260
FXUS63 KGRR 302301
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
701 PM EDT Sun Jun 30 2024

.KEY MESSAGES...

- Chilly night tonight, warmer Monday with low humidity

- Showers and Isolated Storms Possible Tuesday Into Wednesday

- Warm and Humid Mid to Late Week

&&

.DISCUSSION...
Issued at 235 PM EDT Sun Jun 30 2024

- Chilly night tonight, warmer Monday with low humidity

Lower Michigan is under the influence of cool high pressure,
with upper ridging building to our west and the axis of surface
high pressure about to move overhead this evening. This will allow
winds to go calm, and under clear skies tonight temperatures
should drop like a rock. Monday morning will feel distinctly fall-
like with temperatures in the 40s all the way to the
Michigan/Indiana border. Some of our coldest spots (up along
US-10) could see temperatures drop into the 30s!

Warming 850 temps on Monday will allow temperatures to rebound
5-10 degrees warmer than experienced today, but the humidity will
stay low and sunshine abundant - making for an exceptional start
to the holiday week. A few clouds start to build in late Monday
night as more pronounced warm southerly flow starts to bring
humidity and moisture back into the area.

- Showers and Isolated Storms Possible Tuesday Into Wednesday

Southerly flow and a southwesterly low level jet will combine to bring
gradually increasing moisture Tuesday and Tuesday night out ahead of a
weakening cold front. The system will potentially bring a morning round
of diminishing showers to our north to nw fcst area Tuesday morning.
Another round of showers and perhaps a few storms is expected late Tuesday
night into Wednesday with the approach of the front.

Severe wx is not expected given unfavorable frontal timing and weak
instability. A blend of latest ensemble guidance shows rainfall amounts
on average will be rather light at only around a quarter to half an
inch (or less). Locally higher amounts approaching an inch are possible
mainly over our nw fcst area where mid to upper level dynamics are more
favorable.

- Warm and Humid Mid to Late Week

There will effectively be no real airmass change after passage of the
weakening front with high temps mid to late week still reaching well
into the 80s with min temps mainly in the 60s and rather high humidity.
The next system approaching from the west will bring a chance of
showers and storms Friday.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 659 PM EDT Sun Jun 30 2024

Clear skies and light winds are expected through the period thanks
to high pressure moving over the Great Lakes. An onshore breeze
will likely develop at MKG after 18z.

&&

.MARINE...
Issued at 235 PM EDT Sun Jun 30 2024

North wind gusts 20-30 MPH are coming down this afternoon, with
wave heights soon to follow the trend. Small Craft Advisory and
Beach Hazards continue through around sunset this evening, with
conditions improving a bit earlier in the north around Ludington,
and lingering a bit longer in the far south near South Haven.
Overall the trend will be downward at all locations, though.
Monday will be a fantastic day on the water with light winds and
minimal wave action, though the remnants of some upwelling will
keep water temperatures colder than they`ve been recently.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 10 PM EDT this evening for MIZ037-
     043-050-056-064-071.
MARINE...Small Craft Advisory until 10 PM EDT this evening for LMZ844>849.

&&

$$

DISCUSSION...Laurens/AMD
AVIATION...04
MARINE...AMD