05/06/04 FCST: GREAT LAKES

[Tim Stoecklein]

It seems to be playing out further north than I thought it might...How far south are we going to have to go? Later afternoon seems to be the time frame to me. Anyone else? I wouldn't mind it happening earlier since I have a meeting tomorrow night, but since it's an amateur radio club meeting, and I'm the president, we could adjourn for a field exercise right?

Tim

 

[rdale]

"It seems to be playing out further north than I thought it might...How far south are we going to have to go? "

Wow - my head is spinning ;> Where are you saying?

 

[Tony Laubach]

Originally posted by Tim Stoecklein
It seems to be playing out further north than I thought it might...How far south are we going to have to go?

:? That sounds like a chase report I gave a few years ago.. :lol: I got dislexic that day! :lol:

 

[Tim Stoecklein]

Hahaha, you don't speak that language? I meant that the boundary may be a little further north than I initially thought it would be. How far south do you all think it'll initiate? Will it be well ahead of the boundary, along, or behind?

I'm thinking ahead of it right now, but what do I know, you've seen my typing skills.

Tim

 

[Ben Pinette]

21z still looks on track as of this hour. I'm hoping initiation can hold out till around 23z though, as that gives me time to leave work and position somewhere. At this point, I'll take a hail/wind event over nothing!

This will definately be a backyard chase for me, as it'll be run-and-gun right from work.

 

[rdale]

Nothing terribly different from a quick check of 00Z BUFKIT data... The biggest change I can see right now is that low-level winds are no longer weak - but southwest 10-20mph which makes a bit of a difference on my "not enough for tornado" call. Still not screaming helicities, but a little better look to the hodo than earlier. 60+ dew points are currently moving north through southern IL / SW Indiana.

 

[Robert Dewey]

Hmm...Am getting a little concerned about moisture this afternoon. Dewpoints across lower MI are currently in the mid 30's, with the RUC showing dewpoints only reaching low 50's by 21Z (with CAPE of ~500J/KG). RUC does have a slight dry bias of SFC dewpoints, and with mid to upper 50's Td's currently located across the mid/upper MS Valley, am hoping that these will be able to advect in...

Of interest...The latest 06z run of the TAQ RUC (Experimental 10km grid from FSL) shows dewpoints pooling into the low 60's between 21Z-00Z, with CAPE of 2500j/kg...And as I said, with dewpoints of upper 50's just upstream, I could see 58-60F happening by later today...

This is probably just wishcasting kicking in. Does anyone else share the moisture concern as well?

Robert

 

[rdale]

No, with mid-50 DP's in Lafayette already I don't see an issue... Obviously the mid-60's as the 06Z Eta progs are not going to happen, but the Eta also keeps our temps in the mid-70's so tacking on a few more degrees almost offsets the moisture - we'll still have 2000 +/- CAPEs and a nice amount of low-level directional shear.

 

[Robert Dewey]

Originally posted by rdale
No, with mid-50 DP's in Lafayette already I don't see an issue... Obviously the mid-60's as the 06Z Eta progs are not going to happen, but the Eta also keeps our temps in the mid-70's so tacking on a few more degrees almost offsets the moisture - we'll still have 2000 +/- CAPEs and a nice amount of low-level directional shear.

Excellent...RUC does show some good wind fields coming in later this afternoon...If everything goes as planned, could see quite a bit of action later today...

Robert

 

[Tim Stoecklein]

I must say that I am hoping George Lessons with WZZM is right, all the action is going to be up my way.

However, I don't agree with his models, you should have all the fun downstate. It seems to be shaping up. I agree that moisture shouldn't be a problem. We've got pretty healthy S/SW winds right now so it should be in place by this afternoon.

Tim

 

[David Draun]

Right now, here in the Chicago area, temps are in the low 60's and dewpoints are near 60. I am seeing some cirrostratus and ACCAS to the west. Hopefully initiatiion will be much later so the CUBS can get to the seventh inning, and get the game called, hopefully while they're in the lead.

In NWS Chicago discussion: surface temps near 90 predicited south of interstate 80. :shock: CAPE is expected to be near 2000 J/kg.

I think it will be a squall line event this afternoon, and a heavy rain MCS overnight into tomorrow.

 

[Robert Dewey]

I was messing around with soundings in nsharp (modifiying them) for a bit lower dewpoints than what the ETA was suggesting (just to be safe), and temps in the low 80's...Which yeilds widespread 2500-3000j/kg CAPEs. I decided to plug in David Drauns numbers (went with 88/60 T/Td), for the 21-00Z forecast sounding from LOT, which yields 2800J/KG...A sounding from DTX/PTK MI with a parcel of 82/58 yields 2800J/KG as well, with helicity sneaking up around 200m2/s2 and EHI values of >3.1! After looking at the early morning models/data, I would say severe thunderstorms are a very good bet this afternoon from LOT northeast in southern lower MI...

Still waiting for some 12Z data just to make sure...

Robert

 

[David Draun]

I think the cap is begining to strengthen. The cirrostratus has dissipated and the ACCAS are aslo starting to shrink down now.

Aurora, IL now reporting 72/61 T/Td :shock: Nice temp jump from 63/57 an hour ago.

 

[Tim Stoecklein]

I think we're about to get a preliminary shot here shortly. Looks like a line coming across the lake, this may be the warm front getting here finally.

Tim

 

[David Draun]

Thunderstorms approaching LP Michigan have cloud tops to 55K. Another line begining to drop SE into IL. It looks to be weakening. Short term forecast out of LOT predicts thunderstorms across CWA by 11 AM. I assume a NOW thread should be starting soon.

SPC has an MD out for N LP Michigan for isolated wind/hail damage threat.

MESOSCALE DISCUSSION 0567
NWS STORM PREDICTION CENTER NORMAN OK
0936 AM CDT THU MAY 06 2004

SCATTERED STRONG STORMS ARE MOVING QUICKLY ACROSS LAKE MICHIGAN AND
WILL BEGIN AFFECTING LOWER MI. AS SFC TEMPS CONTINUE TO WARM...AN
ISOLATED WIND DAMAGE THREAT WILL INCREASE OVER THE NEXT FEW HOURS
WITH A MARGINAL THREAT FOR HAIL.