910
FXUS63 KGRR 221730
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
130 PM EDT Tue Apr 22 2025

.KEY MESSAGES...

- Scattered Showers Tonight, Chance of Showers Thursday

- Increased Rain Chances and Warming Late Week

&&

.DISCUSSION...
Issued at 236 AM EDT Tue Apr 22 2025

- Scattered Showers Tonight, Chance of Showers Thursday

Conditions will be cry much of the day as surface and upper-level
ridging set up across West Michigan. A warm front is forecast to
lift north today stalling near I94 tonight. Isentropic ascent will
lead to scattered showers, mainly near and south of I94. MUCAPE
values of a few hundred joules could support some isolated thunder
potential. Exact placement and timing of precipitation is limited
due to lack of distinct forcing, and this is reflected in CAM
solutions.

An approaching shortwave may lead to showers across the area
Wednesday Night/Thursday, with the best chance north due to a weak
surface low across Lake Superior. NAM MUCAPE progs show that again
isolated thunder is possible.

- Increased Rain Chances and Warming Late Week

A mid-level wave will drive a surface low through the Mid Mississippi
valley into the Ohio Valley Thursday Night into Friday. This forcing
will lead to increased potential for showers and thunderstorms
across West Michigan. Strong warm air advection will lead to highs
well into the 70s across lower Michigan. Some parts of southern
Michigan will lead to highs making a run towards 80 degrees.
Conditions then dry out for the weekend as surface and upper-level
ridging sets up.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 130 PM EDT Tue Apr 22 2025

Showers and a few storms that were affecting Wisconsin earlier
have dried up quite a bit as they have moved toward Southern Lower
early this afternoon. What is left of these is mainly a cloud deck
around 7-8k ft with maybe a few sprinkles reaching the ground over
Lake Michigan that will move overhead this evening. The northern
terminals along I-96 will likely see the clouds partially clear
out overnight. The southern terminals look to keep the cloud cover
and a few sprinkles overnight. The clouds should then move out of
there in the morning. Another batch of clouds and possible
precipitation will likely come in late Wed, but it will be after
this forecast`s valid period.

&&

.MARINE...
Issued at 236 AM EDT Tue Apr 22 2025

Have allowed the Small Craft Advisory to expire as winds and waves
have fallen below hazardous levels. Weak gradient winds will lead to
benign marine conditions continuing over the next several days.
Periods of showers and isolated storms are possible across the
waters.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Thomas
AVIATION...NJJ
MARINE...Thomas