207
FXUS63 KDTX 101031
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
631 AM EDT Sun Aug 10 2025

.KEY MESSAGES...

- Hot and muggy weather through Monday with heat index well into the
90s.

- Potential for showers and thunderstorms early next week.

&&

.AVIATION...

Another quiet day over SE MI as high pressure remains locked over
the region. Winds will be primarily southwesterly during the day up
to around 10 knots before backing slightly tonight to the south-
southeast and decreasing. With similar airmass to Saturday, would
expect another round of few/sct afternoon cu to develop. MBS is
closer to the moisture axis ahead of the cold front thats hung up
from the UP down through WI so could see cirrus debris over that
area this evening and tonight. There is a chance of a shower or
thunderstorm drifting east toward MBS tonight but confidence is too
low to think about including in the taf at this point.

For DTW/D21 Convection... Thunderstorms are not expected through the
forecast.

THRESHOLD PROBABILITIES...

* None.

&&

.PREV DISCUSSION...
Issued at 352 AM EDT Sun Aug 10 2025

DISCUSSION...

Southeast Michigan will remain positioned to finish the weekend
period within the western flank of predominate large scale upper
ridging. This affords another day of higher magnitude warmth, within
the backdrop of an elevated mean thickness field, full insolation
potential and prevailing low level southerly flow. Model projection
of low level moisture quality points to a similar profile as noted
yesterday, with dewpoint readings largely parked in the upper 60s to
around 70 degrees during peak heating. Highs targeting the 89 to 93
degree range, lending to an afternoon peak in heat index of middle
90s. Environment lacking in meaningful forced ascent to overcome a
capped, stable mid level profile will largely support dry
conditions. Forecast maintains an isolated opportunity for
convective development over the Saginaw valley late today, with some
indication of greater convergence emerging over central lower mi.

Upper ridging will maintain greater influence into Monday, as
impinging weak height falls struggle to gain traction initially with
an initial lead shortwave shearing more toward the northern great
lakes. This solidifies the resident hot and humid conditions, with
little noteworthy change in either the thermal or moisture profile
again translating into a peak heat index of mid 90s. Main impetus
for convective development remains a southwest to northeast oriented
higher theta-e axis aligned along the edge of the height fall
gradient, allowing interludes of dcva and moisture convergence to
anchor ascent within a less capped environment. This axis eases
further into lower Michigan with time, providing at least a low
potential for late day or evening convective development. Higher
probability with northwest extent, but with prospective coverage
muted overall by a poorly forced environment still featuring a warm
mid level profile. Meager wind fields will keep any activity
disorganized, with slow moving singular cells affording some brief
heavy rainfall.

Gradual decline in upper heights ahead of an inbound mid level
trough will ease the attendant main theta-e plume into the region
Tuesday. This affords the most favorable underlying thermodynamic
profile for convective development this forecast period. With that,
forcing field remains quite ill-defined. Governing mid level
southwest flow along the downstream flank of the upper trough may
yield one or more vorticity maximum this period. Weak pre-frontal
low level troughing and/or boundary interaction from outflow/lake
breeze activity also a possibility. Forecast will continue to
highlight a generic, broad mention for showers and thunderstorms,
targeting the afternoon and evening hours. Again convective
organization contained by low bulk wind shear values, with locally
heavy rainfall the main issue should a greater response materialize.

Convective potential may linger into Tuesday night/Wednesday as the
upper trough axis and associated frontal boundary arrive in response
to a stronger mid level wave ejecting across the northern great
lakes. Less humid conditions then emerge for the late week period as
Canadian high pressure takes control. Inbound airmass cooler
relative to this recent hot stretch but still edged on the warmer
side of average for mid August.

MARINE...
Very warm southerly flow continues with strong near water stability
leading to winds generally under 20 knots. Dry mid levels in place
over the Central Great Lakes will mostly cap thunderstorm activity,
but a few storms are likely to sneak into the northern sections of
Lake Huron as a cold front dissipates nearby to the west.

Monday into Tuesday, a second low develops over southern Ontario and
tracks just north of Lake Superior, drawing a more significant cold
front through the area and clearing out the warm/humid airmass by
mid-week. This front will likely trigger showers and thunderstorms.
Southwest winds shift to the northwest as a result of this frontal
passage as well.

&&

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

$$

AVIATION.....DRK
DISCUSSION...MR
MARINE.......SF

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