Area Forecast Discussion

KEY MESSAGES

- Mild still today with light rain showers around for much of the day.

- Briefly drier to start Thursday before scattered shower return late Thursday-Friday.

- Temperatures return to normal values to end the week.

DISCUSSION

Occluding low pressure continues to lift into the northern Great Lakes shifting LLJ structure over the Mississippi up into the southern Great Lakes. Connection to the Gulf draws anomalous moisture into SE MI this morning as PW values push 1.5", near daily climatological maxima, supporting widespread showers throughout the morning into this afternoon. Gusty southerly winds also accompany this structure as diurnal mixing at least partially taps into 30- 35kt flow at 925mb resulting in wind gusts generally in the 25-30mph though with peak potential towards 35mph. LLJ forcing shifts east into Ontario by the latter half of the afternoon tapering off wider spread rain and transitioning to pockets of lingering drizzle/light rain. Secondary window for greater coverage arrives this evening as a broken line of showers tied to the cold front cross the state.

Significantly drier airmass trails this cold fropa late tonight as the system's dry slot works across SE MI through the first half of Thursday. Southwesterly winds post-frontal winds moderate the magnitude of cold advection keeping slightly above normal temperatures around with highs in the upper 50s to around 60. The, by this point, closed low then sinks southeast across Lake Huron latter half of Thursday into Friday offering another period of scattered light showers. Secondary cold front eventually sweeps through the region Friday morning bringing both a window of enhanced shower coverage as well as briefly ushering in a seasonably average airmass to close out the week. Near to sub 0C 850mb temps result in highs only around 50, give or take a couple degrees either side, both Friday and Saturday. Long range models favoring low amplitude ridging redeveloping over the central CONUS by early next week which would bring back above normal temps to SE MI.

MARINE

Low pressure occludes over the western Great Lakes today, maintaining moderate south to southeast wind across the area today. Warm air aloft maintains stability over the lakes that will limit the higher magnitude wind from mixing down. However, gusts as high as 25 to 30 kt are expected over the open waters of Lake Huron this afternoon and evening while shorter fetch over the nearshore waters will limit gusts to the 20 to 25 kt range there. A Small Craft Advisory is in effect for the Thumb shoreline where wave heights are forecast to build over 4 feet. Saginaw Bay, Lake St. Clair, and western Lake Erie may see a brief period of gusts in excess of 25 kt late afternoon, but confidence is too low for an advisory at this time. A cold front brings light rain late in the day and into tonight with wind veering to southwest behind the front after sunset. The weakening low pressure meanders across the western Great Lakes on Thursday while deeper mixing brings southwest wind to 25 kt across Saginaw Bay. A stronger cold front then tracks southward across the region on Friday. This brings gusty north and northeast wind that shifts northwest and weakens by Saturday. Additional light rain will accompany this frontal passage.

PREV DISCUSSION

Issued at 1147 PM EST Tue Nov 3 2026

AVIATION...

Strong anticyclonic vorticity advection is still ongoing across Southeast Michigan as the region remains situated within high amplitude upper level ridging. Persistent subsidence is forecasted to continue through this evening. Strong thetae advection on +45 knot low level jet arrives after 10z with an axis of shower activity and IFR conditions likely. Dry slotting is expected for the midday period with the potential for shower activity along the cold front 2124z. South to southwest winds Wednesday of 25 to 30 knots.

DTW THRESHOLD PROBABILITIES...

* High for ceiling 5000 ft or less late tonight and Wednesday.

DTX WATCHES / WARNINGS / ADVISORIES

MI...None. Lake Huron...Small Craft Advisory from 10 AM this morning to midnight EST tonight for LHZ441>443.

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