017
FXUS63 KGRR 221039
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
639 AM EDT Fri May 22 2026
.KEY MESSAGES...
- Rain event on track for late tonight and first half of Saturday
- Showers still possible Sunday
- Mainly dry next week and warmer
&&
.DISCUSSION...
Issued at 254 AM EDT Fri May 22 2026
- Rain event on track for late tonight and first half of Saturday
The main trend over the past couple of days with this system coming
in tonight and first part of Saturday is generally for less rain
amounts overall. This is mainly due to the feed of dry air that we
continue to tap from Eastern Canada that will eat away at the
lighter rain on the edge of the system. The better rain will
definitely be over the SE portion of the state due to the track of
the upper wave and the proximity of the sfc low.
The thunder threat continues to look very weak at best for the SE
corner of the forecast area. Plan views of Lifted Indices at the sfc
and for elevated parcels indicate values are generally all positive
for Michigan, not good for thunder.
The system should pull out quickly Saturday afternoon with the short
wave exiting Lake Huron at 00z Sunday.
- Showers still possible Sunday
The longer wave trough over the Upper Midwest that is helping steer
the short wave from TX will then advance toward and through the area
on Sunday. The embedded waves in this feature, along with the cooler
air aloft will help to fire some showers, and maybe even some
isolated to scattered thunder as we have some negative values of
LI`s at the sfc and elevated for Sunday.
- Mainly dry next week and warmer
Rain chances will diminish significantly for Monday as the long wave
upper trough over the Upper Midwest moves east of the area by
Monday. We will remain under the influence of the nearly zonal jet
through early next week. This pattern is conducive for weak short
waves to pass through. There is likely just enough moisture for a
shower to pop here or there along lake breeze boundaries or other
mesoscale boundaries. The chance of this is about 10-20%, so most of
the area will remain dry.
Yesterday, it was looking that we may dry out for the latter half of
next week as upper ridging builds in from the west. This still looks
to happen, but could could potentially close off. What this means is
that we could end up with a flow aloft from the NE, and see a
backdoor cool front slip through. If this were to happen, it would
temper our warm up a bit next week, and keep temps from warming up
too much. It also would bring much drier air in, and really limit
any rain chances.
&&
.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 639 AM EDT Fri May 22 2026
No changes to the previous thinking. Mid clouds hanging around
this morning will continue in and out through early this
afternoon. Later this afternoon and evening, lower clouds will
develop/move in from the south ahead of the incoming system. They
will initially be VFR with ceilings 4-5k ft. They will then drop
down to MVFR late this evening and overnight. The I-94 corridor
terminals are likely to see the rain first, and conditions go to
IFR.
Winds will become gusty from the NE later this morning, with gusts
up to 30 mph. Winds will then remain up into the evening at many
places.
&&
.MARINE...
Issued at 254 AM EDT Fri May 22 2026
We continue to believe that while winds will be elevated over Lake
Michigan, they will be just a notch too low to hoist an advisory at
this time. Offshore flow and a cool/stable lake is the main reason,
although some wind from better mixing over the warmer land mass
could approach wind thresholds at times.
Once these higher offshore winds diminish on Saturday, we should see
an extended quiet period for the latter half of the holiday weekend
and for the foreseeable future next week.
&&
.FIRE WEATHER...
Issued at 254 AM EDT Fri May 22 2026
As previously mentioned, we are looking at the very least an
elevated fire danger day today with the dry air and gusty winds
expected. The highest danger will be the further north you go,
especially into Northern Lower. Per coordination with the Land
Management agencies, green up has occurred for areas south of U.S.-
10, lowering the threat a bit. The main concern is in the Jackpine
Forests north of U.S.-10 where they are very volatile at this point
in the green up process.
A coordination call will occur with neighboring NWS offices and
State and Federal land management agencies to determine whether to
handle the elevated fire danger with a Red Flag Warning, or just
enhanced messaging based on fuel conditions and expected wind/low RH
combinations.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...NJJ
AVIATION...NJJ
MARINE...NJJ
FIRE WEATHER...NJJ
NWS GRR Office Area Forecast Discussion
