893
FXUS63 KGRR 130543
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
143 AM EDT Fri Mar 13 2026
.KEY MESSAGES...
- Snowfall through Central Michigan Early Friday
- High Winds Across Southern Lower Michigan Tomorrow
- Significant Late Winter Storm Possible Sunday into Monday
&&
.DISCUSSION...
Issued at 259 PM EDT Thu Mar 12 2026
- Snowfall through Central Michigan Early Friday
Bottom Line Upfront: Have issued a Winter weather advisory for
most of the US 10 Corridor and extended it southward to include
Mecosta and Isabella counties.
The Alberta Clipper system remains on track with a deep low that
is still expected to move through northern Michigan. There is
still a question about how much snow will accumulate. However, The
strong gradient, QPF of upwards of 0.80, and a 2 to 3 KFT DGZ
should allow for inch per hour rates at times from 06Z until
around 15Z. Strong mixing and lapse rates through the DGZ will
help. Considering this is occuring in the pre dawn hours
expecting 4 to 6 inches with locally higher amounts possible north
of the US 10 corridor, especially in any higher elevations. Any
snow accumulations southward will be limited with at most an inch
closer to the I 96 corridor.
- High Winds Across Southern Lower Michigan Tomorrow
Models continue to show a highly anomalous gradient associated
with this low which will begin with strong southerly flow out
ahead of it. It will then sweep across southern Lower Michigan
tomorrow. Mid range models are in fair agreement with lapse rates
of over 9.0 C/km near the SFC in some locations which would mix
down 50 to 60 mph winds. Any precip loading will further add to
the winds. The upper level low is tracking through the Upper
Peninsula mid day tomorrow with downsloping winds and cold air
advection adding to the winds. Winds throughout the day will be
gusty, though there will be two peaks; the first on the onset as
the low moves into the area around 12Z and mid to late in the
afternoon with any amplification from a shortwave through the mid
levels. Winds will finally slacken mid to late Friday evening.
- Significant Late Winter Storm Possible Sunday into Monday
Sunday into Monday looks to potentially be one of the more
impactful events of the winter. There remains a lot of questions
but a swath of ice and significant snowfall is possible Sunday
into Monday. A large upper level low will track through the Great
Plains with strong warm air advection Sunday. That warm front will
bring a chance for storms Sunday afternoon. As the low lifts to
the east the cold air along with strong moisture advection will
pivot a swath of moisture across Lower Michigan with a wintry mix
of precipitation across the region. There could be a narrow band
of freezing rain Sunday night through Central Michigan with heavy
snow to the north. Models are beginning to narrow in on the threat
area, but there remains a focus of freezing rain and heavy snow
north of Muskegon to Mount Pleasant Sunday night into Monday.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 143 AM EDT Fri Mar 13 2026
Low confidence in these TAFs verifying perfectly hour by hour, but
high confidence in this being a difficult and unideal day for
flying. The weather will be as ugly as these TAFs look, with
temporary changes to flight categories around MVFR/IFR as
visibilities and ceilings vary along with precipitation intensity
and rain/snow type. The wind will also gradually veer from
southeast to southwest to northwest throughout the course of the
day. LLWS will be present this morning. Sustained winds today will
often be 20 to 25 knots with gusts 35 to 45 knots, perhaps peaking
once or twice around 50 knots.
&&
.MARINE...
Issued at 259 PM EDT Thu Mar 12 2026
The marine section will have a gusty restart as a strong upper
level system will move through the region tomorrow. Winds will
increase and will amplify from the south with storm force winds
beginning late this evening. Winds will shift to the west on the
backside of the system tomorrow morning but will continue its
intensity through Friday. Waves will increase to 11 to 16 feet
through Friday, The winds will finally begin to slacken overnight
Friday into Saturday with waves subsiding Saturday morning.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...High Wind Warning until 8 PM EDT this evening for MIZ037-043>046-
050>052-056>059-064>067-071>074.
Winter Weather Advisory until 2 PM EDT this afternoon for
MIZ037>040-043>046-051-052.
MARINE...Storm Warning until 11 PM EDT this evening for LMZ844>848.
Gale Warning until 11 PM EDT this evening for LMZ849.
&&
$$
DISCUSSION...Ceru
AVIATION...CAS
MARINE...Ceru
NWS GRR Office Area Forecast Discussion
