626
FXUS63 KGRR 231742
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
142 PM EDT Wed Sep 23 2026
.KEY MESSAGES...
- Dry and warmer through Tuesday, then rain.
&&
.DISCUSSION...
Issued at 142 PM EDT Wed Sep 23 2026
- Dry and warmer through Tuesday, then rain.
A large area of high pressure was noted over western Quebec this
afternoon. Skies were clear to the north and west of the high.
However, IR loop revealed cloudy skies to the south of the ridge
axis where low pressure was located near the Ohio Valley. The
northern edge of the cloud shield has encroached upon the southern
row of counties. While much of the cumulus will dissipate with
sunset, we`ll likely see some mid and high clouds overhead tonight
and tomorrow...most numerous from I-96 southward.
The medium range models are in good agreement through the weekend
and confidence is high we`ll have dry weather with a slight
warming trend through Monday. In fact, all of the ECMWF ensemble
members show no precipitation until next Tuesday. Thus,
comfortable early fall weather is upon us with highs in the upper
60s to lower 70s and dewpoints in the 40s and 50s.
The blocking upper ridge will begin to break down early next week
as a northern stream short wave phases with a southern stream
wave. This combination will carve out a deeper upper trough over
the Rockies which will push a cold front toward the Great Lakes
early next week. We`ll see south flow pull some moisture northward
resulting in rain showers when the cold front moves across Lake MI
Tuesday night and Wednesday. This far out, the models aren`t
showing much instability so we`ll go with mostly rain at this
point Tuesday night and Wednesday.
&&
.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 127 PM EDT Wed Sep 23 2026
Scattered to broken cumulus clouds have developed for this
afternoon, generally above 3,000 feet, but MVFR may persist at AZO
and BTL for a couple more hours. As evening sets in, clouds should
go scattered at or above 5,000 feet. From 01 until 06 Z, there
may be about 20 knots of LLWS from 1,500 feet to ground as winds
at 1,500 feet become approximately 09028KT.
&&
.MARINE...
Issued at 142 PM EDT Wed Sep 23 2026
A persistent high over western Quebec will supply the region with
an east wind through Saturday. The off shore wind combined with a
weak pressure gradient will result in waves less than 2
feet...highest near the 5 mile mark off shore.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...04
AVIATION...CAS
MARINE...04
NWS GRR Office Area Forecast Discussion
