849
FXUS63 KGRR 120548
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
148 AM EDT Sun Jul 12 2026
.KEY MESSAGES...
- Hot and Dry Monday through Wednesday
- Rain Chances Return End of Week
&&
.DISCUSSION...
Issued at 148 AM EDT Sun Jul 12 2026
- Hot and Dry Monday through Wednesday
High pressure will build into the region today through Tuesday. A
weak shortwave may bring a stray shower late tonight or Monday
morning north of I-96, otherwise dry conditions are expected
through midweek.
As pressure heights increase so will temperatures. We`ll see high
temperatures in the mid to upper 80s today increasing into the
upper 80s to mid 90s Monday. 925 mb temperatures peak around 28 C
Tuesday resulting in highs in the mid to upper 90s with some
areas in central lower Michigan potentially hitting 100. Wednesday
the upper level ridge begins to weaken overhead resulting in
slightly lower temperatures in the low to mid 90s.
The best chance for heat index values at or above 100 (Heat
Advisory criteria) will be Tuesday. Long range ensemble members
highlight areas east of US-131 with a 30 to 60 percent chance of
heat index values greater than or equal to 100 on Tuesday.
Temperatures are expected to improve overnight with lows in the
60s to around 70.
- Rain Chances Return End of Week
Northwest flow moves in for the second half of the week with lower
pressure heights. Within the northwest flow shortwave troughs will
move through bringing chances for rain and thunderstorms. At this
time confidence is higher in the Thursday night into Friday
timeframe with a 20 to 40 percent chance for showers and
thunderstorms. There is variability in the overall atmospheric
pattern into the following weekend resulting in continue chances
for rain and thunderstorms.
&&
.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 148 AM EDT Sun Jul 12 2026
VFR conditions are expected today with light easterly winds. A
lake breeze is expected to develop this afternoon with winds
shifting to the northwest at MKG around 17Z.
&&
.MARINE...
Issued at 148 AM EDT Sun Jul 12 2026
Offshore winds are expected early today before the lake breeze
develops this afternoon. Winds then become more westerly for
Monday and Tuesday then turn more northwesterly Wednesday. Winds
may briefly approach Small Craft Advisory levels Wednesday
afternoon. Otherwise winds and waves are expected to remain below
Small Craft Advisory and Beach Hazard Statement levels.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...RAH
AVIATION...RAH
MARINE...RAH
NWS GRR Office Area Forecast Discussion