470
FXUS63 KGRR 201030
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
630 AM EDT Sun Apr 20 2025

.KEY MESSAGES...

- Rain later today into Monday then turning windy

&&

.DISCUSSION...
Issued at 330 AM EDT Sun Apr 20 2025

Looks like rain will be moving in from the southwest later this
morning. Dropped or lowered POPs for early this morning given
current radar trends which are in line with model guidance
currently showing warm advection precip moving north today but
affecting primarily the northwestern half of the forecast area.

Some elevated thunderstorms expected overnight but instability
remains limited. Winds are expected to pick up during Monday
afternoon and especially the evening as cold advection gets
underway. Model guidance shows gusts close to 50 mph possible with
40-45 knots in the mixing layer Monday evening.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 630 AM EDT Sun Apr 20 2025

This forecast period will continue to feature mainly VFR
conditions for most of the period, with deteriorating conditions
later in the period.

Clouds will increase, thicken and lower a bit through the
afternoon. Ceilings look like they will drop to around 5k ft agl
by 21z or so. This is when some light rain showers will become
possible. A lack of good low level moisture still at that time
should support mostly VFR still. Showers will remain possible from
21z into the overnight hours, but the best chance with lower
conditions looks to come in after 09z or so. It will also be at
this time that instability will support a thunder threat, so have
begun the thunder threat around 07-08z.

Winds are starting out light this morning. Winds from the east
will start to increase this morning, and especially this
afternoon. Gusts well into the 20-30 knot range are likely.

&&

.MARINE...
Issued at 330 AM EDT Sun Apr 20 2025

Winds and waves will increase tonight and into Monday. A SCA will
be needed for tonight and a Gale Warning will probably be needed
for Monday.

&&

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

&&

$$

DISCUSSION...Ostuno
AVIATION...NJJ
MARINE...Ostuno