textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry conditions tonight with some areas of fog possible.

- Much warmer conditions Monday with highs near 80 degrees.

- Well above average temperatures continue Monday night and Tuesday, with a chance of showers with isolated thunderstorms.

- More typical fall weather mid to late week.

DISCUSSION

Moist low level easterly flow entrenched locally late this afternoon, maintained within the outer influence of the remnant circulation of post-tropical cyclone Isaias now ejecting northeast across the southern Ohio valley. Any lingering pockets of light showers/drizzle will end as meaningful mid level deformation associated with this system vacates and moisture depth diminishes, leaving simply extensive stratus heading into the evening period. Low to mid level ridging will then build into the region through the night. Combination of increasing magnitude of dry air advection and general subsidence will support a clearing sky from northwest to southeast. Favorable environment will then emerge for some degree of fog development late tonight. Forecast will continue to highlight patchy mention, but a more focused region could materialize should winds fully decouple. Overnight low temperatures will remain mild for mid-October, bottoming out in the Low to mid 50s across most locations, with upper 50s held in the Metro Detroit urban corridor.

Higher magnitude upper ridging briefly takes residence during the early week period. This occurs as departing surface ridging affords a shift toward low level southwest flow, offering a period of strong warm air advection starting Monday. A moderately mixed profile under high insolation potential as 850 mb temperatures push into the mid teens will translate into well above normal temperatures. Highs Monday arriving in the upper 70s to lower 80s most locations. Very mild conditions persist into Monday night with temps holding in the 60s, as a frontal boundary eases southward into the northern great lakes. Meaningful nocturnal window for moist isentropic ascent will bring potential for some shower production during the overnight hours. Mid level instability increases during this time, supportive of an isolated thunder mention. Temperatures will remain a solid 10- 15 degrees above average Tuesday as 850 mb temps peak near 18c ahead of an inbound cold front. Weak cold front slips through late Tuesday, which could offer a lower end probability for shower development although greater ascent will remain positioned to the north.

Shortwave energy working across the lingering elevated frontal slope will bring another opportunity for light rain development Tuesday night into early Wednesday, with greater potential with southward extent. Otherwise, pattern transitions back to more seasonable conditions for the latter half of the work week as transient low to mid level ridging lifts through. Potentially unsettled conditions Thursday night into Friday as general split flow yields an influx of moisture from the south with the possibility of interaction with a more dynamic wave ejecting southeast. This northern stream wave will provide a more noteworthy downward adjustment in temperature for next weekend. Highs likely parked in the 50s, with lows pushing well into the 30s.

MARINE

Remnants from Hurricane Isaias will depart into New England this evening which will be followed by a brief ridge of high pressure building in over the Great Lakes. This will support lighter winds across the region through tomorrow night. A weak low pressure system will then move from the central Plains into northern lower Michigan tomorrow into Tuesday morning. Some slightly elevated wind gusts around 20 knots will be possible across northern Lake Huron with the arrival of this system, along with rain and isolated thunderstorm chances. A cold front will then push through on Wednesday morning, bringing additional chances for precipitation. Northwest flow in the wake of the front will support gust potential aoa 20 knots across northern Lake Huron through Wednesday.

PREV DISCUSSION

Issued at 136 PM EDT Sun Oct 11 2026

AVIATION...

Tropical moisture continues to produce widespread IFR to occasionally LIFR restrictions across the airspace. Showers have been subsiding through the day as moisture depth decreases, although low level moisture will be the last to peel away keeping low stratus around through the evening. As skies clear and the subsidence inversion lowers, the stratus layer transitions to hybrid fog/stratus. Winds shift to the southwest Monday morning ushering in drier and warmer air that helps mix out the remnant moisture to leave just high cloud in place for most of the day.

D21/DTW Convection...No thunderstorms forecast during the period.

DTW THRESHOLD PROBABILITIES...

* High in ceilings aob 5000 feet Sunday.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None.