412
FXUS63 KDTX 120951
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
551 AM EDT Sun Oct 12 2025

.KEY MESSAGES...

- Temperatures run a few degrees above normal today through the
early week period.

- A cold front moves in Monday night and Tuesday but is expected to
pass through with no rain.

- Temperatures return to more typical mid October readings by
Wednesday.

&&

.AVIATION...

Clear sky and light easterly flow off the Great Lakes has been
sufficient for pockets of low stratus and fog to develop this
morning. So far, most of this has occurred across the Thumb and west
of US-23 with only transient impacts at the TAF sites. Intervals of
lower flight category will be likely early in the forecast before
the near surface moisture begins to mix out between 13 and 14Z. VFR
then prevails through the day with continued light east flow.
Another challenging forecast Monday morning with current guidance
highlighting fog and/or low stratus developing near or just west of
the TAF corridor. Favorable radiating conditions and the persistent
moist flow off the lakes offer enough confidence for an introductory
MVFR mention.

For DTW/D21 Convection...No thunderstorms through the taf period.

DTW THRESHOLD PROBABILITIES...

* Medium for ceilings aob 5000 ft agl through 14z. Low late tonight.

* Low for visibilities aob 1/2 sm or ceilings aob 200 ft through 13z.

&&

.PREV DISCUSSION...
Issued at 357 AM EDT Sun Oct 12 2025

DISCUSSION...

Surface high pressure is pinched over the Great Lakes between
intense low pressure systems in central Canada and off the mid
Atlantic coast today. This configuration has easterly boundary layer
wind in place across Lake Huron and Erie that is cool and moist
enough for lake cloud production, and also areas of fog inland where
surface wind has died off. Full sun otherwise will help the fog lift
while remaining low clouds take much of the morning to lift or mix
into a shallow cumulus field, a standard pace for early October. A
sharp mid level/500 mb ridge ensures dry weather accompanies partly
to mostly sunny conditions this afternoon. Consensus of HREF model
soundings is well mixed into the 850-800 mb range, sufficient for a
run toward highs near 70 countered slightly by continued easterly
boundary layer wind into this evening.

Dry and mild conditions continue tonight in a very similar setup to
this morning, if not with a more robust marine layer across SE MI.
The surface ridge is still overhead or just east in southern Ontario
in a position to maintain easterly flow across the Lakes and
potential for low clouds and fog. There is also a greater component
of high clouds associated with the Midwest cold front which thicken
from the west late in the day. The late cloud timing allows a return
to highs around 70, above normal readings supported by thickness
warming ahead of the front and under the 500 mb ridge. The cloud
band is about all that is left of the front as it struggles and
fails to maintain precipitation while moving across Lower Mi Monday
night. There is good model agreement on this precipitation trend
within an otherwise well organized frontal structure, especially
from and a temperature and theta-e perspective in the low levels.
It`s just too far removed from mid level short wave and upper jet
support well to the west and north during the night.

The wind picks up from the NW as the front exits to the south and
east Tuesday morning, however low level cold advection is slow to
accelerate across SE Mi. The Tri Cities and northern Thumb are the
exceptions, but even there temperature guidance only drops back
toward normal mid to upper 60s vs lower to mid 70s near the Ohio
border. A large area of central Canadian surface high pressure then
surges into the Great Lakes Tuesday night to bring temperatures down
into the 50s most locations by Wednesday afternoon.

The mid levels of the frontal zone will have to be monitored for a
stray shower early Wednesday. Otherwise, high pressure dominates the
late week period with dry weather until late Friday. The next low
pressure system organizes in the Prairies/Plains by then with model
depictions of a broad moisture plume extending eastward into the
Great Lakes by Friday night.

MARINE...

Weak ridging expands over the central Great Lakes today through
Monday promoting dry weather. The local gradient never fully relaxes
despite this resulting in persistent modest (10-20kt) east-southeast
winds for the timeframe. Low pressure lifting into northern Ontario
attempts to drag a cold front into the Great Lakes late Monday
however this is expected to largely wash out before reaching the
central lakes. Broad high pressure sinking out of the Canadian
Prairie then builds across the region early Tuesday drifting
overhead through Thursday.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....TF
DISCUSSION...BT
MARINE.......KDK


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