502
FXUS63 KGRR 091706
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
106 PM EDT Mon Mar 9 2026
.KEY MESSAGES...
- Strong to severe storms possible Tuesday evening/night
- Locally heavy rain possible Tuesday through Wednesday
- Light wintry mix across Central Lower Michigan with system
- Clipper may bring accumulating snow Thursday night/Friday
&&
.DISCUSSION...
Issued at 339 AM EDT Mon Mar 9 2026
- Strong to severe storms possible Tuesday evening/night
Winds will still be breezy today, but not quite as strong as
yesterday. Quiet weather for the most part is expected from today
into Tuesday morning. There is a chance of some spotty light rain
tonight into Tuesday associated with a developing warm front. The
majority of the focus of the 7 day forecast in on the potential
for severe weather Tuesday evening into Tuesday night.
A plains upper trough will approach the Great Lakes Tuesday night,
but will not move through until Wednesday. At the surface, low
pressure will form in the plains and lift into the area Tuesday
night. There is still some difference in the models in terms of
low placement, but the ensemble members of both the ECMWF and the
GFS seem to be honing in on Southwest Lower Michigan somewhere
between SBN and GRR at 06z Wednesday. This means the warm front is
likely to lift into our area. Both the GFS and NAM lift the front
into our southern two rows of counties likely ending up somewhere
near a line from South Haven eastward towards Mason and Jackson.
Plenty of low level shear will be in place as a similar setup to
last week takes shape. A strong low level jet (40-45 knots) looks
to intersect the warm front over Southwest Lower Michigan Tuesday
evening with backed low level flow near the warm front. NAM
hodographs are showing 50 knots of deep layer shear with the bulk
of that occurring in the lower 1 km. Rotating updrafts look likely
given the deep layer shear so all hazards are in play...hail,
wind and tornadoes. The Storm Prediction Center has increased our
chance of severe weather bumping the threat from a marginal to a
slight and cannot argue with that. We will be monitoring storms
Tuesday evening very closely. They look to move in after 00z as
the low level jet impinges on the warm front. As far as
instability goes we feel this will be advected into the area on
the strong winds just off the surface.
- Locally heavy rain possible Tuesday through Wednesday
Locally heavy rain looks more than possible as periods of showers
and storms occur from Tuesday afternoon through Wednesday. We are
likely looking at swaths of one to possibly two inches of rain
especially from I-96 to the south. Rivers are higher now given
recent rains so additional precipitation will likely push quite a
few sites towards bankfull/action stage. If the rain ends up
closer to an inch we will likely be able to absorb most of that
without significant issues, but if it overperforms (1.5 to 2.0
inches) we would likely be looking at rivers reaching flood stage
in a few spots in the Kalamazoo and Grand river basins.
- Light wintry mix across Central Lower Michigan with system
This system is dynamic like many systems in the early spring time
frame. While storms will occur in Southern Lower Michigan, Central
Michigan will be closer to the cooler air remaining in the
easterly flow north of the warm front. Temperatures across Central
Lower Michigan will be in the lower to middle 30s Tuesday night
into Wednesday morning, so some wet snow will mix in especially
near U.S. 10. As the low goes by on Wednesday colder air filters
in and the rain/snow mix should chance over to all snow later on
Wednesday. Accumulations are expected to be light given the
marginal surface temperatures for the bulk of event. A touch of
freezing rain is possible especially across Osceola and Clare
Counties Wednesday morning. Given temperatures right around the
freezing mark not expecting significant impacts.
- Clipper may bring accumulating snow Thursday night/Friday
A potent clipper system is expected to sweep from west to east
through the area Thursday night into Friday. Accumulating snow is
expected across Central Lower Michigan with this system. A surge
of warm air ahead of the low complicates the forecast a bit, as
surface temperatures try to push towards 40. Feel the system may
keep the U.S. 10 corridor a bit colder and accumulations of snow
are likely there. More time to look into this system as the week
moves along.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 105 PM EDT Mon Mar 9 2026
Gusts of 25-30 knots from the south are expected this evening
before diminishing to 5-10 knot winds overnight. Tonight, a warm
front pushes north across the area with a significant increase in
low-level moisture behind it. Cigs will quickly fall to IFR with a
15-25% chance of LIFR cigs, highest at MKG and AZO. Visbys are
also to likely to fall to MVFR or lower, with elevated winds
helping limit dense fog potential. Slow improvement of low clouds
is expected over the course of Tuesday morning, with AZO/BTL/JXN
still IFR by 18z.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Duke
AVIATION...Thomas
NWS GRR Office Area Forecast Discussion
