421
FXUS63 KGRR 152330
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
630 PM EST Thu Jan 15 2026
.KEY MESSAGES...
- Southwest Flow Lake Effect Snow Tonight and Friday
- Lake Effect Plus Arctic Blast Next Week
&&
.DISCUSSION...
Issued at 248 PM EST Thu Jan 15 2026
- Southwest Flow Lake Effect Snow Tonight and Friday
Classic southwest flow lake effect snow set up for tonight through
Friday with clipper surface low tracking across northern Lower
Michigan and surface ridge axis to the southeast over the Ohio
Valley. A vorticity maximum at the base of the shortwave trough
axis will aid in providing lift as inversion heights increase from
around 5 kft this evening to over 10 kft by noon on Friday. Expect
bands of heavy snow to be aligned from near South Haven to the
northeast and clipping western Kent and Newaygo Counties.
The flow goes more westerly Friday afternoon as the shortwave
trough axis moves east and the heavier snow should taper off as
inversion heights come down below 10 kft.
- Lake Effect Plus Arctic Blast Next Week
A longwave trough will persist through the weekend and LES will
continue to flare up at times as weak, quick moving shortwave
troughs rotate through. It will be cold through the week with 850
mb temps bottoming out around minus 25C on Monday and Tuesday.
Right now our forecast apparent temperatures are only minus 10F
during this time, but relatively unmodified arctic air coming
around the southern part of Lake Michigan could penetrate into the
southern half of our forecast area and deliver below zero air
temperatures and wind chill/apparent temperatures of minus 20F or
lower. This is something we will focus on the next few days to see
if cold weather headlines will be necessary.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 627 PM EST Thu Jan 15 2026
The last of the lake effect snow is moving east and producing
flurries at the terminals. The next area of snowfall is already in
northeast WI and will begin to affect the terminals after 06z from
west to east. Cigs/vsbys will fall to IFR around 12z...earlier at
MKG...and remain there most of the day as light snow falls.
Snowfall rates from 0.1 to 0.2 in/hr expected.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory from 10 PM this evening to 7 AM EST
Saturday for MIZ037-038-043-044-050-056-057-064-071.
MARINE...Small Craft Advisory from 10 PM this evening to 5 AM EST Monday
for LMZ844>849.
&&
$$
DISCUSSION...Ostuno
AVIATION...04
NWS GRR Office Area Forecast Discussion
