Willis, Michigan Weather Forecast Discussion

321
FXUS63 KDTX 160931
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
531 AM EDT Tue Sep 16 2025
.KEY MESSAGES...
- Above normal high temperatures continue into the weekend.
- Dry weather through the first half of the weekend.
&&
.AVIATION...
Pattern remains the same as prior few nights with high pressure in
place across the Great Lakes. Fog this morning, like yesterday, has
stayed only patchy over the bulk of the region with denser fog
(LIFR) confined just north of MBS. This fog likely creeps south
impacting MBS through the start of the new forecast period.
Lingering areas of fog dissipate by mid-morning as SCT VFR diurnal
cu again develops for the afternoon.
For DTW/D21 Convection... No thunderstorms through the early week
period.
THRESHOLD PROBABILITIES...
* None.
&&
.PREV DISCUSSION...
Issued at 334 AM EDT Tue Sep 16 2025
DISCUSSION...
590 dm upper level high fixated overhead early this morning
maintains full control heading into the mid-week period. This
stagnant pattern lends to virtually no change in sensible weather
conditions through Thursday. Elevated height field contributing to
this stretch of higher magnitude warmth will keep projected high
temperatures generally within the low to mid 80s. Modest daily
moderation of the underlying thermal profile will lend to the
warmest conditions arriving Thursday with some upper 80s plausible.
Surface high pressure anchored to the north and east favors
continued light low level east/northeast flow. This trajectory will
continue to draw marine boundary layer moisture inland during the
overnight hours, favoring some degree of fog formation. Higher
probability for both greater coverage and density will tend reside
within a closer proximity to lake Huron and Saginaw Bay.
Northern stream shortwave glancing across the northern great lakes
will ease a backdoor cold front southward into central lower Mi
Thursday evening and overnight. This frontal zone will linger into
Friday, establishing a greater south to north thermal gradient as
cooler northeast to east flow engages the marine environment to keep
the thumb notably cooler. A brief uptick in frontal convergence with
a narrow plume of higher theta-e present could offer an isolated
opportunity for shower development as the boundary sags into the
region. Otherwise dry conditions hold to finish the week. This
boundary washes out as low-mid level ridging again governs conditions
heading into the first half of the weekend. Temperatures still edged
on the warmer side of average, but muted slightly relative to the
warmth noted this week as easterly flow carries greater influence and
cloud cover may prove more problematic as high level moisture
increases downstream of an inbound mid level wave. Introductory
precip chances creep back into the forecast by the end of the weekend
and early next week as greater mid level pv intrudes.
MARINE...
A ridge of high pressure continues to bring an extended period of
dry weather and lighter winds to the Great Lakes through the week.
Winds continue to favor a light easterly component, with some
gradual backing to the south expected by tomorrow. A secondary high
pressure system is expected to drop from the central Canadian
provinces into Ontario and Quebec late this week, which will
strengthen the pressure gradient over the Great Lakes region. This
will again reinforce northeasterly flow and will bring some elevated
wind speeds for Lake Huron where sustained winds nearing 20 knots
and gust potential to 25 knots will be possible.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
AVIATION.....KDK
DISCUSSION...MR
MARINE.......MR
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NWS DTX Office Area Forecast Discussion