Branch, Michigan Weather Forecast Discussion

631
FXUS63 KGRR 190536
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
136 AM EDT Fri Sep 19 2025
.KEY MESSAGES...
- Showers and a Few Storms This Evening, Fog Returns Tonight
- Cooler and Unsettled Weather This Weekend Through Early Next
  Week
&&
.DISCUSSION...
Issued at 325 PM EDT Thu Sep 18 2025
- Showers and a Few Storms This Evening, Fog Returns Tonight
We remain under the general influence of high pressure, with ample
sunshine across much of Lower Michigan continuing today as
temperatures again surge into the mid 80s, which is about 10 degrees
warmer than normal for this time of year. However, some change is on
the horizon.
Showers and a few thunderstorms have formed and persisted throughout
much of the day over Northern Lake Michigan. This area is slowly
working its way south and east toward Ludington as of this writing.
Numerical guidance continues to struggle mightily with this area of
convection, although with some low-level convergence and several
hundred joules of CAPE it`s not a complete shock to see some slow-
moving showers/storms. Models continue to focus primarily on our
northeast corner counties (Clare, Osceola, Isabella) with convective
development over the next few hours, so the expectation is that the
ongoing weather along the lakeshore will continue to morph eastward
with time. Despite occasional flashes of lightning, these storms
are not severe, and the main impact will be some localized
beneficial rain totals around one-half inch or so.
Low-level winds become prevailing out of the northeast overnight as
surface high pressure shifts into position northeast of Lower
Michigan. This will bring moist flow directly off Lake Huron and
spread it across much of the area. As evening showers and storms
diminish after sunset, and temperatures begin to cool, we`re
expecting even more robust fog formation than we`ve seen the last
few nights. Fog will be thicker in east and northeast parts of the
area due to proximity to Lake Huron, but at least patchy fog is
likely across most of the area. This will burn off shortly after
sunrise on Friday, though, giving way to sunshine and a final day
with temperatures in the 80s south of I-96. Clouds and cooler
temperatures will likely linger over the more northern areas
tomorrow.
- Cooler and Unsettled Weather This Weekend Through Early Next Week
The upper-level ridge axis passes through Lower Michigan Friday
morning, which begins a transition of our weather pattern into more
broad southwesterly flow. This will bring in additional moisture and
generally unsettled weather to the area starting this weekend and
continuing through at least the middle of next week. Temperatures
will steadily return to more seasonably cool conditions, with high
temperatures in the 70s. Rain/shower chances increase during this
period as the remnants of the broad upper low currently in the High
Plains pass near/north of Michigan with accompanying shortwave
troughs moving through Lower Michigan. While none of batches of
showers or storms over the next several days carry much of a risk of
heavy rain, the sheer number of rain chances should eventually
result in beneficial rain for most places, with WPC 7-Day QPF on the
order of 0.50 to 1.0 inches across virtually our entire area. While
this won`t reverse the ongoing drought conditions, it should provide
at least some relief.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 136 AM EDT Fri Sep 19 2025
Only made a slight adjustment to TAFs going into Friday morning.
Stratus developing toward the Saginaw Bay will continue to expand
bringing LIFR and IFR ceilings further southwest. There remains
some uncertainty with how dense fog will become, but overall
expect IFR to MVFR visibilities to develop through the night
toward sunrise Friday morning. These visibilities will be mainly
be along and north of a JXN to GRR line. Visibilities and ceilings
will improve within a few hours of sunrise with VFR conditions
expected the remainder of the forecast period. Winds are expected
to pick up toward the lakeshore this evening with gusts of 20 to
25 knots.
&&
.MARINE...
Issued at 325 PM EDT Thu Sep 18 2025
Light northwesterly winds today become easterly Friday with waves
remaining below Small Craft Advisory levels through this time.
Increasing gradient winds of 15-20 knots from the east develop
Friday Night with Small Craft Advisory level gusts possible over the
waters. Winds subside to the 10-15 knot range for the weekend, with
winds from the southeast on Saturday and from the southwest Sunday.
A few rounds of showers and thunderstorms are possible Saturday
through early next week as a disturbance crosses the Great Lakes
region.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...AMD
AVIATION...RAH
MARINE...Thomas

NWS GRR Office Area Forecast Discussion