FXUS63 KGRR 210556

AFDGRR



Area Forecast Discussion

National Weather Service Grand Rapids MI

156 AM EDT Sun Jun 21 2026



.KEY MESSAGES...



- Rain Chances Tonight and Wednesday



&&



.DISCUSSION...

Issued at 155 AM EDT Sun Jun 21 2026



- Rain Chances Tonight and Wednesday



The Great Lakes region will continue to be in a fast quasi-zonal 

flow regime on the southern edge of persistent upper troughing 

across eastern Canada this week. This will keep temperatures 

below normal with fast-moving shortwave troughs bringing the 

chance for rain tonight and again on Wednesday.



The best chance for rain tonight will be across southern Lower 

Michigan as low pressure tracks across northern Indiana and Ohio.

An area of mid-level frontogenetic forcing brings steady rain 

across the I-94 corridor with QPF close to an inch by the time 

the rain ends on Monday. There will be a sharp gradient to the 

north with around a quarter inch along I-96 and less than a tenth 

of an inch north of there.



A weaker low follows for Wednesday in northwest flow and precip

amounts will probably be less than a quarter inch.



&&



.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...

Issued at 156 AM EDT Sun Jun 21 2026



Except for the possibility of shallow ground fog before sunrise,

VFR conditions are expected this morning before clouds and rain

move in from the southwest this evening. MVFR conditions in

showers and lowering ceilings are expected this evening and 

patchy IFR is possible, especially across southern Lower Michigan.



&&



.MARINE...

Issued at 156 AM EDT Sun Jun 21 2026



Fairly tranquil conditions today then winds and waves will 

increase tonight as low pressure passes just south of Lake 

Michigan. A SCA will be needed for Monday.



&&



.GRR WATCHES/WARNINGS/ADVISORIES...

MI...None.

MARINE...None.



&&



$$



DISCUSSION...

AVIATION...Ostuno

MARINE...Ostuno