022
FXUS63 KGRR 261104
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
704 AM EDT Fri Jun 26 2026
.KEY MESSAGES...
- Hot Weather Ahead
- Chances for showers and storms next week
&&
.DISCUSSION...
Issued at 300 AM EDT Fri Jun 26 2026
- Hot Weather Ahead
A weak ridge with zonal flow will dominate the pattern through the
weekend with mostly fair weather through Sunday. The main caveat
will be the strong moisture advection that will move through
northern Indiana late today. While most of Michigan will remain
clear, the I94 corridor and southward could see cloudy skies and
perhaps light rain this evening. The sfc low will shift into Ohio
by early Saturday and will shift any moisture eastward.
High pressure will build over the region over the weekend with
building temperatures that will continue through next week.
Those building temperatures are the main story and concern.
Headlines could be needed as Max Temperatures will go from 5 below
normal yesterday, to potentially 10 to 15 degrees above normal on
Monday. While these could be overstated, the EC and NAEFS
ensembles continue to show temperatures anomalies continue to
increase into next week. A 2.7 std anomaly is persistent through
next week. That is a good indicator that warm air advection will
be persistent and good correlation that high pressure will
dominate the pattern as it settles over the Tennessee/Kentucky
region.
The other issue is the dewpoints that will be advected along with
the warmth. While the heat alone can be troublesome, the advection
of upwards of mid 70s dewpoints will further complicate the heat
threat. While it may be cliche, it`s not the heat, it`s the
humidity. So the heat and humidity will be problematic through
most of next week.
Heat indices at this time are only in the advisory range at this
time, they will need to be watched closely as they could
increase. Another understated issue for the heat is that overnight
lows Monday evening into Friday morning will generally be 70
degrees and above. That will preclude much nighttime relief from
the accumulating heat.
- Chances for showers and storms next week
Though there will be copious amounts of diurnal heat and humidity
the high pressure should stifle most daytime convection. While the
high will persist, there is a an old meteorological term
colloquially known as a "dirty ridge". This is a ridge with short
waves filtering through it that could provide enough instability
to take advantage of any hot and humid air that is present. The
above pattern could allow for chance showers and storms overnight
Sunday into Monday and potentially midweek.
&&
.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 646 AM EDT Fri Jun 26 2026
IFR cigs have developed at MKG and GRR with periods of IFR at JXN
and LAN. Expect periods of IFR to occur through 14Z. MVFR vsbys
have occurred at JXN this morning as well. This is due to low
level moisture pooling overnight. Expect once the inversion lifts,
these restrictions will lift and dissipate. The next concern is
showers potentially affecting the southern TAF sites of AZO, BTL
and JXN. Any restrictions from light rain would be MVFR and
considering there remains some questions whether or not it will
occur have gone with prob30s.
&&
.MARINE...
Issued at 150 AM EDT Fri Jun 26 2026
Periods of morning fog will be possible through the weekend.
However, winds will be light as high pressure build over the
region with fair winds and waves are expected through the weekend.
Next chance for hazardous winds and waves will be Monday due to
increasing southerly flow.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Ceru
AVIATION...Ceru
MARINE...Ceru
NWS GRR Office Area Forecast Discussion
