07/26/2005 TALK: MIDWEST/GREAT LAKES

[Robert Dewey]

The threat looks like it has transitioned into the 03Z to 12Z timeframe (late tonight/tomorrow morning).

Latest 12Z NAM shows a pretty strong wave developing, with a low level jet increasing to 50knts and 700mb winds increasing to 55-60knts between 06Z and 12Z tomorrow. Low level moisture and instability will increase as a result of the strong low level jet, helping to push the warm front northward again this evening. Instability in the overnight hours remains near 1500-2000J/KG, and with the combination of strong forcing, shear, and modest instability - any MCS that develops further west this evening should advect into the region overnight and maintain its intensity (or intensify with the increasing shear).

Looking at forecast soundings from the NAM, things still appear to be quite unstable overnight. I did have to modify the SFC temperature and low level temperature down a bit, as the NAM had 85F, which is obviously much too high for 09Z. Even with a SFC parcel of 77/71 T/Td, and we still have over 2000J/KG of CAPE, though with quite a bit of CINH (that CINH is a result of the 85F temp at 925mb, which may not happen). Wind fields are quite strong, with 50knts making down as low as 900mb, or less than 1000 meters.

Depending where exactly along the warm front storms fire will really determine the severe threat. If they are relatively far north of the warm front, the main threat would be from hail... If things can root themselves right on the warm front, and take advantage of the SFC based instability, then damaging winds would become a concern, as well as isolated tornadoes.

 

[tom hanlon]

Well the spc has blessed Ohio with a 5% tor. Awfully populated state to consider that a good thing but I intend to chase today.

From the SPC day one CO.
20-30 KT OF SHEAR IN THE LOWEST 1-2 KILOMETERS WILL ALSO FAVOR THE
POTENTIAL FOR A FEW TORNADOES...

I am starting out from Columbus and will head West on I70 NW on 23, or North on 171 depending on circumstance. Targets being Bowling green OH, Dayton OH or mansfield OH.

Mesoscale discussion for MI, IN, IL already this morning.

Here in OH we have decent surface winds from the S to SW and are expecting extreme heating.

The northern IN AFD has added some strong wording this AM regarding today's potential. From the Northern IN AFD..
MORNING SURFACE ANALYSIS SHOWS A PRE-FRONTAL TROUGH ENTERING
NORTHWEST FORECAST AREA. DEWPOINTS POOLING INTO MID 70S JUST AHEAD
OF THIS FEATURE. LINE OF MODERATE CU BEGINNING TO FORM ALONG THIS
AXIS. SATELLITE ALSO SHOWS SEVERAL BOUNDARIES ACROSS AREA...ONE OF
WHICH HAS BEEN LIFTING NORTH THIS MORNING.

All things considered the SPC seems to be the most convinced that todays weather will be severe. Too close to home for me to ignore so I will be out there somewhere today.

I will check back in when I get some more detailed data. Good luck today.

--
tom hanlon

 

[tom hanlon]

Heading to the FT WAYNE IN / TOLEDO OH region.

Not particularly hopeful but it is in my backyard more or less.

Extreme heating and lots of moisture.... something could happen.

--
tom hanlon

 

[nickgrillo]

Wow...

Just had some fun for a few minuites, bunch of large stones fell in my backyard... All of them just under 1"INCH, just reported nickel-sized hail to DTX...

 

[John Thurston]

Was outside working after the 7am mess went through.

100% humidity - not fun.

Another disorganized line just went through around 1pm EDT heading for DTW. Although this was somewhat local so should not mess up everything.

The actual front is still 100 miles to NW I think so provided we get some re-heating and it doesn't go linear right away. Satellite does show some breaks. IF DTX prediction of 90's/70's it could still get interesting.

I will be out if that happens.

JT

 

[nickgrillo]

Overall flow in southeast MI is pretty good at all levels, with +15kts at 850mb, 20-35kts at 700mb, 30-40kts at 500mb... The directional shear is also pretty good, so I am not surprised to see decent low-level rotation from time-to-time, even with that storm that just passed over my house showed some broad-scale rotation.

0120 PM HAIL W ROSEVILLE 42.51N 82.94W
07/26/2005 1.00 INCH MACOMB MI TRAINED SPOTTER

REPORTED JUST SOUTH OF I-696

0124 PM HAIL NW ROSEVILLE 42.51N 82.94W
07/26/2005 0.88 INCH MACOMB MI TRAINED SPOTTER

NEAR M-53/I-696

0130 PM TSTM WND GST SW DEARBORN HEIGHTS 42.33N 83.27W
07/26/2005 60 MPH WAYNE MI TRAINED SPOTTER

SMALL TREE LIMBS DOWN

124 PM is my report, wonder where that other spotter was :lol:

 

[John Thurston]

Unfortunately it looks like there is some lines forming along the front in NW Michigan.

JT

 

[tom hanlon]

Although the activity for today is not all that focused, I guess I have to pick a location, unlike the weather I can not be two places at once. :cry:

New MD from the SPC places a broad swath of concern from OH to NY. The first line of CU that went up in OH seem to be pulse severe rather than building into a solid line. Actually they may grow into strong storms but since we passed under them and they are moving East we have to let them go.

We got West of those and will head North into Findlay OH and see what happens there.

--
tom hanlon

 

[Jeremy Lemanski]

Unfortunately it looks like there is some lines forming along the front in NW Michigan.

JT

honestly, those lines i think will be about it with the front. I think storms will be hard pressed to form along the cold front itself.

 

[nickgrillo]

Unfortunately it looks like there is some lines forming along the front in NW Michigan.

JT

honestly, those lines i think will be about it with the front. I think storms will be hard pressed to form along the cold front itself.

Yeah...

Monroe/Lenawee should be seeing the last of the MI action for the day, as the severe threat continues to diminsh... Overall, I feel kind of good about today - pretty nice backyard chase, with hail nearly 1"INCH.

 

[Robert Dewey]

Unfortunately it looks like there is some lines forming along the front in NW Michigan.

JT

honestly, those lines i think will be about it with the front. I think storms will be hard pressed to form along the cold front itself.

Well, with nearly 30-40KNTS right off the ground, and deep mixing along the front, it wouldn't take much to produce some damaging wind gusts. FNT and OZW both reporting mid 80's with Td's in the mid 70's, so things are still quite unstable.

Latest L2 NEXRAD shows a definite but narrow line forming along the cold front, and as this advects into the moist and unstable airmass, I could imagine more thunderstorms developing.

IWX has something intersesting in their latest AFD:

SOME WIND REPORTS COMING IN ALONG NORTHERN PORTION OF
FRONT AS SHOWERS MIX WINDS TO THE SURFACE.

 

[Andrew Khan]

I have yet to see ANY rotation in this storm, not even low level rotation. I do not think this will produce tornadic activity, in MI, unless new cells develop along the boundary of this old one, perhaps..

 

[rdale]

Since the severe weather is well out of Michigan, I also think it's a good bet MI won't get any tornadoes today ;>

 

[John Thurston]

Looks like we will get the garbage drifting in from Chicago area here in S Michigan.

Still sticky-hot out so the glass is still half full for me.

JT

 

[Andrew Khan]

Yes, RDale, I understand that, I was speaking comparitively. The storm was, when I posted still in southern MI.