Watching For Severe - Updated Information

Good Morning!

Looking at some fresh forecast data for you, and there are a few changes of note.  First of all, the Storm Prediction Center has changed the location of the risk areas for tomorrow.  Let's talk about it in detail for you.

MODERATE RISK TRIMMED:  Yesterday, pretty much the entire blog area was in a risk for an "enhanced" or better chance of severe weather.  As you can see, that has changed...

The entire blog area is still in a at least a "slight" risk for severe storms tomorrow afternoon and evening.  Here's the breakdown:  Moderate: Branch, Hillsdale, southwestern Lenawee, southwestern Calhoun, extreme southwestern Jackson.  Enhanced: Northeastern Lenawee, most of Jackson, a bit more than half of Washtenaw split by a line drawn northwest to southeast, Eaton, the southwestern two-thirds of Ingham, and extreme southern Clinton.  The "moderate" risk includes Coldwater, Hillsdale, Adrian, Battle Creek, Marshall.  The "enhanced" risk will include Jackson, Ann Arbor, Chelsea, Eaton Rapids, Lansing, Okemos.  Let's talk about what to expect.

AFTERNOON STORMS:  While I cannot rule out the possibility of a shower or thunderstorm earlier in the day, the better organized storms that will bring the severe weather are expected anytime after about three PM.  Here's a look at the Hi-Res NAM model FutureCast for 5 PM EDT:

This is the start of the event, as the heavier storms are just getting across the lake into West Michigan at this point.  The southeasterly track will bring the heavier stuff in by about 9 PM into South Central Michigan.  I expect sever weather to be a possibility until pre-dawn Thursday morning with the setup in place.  A trough with a low in the base of it will phase up with a a frontal boundary already on the move.  Add to that some robust wind at 5000 feet up (along the order of 50 MPH), from the south-southwest with due west winds higher up than that, and we'll have most of what we need for severe weather. Moisture will not be an issue, with dew point values into the 60's.

WILDCARDS:  I'm thinking that the majority of the area will be dealing with strong straight-line winds and large hail.  I can't rule out a tornado or two, but I really think that the dynamic support for tornadic storms will be better on the Chicago side of Lake Michigan.  We'll have to watch it and see what we get as the day progresses into evening.

I'll have the updated forecast for you later this morning.  Increase your weather awareness today.  Have a plan, be able to get the warnings from the National Weather Service, and execute your plan.