621
FXUS63 KGRR 271146
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
746 AM EDT Fri Sep 27 2024

.KEY MESSAGES...

- Breezy and Mostly Dry Today

- Scattered Showers Saturday through Tuesday

- Dry Wednesday and Thursday

&&

.DISCUSSION...
Issued at 335 AM EDT Fri Sep 27 2024

- Breezy and Mostly Dry Today

The remnants of Helene will travel northwards into western Kentucky
butting up against surface ridging over the northern Great Lakes.
The pressure gradient over Lower Michigan will strengthen in
response, resulting in breezy easterly winds this afternoon and
evening. Strongest winds will be mainly near and south of I-96.
00z HREF ensemble mean gusts push into the 40 mph range this
evening which may result in some isolated power outages. Mostly
dry conditions expected today, then rain chances increase south
of I-96 late in the day as a stalled upper low pivots south of the
region.

- Scattered Showers Saturday through Tuesday

Stubborn/stalled upper low continues to spin south of Michigan through
Monday so considerable clouds and scattered showers persisting,
particularly south and east of GRR. A northern stream trough and
associated cold front digs south into the GrtLks Rgn on Tuesday,
bringing additional shower chances. cigs

- Dry Wednesday and Thursday

A brief midweek cool down occurs behind the Tuesday cold front with
temperatures dropping from highs in the mid 70s to the mid 60s for
Wednesday. Dry weather and better potential for sunshine looks to
prevail on Wed and Thur thanks to a sfc high which follows the cold
front. Somewhat milder temps expected Thursday in the southerly
return flow on the back side of that high.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 746 AM EDT Fri Sep 27 2024

Northeast winds gusting over 25 kts at times this afternoon into
the evening before relaxing somewhat late tonight. VFR continuing
today with high level cloud bases AOA 20K ft. MVFR cigs and
scattered showers arriving from south to north late tonight, with
some IFR also possible after 09Z Sat mainly south of a AZO to LAN
line.

&&

.MARINE...
Issued at 335 AM EDT Fri Sep 27 2024

Easterly winds build this morning and afternoon as the remnants of
Helene push northwards and interact with a strong surface high over
the northern Great Lakes. Winds on the order of 25 to 30 knots are
expected today, peaking during the evening to early overnight hours.
Winds subside by sunrise Saturday. The easterly component of the
wind will keep waves low for the West Michigan lakeshore, but a
choppy 1 to 2 feet look possible for most areas. Marine zones
further south towards Benton Harbor may see waves up to 3 to 4
feet this evening.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 8 AM EDT Saturday for LMZ844>846.

&&

$$

DISCUSSION...Meade/Thielke
AVIATION...Meade
MARINE...Thielke