Valid:

Synopsis: There is an Elevated Risk of Severe Weather across a large portion of the West Michigan Weather coverage area which includes the following counties in Michigan: Oceana, Newaygo, Muskegon, Kent, Montcalm, Ottawa, Ionia, Allegan, and Barry. Multiple rounds of strong to severe thunderstorms are possible from late this morning through the evening hours. Damaging winds, large hail, and isolated flash flooding and tornadoes will be the main concern with this risk.

---

Discussion: Surface temperature forecasts for today have prompted the issuance of Heat Advisories across much of northwestern Indiana and southwest lower Michigan. Models, including the HRRR are indicating that surface temperatures will be in the extreme upper 80's and into the mid 90's across much of the region today. These high temperatures, coupled with extreme moisture values, will lead to an extremely hot and humid environment, especially across southwest lower Michigan where heat indices could rise above 100 degrees. In terms of the moisture values; surface dew points today are expected to be in the mid 70's throughout the entire day. Even in the wake of frontal and prefrontal convective activity, we will likely see very high dew points and surface temperatures fueled by warm air advection from the Gulf of Mexico being pushed by strong low-mid level flow northeast through the Chicago Metro Area and straight across Lake Michigan into the greater Grand Rapids area. This continuous stream of warm/moist air advection will allow for the recovery of surface heating, moisture, and dew points in a relatively rapid manner in the wake of any convection. This would allow for the sustainment of the severe weather threat well into the overnight hours, though I think that the lack of frontal activity after 11pm will obviously inhibit this potential after that time.