05/06/04 NOW: Great Lakes

[rdale]

A 'surprise' mini-MCS is kicking off severe weather across northern MI -- followed by the main event later this afternoon...

 

[Tom Van Kuiken]

Rob, what is your take on the clouds and rain area that is about to move over W. Mich. Surpress are chances for later today !

 

[David Draun]

Aurora, IL is now reporting 79/61. The wind speed has increased to SW 15-20 mph. Still sunny overhead, but some cloudcover is approaching

 

[Tim Stoecklein]

We had some pea-size hail here, but nothing of terrible interest. Got our spotter group all excited though...the first one of the season usually does.

Tim

 

[Joel Wright]

Here in northwest IL near the Misssissippi River we are currently baking under almost full sunshine. Just a few wisps of cirrus mainly to the north. The temp has jumped to 83 with dewpoints now up to 62. Unfortunately it looks like all we'll see here is elevated nocturnal convection as the cap in this area is very strong. We have to breach 90 degrees to even have a chance at anything popping this afternoon.

 

[rdale]

I don't see the clouds being a big negative - we're still warm with dews in the 60's and temps in the lower 80's. If anything it pushes my "best chance of svr" a little closer to the state line.

I was _very_ surprised at this watch, as the isolated cells clearly were fast developers and in my mind would die quickly as well moving into the not-quite-unstable air. Looks like this watch will be a complete bust, so far no warnings in it and not even any lightning anymore!

 

[David Draun]

Originally posted by Joel Wright
Here in northwest IL near the Misssissippi River we are currently baking under almost full sunshine. Just a few wisps of cirrus mainly to the north. The temp has jumped to 83 with dewpoints now up to 62. Unfortunately it looks like all we'll see here is elevated nocturnal convection as the cap in this area is very strong. We have to breach 90 degrees to even have a chance at anything popping this afternoon.

I may have to agree with you. I'm seeing darker clouds to my NE, but it's all sunny to the west. Now its 81/63 in Aurora, IL. SPC still has Northern IL in the 25% bullseye for hail/wind. And the tornado 2% has been expanded westward. However, I don't see anything happening until later.
At least the CUBS will get the game in

 

[Robert Dewey]

Originally posted by rdale
I was _very_ surprised at this watch, as the isolated cells clearly were fast developers and in my mind would die quickly as well moving into the not-quite-unstable air. Looks like this watch will be a complete bust, so far no warnings in it and not even any lightning anymore!

Same here...From the sounds of the MCD they issued prior, I didn't expect a watch at all. Their MCD basically mentioned that an isolated storm could become severe, which is pretty much what happened...

As for later this afternoon...Modified RUC soundings for a parcel of 82F/62F yields 3000J/KG of CAPE for Detroit and 3100J/KG for Grand Rapids. Depending on which model I look at, I get helicity anywhere from ~135m2/s2 to ~225m2/s2, but with LCL/LFC levels very high, I don't see a significant tornado threat, but one or two (or maybe three :lol: ) tornadoes cannot be ruled out. To me, this looks more like a significant small scale bow echo event or larger scale LEWP...With the potential for some pretty significant wind gusts (>75mph) given some relatively dry air/dewpoint depression in the mid levels and possibly a slightly inverted "V" sounding (particularly further east towards DTX). If this larger CAPE is realized, some pretty good sized hail may also be a good bet, epscially given the relatively low freezing levels/WBZ levels and associated steep lapse rates.

Robert

 

[Tim Stoecklein]

GRR just shut down their "Skywarn Net". They must have decided that's all she wrote for now. I was actually surprised to hear them get it cranking as soon as they did today. Must be "first storm excitement"!

Good luck down south.

 

[Robert Dewey]

Originally posted by Tim Stoecklein
GRR just shut down their \"Skywarn Net\". They must have decided that's all she wrote for now. I was actually surprised to hear them get it cranking as soon as they did today. Must be \"first storm excitement\"!

Good luck down south.

Hopefully they will get activated again, later today :lol: . The next severe threat should exist between 21Z-03Z (or perhaps even a bit later)...At least according to the 15Z RUC data...

Robert

 

[Ben Pinette]

For a change, things decide to wait until I leave work before even developing. I'll be headed out in a couple hours. Probably gonna target tail-end Charlie once things get going. If it's not a LEWP, then who knows where I'll end up?! GL to all venturing out....

 

[David Draun]

84/63 Aurora, IL Hot, humid, and stagnant with a big FAT cap overhead.

Only thing heading my way are virga showers.

20Z convective outlook in from SPC. It mentions supercells for MI/OH, but only elevated severe hail west of that. Looks like a bust now. Better luck tomorrow? Or perhaps the possible MOD on Saturday

 

[Craig Maire II]

Iowa

74F Dewpoint of 58F with a strong northeast wind-Waterloo, Iowa...watching and waiting for now :wink:

 

[David Draun]

NWS Chicago predicts a cap break between 21-22Z in the forecast discussion. This may not be over yet. :wink: The sun is out of the clouds, lets get some (more) heating before the CF!

 

[Joel Wright]

Convective temps for surface based convection here along the river are now over 100 degrees. This is even higher than what was predicted earlier. Very hot air in Kansas is being advected northeastward right into IA and northern IL effictively putting a very tight lid on surface convection. Taking a look out the window and this is very easy to see. I can't see ONE small fragment of a cumulus cloud. Just virga streaks under the upper canopy.