616
FXUS63 KDTX 091742
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1242 PM EST Sun Nov 9 2025

.KEY MESSAGES...

- Winter Weather Advisory now in effect for Midland, Bay, and Tuscola
  Counties for lake effect snow through the evening. Snow accumulations
  of 2 to 6 inches with locally higher amounts will be possible
  between now and midnight.

- Additional snow showers expected during the afternoon and evening
  as lake effect showers push inland. A wider variance in snowfall
  accumulation ranging from less than half an inch to 2 to 3 inches
  near lake Huron outside of the Winter Weather Advisory.

- Much colder air settles into Michigan starting this evening into
  with wind chill dropping into the teens Monday morning.

&&

.AVIATION...

Cold northerly flow with an influence off lake Huron will maintain
potential for some snow shower development through the evening
hours. A more focused corridor of lake effect off Saginaw Bay will
continue to impact MBS, where IFR to LIFR within bursts of heavier
snow showers will persist through the latter half of the day.
Elsewhere, some general improvement relative to this morning, with a
trend toward MVFR expected as coverage and intensity of activity
decreases. Forecast will continue to highlight a window late this
evening for another uptick in higher intensity snow showers, as a
passing trough axis draws greater lake moisture southward and
favorable trajectory continues to direct lake bands downstream.
Lower confidence overall in possible coverage and duration.
Improvement in conditions during the early morning hours, allowing
for recovery into VFR.

For DTW...Pockets of light snow showers will persist through the
the afternoon and evening hours, offering some disruption to
visibility. There remains a window late this evening for some
increase in snowfall intensity as bands of lake Huron track
southward. This would bring a quick reduction in both visibility and
cloud base, potential below 1 mile.

 DTW THRESHOLD PROBABILITIES...

* High in ceilings aob 5000 feet through tonight. Low Monday.

* High for precipitation type as snow through tonight.

&&

.PREV DISCUSSION...
Issued at 1211 PM EST Sun Nov 9 2025

UPDATE...

First snow event of the season is well underway this morning, with
most locations still seeing light snow from the departing synoptic
low. Highest snow accumulations this morning were observed across
the Irish Hills, where around an inch to locally 2 inches of wet
snow were observed.

General forecast sentiment remains on track through the afternoon-
evening hours as lake effect banding becomes more predominant in the
northeast flow regime. Already seeing evidence of a band organizing
downwind of Saginaw Bay as hi-res models have suggested.
Observational trends show a focused axis of surface convergence
collocated with increasing radar returns and visibility down to a
quarter mile at times. A Winter Weather Advisory is in effect, with
anticipation for a range of 2 to localized 6+ inch snowfall where
the band is most intense. Will keep a close eye on observational
trends through the afternoon-evening in case a short-fused upgrade
to a Warning is needed. Will also be keeping an eye on other
locations downwind of the lakeshore for advisory potential, for
example St. Clair/Macomb County where guidance has continued to
place another lake band and convergence is beginning to develop.

Elsewhere, main adjustments to the grids were to increase PoPs
through the rest of the day and lower temperatures to the mid-30s as
lingering snowfall/diabatic cooling has hindered diurnal temperature
recovery.

PREV DISCUSSION...
Issued at 520 AM EST Sun Nov 9 2025

DISCUSSION...

Attention remains on the ongoing snowfall and the subsequent lake
effect snowfall expected to ramp up off Lake Huron later this
afternoon and evening. A surface low is currently working out and
Indiana and through Ohio early this morning while a broad region of
isentropic ascent moves over southeast Michigan. The cooler low
level thermal profiles at the diurnal minimum is allowing for
predominately light snowfall across much of the forecast area.
Towards sunrise southeast Michigan will reside on the northwest
quadrant. Best forcing tied to the deformation/FGEN remains closer
to the low which mostly remains along the souther MI border and
south. However, there remains potential for FGEN in the 800-850mb
layer up towards the I-94 corridor that may produce intervals of
greater intensity snowfall between the hours of 6 am and 10 am. The
well above freezing ground temperatures and air temperatures holding
right around freezing will be limiting factors to accumulation
through these morning hours. Mostly minor accumulations with some
spots seeing up to an inch or possibly two by the end of the
morning. Accumulations should be confined mainly to grassy/elevated
surfaces and mostly focused along the Irish Hills corridor given the
cooler/higher elevations.

