853
FXUS63 KDTX 290345
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1145 PM EDT Mon Sep 28 2026

.KEY MESSAGES...

- Dry and pleasant weather conditions will persist into Wednesday.

- Areas of dense fog expected again Tuesday morning.

- Rain chances increase during the latter half of the week with
cooler temperatures expected.

&&

.AVIATION...

High amplitude H3 to H5 ridging will remain in place over the
Central Great Lakes throughout the taf period. Forecast data
supports the center of the surface anticyclone will arrive causing
the last of the northerly gradient component to break down.
Expecting more in the way of calm and variable winds Tuesday
morning. Given time of year considerations with late season
evapotranspiration, br and fm remain a possibility. Kept with the
inherited mention for Tuesday morning. MOS is decidedly more bullish
on LIFR and IFR visibility restrictions at daybreak. Forecasted
environmental profile supports cumulus development at the top of the
boundary layer Tuesday afternoon.

D21/DTW Convection...No thunderstorms forecast through the TAF
period.

.DTW THRESHOLD PROBABILITIES...

* Low for ceiling/visibility at/below 200 ft / 1/2 SM early Tuesday
  morning.

&&

.PREV DISCUSSION...
Issued at 335 PM EDT Mon Sep 28 2026

DISCUSSION...

Blocking pattern still in place across the conus with the Great
Lakes locked under the stacked ridging. Local weather stays quiet
through Tuesday with the ridge in place but the ridge will begin to
slowly shift eastward as the blocking low off the east coast
releases allowing for a more active mid week stretch.

Center of the surface ridge passes over lower MI tonight leading to
another calm and clear night with varying degrees of fog across the
area. Any fog will again burn off quickly in the morning as temps
once again rise into the 70s. Southwesterly winds return on Tuesday
as the center of the high drifts off to the east while the
positively tilted mid/upper level trough folds over the region. This
will allow for a boost in high temps by a couple degrees into the
mid 70s with the added warm advection. 850mb temps should increase
from the current upper single digits, into the mid teens. Though
high temps mid week will be tempered by the incoming clouds and
rain, we will see a boost in low temps Wednesday night with temps
holding in the mid 60s.

As for the aforementioned clouds and rain, a frontal boundary will
stretch from the broad parent low over central Canada down through
the Midwest and southward to a cutoff low and surface reflection
over the four corners. The front will stall mid week just to our
west before slowly pushing east of the area Thursday night. This
will lead to a long duration light rainfall event with periods of
moderate rain associated with any mid level waves riding up along
the front late Wednesday into Thursday night. The cutoff low will
absorb remnants of a Pacific tropical system adding high moisture
content to the airmass with a strong southwesterly low level jet
ushering some of this moisture into the region. Higher rainfall
totals will occur west of SE MI, with the front becoming more
progressive once it reaches us which will limit totals somewhat
locally. At this point we`re still looking for around a half inch to
three quarters of an inch of rainfall over the 36-48 hour window.
There remains a low chance of some embedded thunder over the area
mainly Thursday when a strong 50 knot low level jet pushes a mid
level wave just south of the area with a theta e plume surging
into SE MI which may be enough forcing to allow some convection.

Friday we could be dealing with some post frontal stratiform light
rain depending on how fast the incoming surface high can push into
the area. Regardless, we are in for a cool weekend as the thermal
trough sets up and sits over the region. High temps will only reach
into the 60s with lows down into the low 40s.

MARINE...

Sprawling high pressure will slowly track through the central Great
Lakes through tomorrow, leading to light and variable winds mainly
under 15 knots. South to southwest winds will then increase ahead of
the next cold front, which slowly moves through on Thursday. With
the warm advection leading to more stable profiles and showers
moving through during this timeframe, wind gusts are expected to top
out only around 25 knots. A better chance to briefly exceed 25 knots
exists behind the front Thursday evening/night with cold advection,
as 850 MB temps lower into the mid single digits by Friday morning.

Another large area of high pressure building in on Friday and
Saturday will promote light winds for the first half of the weekend.
A stronger low tracking through the northern Great Lakes for the
second half of the weekend brings another opportunity for winds to
reach or exceed 25 knots over lake Huron.

&&

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

$$

AVIATION.....CB
DISCUSSION...DRK
MARINE.......SF


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