North Muskegon Michigan Weather Forecast Discussion

381
FXUS63 KGRR 111902 CCA
AFDGRR
Area Forecast Discussion...CORRECTED
National Weather Service Grand Rapids MI
302 PM EDT Sat Oct 11 2025
.KEY MESSAGES...
- Fog Possible Tonight
- Mostly Dry Week Ahead with Slight Rain Chances
&&
.DISCUSSION...
Issued at 300 PM EDT Sat Oct 11 2025
- Fog Possible Tonight
High pressure ridge quickly following the departing low over the
eastern Great Lakes tonight will act to evaporate the
stratocumulus later this evening. A period of mostly clear skies
and light east winds tonight will favor surface temperatures
cooling into the lower 40s. This is expected to be at least a few
degrees below the crossover temperature set this afternoon as dew
points are in the mid to upper 40s. The RAP/HRRR and HRW-ARW both
show near-surface saturation and specific humidity increasing
with height. So will go more aggressive with patchy/areas of fog
in Mid Michigan tonight, and it may spread into parts of West
Michigan too. Possible mitigating factors may be a surface wind
around 5 knots in spots with 15 knot winds several hundred feet
aloft.
Morning low clouds on Sunday will trend more partly to mostly
sunny by afternoon, with high temperatures climbing a few degrees
above normal into the upper 60s.
- Mostly Dry Week Ahead with Slight Rain Chances
Not a lot of significant weather to talk about in the coming
week. Temperatures start off the week seasonably mild then cool
down for Wed-Thu. The most probable night for a frost/freeze would
be Wed night. Then a rebound in temperatures to end the week on
the milder side is favored by most (but not all) ensemble members.
Fair/Good ensemble agreement in the pattern across the CONUS this
week, featuring a trough/low over the western US and a tendency
for ridging over the Midwest. As such, Michigan`s weather will be
influenced mostly by sprawling regional high pressure systems,
which will once again keep us mostly dry with relatively light
winds.
A cold front connected to a Manitoba-to-Hudson-Bay low on Monday
will wash out as it approaches west Michigan, giving the Ludington
area just the slightest chance of showers Mon aftn/eve. There is
another slight chance for showers Tue night, but most ensemble
solutions disfavor anything significant, as the elevated warm air
advection fueling the showers should be well to our west, and we
will more likely be in the midst of northerly flow and cold-air
advection in the low levels given the position of the high.
Chances for showers and even some thunderstorms do go up for Fri
into the weekend as the synoptic pattern breaks down, with a
greater tendency for troughing across the Plains and Midwest. The
solution envelope spreads out a bit by this point, making the day
by day details more murky, but the general signal from ensemble
systems is for better odds of more true-to-the-season low pressure
systems in the Midwest with periods of rainier and windier
conditions.
&&
.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 150 PM EDT Sat Oct 11 2025
Key changes:
- extended duration of MVFR ceilings this afternoon into tonight
- introduced IFR visibility restrictions Sunday morning for most
  terminals
Current satellite shows extensive stratocumulus across Lower MI
that is roughly 2000 feet deep per pilot reports. The associated
inversion layer appears well established given the appearance of
several internal gravity waves within the cloud layer visible on
GOES visible satellite. Given this and the fact we are well into
Fall, it`s unlikely ceilings will erode until around sunset at
best and even that is somewhat in question.
Running under the assumption that we lose ceilings at some point
tonight, we will be in a favorable setup for fog development at
all terminals with the probable exception of MKG. Minimum
temperatures are expected to be substantially below current
observed dewpoints. Moreover, we expect a reinforcement of near
surface moisture with weak northeast flow off Lake Huron and
Saginaw Bay. The only uncertainty is how strong winds will be
overnight. Given the close proximity of the surface low, expect
decoupling of winds which will be favorable for fog formation.
&&
.MARINE...
Issued at 300 PM EDT Sat Oct 11 2025
Winds and waves are expected to remain below hazardous levels
through Monday. Tuesday looks to feature long fetch, moderate
strength northerly flow over Lake Michigan with an associated
spread of probable Small Craft Advisory level waves from north to
south that last for perhaps a day or two. Details at this time
range are far from certain, however.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...CAS
AVIATION...TJT
MARINE...TJT

NWS grr Office Area Forecast Discussion