Portage, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

229
FXUS63 KGRR 260611
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
211 AM EDT Sun Jul 26 2026

.KEY MESSAGES...

- Northwest flow regime with occasional chances for rain but low
  confidence in convective details

&&

.DISCUSSION...
Issued at 211 AM EDT Sun Jul 26 2026

- Northwest flow regime with occasional chances for rain but low
  confidence in convective details

The Great Lakes region remains in between an upper high across
the western CONUS and longwave troughing across the eastern CONUS
with occasional shortwave troughs passing through and bringing
the chance for some much-needed rain.

A weakening shortwave trough moving through early this morning
has yet to initiate any showers, which is not surprising given
limited moisture and lift. Isolated showers are possible through
the afternoon.

Still low confidence in the details of how things play out tonight
through MOnday night in terms of organized convection, but
instability and shear are sufficient for a slow-moving front and
weak midlevel vorticity max to focus convection across Minnesota
and into Wisconsin this afternoon which eventually moves southeast
across Lake Michigan and perhaps western Lower Michigan.

The hi-res convective allowing models take the bulk of the storms
west of our forecast area, but there is a chance an MCS could
impinge on the western or southwest zones late tonight or early
Monday morning. Additional convection is possible across the rest
of the forecast area during Monday and Monday night as the front
pushes south.

The front moves through by Tuesday with fair weather for mid to
late week before the longwave upper trough amplifies with a cold
front bringing another chance of rain by next weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 211 AM EDT Sun Jul 26 2026

VFR conditions expected to continue through this afternoon.
Scattered thunderstorms could bring brief IFR conditions along
with hail and strong wind gusts tonight.

&&

.MARINE...
Issued at 211 AM EDT Sun Jul 26 2026

Today should see a continuation of southwest winds around 10 to 15
knots then thunderstorms could bring strong wind gusts over Lake
Michigan tonight. A cold front moves through Monday night and
north winds increase to near 30 knots with waves building over 4
feet on Tuesday and continuing into Wednesday.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Ostuno
AVIATION...Ostuno
MARINE...Ostuno