183
FXUS63 KGRR 251845
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
245 PM EDT Sat Apr 25 2026
.KEY MESSAGES...
- Dry Until Chances for Rain and Thunderstorms Monday Night
- Mainly Dry and Cooler for the Remainder of Next Week
&&
.DISCUSSION...
Issued at 245 PM EDT Sat Apr 25 2026
- Dry Until Chances for Rain and Thunderstorms Monday Night
Upper level ridging and high pressure will remain in place through
the weekend resulting in dry conditions. Southwest flow moves in
Monday ahead of the shortwave trough. Upper level divergence,
positive vorticity advection, and the low level jet line up for
late Monday afternoon into Monday night. There will be plenty of
shear in place with the 50 knot low level jet with winds up to 70
knots in the mid levels. The question on our severe potential will
largely be up to how much instability is available. NBM mean
SBCAPE has instability ranging from a few hundred to a couple
hundred J/kg toward US-10 to near 1000 J/kg toward the I-94
corridor. If these instability values remain the same or increase,
the SPC outlook would likely trend upward as we get closer. After
the initial round of thunderstorms Monday night, some lingering
rain showers are possible into Tuesday morning.
- Mainly Dry and Cooler for the Remainder of Next Week
Overall we`ll remain under the upper level trough with the
potential for a couple shortwave troughs to move through. These
troughs could bring some chances (20 percent) for light showers,
but moisture is limited with precipitable water values remaining
low. Highs through the week are expected to be in the 50s with
lows in the 30s bringing the risk for a widespread frost.
&&
.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 111 PM EDT Sat Apr 25 2026
Skies have already cleared at MKG/GRR/AZO with BTL likely to
follow in the next 1-2 hours as the cloud edge slowly works east.
LAN and JXN will be MVFR much of the rest of the day, potentially
not breaking into VFR at all until mid day Sunday. MVFR cigs
redevelop/persist overnight at all terminals except GRR/MKG before
scattering out Sunday as temps warm and low-level moisture
decreases.
&&
.MARINE...
Issued at 245 PM EDT Sat Apr 25 2026
Winds are overachieving this afternoon and with an expected trend
upward, expect gusts to be in the 25 to 30 knot range until this
evening. With this change have issued a Small Craft Advisory until
8PM. Winds are expected to weaken and turn more easterly tonight
into Sunday with low wave heights.
Monday winds turn to the southwest with a chance for thunderstorms
to move in during the late afternoon and evening. Small craft
advisory conditions are likely for Monday into Tuesday. Winds
should remain below gales due to the cold waters, however storms
could be strong to severe and mix down stronger winds from aloft.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for LMZ844>849.
&&
$$
DISCUSSION...RAH
AVIATION...Thomas
MARINE...RAH
NWS GRR Office Area Forecast Discussion
