714
FXUS63 KDTX 072309
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
709 PM EDT Sat Jun 7 2025

.KEY MESSAGES...

- Periodic low end chances for showers late tonight through Tuesday.

- Daytime highs in the 70s through Tuesday, then a slight warming
  trend mid week.

&&

.AVIATION...

Weather conditions across the airspace will be benign overnight.
Light easterly flow will continue while mid/high level clouds build
back in, as a batch of showers churns across Central Illinois and
Indiana. The northern periphery of this activity will try to scrape
through southern portions of the airspace Sunday morning. However,
the low-level easterly flow will continue to have a drying
influence; thus, limiting shower coverage and intensity.

Low-level moisture will begin pooling along an approaching cold
front at the end of the forecast period. Anticipating MFVR ceilings
may occur around and after Sunday`s sunset. Meanwhile, showers with
a few thunderstorms will accompany this front, as it moves through
the region Sunday night.

For DTW/D21 Convection...A cold front will approach from the west
very late in the forecast window. A band of showers with an embedded
thunderstorm or two is possible late Sunday evening.

THRESHOLD PROBABILITIES...

* Low for ceilings below 5000-ft Sunday morning and Medium Sunday
  evening.

* Low for a thunderstorm after 03z Monday (late Sunday evening)

&&

.PREV DISCUSSION...
Issued at 313 PM EDT Sat Jun 7 2025

DISCUSSION...

East-northeast low level winds will prevail through the evening,
circulating around an elongated ridge of high pressure extending
from nrn Quebec into eastern Lower Mi. The flow has largely driven
the surface smoke out of the area for the time being. Satellite data
shows more wildfire smoke across nrn and cntl Lake Huron, with the
HRRR bringing this near sfc smoke layer into the thumb and tri
cities region this evening.

The upper low now churning over Saskatchewan is forecast to drop
into nrn Minnesota Sunday/Sunday night. The amplification in the
long wave trough across the northern plains and relatively strong
flow will drive the mid level short wave over the Mid Mississippi
Valley across the nrn Ohio Valley tonight before weakening as it
crosses Se Mi/ern Great Lakes Sunday. This wave will advect high
level moisture across Se Mi this evening, with mid level moisture
increasing overnight into Sun morning. The overall weak large scale
ascent and lack of instability will simply warrant a chance of light
showers, mainly across the southern half of the forecast area. The
expected cloud cover will limit forecast highs on Sunday to the
lower 70s (a few degrees warmer in the tri cities where more sun is
possible).

The lead edge of the mid level height falls associated with the
aforementioned upper low will traverse Lower Mi Sunday night into
early morning. A stream of mid level positive vorticity within a
narrow theta e plume will accompany the lead edge of the height
falls. Some steepening of the mid level lapse rates will support a
chance for showers, lingering into Mon morning across the eastern
half of the forecast area. Upper level divergence/diffluence and
better mid level vorticity advection is forecast across nrn Lower Mi
and Lake Huron, supporting the higher rain chances north. An axis of
mid level dry air in the wave of this initial theta e plume will
likely keep conditions dry through much of the day Monday. The
opportunity for decent daytime insolation will boost mixing depths
and support high temps well into the 70s. The upper low is forecast
to lift into the northern Great Lakes Mon night, with a trailing mid
level trough axis passing across Se Mi. Weak elevated instability
within this axis of larger scale ascent will support a chance of
showers and a few thunderstorms. As the upper low is forecast to
exit northeast of the Great Lakes on Tuesday, the associated cold
pool aloft will support additional chances for convection. The
better chances will be north of the I-69 corridor where mid level
lapse rates and MU CAPE values will be a little higher.

A transition toward mid level zonal flow across the eastern US is
forecast late in the work week. Building heights and west-southwest
flow is forecast to driver warmer and more humid air into the region
Wed into Thursday.

MARINE...

High pressure drifts across Lake Huron supporting light winds and
low waves through the weekend. Northeast winds this afternoon will
begin to veer more easterly tomorrow in response to the exiting high
pressure. Expecting most marine areas to remain dry through tomorrow
with the exception of Lake Erie to Lake St. Clair where scattered
showers chances exist tomorrow north of a low pressure system moving
across the Ohio Valley. Widespread rain chances then arrive Sunday
night. An active pattern continues through early next week as an
upper low encompassing the Great Lakes and brings daily shower and
thunderstorm chances. Models indicating waves and winds hold mostly
below any headline criteria for the bulk of this stretch, but will
monitor wind trends both Monday and Tuesday as southwest winds perk
up and approach small craft advisory level winds in some spots.

&&

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

$$

AVIATION.....Mann
DISCUSSION...SC
MARINE.......AA


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