4/11/08 FCST: MI/OH/PA

[Andrew Herron]

While I was at the DTX office this past weekend they made mention of a concern for severe weather tomorrow. Looks like the SPC is agreeing and putting SE Michigan and North Ohio into a +10% risk for significant severe weather.

If we can get the dry slot to hang around long enough we should see CAPEs in excess of 1200 j/kg. Shear profiles look good too though there is some unidirectional forcing that could lead to a bow structure rather than supercell.

Depending on timing and whether I can get out of work I may head down into Monroe County.

 

[Mike Kovalchick]

While I was at the DTX office this past weekend they made mention of a concern for severe weather tomorrow. Looks like the SPC is agreeing and putting SE Michigan and North Ohio into a +10% risk for significant severe weather.

If we can get the dry slot to hang around long enough we should see CAPEs in excess of 1200 j/kg. Shear profiles look good too though there is some unidirectional forcing that could lead to a bow structure rather than supercell.

Depending on timing and whether I can get out of work I may head down into Monroe County.

The warm front should make it to between Flint and Saginaw Friday afternoon so that area might be a better tornado target assuming some good heating occurs early South of the boundary. Further South, that unidirectional flow will make it tough to get anything discrete but the speed shear suggests some supercells in a nice squall line. Michigan tornadoes love a good warm front! The 12 Z NAM highlights a small area just North of Flint at 21Z.

http://wxcaster4.com/nam/CONUS_ETA212_ATMOS_STP_33HR.gif

 

[Darrin Rasberry]

I wonder if the current advancing squall line isn't going to kill this area the same way the previous evening's squall line killed the moderate risk and severe superpotential today. That unbelievable squall by Odessa, Texas on Wednesday evening could have started a supercell-killing domino effect for this advancing system. Butterflies flapping wings indeed!

Moisture returns and heating will again be questioned, but there's not too many expectations with this system according to the SPC - save a high-end SLGT in central to northern Ohio, conditional on the aforementioned parameters (specifically how long that the morning gunk sticks around there).

 

[rdale]

I don't see any interference from activity to the south - I'd say this is COMPLETELY a sun-dependent outlook. No sun = no severe. Yes sun = realizing some healthy CAPE and high helicity.

I'd pick eastern lower MI / northern OH as the prime spot this afternoon. MI with a better chance of tornadoes with the triple-point moving through, OH better overall odds with increased heating.

 

[Mike Kovalchick]

I don't see any interference from activity to the south - I'd say this is COMPLETELY a sun-dependent outlook. No sun = no severe. Yes sun = realizing some healthy CAPE and high helicity.

I'd pick eastern lower MI / northern OH as the prime spot this afternoon. MI with a better chance of tornadoes with the triple-point moving through, OH better overall odds with increased heating.

I agree. My first thoughts this morning about an initial target would be Alma(30 miles North of Lansing) and then play East from there. Will see where the boundary actually stalls out and how much heating we get to decide if it worth going after this rather fast moving marginal setup.

 

[rdale]

I'm shocked at the visible satellite this morning... Who would have thought sunrise could look so pretty! Already 60 at the MI/IN border, and 6Z NAM has even higher CAPE/Helicity numbers over the Lansing area. I'll be out chasing after lunch, visible on SpotterNet (and hopefully video too on SS)

 

[Mike Kovalchick]

I'm shooting to be near Marshall by 130ish, under the impression that the cumulus row forming in eastern IL is going to be our generator...

I might take up position just on the North side of Lansing as I don't want to chase back towards the city. FYI-outstanding heating going on locally now and that 500 mb cold pool that has just crossed Lake MI should get things popping!


EDIT: SPC will be upping the tornado risk to 10% in Michigan at 16:30Z.