Lenawee County Michigan Weather Forecast Discussion

325
FXUS63 KDTX 151057
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
657 AM EDT Wed Oct 15 2025
.KEY MESSAGES...
- Brief light rain early this morning.
- Dry weather and normal mid October temperatures resume this
  afternoon through Thursday.
- Warmer air but a more active rain pattern is expected late Friday
  through this weekend.
&&
.AVIATION...
Surface high pressure spans the area from central Canada across the
Great Lakes this morning, but SE Mi also lies under the mid levels
of the shallow front stalled in the Ohio valley at the surface. The
elevated frontal zone is supporting clusters of VFR light rain
showers which gradually shift south during the morning. A decreasing
cloud trend combined with continued north wind this afternoon
reflects the increasing high pressure influence that continues into
this evening. VFR consists of clear sky for the bulk of tonight
along with a few clusters of MVFR stratocu developing off Lake Huron
toward sunrise Thursday.
For DTW/D21 Convection... The high pressure dominated weather
pattern does not support thunderstorms today and tonight.
DTW THRESHOLD PROBABILITIES...
*  Low for ceiling at or below 5000 ft today.
&&
.PREV DISCUSSION...
Issued at 356 AM EDT Wed Oct 15 2025
DISCUSSION...
Mid-level fgen engaging a swath of moisture along an elevated
frontal slope is driving scattered coverage of light rain across the
area early this morning. Upper jet forcing has begun to depart east
and system-relative progs will increasingly favor isentropic descent
over the next few hours - this will support gradual shrinking of
saturation depth and decreasing probability for rain through the
rest of the morning. The parent wave exiting east will drive the
elevated front south and allow cooler, drier air to settle across
the area today. Clouds will gradually clear from north to south with
mostly clear skies expected by this evening. The Thumb will take the
most direct cold advection which keeps highs around or just shy of
60. Elsewhere, lower to mid 60s will be common.
High pressure building in across the northern Great Lakes maintains
clear skies and very light wind overnight to bring favorable
radiating conditions and a cooler start to Thursday morning. Outside
of Metro Detroit and immediate lakeshore communities, guidance
offers lows in the mid to upper 30s - supportive of some patchy
frost, especially inland. The complicating factor to temps dropping
further will be weak moisture flux off Lake Huron as northerly
gradient flow stays active around the high pressure up north. This
may bring in low stratus and/or fog, or at the very least slightly
higher boundary layer moisture that would raise the floor for low
temps. Low confidence exists in more than just patchy coverage of
frost at this point, exhibited by HREF and REFS offering only 10 to
30% probability for lows below 35F for isolated locations.
The pattern aloft becomes increasingly amplified by Thursday as a
deep cutoff low migrates across the high plains and another upper
low digs south from Quebec. This leaves the Great Lakes within the
strengthening ridge between, marked by stable and dry conditions
Thursday into early Friday. The ridge axis passes overhead early
Friday with a slug of mid-level moisture then riding in along an
elevated warm front. This brings increasing cloud cover through the
day and a chance of rain mainly across the north at first, then
spreading south Friday night. Higher confidence exists for a period
of wet weather Saturday into Sunday as the deep troughing to the
west eases in, taking on a negative tilt over the region and
bringing increasing likelihood for a dynamic low to track nearby.
This brings relatively high confidence for some much needed rainfall
and potential for gusty winds.
MARINE...
A cold front will move across the Great Lakes this morning which
will maintain northeast flow through the early afternoon, with
backing wind direction to the northwest by the evening hours. This
has allowed wave heights to increase in the outer Saginaw Bay and
Lake Huron shoreline, where Small Craft Advisories are in place.
Lingering rain showers also remain possible through the morning with
the frontal passage. High pressure will then quickly build in later
today and hold through Thursday, which will decrease wind speeds and
thus wave heights through the afternoon. Light winds and dry weather
continues tomorrow.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 10 AM EDT this morning for LHZ421-
     441>443.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
AVIATION.....BT
DISCUSSION...TF
MARINE.......AM
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

NWS DTX Office Area Forecast Discussion