Portland, Michigan Weather Forecast Discussion

869
FXUS63 KGRR 291745
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
145 PM EDT Mon Sep 29 2025
.KEY MESSAGES...
- Warm and dry conditions will continue this week
&&
.DISCUSSION...
Issued at 320 AM EDT Mon Sep 29 2025
- Warm and dry conditions will continue this week
Shallow Patchy fog will again greet portions of southwest and
central Michigan this morning. The cool overnight lows, coupled
with calm winds will allow for another, albeit weaker, round of
shallow fog. Any fog that forms will lift/dissipate shortly
after sunrise.
Forecast and models remain fairly unchanged. The large upper
ridge will dominate the pattern through the week. Temperatures
will continue their trend into the 80s today and tomorrow. Tuesday
will see a back door cool front swing through the which will
shift the high pressure to the west slightly and bring cooler air,
dropping temperatures back into the 70s Tuesday and Wednesday.
That will be short lived as that front moves east and the high
settles again over the upper midwest. Temps should then climb back
into the 80s through the end of the week and into the weekend.
The ridge should flatten into the weekend.
Next chance for precipitation is potentially next week. However
given model variability timing remains uncertain.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 145 PM EDT Mon Sep 29 2025
VFR is very likely today into tomorrow, with the exception of a
chance of shallow or patchy fog 09 to 12 Z. Models are tending to
show higher humidity air from Lake Huron nudging into MOP, AMN,
LAN, JXN areas late tonight amid light northeast flow, and this is
where the chance of any fog would be relatively higher. Confidence
in IFR occurring is low.
&&
.MARINE...
Issued at 145 PM EDT Mon Sep 29 2025
Light winds and low waves are expected through much of Tuesday.
Wind direction will tend to get tugged northwest this afternoon
and Tue afternoon with the contribution of the daytime lake
breeze, otherwise winds will mostly be from the northeast/east
tonight through Wednesday. Tuesday night, breezier east-northeast
winds 10-20 knots are possible, which will build up larger waves
toward midlake.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Ceru
AVIATION...CAS
MARINE...CAS

NWS GRR Office Area Forecast Discussion