966
FXUS63 KGRR 200802
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
302 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 /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1139 PM EST Wed Nov 19 2025

The main focus for the 06z set of forecasts is on the low cloud
trends through the period. Nighttime microphysics satellite
imagery shows the low cloud deck sprawling northward. As of
1130 pm EST/0430z it has spread across all of the forecast
terminals except KLAN, where it should over very soon. The clouds
start out in the higher end of MVFR, and have been lowering to the
lower end of MVFR. This trend will continue, with IFR likely at
most of the sites by mid morning.

Model cross section RH progs show this will stay in place through
tomorrow. There could be some slight improvement late in the
afternoon, but will stay IFR most of the day, and tomorrow
evening. Definitely will play this pessimistic given we are almost
at the weakest sun angle of the year.

&&

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

&&

$$

DISCUSSION...Ostuno
AVIATION...NJJ