934
FXUS63 KGRR 020754
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
354 AM EDT Thu Apr 2 2026
.KEY MESSAGES...
- Freezing rain expected this morning across Central Lower
- Thunderstorms with severe possible today into tonight
- Another round of storms Friday night into Saturday
&&
.DISCUSSION...
Issued at 354 AM EDT Thu Apr 2 2026
- Freezing rain expected this morning across Central Lower
We have maintained the Winter Weather Advisory as is this morning.
The headlines continue through 10am and noon across interior
Central Lower Michigan. Even though the surge of warm air
advection is strong and temperatures will surge into the 60s today
across portions of the area, it is the dry low levels (evaporative
cooling) that will take place this morning that is the key
component to the forecast. The observations just north of our area
tell the story with Manistee at 22F for a dew point at present,
Cadillac 23F and Houghton Lake 23F. As the precipitation begins
this morning wet bulb affects will drop temperatures allowing
freezing rain to persist for 3-6 hours at locations across
interior Central Lower Michigan. The highest ground will be the
areas that see the most freezing rain and that is across Eastern
Lake, Osceola and Clare counties. Most areas in the advisory have
the potential to see at least trace amounts of icing to around a
tenth of an inch. Our internal procedures are two tenths of an
inch being the max if the freezing rain can persist.
- Thunderstorms with severe possible today into tonight
Thunderstorms will be possible both today along a surging warm
front and this evening into tonight ahead of a cold front.
Instability is the variable that is a bit in question still with
the HREF only showing 500-1000 j/kg of MUCAPE at best today. Still
feel that is a bit underdone given surface dew points pushing to
around 60F ahead of a cold front. Will not be surprised to see
MUCAPE values of 1000-1500 j/kg. Strong wind fields are certainly
in place today with 50-60+ knots noted at 850mb. Feel the clouds
and showers of this morning will temper the instability with the
warm frontal surge today. We will still need to monitor storms
though given we are talking about a warm front and a fairly
dynamic system in the spring. Feel our bigger threat will come
this afternoon and into the evening as storms roll in along and
ahead of the cold front. Given the wind fields and long and fairly
straight hodographs feel wind is our biggest threat from both
today and tonight. All hazards are in play today, but machine
learning systems like nadocast and the day 1 SPC outlook agree
that wind is likely our biggest threat. Cannot rule out some QLCS
spinups associated with lines and bows that will likely occur
later today.
- Another round of storms Friday night into Saturday
The day 3 outlook from SPC has us in General Thunder at this
point, but we will be monitoring trends as the cold front is
still in our CWA in the early to mid afternoon. This is another
dynamic system with strong wind fields in place. Feel another wind
threat is possible especially for areas to the south and east of
GRR in the afternoon. We will have more time to focus on this
system once we get by today`s freezing rain and storms.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 211 AM EDT Thu Apr 2 2026
An active period of aviation weather is expected the next 24
hours, with a warm front lifting into the area today and a cold
front sweeping through tonight. Ceilings will steadily decline
this morning with MVFR conditions moving in at present. IFR and
LIFR weather is expected between 10z and 18z especially with the
warm front in the area. There will be some improvement this
afternoon as we break into the warm sector with MVFR and VFR
conditions developing. Tonight as the cold front moves in
conditions will trend back to MVFR. A round of showers will move
through the area this morning associated with the warm front
between 09z and 18z. Another round of showers and embedded
thunderstorms will sweep in from the west with the cold front
between 22z and 04z.
An east wind of 10 to 20 knots with gusts to 25 knots or so will
veer to the southeast this afternoon. Winds will then veer to the
south late this afternoon and evening ahead of the cold front.
Gusts to around 30 knots can be expected between 18z and 06z.
&&
.MARINE...
Issued at 354 AM EDT Thu Apr 2 2026
Considered upgrading the Small Craft Advisory to a Gale Warning
for tonight, but decided to hold off given this is a warm air
advection wind. Confidence was not high enough to upgrade. We are
expecting SCA conditions today in an off shore flow and the
question arises how high the winds get tonight as they veer to
south and southwest. Potential for some gale gusts is certainly
there, but at this point feel 15-25 knots with gusts to around 30
knots is a better bet over the nearshore waters given the strong
inversion that normally occurs this time of year. Lake wide
average water temperature is running +2C right now and the
overriding air will be in the upper teens C. This is not an
effective mixing regime. That said will not be surprised to see
gale gusts at the ob sites along the lakeshore as the winds
descend off the cold dome of air over the lake. Waves of 4 to 8
feet look likely.
&&
.HYDROLOGY...
Issued at 354 AM EDT Thu Apr 2 2026
River levels across the area this morning are either near normal
levels or even slightly below normal for this time of year. So,
we are starting into a wet period in a fairly good spot. Bottom
line is most river levels are well with in bank. The exception
being Maple Rapids which is near bankfull.
Two separate systems will move through the Great Lakes region,
one today into tonight and another Friday night into Saturday.
Each low pressure system will bring a surge of wind and moisture
out of the south. Precipitable water values with each will surge
to 1.5 inches or so. These values when compared to the SPC
sounding climatology are not only above the daily max for the days
in question, but also above the daily max for almost all days in
the month of April. What this tells us is the warm/moist air masses
that surge in from the south over the next few days will have
abundant moisture for this time of year and they will be
efficient rain producers. Models have been consistent in showing
1-2 inches area wide by Sunday. They also show a maximum of over 2
inches in West Central Lower Michigan for areas along the Pere
Marquette and White Rivers, essentially areas north and west of
GRR. We should be able to absorb this moisture without significant
issues given the current state of the rivers, but where the
heavier totals fall (2+ inches) we will likely see both some short
time scale localized flooding as the rain is falling as well as
some potential for river flooding as we work into the weekend and
early next week. We will be monitoring conditions.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory until 10 AM EDT this morning for MIZ038-
044>046.
Winter Weather Advisory until noon EDT today for MIZ039-040.
MARINE...Small Craft Advisory until 8 AM EDT Friday for LMZ844>849.
&&
$$
DISCUSSION...Duke
AVIATION...Duke
MARINE...Duke
HYDROLOGY...Duke
NWS GRR Office Area Forecast Discussion
