Saint Johns, Michigan Weather Forecast Discussion

955
FXUS63 KGRR 011942
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
342 PM EDT Wed Oct 1 2025
.KEY MESSAGES...
- Dry through the Weekend
- Chance of Rain Early Next Week
&&
.DISCUSSION...
Issued at 342 PM EDT Wed Oct 1 2025
- Dry through the Weekend
Dry easterly flow goes southeast then south into the weekend with
modest moisture return by early next week. Upper ridging slowly
flattens over the next few days but temperatures return to the 80s
as the sfc high moves east and 850 mb temps are again around 15C
Friday through Sunday. A western CONUS trough advances east by
early next week.
- Chance of Rain Early Next Week
As the upper trough advances, a cold front will provide enough low
level convergence for some showers to move in late Monday, but
instability is limited and thunder chances appear to be low. The
front should move through by late Tuesday with surface high
pressure building in for Wednesday. Thursday morning could see
temperatures in the 30s with some frost/freeze conditions.
&&
.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 157 PM EDT Wed Oct 1 2025
VFR is likely with 6-12 knot winds from the east-northeast
becoming more from the southeast tomorrow. About 20 knots of wind
shear between 1,000 feet and ground will be present again tonight
03 to 12 Z, as winds at 1,000 feet should be around 25 knots from
120 degrees.
Similar to last night, moisture below 1,000 feet will flow in off
Lake Erie, and some of the high res models are bringing that
layer very close to saturation and cloud development. However, IFR
late tonight is low confidence given that it did not materialize
last night.
&&
.MARINE...
Issued at 157 PM EDT Wed Oct 1 2025
10 to 20 knot winds from the southeast tonight will build larger
waves away from the nearshore out into the open lake. Winds
turning from the south later in the week will make 2 to 4 footers
more common north of Grand Haven for Friday and Saturday. A small
craft advisory may be needed for Big and Little Sable Points on
Saturday and north of Holland on Sunday.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Ostuno
AVIATION...CAS
MARINE...CAS

NWS GRR Office Area Forecast Discussion