WEST MICHIGAN– Muggy weather continues for one more afternoon across West Michigan before drier air settles in for a few days. First though, we must deal with a few more spotty afternoon showers and thunderstorms.
The National Weather Service tweeted around 3:25 p.m. Saturday that “dangerous swim conditions” were developing, with waves building to 3 to 5 feet.
Thunderstorms were sweeping through portions of Branch and Calhoun counties around 3:30 p.m. Saturday. Earlier, an isolated thunderstorm developed during the mid-morning period over Berrien and Cass counties producing heavy rainfall and frequent lightning – before slowly shifting eastward across St. Joseph County and then Branch County. This activity will have completely moved out of the West Michigan viewing area by early this afternoon leaving us with partly sunny skies into the afternoon.
A new chance for a few spotty showers and thundershowers comes about this afternoon as a lake breeze heads inland and causes some surface convergence. Moisture levels are to be most sufficient around and south of I-96. Therefore, it is these southern locales that can deal with some additional spotty heavy downpours as we go through the afternoon. Severe weather, however, is not expected.
The best chance to see a thunderstorm develop this afternoon / early evening will be the closer you get to the Indiana state line. Nonetheless, a slight chance exists for a shower, perhaps a thundershower, even northward from Grand Rapids in isolated fashion as a moisture discontinuity boundary edges southward and some subtle upper-air disturbances cross the region from west to east. When I say moisture discontinuity boundary, I am referring to the zone where the extremely muggy air meets noticeably drier air arriving form the north. This zone will slowly but surely be settling south across the state of Michigan later today into tonight.
Nonetheless, all activity either weakens or shifts southward of West Michigan by the early overnight period tonight. A much drier day sets up for Sunday with no precipitation and more importantly much lower humidity. Dew points will be closer to 60 degrees on Sunday versus the lower and middle 70s that have been experienced in our region over the past few days. Despite the drop back in humidity, the actual air temperatures will still be on the warm side in the low to mid 80s for the back half of our weekend except along the immediate Lakeshore. Expect that trend to continue into Monday and Tuesday with lower level humidity and rather warm afternoons on tap. Monday and Tuesday go completely rain-free with highs on Monday in the low to mid 80s and highs on Tuesday in the mid to upper 80s. Our next chance for a few showers or a thunderstorm waits until Wednesday to arrive.