Port Sanilac, Michigan Weather Forecast Discussion

800
FXUS63 KDTX 140747
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
347 AM EDT Sun Sep 14 2025
.KEY MESSAGES...
- Much above normal highs with continuing dry weather into next
  week.
&&
.DISCUSSION...
A blocked, high amplitude upper level pattern featured over the next
week ensures an extended stretch of benign weather with conditions
marked by well above average warmth. This pattern solidified over
the next 24 hours as a narrow upper ridge squeezes into the upper
midwest and great lakes before closing off. This process occurs as
high pressure anchors to the north, maintaining a light easterly
gradient to finish the weekend period. Moderating thermal profile
within the background of increasing geopotential heights and full
insolation yields roughly 2-3 degrees warming across 850-925 mb
layer relative to recent days. This translates into highs mainly in
the lower 80s, but with the onshore flow contributing to slightly
cooler readings for locales within immediate proximity to lake
influence. Potential for conditions to again be conducive for some
areas of fog development late tonight, particularly across the thumb
as light east/northeast flow draws moisture off lake Huron.
Upper level high pressure system peaking around 593 dm will remain
fixated over the region through the middle of next week. Neutral
thermal advection overall with low level flow generally lacking a
southerly component lends to gradual moderation of the resident
above average thermal profile given the high magnitude height field.
Highs inching upward into the middle to possibly upper 80s by
Wed/Thu - or just shy of records levels. Dry conditions persist
given the stability, with generally manageable humidity held in
check as adequate diurnal mixing maintains a dewpoint near or below
60 degrees. Some indication within extended model output for this
pattern to gradually break down next weekend, offering the next
opportunity for meaningful rainfall should greater forcing
materialize as heights fall.
&&
.MARINE...
A ridge of high pressure will build through the day today and will
hold through the the middle of the week, bringing an extended period
of dry weather along with light winds. Winds direction does turn
more uniform this afternoon from the northeast, which will bring
some localized gust potential towards 20 knots into the Saginaw Bay
given the favorable fetch. These localized higher winds will subside
into tomorrow morning.
&&
.PREV DISCUSSION...
Issued at 1157 PM EDT Sat Sep 13 2025
AVIATION...
Sky has cleared along the terminal corridor and over all of SE Mi
outside of a few pockets of mid level clouds toward the Ohio border
and toward Saginaw Bay leading up to midnight. Diffuse surface
pressure and light/variable to calm wind accompany the clear sky to
promote narrowing T/Td spread favorable for fog development. The
scenario has standard onset, density, and duration challenges
leading into MVFR and approaching IFR at times toward sunrise. The
DTW corridor appears most susceptible to lower visibility depending
on late developing surface or boundary layer wind having a SE
component off Lake Erie. Patches of mid level clouds near MBS aside,
full sun brings quick improvement early in the morning. High pressure
is then reinforced from Ontario and Lake Huron during the day
signaled by light easterly wind picking up slightly from the NE into
Sunday evening.
For DTW/D21 Convection... Weather conditions do not support
thunderstorms for the next several days.
THRESHOLD PROBABILITIES...
* None.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
DISCUSSION...MR
MARINE.......MR
AVIATION.....BT
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NWS dtx Office Area Forecast Discussion