752
FXUS63 KDTX 272305
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
705 PM EDT Fri Jun 27 2025

.KEY MESSAGES...

- Temperatures cool into the mid 80s Saturday before climbing back
toward 90 degrees Sunday and Monday

- Another cold front brings chances for showers and thunderstorms on
Monday.

&&

.AVIATION...

Lingering window for additional isolated convective development as
the cold front moves across the region. Upstream observational
trends and latest model guidance suggest potential remains too
limited to highlight attm. Moist low level environment will again
bring potential for lower stratus develop overnight within the
immediate post-frontal environment. Sufficient gradient suggests
less likelihood for fog formation despite the elevated near surface
moisture enhanced by recent rainfall. Forecast will continue to
highlight a window for MVFR cigs. Drier and more stable conditions
will exist Saturday, with limited cu potential within a modest west-
northwest wind.

For DTW/D21 Convection...An isolated thunderstorm remains possible
through the remainder of the evening.

 THRESHOLD PROBABILITIES...

* Low for thunderstorms late this evening.

* Low in ceilings at or below 5000 through tonight.

&&

.PREV DISCUSSION...
Issued at 332 PM EDT Fri Jun 27 2025

DISCUSSION...

Per SPC/RAP mesoanalysis, a theta-e local minima currently sliding
across SE MI has aided in hampering any early convection this
afternoon. Instead the tongue of enhanced theta-e just east of Lake
Michigan is favored area for convective development which can
already an be seen on satellite/radar obs over NW IN/SW MI. Overall,
forecast thoughts remain the same from morning update so details
won`t be repeated here. The whole CWA has been placed under a Severe
Thunderstorm Watch until 9PM.

Surface cold front tied to low pressure sliding into northern
Ontario/Quebec clears the region by Saturday morning ushering in a
slightly cooler, drier airmass to start the weekend. Dewpoints drop
to the lower 60s/upper 50s as mid-level height rises build into
southern lower MI. Combination of both decreases lingering cloud
cover promoting mostly sunny skies by afternoon as well as
preventing any pop-up late day convection. Highs hold near average
in the lower to mid 80s with some upper 70s possible in the Thumb
owing to closer proximity to transient thermal trough.

Developing low pressure over the northern Plains/Great Lakes lifts
another warm front through the central Great Lakes Saturday night-
Sunday bringing a return of deeper layer south-southwest flow
pushing 850mb temps to 18-20C and dewpoints to the upper 60s-near
70F. No convection is anticipated daytime Sunday as the region
remains under mid-upper ridging and strong elevated warm advection
caps the environment. This breaks down by early Monday as height
falls tied to the Plains upper trough arrives over the Great Lakes.
Some early day convection is possible given the humid airmass is
place however the bulk of storm chances are focused the latter half
of Sunday as the attendant cold front advances through the western
Great Lakes. Similar to this week, an isolated strong to severe
storm looks possible with 0-6km bulk shear holding around 25kts and
>1000J/kg of SBCAPE. Cold front clears the area overnight Monday.

Midweek period is favored to be dominated by upper troughing over
the eastern CONUS with surface high pressure over the central
portions of the country. This promotes a more seasonably average
airmass and very limited precip chances.

MARINE...

A warm and humid airmass is in place offering opportunities for
showers and thunderstorms later today as instability builds through
the peak of the diurnal cycle. The time-frame of greatest concern
will be between 21Z and 02Z as a cold front works across the central
Great Lakes. A Severe Thunderstorm Watch is in effect for the
southern waterways (south of Point Au Gres) until 9 PM for the
anticipated storms. These could lead to rapid visibility reductions
due to torrential rainfall and strong gusty winds in excess of 40
knots. Given that the prevailing SW gradient winds should generally
hold below 15 knots (and gusts below 25 knots), no marine hazards
are currently in effect, although Saginaw Bay and portions of the
southern Lake Huron shoreline may approach the gust threshold. Short-
fuse marine weather statements (MWSs) and/or special marine warnings
(SMWs) will likely be needed once activity approaches the waterways.
Winds then veer toward the WNW after the front clears through with
lighter winds and drier conditions Saturday as high pressure fills
in. The next low pressure system enters the northern Great Lakes
Sunday night into Monday driving a stronger cold front through the
region providing additional storms Monday and a stronger post-
frontal wind field Tuesday.

HYDROLOGY...

A cold front tracks across SE Michigan this evening, bringing a
broken line of thunderstorms through the region between roughly 4 PM
and 9 PM. These storms will occur in a warm and moisture-rich
airmass which will be favorable for rainfall rates to exceed 1 inch
per hour. Localized flooding will be possible, especially
considering the several inches of rain that has already fallen in
some spots this week. Typical urban, small stream, and flood prone
areas are most at risk but also any location that has experienced
repeated rounds of showers and thunderstorms.

&&

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

$$

AVIATION.....MR
DISCUSSION...KDK
MARINE.......KGK
HYDROLOGY....MV/SF/KDK

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at www.weather.gov/detroit.