566
FXUS63 KGRR 110542
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
142 AM EDT Wed Mar 11 2026
.KEY MESSAGES...
- Severe storms possible tonight
- Freezing rain north tonight
- Wind/snow Friday
- Colder next week
&&
.DISCUSSION...
Issued at 234 PM EDT Tue Mar 10 2026
- Severe storms possible tonight
The atmosphere is setting up for a possible severe weather event
tonight. We`ve been watching the slow southward movement of a
cold front that currently stretches from near Grand Haven to
Middleville to just south of Mason. Visible satellite imagery
shows this well. The current temperature is 46 at Lansing and 68
at Jackson. Short range models show this frontal boundary sagging
south to the I-94 row of counties by late this afternoon.
In the warm sector, conditons are ripe for the development of
strong to severe thunderstorms. Between 00z-03z, 0-1km bulk shear
increases to 60kts along I-94 and 40 kts over the northern cwa as
a LLJ intersects the frontal boundary and low pressure rides
northeastward along the boundary from northern Missouri. HRRR
SBCAPE maxes around 2200 j/kg around 00z over the I-94 corridor
but falls to near 0 j/kg north of the frontal boundary. 0-1km SRH
is near 300 m2/s2 indicating updraft rotation and supercell
development likely. Tornadoes are possible near the frontal
boundary this evening. Given STP values over 2 as seen on the
latest HRRR and WoFs, a stronger tornado potential has to be
considered as well.
The severe wx potential isn`t limited to the southern cwa. North
of the frontal boundary, elevated instability and shear is also
impressive too. Additionally, RRFS-EMC shows updraft helicity
swaths across the central cwa this evening; large hail is the
main threat north of the frontal boundary.
CAMs indicate the core of the storms moving east by 08z with an
area additional weaker development 10-12z. However, as we`ve seen
many times, severe storms often work the atmosphere over which
limits subsequent development, and that may be the case late
tonight.
- Freezing rain north tonight
Surface temperatures around 30 tonight near the US-10 corridor
will set the stage for some freezing rain development. A winter
weather advisory remains in effect for Lake, Osceola, and Clare
counties tonight. Ice accumulations of a tenth or two are
expected.
- Wind/snow Friday
A strengthening clipper will move southeast across Lower MI. This
clipper will bring a mix of rain and snow, and more significantly,
wind. ECMWF ensembles show winds gusting to 55-60 mph Friday as
the clipper strengthens to the north. A wind advisory and/or high
wind warning may be needed.
- Colder next week
Another strong low is seen in the models Sunday dropping freezing
rain and snow. The GFS continues to show a lot of snow, while the
ECMWF ensembles only average around an inch. However, there were a
couple of ensemble members that produced around a foot. We`ll
continue to keep an eye on this system. A return to winter-like
temperatures is also expected with highs in the mid to upper 20s
next Monday and Tuesday.
&&
.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 142 AM EDT Wed Mar 11 2026
Thunderstorms will be moving out this morning but low clouds will
remain with areas of IFR continuing into the afternoon. Rain and
snow showers in the afternoon could also bring patchy IFR,
especially in western Lower Michigan. Winds will go from east to
northwest on Wednesday and gust over 20 knots at times.
&&
.HYDROLOGY...
Issued at 234 PM EDT Tue Mar 10 2026
More thunderstorms and heavy rain are on track to move through
Southern Lower Michigan this evening and overnight. The hydro threat
is two-fold over the next few days. First will be the risk for
impacts - primarily to travelers - as roads and poor drainage areas
likely fill up with standing water during the storms. This is most
likely in urban areas, especially those (like Kalamazoo, Jackson,
and Lansing) that received heavy rain a few days ago. 1-1.5 inches
of rain a few days ago was enough to cause some street flooding, and
we are expecting similar amounts tonight.
As this water makes its way into the river systems, it is likely we
will see a few spots experience some minor flooding over the coming
days. The water is still high from last weekend`s rain, so the most
vulnerable and likely to cross above flood stage will be some of our
typical trouble spots for river flooding, which are mostly along
the smaller rivers/tributaries that flow into the Grand River.
However, depending on exact rain amounts, the Grand River itself
in Comstock Park could eventually see some flooding by late this
week as the water makes its way through.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory until 2 PM EDT this afternoon for
MIZ038>040.
Flood Watch until 11 AM EDT this morning for MIZ050>052-056>059-
064>067-071>074.
MARINE...None.
&&
$$
DISCUSSION...04
AVIATION...Ostuno
HYDROLOGY...AMD
NWS GRR Office Area Forecast Discussion
