708
FXUS63 KGRR 271705
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
105 PM EDT Sat Jun 27 2026
.KEY MESSAGES...
- Extreme heat risk next week
- Chances for showers and storms next week
&&
.DISCUSSION...
Issued at 300 AM EDT Sat Jun 27 2026
- Extreme heat risk next week
Main weather concern continues to be the onset of heat and
humidity after the weekend. After a comfortable weekend...hot
temperatures and humidity build Monday and remain through at
least the end of the week. High temperatures in the mid 90s at
least can be expected with lows likely staying in at least the mid
70s. Heat index values over 100 likely Tuesday through Thursday
at least with potential for 110 plus remaining...especially as you
move east and south across lower Michigan.
The lack of cooling at night and the expected humidity in place
day and night through the week will bring extreme heat hazards to
lower Michigan. Preparations should be made to mitigate the
impacts of extreme heat to people and animals before the heat
arrives.
Heat safety tips and resources can be found by visiting:
weather.gov/heat
Some relief from the extreme heat may occur at the end of the
week...but prolonged summer temperatures in the 80s and maybe 90s
are expected to persist through at least the holiday weekend...if
not through the entire first week of July.
- Chances for showers and storms next week
With this much heat and humidity in place it is not uncommon for
us to see some afternoon/evening isolated storms or more organized
activity as shortwaves move through the Great Lakes region. Best
chance for showers/storms at this point still looks to be late
Sunday night and Monday and again maybe the middle to the end of
the week.
.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 126 AM EDT
Sat Jun 27 2026
Occasional MVFR at KJXN during the first 6 hours of the TAF
period. Otherwise...expect VFR conditions at the terminals into
Saturday night.
&&
.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 105 PM EDT Sat Jun 27 2026
MKG and GRR have seen cigs lift to VFR over the last 1-2 hours.
VFR is expected to continue through the rest of the TAF period.
There is the caveat of a 10-20% chance of MVFR fog overnight
driven by light easterly flow off of Lakes Huron/Erie, with
confidence too low for TAF inclusion. Easterly flow aob 8 knots
is expected with the exception of MKG which will see a northerly
lake breeze this afternoon.
&&
.MARINE...
Issued at 300 AM EDT Sat Jun 27 2026
Some light morning fog may be possible through the weekend.
Lights winds and waves today and again Sunday. Winds look to
increase Monday with potential for hazardous winds and waves
Monday.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Maczko
AVIATION...Thomas
MARINE...Maczko
NWS GRR Office Area Forecast Discussion
