444
FXUS63 KGRR 011702
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
102 PM EDT Sat Nov 1 2025

.KEY MESSAGES...

- Some Showers Possible Mainly Near/South of I-96 Today

- A Few Showers Early Monday and Then Again Wednesday

- Additional Rain Possible Next Weekend

&&

.DISCUSSION...
Issued at 330 AM EDT Sat Nov 1 2025

- Some Showers Possible Mainly Near/South of I-96 Today

Lake effect rain showers have been ongoing this morning but the
activity has been light. Steadier showers through the morning and
early afternoon hours will likely be confined to near and south
of I-96 and especially across Ottawa and Allegan counties where
HREF LPMM 24 hr QPF is showing 0.25"-0.50" or a bit more possible.
Can`t totally rule out a rumble of thunder with lake induced
MUCAPE values of 100-150 J/kg right along the immediate lakeshore.
Elsewhere, periodic showers are possible with light amounts
expected. This activity may continue into the afternoon hours
before diminishing.

- A Few Showers Early Monday and Then Again Wednesday

Monday will feature some early morning showers as an upper
shortwave trough and trailing surface cold front clips central and
northern Lower MI. Highest POPs are featured north of I-96, but
many areas should see some early morning showers Monday before
rapidly moving out of the region. Breezy conditions Monday are
likely with wind gusts around 30 mph possible.

For Wednesday, another upper shortwave passes through the Great
Lakes with a quick hitting, weak surface low forecast to impact
the state. Again, some morning showers look possible and breezy
conditions during the day similar to Monday could occur.

- Additional Rain Possible Next Weekend

Ensemble and deterministic model guidance favor an active pattern
Friday into the weekend with steadier rain possible, including a
risk for some thunderstorms and gusty synoptic scale winds. ECE
and CMC ensemble mean 500 mb heights/vorticity favor a seasonably
deep upper trough moving through during this timeframe with
surface cyclogenesis possible over the Great Lakes. Depending on
strength, location, and timing of this potential system, a more
widespread rainfall could occur and some MUCAPE is hinted at from
ECE members so not out of the question some thunderstorms could
occur.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 102 PM EDT Sat Nov 1 2025

Cloud bases are chaotic across the area this afternoon.
Conditions will primarily be VFR through the period but the
combination of low-level cu development, showers, and a nearby
low/front are supporting some MVFR to IFR cloud bases. Confidence
is low in location and timing, but brief periods of MVFR and
lower ceilings are possible as a result through today and into
tonight. Winds will be mainly light and variable through tonight
with the low nearby. Winds shift to southerly and increase Sunday,
which also causes lake effect stratocu development to shift north
of the terminals allowing skies to clear somewhat. The
aforementioned showers may also lead to temporary MVFR visbys
through the afternoon. However with the sporadic and chaotic
nature of showers have kept the PROB30s/VCSH in place. There are
some signals for fog development tonight similar to last night.
Probability is too low in restrictions (10-20%) for TAF inclusion
now, but will re- evaluate with the 00z package.

&&

.MARINE...
Issued at 330 AM EDT Sat Nov 1 2025

Gale Watch is being issued from Pentwater to the north for
potential gales Sunday evening into Monday as SW winds strengthen
over the lake ahead of the next system to move through the region.
Wave action could exceed 10 feet into Monday for portions of our
nearshore waters.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Gale Watch from Sunday afternoon through Monday morning for
     LMZ849.

&&

$$

DISCUSSION...Hoving
AVIATION...Thomas
MARINE...Hoving