995
FXUS63 KGRR 161052
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
652 AM EDT Mon Mar 16 2026
.KEY MESSAGES...
- Colder today with lake effect snow into Tuesday morning
&&
.DISCUSSION...
Issued at 331 AM EDT Mon Mar 16 2026
- Colder today with lake effect snow into Tuesday morning
Surface low at 06Z early this morning was located over far southwest
Lower MI. Flow across much of the CWA is relatively light out of the
east-northeast but this will change dramatically as the surface low
moves northeast across Lower MI while continuing to deepen, reaching
the northern Lake Huron region by early this afternoon. This will
yield a strong pressure gradient across the entire CWA in the late
morning/early afternoon timeframe with wind advisory (WI.Y) level
winds expected. Have added our northwest zones to the WI.Y ... and
Mason and Oceana Counties in particular could see borderline warning
criteria with gusts approaching 60 mph. This forecast outcome is
shared by a relatively small fraction of the model suite, so will
stick with WI.Y areawide for now and a possible upgrade in the
far northwest can be considered later this morning.
As noted previously, cold advection will be strong, resulting in a
transition to LES by this afternoon. Snowfall will be especially
impressive over our northwest CWA thanks to lake aggregate
enhancement. This, combined with the aforementioned strong gradient
winds, could result in occasional whiteout conditions, especially
by the lakeshore.
Strong, favorably oriented winds with a marginally deep boundary
layer will allow LES bands to easily reach the US-131 corridor.
Blowing snow may persist from this afternoon well into Tuesday
morning, although it may become a bit more ephemeral and dependent
on actual LES band evolution and placement. Snow showers are
expected to diminish during the day Tuesday as the upper trough axis
shifts east surface high pressure builds in.
&&
.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 652 AM EDT Mon Mar 16 2026
Main change this update was to add a bit more detail regarding
occasional IFR restrictions in Lake Effect Snow (LES). It`s still
looking likely that LES bands will develop by early afternoon,
chiefly affecting terminals closest to Lake MI (MKG/GRR/AZO).
However, LES could substantially affect other terminals such as
LAN and JXN, given the cyclonically curved trajectories of the LES
bands on the back side of the exiting surface low.
LIFR visibility restrictions will be commonplace under the bands in
snow and blowing snow. However, predicting the exact location of
these bands relative to the terminals is implausible at this
forecast projection, so PROB30 seems the most appropriate way to
handle this scenario at this time.
&&
.MARINE...
Issued at 331 AM EDT Mon Mar 16 2026
Have upgraded our northern zones to a storm warning, which aligns
with the Open water zones. Heavy freezing spray will become an
increasing concern today as temperatures plummet across Lake
Michigan. Gale conditions are still expected from Grand Haven
southward.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory until 11 AM EDT Tuesday for MIZ037-038-
043-044.
Wind Advisory until 11 PM EDT this evening for MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
Winter Weather Advisory until 8 AM EDT this morning for MIZ039-
040.
Winter Weather Advisory until 11 AM EDT Tuesday for MIZ050-056-
064-071-072.
Winter Weather Advisory until 11 PM EDT this evening for MIZ057-
065.
MARINE...Gale Warning until 5 AM EDT Tuesday for LMZ844>846.
Heavy Freezing Spray Warning until noon EDT Tuesday for
LMZ844>849.
Storm Warning until 8 PM EDT this evening for LMZ847>849.
&&
$$
DISCUSSION...TJT
AVIATION...TJT
MARINE...TJT
NWS GRR Office Area Forecast Discussion
