textproduct: Detroit/Pontiac

KEY MESSAGES

- A Dense Fog Advisory is in effect for SE Michigan until 10 AM this morning, except for the Tri Cities and northern Thumb.

- There is potential for more dense fog Monday morning with similar late morning dissipation timing.

- High temperatures increase to around 70 today before a dry cold front drops readings back into the upper 50s to low 60s Monday and Tuesday.

- Dry weather continues through the middle of next week.

DISCUSSION

High pressure centered on the mid Atlantic coast extends back across the Ohio valley while remaining the primary weather influence in SE Mi today. As has been the case the last few mornings, fog is once again a factor leading up to sunrise with a slightly different footprint each night depending on boundary layer wind direction. The SE component this morning has a plume augmented by Lake Erie and St Clair moisture moving inland leading up to forecast issuance time. Hi-res model wind guidance indicates continued veering of the boundary layer flow that favors a shift toward the north and east during the early morning. The Dense Fog Advisory factors this in although with a chance for additional refinement on areal coverage based on observations leading up to sunrise.

Conditions otherwise exhibit thickening mid and high clouds moving in ahead of the Midwest frontal system. The leading low to mid level moisture axis is also producing pockets of radar returns from NW Lower Mi back into southern WI. Model depictions of theta-e advection are modest over top of dry air below 700 mb leaving little more than virga indications through the day. High temperatures near 70 are the weather highlight, averaging 10 to 15 degrees above normal for late October.

The surface cold front is slightly more productive as it enters northern Lower Mi this evening with the chance for a sprinkle grazing Saginaw Bay and northern Thumb by sunrise Monday. Even that tends to fade as the low level frontal zone settles farther south from mid level short wave and upper level jet support that is well north in Canada. The system lacks moisture but does carry in enough cooler air to drop temperatures back down toward more typical late October readings in the upper 50s and lower 60s Monday afternoon and lows in the mid 30s to around 40 by Tuesday morning.

The mid to late week period is set for resumption of above normal temperatures as low pressure organizes across the Plains and central Canada. The early week Great Lakes front stalls in the Ohio valley and is then pulled back north across the area by the Plains to Midwest low pressure system. Solutions among the 25/00Z models are once again lean on QPF due to limited forcing this far east along the warm front. Prospects for rain look better along the trailing cold front expected in Lower Mi late Thursday into Friday.

MARINE

An uptick in southwest winds over Lake Huron is anticipated today, ahead of a cold front that will slowly drop south across the region later today through tonight. Overall, the front is progged to weaken and slow down as it moves through. Thus, shower chances are highest up across northern portions of Lake Huron today. By morning Monday, post-frontal northerly winds will prevail across Lake Huron. As the front continues to sag southward these north winds will gradually take over across Lake St. Clair and the Michigan waters of Lake Erie during the day Monday. With the return of onshore flow, waves build to around 2-3 feet along the Lake Huron shoreline. Falling short of small craft concerns, but something to keep an eye on.

High pressure quickly transits the region Monday night into Tuesday, moving across eastern Canada and into New England area. This trajectory puts us in a favorable environmental for more onshore flow as north winds become northeast and easterly Monday night through Tuesday. The pattern then becomes more progressive, with a series of low pressure systems tracking through the western Great Lakes region.

PREV DISCUSSION

Issued at 1150 PM EDT Sat Oct 24 2026

AVIATION...

Generally dry and stable conditions will persist throughout southeast Michigan this period, as high pressure centered to the east maintains control. This environment will again offer a favorable environment for some degree of fog formation overnight into Sunday morning. Prevailing light low level east to southeast flow will support moisture flux off lake Erie, with a noted increase in fog just south of the Detroit corridor already. This suggests an increasingly likelihood for LIFR fog to emerge across this area during the early morning. Less confidence overall toward the north, but with some persistence within this pattern suggesting the likelihood remains high enough to maintain LIFR in the forecast for all locations. Standard improvement in conditions where fog becomes dense during the late morning hours, leaving another day of VFR/clear skies into the afternoon and evening Sunday.

D21/DTW Convection... Thunderstorms are not forecast through the TAF period.

DTW THRESHOLD PROBABILITIES...

* Moderate for cigs/vsby below 200 ft and/or 1/2SM Sunday morning.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Dense Fog Advisory until 10 AM EDT this morning for MIZ055-060>063- 068>070-075-076-082-083.

Lake Huron...None.

Lake St Clair...None.

Michigan waters of Lake Erie...None.