832
FXUS63 KGRR 281112
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
712 AM EDT Mon Apr 28 2025

.KEY MESSAGES...

- Elevated fire danger Today

- Storms Possible Tonight into Tomorrow

- Showers and storms Possible through the latter half of the week

&&

.DISCUSSION...
Issued at 330 AM EDT Mon Apr 28 2025

- Elevated fire danger Today

Bottom Line Up Front: Highs in the mid to upper 70s, low RH values
and wind gusts upwards of 25 mph will bring an elevated fire
danger to Lower Michigan Today.

High pressure will build over the region today with clear skies and
warm air advection. The clear skies along with that warm air
advection will bring temps into the mid to upper 70s this
afternoon. As far as Dew points, there is some question with some
models dropping DP`s into the 30s. The overall CAM consensus is
that Dewpoints will be in the 40s along and west of US 131 with
Dew points in the upper 30s east of US 131. Looking at soundings,
there is some dry air aloft, approx 3-4kft, currently, the region
should mix to about 1.5-2KFT. That would drop dew points lower
potentially dropping RH`s into the mid to low 20s. As it stands
have RH`s in the upper 20s to low 30s. As stated above, winds will
mix down to the SFC cut gusts upwards of 25 to 30 mph will be
possible this afternoon. Given these conditions, an elevated fire
danger is a concern, particularly vulnerable will be the Manistee
National Forest area. Will hold off on any headlines for now but
will continue to coordinate with Land Management Agencies.

- Storms Possible Tonight into Tomorrow

Latest 00Z CAMS continue to downplay convection tonight into
tomorrow. The best CAPE will be north and south of southern lower
Michigan, bifurcating the region. The ARW seems to have the best
handle on latest convection through the west. There continues to
be a strong low level jet moving over the region tonight. If
convection is able to fire, this jet and shear will be able to
sustain storms overnight. However, low levels are very dry, and
given the system will moving in late, the convection will be
elevated with a stable later near the SFC. Given those conditions
storms will have difficulty forming. Best chance for storms will
be through the NW region, primarily north of Muskegon. Best time
of convection will be late tonight, early Tuesday morning as the
front moves through. Given the change, have lowered POPS through
much of the region to focus on NW. There remains some timing
concerns as the front moves east so have kept higher POPS near
Jackson to account for afternoon convection if the cold front
lingers.

- Showers and storms Possible through the latter half of the week

While the upper level forcing for Wednesday evening through
Friday`s system isn`t hugely robust, there remains good moisture
advection along with strong warm air advection. Mid range models
remain fairly consistent so a warm and wet pattern looks to be in
store. The precip on Thursday will be focused due to a shortwave
and its sfc reflection as it tracks northeast along the frontal
boundary south of MI. Some stronger storms late Thursday are
possible if the low shifts northward. As the sfc low moves to the
east, the region should receive more precipitation on the
backside of the low, especially from a secondary front from the
passage of an upper level trough on Friday. Cooler air will then
filter in next weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 712 AM EDT Mon Apr 28 2025

Gusty southerly winds around 25 knots this afternoon are expected
with high clouds streaming in overhead. Low level wind shear
develops this evening as the low level jet moves overhead and
continues into Tuesday morning. There is lower confidence for
thunderstorms to impact the area overnight, but chances are high
enough to include Prob30s in the TAFs. If thunderstorms move in
they could be severe with gusty winds and hail being the primary
concern.

&&

.MARINE...
Issued at 340 AM EDT Mon Apr 28 2025

Increasing southerly flow Monday on the back side of a departing
sfc high leads to hazardous winds and waves developing; initially
north of Grand Haven Monday morning then over the rest of the
nearshore by Monday evening. Latest guidance shows some brief
periods of gales late Monday, early Tuesday. However, they are low
end and short lived. Will keep an eye out but an upgrade may be
needed.

Hazardous winds and waves will continue into Monday night and
Tuesday with a cold frontal passage bringing the threat for a few
strong to severe storms and a wind shift.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 8 PM EDT
     Tuesday for LMZ844>846.
     Small Craft Advisory until 8 PM EDT Tuesday for LMZ847>849.

&&

$$

DISCUSSION...Ceru
AVIATION...RAH
MARINE...Ceru

NWS GRR Office Area Forecast Discussion