884
FXUS63 KGRR 292313
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
713 PM EDT Mon Jun 29 2026

.KEY MESSAGES...

- Extreme Heat Today Through At Least Thursday

- Chances for Storms Later in the Week

&&

.DISCUSSION...
Issued at 243 PM EDT Mon Jun 29 2026

- Extreme Heat Today Through At Least Thursday

Temperatures climbing into the low to mid 90s with dew points in
the low to mid 70s is expected to bring heat indexes to around 100
to 110 for four days in a row, which is a fairly impressive heat
wave and one with a major heat risk to people acclimated to normal
Michigan weather. Temperatures will naturally be cooler along the
Lake Michigan shore especially north of Holland.

850 mb temperatures 19 to 23 C are expected today through
Thursday as southwesterly flow transports hot air around a 596
dekameter 500 mb high centered over Kentucky. A few locations may
come close to record daily highs, particularly Lansing on Wed and
Thu. More likely will be challenging record warm nighttime lows
Wed morning and Thu morning.

Temperatures by Friday may trend slightly cooler as the ridge
flattens a little and waves of convection have a greater chance of
occurring father south than earlier in the week. 75 percent of
ECE members give highs below 90 on Friday.

- Chances for Storms Later in the Week

Elevated thunderstorms this morning stayed in northern Lower
Michigan and will not be a factor in our weather to the south. A
strong convective cap forming from subsiding air within the ridge
will limit our thunderstorm potential today and likely Tuesday.
Only a few experimental models, including some runs of the RRFS
and some MPAS-based models, develop storms in Nebraska this
evening and bring the resulting atmospheric wave as far south as
west-central Lower, near US-10, by late Tue morning. All of the
models within the HREF are keeping that threat farther north.

As the upper-level ridge flattens slightly later in the week and
successive shortwaves with associated thunderstorms around the "ring
of fire" continue marching through, generally a little more south
with time, the chance of an MCS or two in Southern Lower MI will
increase, particularly between late in the day Thursday and Friday
night, as indicated by most global model ensemble members.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 712 PM EDT Mon Jun 29 2026

Little change expected during the next 24 hours. VFR conditions
expected with gusty SSW winds.

&&

.MARINE...
Issued at 243 PM EDT Mon Jun 29 2026

Small Craft Advisory and Beach Hazards Statement continues
through Tuesday, for areas north of Holland toward
Ludington/Manistee, as south winds will be present. These winds
are expected to be fairly breezy over the land, but over the
water, should be limited by a sharp marine temperature inversion
layer. Air temperatures flowing in from the south are expected to
stay much warmer than the water even through the overnight,
limiting the amount of winds aloft that will mix down to impart
momentum onto the water.

It is quite possible that our advisory busts too high today and
Tuesday, given that at noon today, wind and wave values at the
Port Sheldon, South Midlake, and Central Midlake buoys are
meaningfully lower than the NBM winds and the resulting WW3 model
waves. This matches a similar bust scenario that occurred at a
couple times last summer, with breezy south-southwest winds
occurring at the onset of extreme heat. Nonetheless, at least
moderate swim risk should still be planned for and extra care
taken south of south piers.

&&

.CLIMATE...
Issued at 245 PM EDT Mon Jun 29 2026

Records for June 28 - July 2

Record High Temperatures for June 28
Grand Rapids     97 (1913)
Lansing          96 (1964)
Muskegon         93 (1964)
Kalamazoo       100 (1934)
Battle Creek     99 (1934)
Holland          96 (1906)

Record High Temperatures for June 29
Grand Rapids     99 (1931)
Lansing          98 (1913)
Muskegon         92 (2020)
Kalamazoo        98 (1934)
Battle Creek    100 (1913)
Holland          95 (1921)

Record High Temperatures for July 1
Grand Rapids    101 (1931)
Lansing          97 (1913)
Muskegon         93 (2018)
Kalamazoo       101 (1931)
Battle Creek    100 (1931)
Holland          96 (1949)

Record High Temperatures for July 2
Grand Rapids     97 (1913)
Lansing          98 (1966)
Muskegon         95 (1966)
Kalamazoo       100 (1911)
Battle Creek     98 (1949)
Holland          96 (2012)

Record Warm Low Temperatures for June 28
Grand Rapids     76 (1931)
Lansing          73 (1996)
Muskegon         76 (1931)
Kalamazoo        78 (1901)
Battle Creek     74 (1920)
Holland          76 (1931)

Record Warm Low Temperatures for June 29
Grand Rapids     76 (1931)
Lansing          77 (2018)
Muskegon         78 (1913)
Kalamazoo        76 (2018)
Battle Creek     76 (2018)
Holland          72 (2002)

Record Warm Low Temperatures for July 1
Grand Rapids     78 (1931)
Lansing          74 (1931)
Muskegon         74 (2018)
Kalamazoo        77 (1931)
Battle Creek     74 (1970)
Holland          77 (1934)

Record Warm Low Temperatures for July 2
Grand Rapids     74 (1911)
Lansing          74 (1931)
Muskegon         73 (2002)
Kalamazoo        75 (1931)
Battle Creek     75 (1931)
Holland          72 (2002)

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through Tuesday evening for MIZ037-043-
     050-056.
     Extreme Heat Warning until 8 PM EDT Thursday for MIZ037>040-
     043>046-050>052-056>059-064>067-071>074.
     Air Quality Alert from midnight tonight to midnight EDT Tuesday
     night for MIZ050-056-057-064-071.
MARINE...Small Craft Advisory until 8 PM EDT Tuesday for LMZ846>849.

&&

$$

DISCUSSION...CAS
AVIATION...04
MARINE...CAS
CLIMATE...Thomas