406 
FXUS63 KGRR 031905
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
305 PM EDT Fri Oct 3 2025

.KEY MESSAGES...

- Near Record Warmth and Dry through Sunday

- Rain Chances Increase Monday through Tuesday

- Pleasant Fall Conditions Wednesday and Thursday

&&

.DISCUSSION...
Issued at 305 PM EDT Fri Oct 3 2025

- Near Record Warmth and Dry through Sunday

The hot temperatures continue through the weekend as the upper
level ridge and high pressure remain in place. Temperatures are
currently in the low to mid 80s, but still a few degrees from
today's records, we'll have to see how much temperatures rise in
the next few hours to see if we tie or break any records.

The mentioned non-zero rain chance in Ludington tonight is looking
more like a 0 percent chance with the latest satellite and model
trends. Cloud cover will increase slightly overnight but moisture
is not deep and with plenty of dry air below the cloud layer,
would expect any drops of rain to evaporate before hitting the
surface.

Saturday will be a few degrees warmer and take another run at the
high temperature records (see CLIMATE section). Another round of 
diurnal cumulus develops for the afternoon. Some of the CAMs show 
the potential for a few showers, but with the shallow moisture 
level and ample dry air above and below the cloud layer stuck with
the NBM guidance with PoPs near 0 percent.

Sunday 925 mb temperatures are not as warm and therefore highs
will likely be similar today. While we have this warm stretch
you'll still need a jacket early in the morning as temperatures
drop overnight in the 50s to low 60s.

- Rain Chances Increase Monday through Tuesday

As the ridge shifts east, southwest flow moves in ahead of the
trough with lowering heights, 500 mb positive vorticity advection,
and the low level jet. Showers could develop as early as late
Sunday night toward Ludington but better chances move in during
the late afternoon expanding southeast through Monday night and
lingering into Tuesday. MUCAPE values only look to be a couple
hundred J/kg looking at the long range ensembles with bulk shear
values in the 30 to 40 knot range. So there is a potential for a
few rumbles of thunder and maybe some gustier winds, but no severe
weather is expected. 

- Pleasant Fall Conditions Wednesday and Thursday

As the rain clears Tuesday, drier and cooler conditions move in
for the remainder of the week. Highs in the 60s with lows largely
in the mid 30s to 40s. Looking at the distribution we'll have to
monitor temperatures Wednesday night into Thursday for frost. The
current NBM forecast is near the 10th percentile compared to 
other guidance which means it is the on of the colder solutions
and actual values have a higher chance of being warmer. However, this
is about the time we see our first freezing temperatures across 
the area, so temperatures like this are typical for the time of 
year.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 146 PM EDT Fri Oct 3 2025

VFR is expected through tomorrow. Cumulus clouds bubbling up mid 
day through late afternoon today and tomorrow will be based around
5,000 feet. Fog potential late tonight / early morning appears 
low with 15-20 knot winds several hundred feet above ground.

&&

.MARINE...
Issued at 146 PM EDT Fri Oct 3 2025

A period of breezier south-southwest winds this weekend, prior to
the arrival of a cold front early next week, is expected to build
waves which will become hazardous to small craft along portions 
of the West Michigan shore.

Saturday afternoon, at least 2-4 footers are likely north of 
Whitehall. Waves increase Saturday night through Sunday night,
with 3-5 feet likely near and north of Holland, and 5-7 feet
likely north of Whitehall. It is possible in this pattern of air
warmer than the water (a little unusual for this time of year),
models are somewhat overdoing the winds and therefore also the 
waves. Nonetheless, Small Craft Advisory conditions are
anticipated at least for Saturday night into Monday morning.

&&

.CLIMATE...
Issued at 331 AM EDT Fri Oct 3 2025

Once again, the current records are listed for the next three days, 
when they will be approached, or likely exceeded at many sites.

Today, except for Lansing, forecast highs are mostly within a degree
of the current records at the rest of the sites.  

                   Fri              Sat                 Sun 
Grand Rapids    86 - 2023       87 - 1951         85 - 1946, 1922 
Lansing         90 - 1898       86 - 1951, 1900   87 - 1922, 1900 
Muskegon        85 - 2023       84 - 2023         83 - 2007 
Kalamazoo       88 - 1953       90 - 1951         87 - 1922 
Battle Creek    88 - 1953       87 - 1951         89 - 1900 
Holland         86 - 1919       89 - 1951         85 - 2007

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

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