583
FXUS63 KGRR 230143
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
943 PM EDT Sun Sep 22 2024

.KEY MESSAGES...

- Rain moves out tonight

- Rain chances Tuesday into Wednesday

- Break in precip late work week, wet into next week

&&

.UPDATE...
Issued at 940 PM EDT Sun Sep 22 2024

We will continue the theme of decreasing POPs for the remainder of
the night. Radar, observational and model trends support this
scenario. With the north to northeast flow increasing considerably
over the lakeshore the past few hours, waves have built quickly.
Ludington was reporting wave heights up to around 7 feet. We will
therefore maintain the hazardous conditions for the nearshore
waters and lakeshore zones for small craft and swimmers.

&&

.DISCUSSION...
Issued at 337 PM EDT Sun Sep 22 2024

- Rain moves out tonight

Low pressure is currently centered just southwest of GRR
according to surface obs and radar. The low is moving east and
will take the steadier rain with it the next few hours. The chance
for showers will linger through the evening until a secondary
cold front with a push of drier air moves through overnight.

Astronomically speaking, summer ended this morning but it also
looks to have ended meteorologically with temperatures closer to
long term averages the next couple days. That means lows in the
upper 40s to lower 50s and highs in the lower 70s.

- Rain chances through Wednesday

A building ridge over the east coast will allow a trough situated
over the central Plains to deepen. This pattern will then set up
for a shortwave to swing through the region Tuesday into
Wednesday. PWATS of 1 to 1.5 inches should aid the mid level low
to bring more precipitation to the region Tuesday. As the trough
swings to the northeast precipitation will fade Tuesday night into
early Wednesday.

- Break in precip late work week, wet into next week

While there continues to be some differences in the mid to long
range models the trends continue to show agreement on position and
passage of the large 500mb trough over the central United states
Thursday through the weekend. The consensus is that a positively
tilted ridge of high pressure will build over the Great lakes
bringing more warm and dry weather over Michigan, though
temperatures should remain in the upper 70s, which is still around
10 degrees above normal. The before mentioned low that will be
meandering through the central Plains this week is progged to make
its way to the northwest which could bring the region showers
early next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 615 PM EDT Sun Sep 22 2024

Primarily MVFR/IFR conditions will persist this evening into the
overnight period due to low cigs and lingering evening showers
and patchy fog. MVFR/IFR conditions will likely linger at most of
the terminals overnight into Monday morning before gradually
improving to VFR in the afternoon as low clouds finally move out.
Winds will become northerly at all the terminals at around 5 to
10 kts overnight. Winds will become NE at 5-10 kts Monday.

&&

.MARINE...
Issued at 337 PM EDT Sun Sep 22 2024

No changes to the SCA. Winds and waves will decrease later Monday
but could spike up again by late Tuesday.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through Monday morning for MIZ037-043-
     050-056-064-071.
MARINE...Small Craft Advisory until 11 AM EDT Monday for LMZ844>849.

&&

$$

UPDATE...MJS
DISCUSSION...Ostuno/Ceru
AVIATION...Laurens
MARINE...Ostuno