707
FXUS63 KGRR 311844
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
244 PM EDT Sat Oct 31 2026

.KEY MESSAGES...

- Slight chance for rain Tonight and Tomorrow

- Warm and wet weather ahead

- Chances for rain midweek onward

&&

.DISCUSSION...
Issued at 244 PM EDT Sat Oct 31 2026

- Slight chance for rain Tonight and Tomorrow

 Current radar has light precipitation streaming through lower
Michigan this afternoon. Most of if is bifurcating the region, with
a band of scattered showers moving north of the I 96 corridor and a
band moving along and south of the I 94 corridor. As most of the
region is dry, it will take a bit to moisten up the lower levels for
any rain to accumulate. Any precipitation will be falling from a
cloud deck around 5 to 10KFT. Soundings show fairly dry air above
and below, so any rain falling will have to saturate the lower
levels. All this is to say, with a lack of moisture, and while
there is scattered showers possible, any rain that does fall will
be light at best through the early evening. More moisture will
advect in tonight, mainly after 10 PM, however while there is an
increase, it remains sparse and all in told, total QPF will
struggle to be measurable in most locations.

  A weak, divergent trough will be squeezing its way through the
upper level ridge through tomorrow. and while there is some mid
level moisture which will result in some clouds, the divergent
pattern and dry lower levels will keep most, if not all,
precipitation at bay.

- Warm and wet weather ahead

 As stated in previous discussions, the pattern is changing. A
deep upper trough will trek across the CONUS early week, making
its way into the Great Lakes region on Tuesday. A warm conveyor
belt will bring moisture up from the Gulf out ahead of this
system, and as it moves into the Great Lakes the models continue
to have it become more positively tilted which indicates a more
progressive, fast moving, nature. Latest NAEFS ensembles have
PWATS upwards of 1.25 inches which is highly anomalous for this
time of year. CAPEs remain fairly low so thunder is not expected.
However, give the fast, moist nature of this system, a period of
heavy rainfall are not out of the question. With that said, there
is a concern for leaf clogged storm drains Tuesday into Wednesday
morning. While it is fairly far out, there is the potential of 0.5
to 1.0 of rainfall in a short period of time.

 Warmer than normal temperatures will continue with highs in the
upper 60s to low 70s through midweek. While temperatures should drop
into the low 60s through the latter half of the week, overall
temperatures will be 10 to 15 degrees above normal.

- Chances for rain midweek onward

Beyond the above mentioned system, the models diverge on a
consensus beyond midweek. However, there is a signal for
successive waves which could allow for periods of showers to be
possible, currently only a 20 to 30 percent chance.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 139 PM EDT Sat Oct 31 2026

VFR conditions are expected through this forecast period. Mid
clouds are currently in place, and will remain so through the
majority of the period. We will see a batch of a few scattered
showers move through the terminals from around now at KAZO, and
then the remainder of the terminals by 22z. This is likely to
lower ceilings slightly to around 6k ft, but staying VFR. The lack
of low level moisture will limit the amount of rain that reaches
the ground.

After the few rain showers pass through by about 06-07z, we will
go back to just mid clouds, and light winds from the SE through
18z Sunday.

&&

.MARINE...
Issued at 244 PM EDT Sat Oct 31 2026

Winds will shift to the south with conditions below SCY through
most of Monday.

&&

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

&&

$$

DISCUSSION...Ceru
AVIATION...NJJ
MARINE...Ceru