Fowler, Michigan Weather Forecast Discussion

807
FXUS63 KGRR 191715
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
115 PM EDT Fri Sep 19 2025
.KEY MESSAGES...
- Morning Fog For Some
- Periods of Rain and Cooler This Weekend into Next Week
&&
.DISCUSSION...
Issued at 346 AM EDT Fri Sep 19 2025
- Morning Fog For Some
Moisture advection behind the backdoor cold front is working its
way southwest. With this increased moisture and low level cloud
deck visibilities are beginning to fall east of a Battle Creek to
Grand Rapids to Big Rapids line. Some spots are already dropping
below a mile, but it is uncertain how widespread these lower
values will be. Any reduced visibilities should clear within a
couple hours after sunrise. Otherwise dry conditions are expected
today with highs in the low 70s toward Clare and mid 80s around
Kalamazoo.
- Periods of Rain and Cooler This Weekend into Next Week
The upper level low over the Plains will slowly gravitate to the
western Great Lakes Saturday morning. 250mb directional
divergence, 500mb positive vorticity advection, warm air
advection, the low level jet, and warm front Saturday morning and
afternoon may bring some showers and storms to the area with the
best chances along the lakeshore. The better push of lift as the
low continues to shift east arrives Saturday night into Sunday.
We`ll still be under the influence of the upper level trough
Sunday night into Tuesday with rain and thunderstorm chances
continuing through then. Total rainfall amounts in the 25th to
75th percentile during this time range around a quarter of an inch
to just over an inch with the highest amounts along and south of
I-94. The 90th percentile highlights amounts of 1 to 2 inches from
north to south.
After the low clears Tuesday, the synoptic pattern becomes a
little more uncertain. There is a trend toward drier conditions as
we may move into a blocking pattern with the cut off low remaining
to our south. With this trend NBM PoPs have decreased to 20
percent for the remainder of the extended forecast.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 115 PM EDT Fri Sep 19 2025
VFR conditions are ongoing at all terminals and will persist
through the end of the TAF period. Cirrus will increase in
coverage into the overnight hours with a lowering of cloud bases
to 10kft near and after the end of the TAF window. No fog is
expected tonight due to both the cirrus and winds being higher
than the previous nights. Winds will increase into the evening
with gusts to around 20 knots at GRR and MKG overnight. Winds then
diminish to 5-10 knots for the day on Saturday.
&&
.MARINE...
Issued at 346 AM EDT Fri Sep 19 2025
East to southeast offshore winds are expected today an increase
tonight reaching Small Craft Advisory levels. Lighter southeast
winds move in for Saturday with the potential for a few showers
and thunderstorms along the lakeshore. Better chance move in
Saturday night into Sunday. Under the influence of low pressure
chances for rain and storms continue into Tuesday. Waves during
this timeframe remain 2 feet our less.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory from 11 PM this evening to 8 AM EDT
     Saturday for LMZ846>849.
&&
$$
DISCUSSION...RAH
AVIATION...Thomas
MARINE...RAH

NWS GRR Office Area Forecast Discussion