606
FXUS63 KGRR 062353
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
753 PM EDT Fri Jun 6 2025

.KEY MESSAGES...

- Near Normal Temperatures with Some Shower/Storm Chances

- Warming Up Later Next Week

&&

.DISCUSSION...
Issued at 245 PM EDT Fri Jun 6 2025

- Near Normal Temperatures with Some Shower/Storm Chances

Expecting temperatures to be around normal for the time of year
(highs in the mid-upper 70s, lows in the mid 60s)... slightly warmer
on Saturday but with dry/comfortable dew point and humidity, and a
slight cool down for Mon-Tue.

There is about a 30 pct chance of light rain in southern portions of
Lower Michigan Saturday night to Sunday morning as a weak upper-
level shortwave and Ohio valley low pass by. Quickly following will
be a larger upper-level low lumbering in from south-central Canada.
A leading cold front is more likely to touch off scattered showers
or storms Sunday evening into the night. Models suggest modest
instability with CAPE focused mainly in the lower mid-levels but
just enough for lightning potential. A few showers may develop with
daytime heating underneath the low Mon-Tue.

- Warming Up Later Next Week

The pattern shifts toward generally weak southwesterly flow from the
central CONUS to Great Lakes mid-late week. Good confidence in
temperatures climbing into the 80s Thu-Fri with dew points /
humidity also starting to creep up. Ensemble clusters show only
subtle differences in the overall synoptic pattern at this time.
CAPE and QPF among model ensemble members also become more common
starting mainly Friday into the weekend, the upshot being chances
for thunderstorms. Minor upper-level disturbances in this weak flow
regime and relatively weak shear should keep the severe weather
threat subdued with hit-or-miss downpours being more of the
convective mode.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 749 PM EDT Fri Jun 6 2025

MVFR vsbys due to smoke/haze continue at AZO and JXN. While BTL
does have reducing vsbys it is only 6SM. MVFR vsbys at those
three TAF sites are probable through the TAF period as smoke
continues to linger over SW Michigan. Otherwise VFR will continue
to dominate the weather pattern through tomorrow. There is a weak
LLJ that could form over the region between 400FT to 800FT
However, have left LLWS out of the TAF`s as it looks to be at most
25 kts, so below criteria.

&&

.MARINE...
Issued at 245 PM EDT Fri Jun 6 2025

Daytime lake breeze with northwest winds and nighttime land breeze
with east-northeast winds will be the pattern through Saturday
night, with relatively light winds and low wave heights. Southwest
winds 10-15 knots on Sunday should build up waves to 2-3 feet. There
is a chance of swim risk becoming moderate with 2-4 ft waves on
Monday.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Air Quality Alert until midnight EDT tonight for MIZ071>074.
MARINE...None.

&&

$$

DISCUSSION...CAS
AVIATION...Ceru
MARINE...CAS