320
FXUS63 KGRR 180738
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
238 AM EST Tue Nov 18 2025

.KEY MESSAGES...

- Wintry Mix Today

- Chance for Rain Thursday into Friday

&&

.DISCUSSION...
Issued at 238 AM EST Tue Nov 18 2025

- Wintry Mix Today

Our round of wintry weather today is currently expanding from
Wisconsin into southern Lake Michigan and tied to the 700mb
frontogenesis and 500 mb positive vorticity advection. Forecast
remains on track for this to move into southwest Michigan in the
next few hours with South Haven already observing rain.

Our best lift will be through early to mid morning with this area
700 mb frontogenesis. 925mb to 850mb temperatures are currently
around 0C which you can also see reflected on the surface
temperatures. Depending on where you are in this temperature
profile will determine the precipitation type you see. Initially
expecting rain in southwest Michigan with a transition to snow
to the northeast. As the low to mid level temperature profile
adjusts we could see more of a rain/snow/sleet mix. At this time
freezing rain is limited as ground temperatures are still warm,
and with the cloud cover increasing road temperatures have also
increased to around 3 degrees or so warmer than the air
temperature. The better chances are with elevated surfaces like
bridges and overpasses that will be closer to the air
temperature. If we see a good burst of sleet that could also drop
surface temperatures creating slick conditions. Any snow
accumulations are expected to be less than an inch. Overall there
could be some slick spots for the morning commute with the wintry
mix, make sure to give yourself a little extra time this morning.

As we head into the afternoon we could see more of a transition to
rain across much of the area as we lose cloud ice. Showers will
clear during the late afternoon and early evening with dry
conditions expected overnight into Wednesday morning.

- Chance for Rain Thursday into Friday

Temperatures will warm through the week with a return to the 50s
Thursday into Friday. However that will bring a chance for rain
Thursday night through Friday morning. Precipitation amounts will
be determined on low position, but at this time the best QPF
remains north and southward of Lower Michigan. Temperatures will
continue to trend around to just above normal through the end of
the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1219 AM EST Tue Nov 18 2025

A low pressure system moving towards the Southern Great Lakes from
the Plains states tonight will bring lower ceilings and some
winter weather to the TAF sites Tuesday morning. Aviation
conditions will dip to MVFR and IFR as the precipitation moves in
towards morning. Conditions should begin to dip to MVFR around
12z at AZO and the progressively work through the rest of the TAF
sites during the morning. By 16z all TAF sites will have MVFR and
IFR conditions. Precipitation will start off as snow and gradually
mix with and change over to rain and drizzle as we head into the
afternoon. There is a period of time during the morning hours, 13z
to 15z especially where a little freezing rain may mix in, but we
do not feel this will be the dominant precipitation type given
air temperatures warm above freezing by midday and ground
temperatures are above freezing as well from the I-96 corridor TAF
sites southward. The precipitation should come to an end through
the afternoon with lower ceilings persisting past 00z along I-94.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Ceru/RAH
AVIATION...Duke