941
FXUS63 KGRR 201657
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1157 AM EST Thu Nov 20 2025

.KEY MESSAGES...

- Mostly Dry through the Weekend

- Pattern change to cold next week

&&

.DISCUSSION...
Issued at 302 AM EST Thu Nov 20 2025

- Mostly Dry through the Weekend

Model guidance is consistent with keeping northern and southern
stream separate as the troughs move east of Lower Michigan
through Friday. This means southwest Lower Michigan will see
little in the way of measurable rain with the showers remaining
south and mostly north. Another northern stream shortwave trough
axis moves through Saturday night, but favorable jet dynamics are
north of the forecast area and once again the precip misses
southwest Lower Michigan.

- Pattern change to cold next week

Phasing of the northern and southern streams eventually happens
early next week with cyclogenesis across the Northern Plains into
Canada and a trailing front/trough concentrating an area of rain
moving through Lower Michigan on Tuesday. A longwave trough in the
wake of this low will bring a drop in temperatures for the middle
of next week. Cyclonic flow with a potential shortwave trough
axis rotating through could bring lake effect snow showers by the
middle of the week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1156 AM EST Thu Nov 20 2025

Moisture trapped under an inversion in combination with the
unfavorable sun angle is keeping IFR to LIFR ceilings in place,
with a brief window of improvement to low-end MVFR likely late
this afternoon before IFR ceilings redevelop tonight. Periods of
LIFR are possible as well. Have favored short term model guidance,
particularly the NAMNEST which has handled this setup well over
the last 24 hours. After 12z, conditions slowly begin to improve
from west to east behind a cold front. MVFR fog also mixes out
this afternoon, before returning overnight.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Ostuno
AVIATION...Thomas