864
FXUS63 KGRR 231824
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
224 PM EDT Thu Apr 23 2026
.KEY MESSAGES...
- Slight chance of showers/storms this afternoon/evening, better
chance Friday
- Chance of storms Monday
- Cooler next week
&&
.DISCUSSION...
Issued at 224 PM EDT Thu Apr 23 2026
- Slight chance of showers/storms this afternoon/evening, better
chance Friday
There`s been a surge of moisture today across the cwa behind a
warm front and surface dewpoints are near 60 in many locations.
Additionally, a weak short wave is riding over the upper ridge
across the state. As such, some of the CAMs are pointing toward
some isolated convection developing later this afternoon after 3-4
pm, mainly southeast of Grand Rapids. SBCAPE is progd to increase
to 1000-1500 j/kg this afternoon. Any storms that develop,
however, are expected to be sub-severe as bulk shear is progd to
remain below 20 knots which will limit storm organization.
The next chance of storms will arrive Friday when a cold front
moves through the region. RRFS-EMC progs point toward decaying
showers/storms moving across the cwa Friday morning with a
potential refiring Friday afternoon. The clouds and lingering
precipitation Friday morning may keep a lid on instability through
much of the cwa Friday. CAMs show this with storms redeveloping
east of Lansing Friday afternoon where morning convection didn`t
have as much of an influence on atmospheric instability.
Nevertheless, CAMs also show some redevelopment along the cold
front after 20z east of US-131, so there`s likely to be some
recovery after the morning precipitation with a likelihood of
strong storms southeast of the cwa.
- Chance of storms Monday
After a weekend featuring partly to mostly sunny skies, highs in
the mid 60s and dewpoints in the 40s, the next system will arrive
Monday night and Tuesday. The next cold front will move in Monday
night. SBCAPE is progd near 500 j/kg early Tuesday morning. Thus
storms are possible, but the late night arrival will diminish
chances for severe storms.
- Cooler next week
Once the cold front moves through Tuesday, h8 temperatures will
fall from 12c Tuesday to 0c Wednesday morning. That will set the
stage for cooler weather mid to late week. We`ll see highs in the
mid 50s Wednesday and Thursday. Surface high pressure will build
in from the northwest, but zonal flow aloft will likely supply
some high clouds.
&&
.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 205 PM EDT Thu Apr 23 2026
As previously noted, a small risk for isolated showers exists between
roughly 20-22Z over eastern areas /specifically LAN and JXN/. Latest
HRRR output still suggests possibility, thought perhaps east/north of
LAN/JXN. Any pop up showers will be the result of daytime
heating, boundary layer moisture advection, and remnants of weak
warm front lifting northeast. Otherwise, expect SCT-BKN CU around
4kft /VFR/ this afternoon with S/SW breezes near 10 kt.
Clouds will increase tonight as cold front approaches from the west,
with BKN clouds 5-7kft developing after 08Z. The 30-40% risk for
showers, and perhaps a thunderstorm, will arrive after 09-10Z and
spread from west to east. Don`t expect any severe storms or
widespread flight restrictions.
&&
.MARINE...
Issued at 224 PM EDT Thu Apr 23 2026
High pressure overhead is keeping wind and waves below advisory
criteria. South winds will increase Friday ahead of the next cold
front and waves will build to 2 to 4 feet north of Grand Haven.
It`s not out of the question that a small craft advisory may be
needed Friday, but confidence is`t high enough to issue yet.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...04
AVIATION...Smith
MARINE...04
NWS GRR Office Area Forecast Discussion
