378
FXUS63 KGRR 121620
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
Issued by National Weather Service Detroit/Pontiac MI
1120 AM EST Thu Nov 12 2026
.KEY MESSAGES...
- Batch of moderate rain along the US-131 corridor this afternoon
- Lake Effect Rain and Snow Showers
&&
.UPDATE...
Issued at 1120 AM EST Thu Nov 12 2026
Ribbon of intense showers currently over eastern Kent and nearly
all of Barry counties is showing signs of weakening as it plods
west-southwestward. Radar estimates of around an inch of rainfall
across east-central Ionia county will certainly be at the top
end. The forcing supporting this feature will continue to lose
vigor and the supporting deformation axis broadens while the
primary system exits the Eastern Great Lakes region.
&&
.DISCUSSION...
Issued at 208 AM EST Thu Nov 12 2026
- Lake Effect Rain and Snow Showers
Cyclonic flow continues across Lower Michigan through Saturday as
an amplified omega block forms over the CONUS with upper
troughing to the east and a sharp ridge to the west. Lake effect
rain and snow showers will be confined to mostly near and off the
Lake Michigan coast in north flow. Some light snow accums are
possible across the northwest zones.
The blocking regime breaks down over the weekend and showers end
as heights rise. The amplified ridging flattens as it moves east
bringing dry and mild weather into the middle of next week.
&&
.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 628 AM EST Thu Nov 12 2026
Areas of IFR conditions today with occasional rain and snow
showers, improving to MVFR and then VFR by evening. North winds
will gust to 20 knots at times today.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 7 PM EST Friday for LMZ844>849.
&&
$$
UPDATE...Mann
DISCUSSION...Ostuno
AVIATION...Ostuno
NWS GRR Office Area Forecast Discussion
