Saint Charles Michigan Weather Forecast Discussion

275
FXUS63 KDTX 101936
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
336 PM EDT Fri Oct 10 2025
.KEY MESSAGES...
- Scattered light showers this evening across the Tri-Cities and
Thumb, with coverage more isolated toward Metro Detroit. Additional
isolated light showers are possible on Saturday.
- Milder conditions through this weekend into early next week.
&&
.DISCUSSION...
A stacked low over Lake Superior this afternoon will drop
southeastward along Lake Huron tonight before stalling over Lakes
Erie and Ontario on Saturday. Though the compact mid level low
remains strong, many of the other features of this system are either
not very impressive or not lining up in terms of producing
precipitation across SE MI.
A narrow corridor of moisture in advance of the cold front will push
through lower MI the latter half of the day bringing increased
clouds and isolated showers to the area, with the showers mainly
north of M59 due to the positive tilt to the prefrontal boundary
moving through. SPC mesoanalysis shows the 700mb moisture ridge
quickly drying out and retreating to the south as it pushes across
Lake MI. Still some remnants of the southwesterly 850mb jet around
30 knots which has been holding back to the NW but should slide
through Mid MI and the Thumb to accompany the actual cold front this
evening into tonight. Narrow axis of surface convergence along the
front with a brief increase in PWATs to around 0.75 inches and some
lower level forcing should help bring about a better coverage of
light showers between 00-06Z. The airmass quickly dries out in the
wake of the cold front with PWATs dropping to less than a half inch.
The strong upper low stalls over the eastern Lakes while the surface
low continues to weaken to around 1019mb by Saturday afternoon. We
will still be under the cyclonic flow in the mid levels under the
upper low with 850mb temps around 5C holding over MI. Upper level
ridging will be building into MI from the west compressing the
moisture to the lowest 10kft or so. Expectations are for diurnally
driven scattered light showers to develop Saturday under the upper
low before it gets pushed east by the ridge. POPs remain capped
around 20-25 percent for low confidence in coverage and low
potential to actually measure precipitation.
Ridging will carry us through Sunday and into the new week as the
upper low shifts to the east coast and stalls again as it phases
with another low lifting up the coast from FL. Temps will slowly
moderate toward 70 through this time before the next cold front
arrives Tuesday bringing back highs around 60 for the mid week.
&&
.MARINE...
Southwest winds gusting around 25 knots across Central Lake Huron
this afternoon ahead of a cold front. A Small Craft Advisory remains
in effect for Saginaw Bay and around the tip of the Thumb into the
evening. A cold front triggering scattered showers and a slight
chance of thunderstorms/waterspouts will track south through the
Central Great Lakes tonight. Northerly winds behind the front will
slowly diminish and become easterly on Saturday as a ridge of high
pressure builds in, holding into Monday. Even with the east winds on
Saturday, with wind speeds predominately around 15 knots, waves
expected to remain mostly below 4 feet.
&&
.PREV DISCUSSION...
Issued at 221 PM EDT Fri Oct 10 2025
AVIATION...
Deep-layer low pressure system spins southeastward across the state
today and tomorrow. This promotes an influx of atmospheric moisture
with a band of thickening clouds and eventually some showers well
ahead of the system`s cold front, which is currently still west of
Lake Michigan. Stubborn resident dry air supported by Mid-Atlantic
high pressure helps keep rainfall rates in-check, therefore no
visibility restrictions were included this TAF cycle. Main forecast
consideration is how low ceilings get late this evening and into
Saturday morning. The bulk of the model data suggests high-end MVFR
to low-end VFR ceilings fill in with the passage of the front
Saturday morning before lifting and scattering out midday Saturday.
Winds flip from SSW to NNW behind the front.
For DTW/D21 Convection...Thunderstorms are unlikely tonight or
Saturday.
DTW THRESHOLD PROBABILITIES...
* Moderate for ceilings at or below 5000 feet tonight and Saturday
  morning.
* Low for thunder tonight.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 10 PM EDT this evening for LHZ421-422-
     441.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
DISCUSSION...DRK
MARINE.......SF
AVIATION.....KGK
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

NWS DTX Office Area Forecast Discussion