Beautiful weather will give way to an active, stormy period mid next week

Some very potent, moist air will likely be moving into the state next week, and, in tandem with several upper-level short wave impulses, could generate multiple rounds of strong/potentially severe thunderstorms over the course of several days.

The humid air begins to move in on Tuesday. By Tuesday afternoon, the GFS is predicting dewpoints in the 60s, and possibly the upper 60s in some areas of the state. The ECMWF is a bit more conservative for now, but only a touch, predicting dewpoints in the low 60s. While thunderstorms could develop along this warm front as it moves into the state, not much instability is forecast to be present, so they should be on the weaker side if they do occur.

Wednesday is going to be much more interesting. Both the ECMWF and GFS models are indicating that dewpoints could reach 70°F by late afternoon. This will make the amount of instability in the state quite high - the GFS is forecasting 1500-2500j/kg of SBCAPE for regions north of I-69 and 2500j/kg+ of SBCAPE to the south. Outflow boundaries from previous-day storms (and/or re-intensification of what still remained) could initiate thunderstorms in this environment, and there's definitely enough instability there to warrant a severe threat. As such, I believe severe thunderstorms are likely along and south of the I-69 corridor, and a chance of isolated severe weather exists from US-10 southward. Primary threats should be large hail and damaging winds. Wind profiles do not support a tornado risk at this time.

Things start to get a little less concrete by Thursday, as the models start to diverge. The ECMWF has a cold front moving through mid-day Thursday. This would bring more thunderstorms, but as it wouldn't coincide with peak heating, they probably wouldn't be severe. The GFS has a much more progressive development to this wave, keeping the colder air to the west/north, and allowing for ample moisture return from the south. Truthfully, I'm leaning more toward the GFS's solution, as it has been consistent over the past few days and falls more in line with the pattern that the climate prediction center is forecasting for 6-10 days out, both in terms of temperatures and precipitation. This forecast makes Thursday essentially a repeat of Wednesday, only to an even stronger degree. Widespread 70° dewpoints would exist throughout the lower peninsula - even the U.P. would be looking at dewpoints in the mid-to-upper 60s. A quasi-stationary front is forecast to dip southward, which could initiate storms along the northern regions. Outflow boundaries from/remnants of previous-day convection would also support storm initiation/re-intensification to the south, and a potential severe threat.

GFS forecast sounding for the area near Midland, MI for next Thursday afternoon predicts a very unstable environment. Should this verify and storms form in this environment, they'd probably be capable of some damaging winds and prolific hail, but the tornado threat would again be low.

Depending on the accuracy of the GFS, Friday and even Saturday could be similar to Thursday. Westerlies are expected to strengthen on Thursday and it remains to be seen if a severe threat will persist, but as of right now the last full week of May is appearing as though it could be quite active.