The various models I have looked at are all over the place in precipitation accumulation for today probably because it is hard to guess where the heaviest storms may develop. The NAM NEST is guessing the cold front will move through this evening around sunset thus we have chances of storm development any time today. Currently, as of 6:30 am we have showers across central Michigan.
The SPC continues to have placed us under the slight risk for severe weather across most of southern lower Michigan with the enhanced risk to out west.
--Showers and thunderstorms through this morning-- Scattered showers and isolated thunderstorms continue to traverse the region along and north of the I 96 corridor early Friday morning. These showers and storms are sparking off a warm frontal boundary that is draped east to west across the region. Looking at the NAEFS mean PWATS there is a decent amount through 15Z this morning, though only slightly anomalous. The 850mb jet is similar with a LLJ max around 25 kts. The latest CAMS continue to show the convection to continue through 15Z before slackening late in the morning. Elevated cores and decent rain rates are common with any thunderstorms. There is a lack of DCAPE so gusty winds are less of a threat. The rainfall into Friday morning will be set the stage for the stronger event, Friday night into Saturday. --Another more potent round of storms through Friday night-- There is a threat for damaging winds and hail, along with excessive rainfall that could lead to minor flooding. SPC has the region in a slight risk due to these threats. Following the boundary and the corresponding warm front will be a cold frontal boundary that will move through the region Friday night into Saturday. Looking at the NAEFS Mean PWATS the largest PWATs are between 00Z Saturday into 06Z. With +3 Std there is a good signal for significant rain. Along with this is the fact that the moisture is through the atmosphere and the moisture transfer is fairly strong considering a stronger LLJ, upwards of 30 to 35 kts. Along with this in the GEFS mean and M climate anomalies is an anomalous SFC low by 06Z Saturday. The CAMS have some variation in timing and organization in this system but the consensus is that lines of showers and storms will move through between 00Z to 08Z, most likely around 04Z. --Cooler trends through weekend-- Temperatures will cool down behind the front Saturday. Expect highs to be back to near normal, in the mid to upper 70s, through the weekend into next week.