908
FXUS63 KGRR 091835
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
235 PM EDT Mon Mar 9 2026
.KEY MESSAGES...
- Increasing clouds tonight
- Strong/severe storms Tuesday night, freezing rain north
- Cooler with snow/rain midweek on
&&
.DISCUSSION...
Issued at 235 PM EDT Mon Mar 9 2026
- Increasing clouds tonight
Satellite imagery shows mostly clear skies over southwest Lower,
but changes are looming to the south. Latest visible loop shows an
area of stratus over southern IL/IN moving north. MOS guidance and
RH profiles indicates these low clouds will advect north across
the cwa tonight. Drizzle is possible too given the omega seen in
the cloud layer.
- Strong/severe storms Tuesday night, freezing rain north
Models remain in decent agreement regarding a potential severe
weather event Tuesday night. Somewhat similar to a few days ago, a
warm front will move north in response to strengthening low
pressure over the Missouri Valley. This warm front will be the
focal point to strong to severe storms Tuesday night across the
cwa. Dynamics are fairly strong with bulk shear around 50 kts and
SBCAPE 1500 j/kg along the I-94 corridor. The models are
suggesting that the warm front won`t get much farther than a
Allegan to Lansing line. If that`s the case, then the strongest
storms would be in this surface based environment. RRFS-EMC and
HREF guidance shows the strongest updraft helicity along the I-94
corridor. All modes of severe storms appear possible within the
corridor: tornadoes, large hail and strong winds. North of that
boundary, the storms will be elevated...suggesting that hail
would be the main threat. MUCAPE climbs to around 2500 j/kg along
the I-96/M-57 corridors. SPC has continued the slight risk
along/south of I-96.
Timing wise, guidance points toward storm development commencing
around 00z and continuing overnight.
The storms will move east of the cwa Wednesday morning once the
low moves by and northwest winds advect colder air into the cwa.
Temperatures will be cold enough along the US-10 corridor east of
Baldwin for some freezing rain to develop Tuesday night. Perhaps a
few hundredths of an inch of ice are possible by Wednesday
morning.
- Cooler with snow/rain midweek on
Colder air Wednesday will result in some light snow across the
northern cwa; accumulations will be an inch or less.
A clipper system will move across the region Thursday night and
Friday bringing mixed rain and snow and another system Saturday
night and sunday will be stronger and colder and potentially bring
some freezing rain, snow, and rain to the cwa; winter isn`t done
yet!
Highs will mainly be in the 40s from midweek through the weekend
before falling into the 30s early next week.
&&
.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.
&&
.HYDROLOGY...
Issued at 235 PM EDT Mon Mar 9 2026
Another round of widespread rain is expected Tuesday night through
Wednesday morning across the area. It`s currently looking like the
heaviest rain will fall along the I-94 corridor (1-1.5 inches, with
locally more), with slightly lesser amounts along the I-96 corridor
(0.5-1.0, with locally more), and incrementally less as you go north
from there. With soils still quite wet, and rivers high, we`re
expecting a dual hydro threat from this next storm system. We very
well could end up needing a few flood advisories, especially if
storms track over any urban areas repeatedly. Meanwhile, for the 2nd
half of the week, even 1.0 basin-averaged rain amounts will likely
cause some minor river flooding, especially on some of the smaller
rivers and streams like the Red Cedar at East Lansing, Maple River
at Maple Rapids, and Portage River at Vicksburg. If the higher rain
amounts occur, additional rivers will likely see minor flood
conditions. Now is the time to prepare for renewed rising water
levels, and have a plan to monitor and respond to river
conditions.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...04
AVIATION...Thomas
HYDROLOGY...AMD
NWS GRR Office Area Forecast Discussion
