267
FXUS63 KGRR 241744
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1244 PM EST Mon Nov 24 2025

.KEY MESSAGES...

- Rain Moving in Tonight

- Cold, Windy, Snow Showers Wednesday and Thursday

- Snow/Mix for the Weekend

&&

.DISCUSSION...
Issued at 257 AM EST Mon Nov 24 2025

- Rain Moving in Tonight

A southern stream upper low ejecting out of the Southwest U.S.
brings cyclogenesis across the Plains today. The surface low
tracks into Lower Michigan with rain arriving tonight into
Tuesday. This is quickly followed by a northern stream shortwave
trough amplifying into a closed upper low and full latitude
troughing by Wednesday,

- Cold, Windy, Snow Showers Wednesday and Thursday

Colder air wraps in behind the low with 850mb temps falling below
minus 10C on Wednesday into Thanksgiving. Broad cyclonic flow
along with inversion heights near 8 kft will allow snow showers to
develop and these should penetrate far inland given the west-
northwest flow and mean boundary layer winds near 40 mph. Wind
gusts of 35 to 45 mph are possible Wednesday afternoon, especially
adjacent to Lake Michigan.

Snow showers should diminish by Friday as heights rise with the
upper trough shifting east. Snow amounts uncertain at this range
but it should be cold enough for snow to accumulate on roads and
affect travel from Wednesday to Thursday night.

- Snow/Mix for the Weekend

A longwave trough amplifying across the western CONUS phases with
an upper low across Hudson Bay creating a large baroclinic zone
across the central U.S. with an active storm track bringing rounds
of wintry precip to the Great Lakes beginning on Saturday. This
could cause travel impacts during the busy travel period next
weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1244 PM EST Mon Nov 24 2025

VFR with ceilings above 12,000 feet this afternoon and part of the
evening. Ceilings gradually deteriorate toward MVFR then IFR late
tonight or Tuesday morning. MVFR may develop first around
Ludington (LDM) after 00Z, then last around Lansing and Mount
Pleasant (LAN, MOP) around 12Z. IFR with rain is likely to
develop over the area between 12 and 15Z. A couple hours of error
with the arrival of MVFR and IFR is possible for each TAF given
the variance of models handling the increasing moisture in the
lower atmosphere.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Gale Watch from late Tuesday night through Thursday evening for
     LMZ844>848.
     Small Craft Advisory until midnight EST tonight for LMZ846>849.
     Gale Watch from Wednesday morning through late Thursday night
     for LMZ849.

&&

$$

DISCUSSION...Ostuno
AVIATION...CAS