040
FXUS63 KGRR 041839
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
139 PM EST Wed Nov 4 2026

.KEY MESSAGES...

- Rain Continues into Thursday; Lakeshore Rain Chances Friday

- Cooler Temperatures Settle in Through The Weekend


&&

.DISCUSSION...
Issued at 139 PM EST Wed Nov 4 2026

- Rain Continues into Thursday; Lakeshore Showers Possible Friday

The surface low bringing showers and mild temperatures to the
region today will move across the U.P. into Ontario Thursday. As
it does so, a cold front will move through the region this evening
with a narrow band of showers and perhaps a few rumbles of thunder
that will precede a drop in temperatures for the area.

Upper troughing moves in later tonight into Thursday providing
synoptic forcing over Lake Michigan. Low level trajectories in the
925-700mb layer will be SW to WSW Thursday morning into the
afternoon and the layer will be saturated. RRFS Bufkit soundings
over Lake Michigan indicate lake induced CAPE values of 200-300
J/kg and plenty of low level moisture available. Lake enhanced
showers should get going overnight and continue into Thursday
afternoon under a SW flow regime. This will bring a fresh
0.10"-0.25" of rain Thursday mainly for areas near and north of a
South Haven to Ionia to Alma line. The highest amounts will likely
be across Muskegon, Newaygo, Ottawa, and Kent Counties.

A secondary, and more powerful, cold front moves in Thursday night
with 850mb temperatures falling to around -4C by Friday. This
occurs via a deeper upper low diving south into the Great Lakes.
Low level flows shifts N/NNW during the day Friday. Shallower
moisture is shown Friday but still present in the 925-850mb layer.
Either a dominant band or a few broken bands of lake effect rain
showers in N/NNW flow should hug the lakeshore counties during the
day with periodic wet weather, but with some dry periods as well.
Just depends on how the band or bands meander during the day
along the coast or just offshore. Additional areas such as near
and north of US 10 and near/east of US 127 may also see some lake
enhanced or lake effect rain showers off far northern Lake
Michigan or via lake aggregate troughing occurring over Lake
Huron.

- Cooler Temperatures Settle in Through The Weekend

Temperatures more reflective of early November are set to move in.
As mentioned, 850mb temperatures bottom out around -4C Friday and
this will yield highs in the mid to upper 40s. Combined with 10-20
mph winds, wind chill readings in the upper 30s to low 40s are
forecast. It will feel more like November for sure. Highs Saturday
into Sunday are forecast to be in the low to mid 50s, pretty
typical for early November.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1238 PM EST Wed Nov 4 2026

Generally went more pessimistic with ceilings for the next 24
hours, keeping them around 1,500 feet much of the time. There may
be times when ceilings dip to IFR below 1,000 feet or climb above
2,000. Rain showers this afternoon in the vicinity of a cold front
are bringing visibility to temporary IFR also. There is less than
a 30 percent chance of a thunderstorm over the next several hours,
though some showers could become moderate to briefly heavy with
convective tops to 15,000 feet which is presently about -10 C.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 7 PM EST Thursday for LMZ844>846.
     Small Craft Advisory until 7 PM EST Thursday for LMZ847>849.

&&

$$

DISCUSSION...Hoving
AVIATION...CAS