488
FXUS63 KGRR 142357
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
757 PM EDT Tue Jul 14 2026

.KEY MESSAGES...

- Heat to continue with wildfire smoke likely moving overhead

- Slow cooling trend starts Thursday with small chances of rain

- Best rain chances arrive early next week

&&

.DISCUSSION...
Issued at 253 PM EDT Tue Jul 14 2026

- Heat to continue with wildfire smoke likely moving overhead

Large and strong upper ridge is almost right overhead this afternoon
per the upper air charts, and per the visible satellite imagery with
the wildfire smoke around its periphery circling the state.

The ridge axis is going to slowly drift southward over the next
couple of days. The hottest temperatures are expected to be today
and tomorrow with the highest heights aloft, and with better mixing
on Wednesday and similar temperatures at 850 mb. We extended the
Heat Advisory through Wednesday earlier to just keep things simple
from the messaging aspect of this.

The upper ridge axis shifting south is also likely going to allow
the wildfire smoke from the massive fires north of Lake Superior
to come further south. Michigan EGLE has addressed this by issuing
a statewide air quality alert for Wednesday. Some of the smoke
models indicate this will come in the latter half of Wednesday for
most of our area.

- Slow cooling trend starts Thursday with small chances of rain

In addition to the smoke plume dropping down, it appears that a very
weak front will drop down also Wednesday night and early Thursday
morning. Temperatures aloft will be more noticeably cooler going
from +25C today to +19C Thursday. Better mixing will offset some of
this cooling aloft, but we will see a slight cooling trend down for
sfc max temps also of a couple of degrees F.

The front will lift back north as a warm front late Friday and
Friday night. The various models indicate that there will be some
increase in the chance of showers/storms Friday afternoon. These
look to be mostly air mass storms as the return flow in the wake of
the front moving north will bring much more humid conditions. These
should mostly dissipate after sunset with the loss of diurnal
heating.

Shower/storm chance then return Saturday afternoon and evening as
the low driving the front northward pushes through. The past few
model runs have a better organized short wave dropping down during
peak heating on Saturday. This is potentially increasing the threat
for some strong to severe storms. Definitely not set in stone yet
being 4 days out. This stronger shortwave moving through, will allow
for a drier and cooler day on Sunday with a better ridge moving in.

- Best rain chances arrive early next week

The system that looked to move in Sunday yesterday, has now been
delayed until Monday. This delay is likely due to a more amplified
flow regarding the short waves Saturday and Monday. The short wave
on Monday is larger scale, with widespread vorticity advection and
cooler mid levels helping with overall instability. In addition, it
looks to pick up larger scale moisture ahead of it.

The amplification also looks to be trending the air mass behind the
now Monday system to be much cooler. Cooler like 850 mb temperatures
dropping to +7C or so. We will see about that, as the Euro tends to
overamplify systems at this time range.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 757 PM EDT Tue Jul 14 2026

Not much significant weather tonight under clear skies and light
southwest winds. There may be about 20 knots of LLWS below 1,000
feet, as southwest winds at that height strengthen to about 20 to
25 knots between 05 and 10 Z. Some models develop isolated shower
or thunderstorm cells vicinity of LAN/JXN after 21 Z, moving
southeast. A prob30 will cover that chance for now. Also will be
monitoring visibility trends on Wednesday as wildfire smoke moves
southward into the area from northern Michigan. Fair to say MVFR
to IFR visibility with smoke is possible from late Wednesday
through Thursday.

&&

.MARINE...
Issued at 253 PM EDT Tue Jul 14 2026

Weak pressure gradient remaining in place through Friday with the
ridge nearby will keep conditions short of criteria for wind/wave
headlines. Winds will creep up some, but will stay below 20 knots,
mainly from the SW through Friday. Smoke will likely become a
factor for visibilities later Wednesday. Some visibilities could
drop to 1- 3 miles.

Our next marine hazards event looks likely to occur on Saturday.
This is when a more noticeable front will approach and move through
with cooler air. This will bring conditions up to near
advisory/statement levels.

&&

.CLIMATE...
Issued at 214 AM EDT Tue Jul 14 2026

Here are the high temperature records for July 14 and 15.

Location           July 14      July 15

Grand Rapids      102 (1936)    95 (2013)
Lansing           101 (1936)    99 (1977)
Muskegon           94 (1995)    93 (1995)
Kalamazoo         108 (1936)   103 (1936)
Battle Creek      104 (1936)   100 (1977)
Holland            98 (1995)    98 (1932)

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Heat Advisory until 8 PM EDT Wednesday for MIZ037>040-043>046-
     050>052-056>059-064>067-071>074.
     Air Quality Alert from midnight tonight to midnight EDT
     Wednesday night for MIZ037>040-043>046-050>052-056>059-
     064>067-071>074.
MARINE...None.

&&

$$

DISCUSSION...NJJ
AVIATION...CAS
MARINE...NJJ
CLIMATE...RAH