Portage, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

844
FXUS63 KGRR 071145
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
745 AM EDT Mon Jul 7 2025

.KEY MESSAGES...

- Clearing out with less heat and humidity today

- Almost daily chances for showers or storms Tuesday night into
  the weekend

&&

.DISCUSSION...
Issued at 408 AM EDT Mon Jul 7 2025

- Clearing out with less heat and humidity today

Early morning low stratus and drizzly rain showers will gradually
lift and clear out from northwest to southeast during the day.
High temperatures will be closer to seasonal normals today, in the
lower 80s in most spots, with lower dew points in the upper 50s
to mid 60s. More information on the potential late-day increasing
swim risk (beach hazards) in the Marine section below.

- Almost daily chances for showers or storms Tuesday night into
  the weekend

Quasi-zonal but relatively weak 500 mb flow with a few shortwaves
rippling through, plus gradually increasing heat and moisture in
the the low levels, will support frequent chances for showers or
thunderstorms popping up between Tuesday night and the weekend.
Per ensembles, chances are relatively higher between Tuesday night
and Wednesday afternoon, then Friday night through Saturday
evening in association with the more pronounced upper-level
shortwave troughs.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 745 AM EDT Mon Jul 7 2025

Feels more like autumn out there this morning, with variable IFR
to MVFR ceilings and visibility plus some areas of drizzle.
Conditions should gradually improve as cloud bases lift and
scatter. Not very good confidence in getting the change in flight
categories down to the exact hour as models handle the mixing and
drying of the lower atmosphere quite differently. But solar
heating doesn`t get much stronger during the year than now, so
there is optimism for VFR by afternoon. Generally, the trend to
VFR will occur sooner northwest and later southeast. Winds will
mostly be from the north, becoming more variable this evening and
overnight.

&&

.MARINE...
Issued at 408 AM EDT Mon Jul 7 2025

Waves in the nearshore are coming down following yesterday`s
evening increase in winds and waves. Winds from the north becoming
northwest and increasing this afternoon will trend conditions
toward a late-day moderate to high swim risk (beach hazard)
for Muskegon county and south. Combination of post-cold-frontal
high pressure nudging into the U.P. and the afternoon development
of the lake breeze circulation will intensify winds toward 18-20
knots in the nearshore off Muskegon, Grand Haven, and Holland, per
the HREF mean. This is a scenario that often yields a moderate
becoming high swim risk late in the day for Muskegon State Park,
Holland State Park, and South Haven North Beach.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from 4 PM EDT this afternoon through
     this evening for MIZ050-056-064-071.
MARINE...Small Craft Advisory from 4 PM this afternoon to 10 PM EDT this
     evening for LMZ844>847.

&&

$$

DISCUSSION...CAS
AVIATION...CAS
MARINE...CAS