Greater attention turns toward this afternoon and evening as the
aforementioned surface low pivots across the eastern Great Lakes and
deep troughing engulfs the region with a mid level closed low
dropping across Lake Michigan. This results in an organized northeast
fetch off Lake Huron. Some hi-res models, which includes the HRRR,
continue to point toward an impressive enhanced convergence zone
developing off Lake Huron through Saginaw Bay and pushing inland
through Bay/Saginaw County this afternoon/early evening. Dynamics
with this lake effect event should be supportive of some intense snow
showers. The degree of cold air arriving will contribute to steep
lapse rates and convective depths above 10kft, which will extend into
and through the DGZ helping support intense snow bands that will
have potential to produce several inches of snow in a short period of
time.

There appears to be two periods of focused lake effect snow off
Saginaw Bay, once this afternoon and a secondary period in the early
evening. The evening period will carry best accumulation potential
as temperatures are expected to cool to freezing and into the mid
20s by early tomorrow morning. Some limiting factors to keep in
mind. Afternoon snowfall will be working against afternoon high
temperatures that should reach at least into the mid 30s. Though,
dynamic cooling under more intense snow bands should easily bring
temperatures down for better accumulating snowfall. Secondly, warm
Saginaw Bay waters may also introduce some potential for rain to mix
in at times, at least during the day, which would also cut into
totals. And lastly, a more rapid turn of winds to the north would
limit duration of any intense lake effect snow bands extending into
Bay and Midland County.

With that said, enough of a signal exists to move forth with a
Winter Weather Advisory for Bay, Midland, Tuscola County. The
inclusion of Tuscola county is to account for the shorelines areas
they will have potential to experience the intense lake effect snow
bands, especially if a slightly more northerly wind component
develops. Warning criteria certainly has potential to be met with
this event and may require a short fused upgrade to Winter Storm
Warning. An expansion of the Winter Weather Advisory may be needed as
well, which could include eastern portions of the Thumb if more
organized longer duration lake effect bands emerge.

The remainder of the area can expect snowfall accumulations of 1 to
3 inch range through tonight. Highly variable amounts can be
expected further inland given the lake effect nature of the activity
when better accumulation potential arrives this evening with cooling
temperatures.

Drier air arrives Monday with the passage of the trough axis leading
to much lower moisture depth. This will bring more flurry/light snow
shower activity during the early week. Wind chills Monday morning
will drop into the teens with daytime highs on Monday holding in the
mid 30s. A warmup back into the 40s for daytime highs will occur mid-
week.

MARINE...

North to northeast wind becomes increasingly gusty across the
central Great Lakes this morning as low pressure tracks through into
the Ohio Valley. Gusts are forecast to peak at 20 to 25 knots for
most of the area, but southern Lake Huron and Saginaw Bay will see
locally higher gusts to 30 knots at times this afternoon and evening
as the low passes south of Lake Erie. A Small Craft Advisory remains
in effect for the nearshore waters from Saginaw Bay to Port Huron.
Scattered rain and snow showers will accompany the passing low.

Arctic air arrives as the system departs tonight into Monday. This
sustains gusty north to northwest wind to 20 to 25 kt with scattered
lake effect snow showers. Small Craft Advisories will continue
through this period. Flow then flips to southwest on Tuesday and
remains gusty as milder air returns. A brief period of gusts in
excess of 30 knots will be possible late in the day Tuesday but
confidence is too low for a Gale Watch at this time. Another cold
front moves through on Wednesday, continuing the active westerly
flow pattern with additional chances for showers into the late week.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory until 10 PM EST this evening for MIZ048-053-
     054.

Lake Huron...Small Craft Advisory until 10 AM EST Tuesday for LHZ421-441>443.

     Small Craft Advisory until 4 PM EST Monday for LHZ422.

Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....MR
UPDATE.......MV
DISCUSSION...AA
MARINE.......TF

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