's yield a pretty volatile atmosphere here... The storms in MI may organize into a large-scale bow later on, but I'd see that affecting more of OH than IN. I suppose things may nudge right up against the outflow-modified environment in northern IN, and propagate into OH from there... RUC is not handling the situation very well (e.g. storms in east-central MO soon ?), so it's hard to know what'll happen...

 

[rdale]

From IND:

...TORNADO WATCH #623 HAS BEEN CANCELLED...

THE SEVERE WEATHER THREAT HAS MOVED SOUTH OF THE AREA.

 

[Dan Robinson]

I agree with Jeff, the complex moving south through Indiana may be the show of the day, the rest of the outlooked area looks to have escaped a siginficant severe event. The trajectory of the MCS is a lot more southerly than I thought.

The RUC does break out a large area of precip west of the current MCS in IL/IN, but it is also wanting to slow the progress of the frontal precip into central Ohio until around dawn. The lack of any activity heading into this area at the moment seems to verify this. So, looks like no nighttime lightning show for eastern Ohio and WV tonight Anything that does come through here will be in the late morning and will likely be a weak line at best.

I hope I'm wrong - but I'm not planning on staying up to wait for anything at this point.

 

[Robert Dewey]

The junk here in MI isn't looking all that good either... Best mid level winds are actually moving southwest of the lower Lakes region, which isn't helping. Temps remain in the low 80's with dewpoints in the low 70's, with SBCAPE of >3000J/KG, so I'm not totally giving up...

 

[Robert Dewey]

SWODY1 0100Z still holds on to the MDT risk over a large area from southeastern lower MI southward.

Activity in MI is trying to get better organized, but don't expect a derecho event...

 

[Jeff Snyder]

Some decent LSRs coming out of the Louisville NWSFO ... Seems like just about every county affected has trees and powerlines down countywide. Quite an impressive bow...

LOL about the SWODY1... that's quite a shape that the mdt risk has... Don't exactly agree with maintaining the mdt for western/eastern KY and western TN, but this has been a pretty tough-to-forecast event (the intense bow echo moving into TN)..

 

[Dan Robinson]

TWC has been showing video of a large low-contrast stovepipe tornado in Illinois.

 

[Steve Fitzsimmons]

I can see the huge supercell just east of Chicago, from Madison, WI - 160 miles away!

 

[Bob Hartig]

Just returned from a chase that took us from Grand Rapids, MI, south to Berrien Springs. I'd about decided to just hang out at my apartment and wait for the line of storms to blow in, but the cells seemed to be keeping fairly discreet, and after a quick call to my buddy, Bill, we decided to target tail-end Charlie. The cell had shown a TVS over Lake Michigan and seemed to be holding together fairly well. It made landfall at Benton Harbor, strengthened for a bit, then a second cell popped up just behind it and ate its lunch--more cells fired up, and the whole thing eventually became a healthy, SE-moving squall.

Nifty gust front, some high winds and heap-much rain, followed by a beautiful sunset, and a lightning display that continues to my east as I write. Nothing like the doomsday derecho I was expecting, but a fun chase for southwest Michigan.

 

[Dan Robinson]

Interestingly, convection is refiring in the wake of the derecho in southern Indiana.

http://www.spc.noaa.gov/products/md/md1659.html

 

[David Draun]

I can see the huge supercell just east of Chicago, from Madison, WI - 160 miles away!

I know. In northern Cook county two developed around sunset and blasted SE. They did not become severe until later. However, they did show some excellent supercellular structure. Backsheared anvils w/knuckles, overshooting tops, building cumulus flanking lines, and as the sun went down, frequent in-cloud lightning. Another one went up in Will county which I saw more awesome storm structure to my south. I was surprised, as most area forecasters removed the sevwx threat from the area. Before the storms developed, there was a definite increase in TCU and "turkey tower" activity. That first storm orphaned its anvil 3 times before punching hard against the tropopause. I just love watching thunderheads develop.