Caledonia, Michigan Weather Forecast Discussion

883
FXUS63 KGRR 140538
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
138 AM EDT Sun Sep 14 2025
.KEY MESSAGES...
- Dry weather through early next week
- Chance of showers/storms late next week
&&
.DISCUSSION...
Issued at 255 PM EDT Sat Sep 13 2025
- Dry weather through early next week
The trough that brought rainfall this morning will continue to move
southward this afternoon with dry air filling in behind it. A
Building high will move over the Midwest and dominate the pattern
through the upcoming week. Models remain in good agreement as the
high will bring fair weather with warm air advection through mid
week.
 The high will remain entrenched over the region with weak flow
through that time frame. With 850mb temps increasing as the week
progresses, temps at 850 mb should build to upwards of +20C by
Wednesday. That will correlate to bringing maximum surface temps
from Sunday through Thursday in the mid to upper 80s, with 90 not
necessarily out of reach on Wednesday. The Warm and dry weather
should linger into Thursday.
- Chance of showers/storms late next week
The high pressure that will dominate the first half of the week
will be ejected by an upper level low as it moves along the
Canadian border and through the region late Thursday into
Saturday.
 There is some disparity in the models but ensembles bring the
front through Friday into Saturday. Some runs move it quicker
depending on the cold air and the strength of the high. Given
those considerations have a broad period of chance Pops.
Currently, there is good mid to low level forcing with that
system. The latest EC shows the presence of an LLJ Friday
afternoon. That correlates with increased CAPE through the
ensembles. So there is the potential for storms along the frontal
boundary Friday into Saturday. Position, timing and strength will
vary as that timeframe marches closer.
&&
.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 138 AM EDT Sun Sep 14 2025
No substantive changes from the 00Z TAF issuance. Nighttime GOES
microphysics RGB product shows a persistent cloud deck extending
north through AZO/BTL and terminating west of GRR. Associated ceilings
range from 5000-6000 ft AGL. This is marginally close enough to
the ground to hamper radiation fog (due to interrupted upwelling
of longwave radiation that is required to produce and sustain
fog). Will continue MVFR visibility restrictions at AZO/BTL to
account for the possibility of this cloud deck dissipating or
being less of a factor.
Farther east, under clear skies, we already are seeing fog
reported at sites in the vicinity of the LAN and JXN terminals,
so the inherited TAFs featuring IFR visibility look on track.
&&
.MARINE...
Issued at 240 PM EDT Sat Sep 13 2025
Prevailing winds will be light from east the next few days, though
the direction may flop around during afternoons as the lake breeze
partially counteracts the prevailing flow. Waves will stay 1 foot or
less.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Ceru
AVIATION...TJT
MARINE...Ostuno

NWS GRR Office Area Forecast Discussion