916
FXUS63 KGRR 130430
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
1130 PM EST Mon Jan 12 2026
.KEY MESSAGES...
- Light Rain Tuesday Transitions To Snow Tuesday Night/Wednesday
- Notably Colder Late Week With Periods of Lake Enhanced Snow
&&
.DISCUSSION...
Issued at 248 PM EST Mon Jan 12 2026
- Light Rain Tuesday Transitions To Snow Tuesday Night/Wednesday
Satellite shows substantial clearing across the area this afternoon
as the result of surface and upper level ridging crossing the area.
This reprieve is brief as a mid-level wave approaches the area
tonight. Warm air advection with 850 mb temps around 2C will keep
precipitation as rain Tuesday morning, transitioning to drizzle in
the afternoon as the DGZ becomes unsaturated. Given poor moisture
depth/quality, am expecting meager precipitation totals across the
area Tuesday. Northerly flow Tuesday night causes 850mb temps to
fall into the negatives causing precipitation to mix with, and
eventually transition over to, snow. Northerly flow behind the
associated cold front will keep the best precipitation chances near
the lakeshore early Wednesday
- Notably Colder Late Week With Periods of Lake Enhanced Snow
Early Wednesday marks the arrival of an arctic front with 850mb
temps crashing well into the negative teens. Robust ridging across
the western CONUS and deep troughing over the eastern CONUS will
develop and persist into the weekend. A burst of snow along the
initial arctic front is likely before the arrival of shortwave
ridging late Wednesday into Thursday brings a lull in the snowfall.
One thing we will have to watch is a trend in the last few runs of
several deterministic models bringing the best convergence and
associated snow a bit further east, which could bring a few
inches of accumulation into western Mason/Oceana/Van Buren Cos.
This is also reflected into the LREF constituent ensemble means.
This is highly sensitive to wind direction so confidence is low,
with chances of over 2 inches of snow 25-40% in western
Mason/Oceana/Van Buren.
While, as is normal at this range, the exact timing and placement of
synoptic features is uncertain, there is a strong signal for several
shortwaves to reinforce the cold air in the trough and send a few
clippers through the area starting Friday. This is a very favorable
pattern for lake effect snow given the robust cold pool and position
in cyclonic flow. This will support lake effect snow chances Friday
into early next week. The progression of the aforementioned clippers
will add synoptic enhancement to the pattern. What this means for
West Michigan is several days of lighter lake enhanced snow events
that will pile up over time, in addition to an extended period of
cold conditions. These rounds of snow may lead to slick travel at
times, especially west of US131.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1130 PM EST Mon Jan 12 2026
VFR conditions are expected into Tuesday morning with some low
level wind shear developing around 12Z as the low level jet moves
through the region. We`ll see some of those stronger gusts mix
down to the surface later Tuesday morning and continuing through
the day with southwest winds gusting around 25 knots. Overall
confidence is not high for showers to make it south toward the TAF
sites Tuesday. Ceilings are expected to lower to MVFR after 20Z
with the potential for some drizzle after 3Z as winds shift to the
west.
&&
.MARINE...
Issued at 248 PM EST Mon Jan 12 2026
Southwest flow keeps Small Craft Advisory level conditions going
through this evening with a brief lull overnight. We then see winds
and waves ramp up early Tuesday morning from the southwest. Given
the lull across our southern zones is 6 hours or less, have elected
to just extend the current advisory through 4am Wednesday morning at
which point a Gale Watch goes into effect. In strong cold air
advection behind an arctic front winds in excess of 40 knots in the
mixed layer has growing confidence in a solid gale event from late
Tuesday Night into late Wednesday Night. With some BUFKIT overviews
showing 50 knots in the mixed layer a low (10% or less) chance of
storm force gusts exists as well. In coordination with neighboring
offices, will be issuing a Gale Watch for the entire nearshore from
4am Wednesday through 1am Thursday, Given how cold the airmass is
arriving over the lake, freezing spray is also a concern.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 4 AM EST Wednesday for LMZ844>849.
Gale Watch from late Tuesday night through late Wednesday night
for LMZ844>849.
&&
$$
DISCUSSION...Thomas
AVIATION...RAH
MARINE...Thomas
NWS GRR Office Area Forecast Discussion
