textproduct: Detroit/Pontiac

KEY MESSAGES

- Chance for drizzle and rain showers this evening.

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

- Temperatures return to normal values to end the week.

DTW THRESHOLD PROBABILITIES

* High for ceiling 5000 ft or less tonight and Thursday.

PREV DISCUSSION

Issued at 335 PM EST Wed Nov 4 2026

DISCUSSION...

The occluded low pressure system now centered over northern Wisconsin will continue to progress east-northeast into Lake Superior and southern Ontario this evening and overnight. This will allow a cold front to traverse across SE MI this evening, with a broken line of showers likely developing along the boundary. A dry slot will build in in the wake of the front as shallow boundary layer mixing commences due to cold air advection. This will bring a period of dry weather overnight with temperatures falling into the upper 40s. Wrap around moisture from the departing low in conjunction with subtle moisture advection from Lake Michigan under west low-level flow with the broader upper-level trough will renew rain chances later in the day on Thursday and through Friday morning. A passage of a secondary cold front will also provide additional forcing and will bring in even cooler air with 850 temperatures dropping down into the negative single digits by Friday morning.

A strong upper-level wave will drive south into the Great Lakes Friday morning before closing off as it progresses into Lake Erie by Saturday morning. This feature will strengthen cyclonic low to mid- level flow, bringing rain chances through Friday especially across the Tri-Cities and Thumb where better moisture advection coming off of Lake Huron resides. Seasonal normal values settle in Friday and Saturday. Highs in the 50s and lows in the 30s are expected. As the upper-level wave departs, influence of the thermal trough will weaken, allowing for a subtle rise in highs through the mid-week period albeit still more in line with seasonal normals. Another trough will build in across Lake Huron Sunday into Monday providing another chance for rain showers, but otherwise there will be a pretty muted signal for precipitation chances into the midweek period.

MARINE...

Occluded low pressure system over the western Lakes will track northeast into Quebec by Thursday morning while pulling a cold front though the area tonight. Lingering stacked upper level and surface troughs will remain draped across the region keeping a southwesterly gradient across the area and continued gusty winds. A Small Craft Advisory is in effect for the Thumb shoreline into tonight where wave heights are forecast to build over 4 feet. Lake St. Clair, and western Lake Erie may see a brief period of gusts in excess of 25 kt late afternoon so they too have a Small Craft Advisory. Deeper mixing in the wake of a cold front tonight brings southwest wind to 25 kt across Saginaw Bay Thursday so a new Small Craft Advisory has been issued for the bulk of the day. 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.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until midnight EST tonight for LHZ441>443.

Small Craft Advisory from 4 AM to 10 PM EST Thursday for LHZ421-422.

Lake St Clair...Small Craft Advisory until midnight EST tonight for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory until midnight EST tonight for LEZ444.