995
FXUS63 KGRR 310526
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
126 AM EDT Sat Oct 31 2026
.KEY MESSAGES...
- Slight Chances for Rain Saturday
- Warmer Than normal Trends trough the week
- Unsettled weather ahead with several precip chances next week
&&
.DISCUSSION...
Issued at 141 PM EDT Fri Oct 30 2026
- Slight Chances for Rain Saturday
A negatively tilted ridge will continue to build as it extends
from the southeast US across the Great Plains and the upper
midwest into Southern Canada. This is further amplified with high
pressure through the mid levels to the sfc.
While the upper level ridge will maintain, the mid level and sfc
high pressure will erode as a short wave perturbation creeps
through the upper level ridge, bringing warm air advection from
the southwest tomorrow.
That trough will have some mid level moisture that has been the
reason for some consternation for tomorrow given any precipitation
chances.
As that moisture creeps into southern Lower from the southwest
tomorrow, there could be enough mid level instability to allow for
some isolated showers tomorrow.
While overall the precipitation chances continues to dwindle, the
mid to near range guidance is showing slightly better chances,
around 15 to 30 percent, and that would be early Saturday morning
and late Saturday evening, after 8 PM.
Any rainfall amounts will be light, with less than a tenth of
precipitation expected.
- Warmer Than normal Trends trough the week
While we fall behind in time this weekend, and we enter into
November, the warm seasonal temperatures continue.
An large upper level low will pass through the intermountain west
and deepen as it moves through the Great Plains. The flow out
ahead of this system will keep the warm conveyor belt continuing
through the week. While any precip that we discuss below will
bring some cooling effects, overall temperatures will remain
around 10 to 15 degrees above normal. Max temperatures will warm
through the weekend, and will be in the mid to upper 60s through
the week. Lows temperatures overall are trending 10 to 20 degrees
above normal. Lows along and north of the US 10 corridor will be
at or below freezing tonight. Otherwise, Low temps will rebound to
above freezing and remain there through most of the week.
- Unsettled weather ahead with several precip chances next week
The above mentioned upper level low will be driving the weather
pattern over the next week. That low will bring several chances
for precipitation, the first being with a warm frontal band out
ahead of the low. There is a weak wave aloft, along with some 500
mb vort maxes that correspond to a mid level negatively tilted
short wave that will pass through the Great Lakes region late
Monday into Tuesday. While flow is divergent, NAEFS has PWATS
advecting through the Upper Peninsula, northern Lower and the
northern portion of southern Michigan. Anomalous PWATS of around
1.25 inches will linger over the state Tuesday. Both the GFS, EC
and various ensembles show this trend. Given the current
locations, this should bring showers along and northward of the I
96 corridor. This could envelop the rest of the state if the
moisture shifts slightly to the south. While the models begin to
diverge in a consensus, there remains a trend for the open wave
to have a cold front pass through the area Wednesday into Thursday
with strong flow behind hit. There isn`t much CAPE associated
with this system at this time and 850 mb temps behind the from
range from +6 to +9 C so not expecting snow with little chance for
thunder.
&&
.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 126 AM EDT Sat Oct 31 2026
No changes to previous thinking.
Probability of VFR at all terminals through 12Z: 95 percent
Probability of VFR at all terminals through 18Z: 90 percent
Probability of IFR at any terminals through 18Z: 3 percent
Brief light rain is possible at some of the terminals this
morning with no associated visibility or ceiling restrictions
anticipated.
As noted previously, fog this morning looks unlikely due to a
combination of increasing low to mid-level cloudiness and
stronger nocturnal boundary layer winds; these factors should
mitigate outgoing longwave radiation flux necessary for radiation
fog.
&&
.MARINE...
Issued at 141 PM EDT Fri Oct 30 2026
Fairly light northwesterly flow continues today. Fair winds and
calmer waves will continue with winds shifting to offshore tonight
into Saturday morning. Winds will slightly increase tomorrow
afternoon but will be far below criteria. Southerly flow will
continue through Sunday. Next chance for any advisory criteria won`t
be until next week.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Ceru
AVIATION...TJT
MARINE...Ceru
NWS GRR Office Area Forecast Discussion
