733
FXUS63 KGRR 221835
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
235 PM EDT Sun Mar 22 2026
.KEY MESSAGES...
- Mostly dry through Wednesday with moderating temperatures
- Chance of rain on Thursday
- Drying out for Friday and beyond with warming temperatures
&&
.DISCUSSION...
Issued at 235 PM EDT Sun Mar 22 2026
- Mostly dry through Wednesday with moderating temperatures
We are seeing an uptick in radar returns this afternoon as expected,
with some light rain reaching the ground at some isolated locations.
This scenario is a bit disjointed as the sfc cold front moved
through earlier and is over Indiana and Ohio as of 18z. There is
just enough moisture left in the column for some forcing via a short
wave and some right rear quad upper jet dynamics moving in to act
on. Many locations along and south of I-96 will some some rain, but
it will be quite light with less than a tenth of an inch expected.
This should clear the forecast area to the south just after 00z this
evening as much drier air moves in behind the wave and jet streak.
There may be a few light flurries late tonight and Monday morning as
the main short wave passes through the area. 850 mb temps drop to
the lower negative teens, which would be just enough instability
over the lake for some lake effect. Flurries will be about it though
with a flow from the NNE being offshore, and inversion heights being
quite low with ridging building in quickly.
After the wave moves by early Monday, we will be rather quiet here
through Wednesday. The northern and southern branches of the jet
will be well north and south of the area respectively. In addition,
the column will be very dry as PWATS will be around 0.20 inches
starting Monday afternoon. They will inch up a tiny amount through
Wednesday, but will not be enough along with little to no forcing to
act on it through Tuesday. A weak front Wednesday dropping through
will bring a small chance of some rain. Temperatures will moderate
after Monday as 850 mb temps increase from around -11C Monday to +5C
on Wednesday.
- Chance of rain on Thursday
The best chance of rain looks to come late Thursday and Thursday
night with another weak system passing through in the northern
stream well north of the area. The difference with this system that
brings a better chance of rain is that the flow from the Gulf is
better established ahead of this system, and saturates the column
better.
- Drying out for Friday and beyond with warming temperatures
The pattern for the end of the week looks like it will be a similar
repeat of the pattern of the next few days.
That repeat pattern starts with the system late Thursday and
Thursday night moving south of the area. In the wake of the frontal
passage, we will see quite a dry air mass advect in on the front
side of a Canadian ridge building in. The flow around this ridge
will also tap some much cooler weather beginning on Friday as we see
850 mb temperatures drop to around -11C once again.
We will see the flow gradually come around from the south by later
next weekend as the ridge moves by. Surface temperatures will
recover once again into the 50s by Sunday as 850 mb temperature
increase to +2C or so.
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 215 PM EDT Sun Mar 22 2026
N/NE winds are bringing cooler air into West Michigan this
afternoon behind W-E frontal boundary currently located over
northern Indiana/Ohio. This cool flow is also bringing BKN-OVC
MVFR ceilings into the area from the north /generally 1.5 to 2.5
kft/. These clouds have reached MKG/GRR/LAN, and will likely
continue to spread southward into AZO/BTL/JXN area by late
afternoon. Weak frontal support aloft is also generating a few
light showers, which may linger through 00-01Z, particularly over
far southern areas.
Northerly flow and MVFR ceiling are expected to persist overnight.
Then, as high pressure currently over the Dakotas advances east
into the western Great Lakes on Monday, expect these clouds to
become SCT by late morning /aided by March sun angle/. Expect a
brink N/NW wind Monday, with gusts nearing 20kt.
&&
.MARINE...
Issued at 235 PM EDT Sun Mar 22 2026
We are going to be extending the current Small Craft Advisory out a
bit in time so that the northern half of the nearshore expires at
18z Monday, and the southern half expires at 00z Tuesday.
These changes are based on their forecast wave heights lingering
longer before diminishing. Winds are forecast to remain up through
Monday morning, before everything else.
Once this current SCA ends on Monday, we are looking at sub-SCA
conditions likely to hold until late Tuesday night or Wednesday.
Winds will ramp up then behind a weak front that passes through, and
brings a decent offshore flow over the area.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 8 PM EDT Monday for LMZ844>846.
Small Craft Advisory until 2 PM EDT Monday for LMZ847>849.
&&
$$
DISCUSSION...NJJ
AVIATION...Smith
MARINE...NJJ
NWS GRR Office Area Forecast Discussion