textproduct: Detroit/Pontiac

KEY MESSAGES

- Patchy fog possible this morning with better coverage of fog for Friday morning.

- Mild and dry through the weekend.

DTW THRESHOLD PROBABILITIES

* None.

PREV DISCUSSION

Issued at 332 AM EDT Thu Oct 22 2026

DISCUSSION...

Longwave ridging over the central Plains will strengthen and expand into the Great Lakes through Saturday in response to a closed low near the Four corners opening up across the Rockies with and interaction with additional upper level disturbances/troughing that builds in across the Pacific Northwest. This will reinforce high pressure across the Great Lakes resulting in persistence forecast to end the week. Highs will again push into the upper 60s today, possibly peaking around 70 under mostly sunny skies. Clear skies and light winds overnight will likely lead to patchy or areas of fog, possibly dense, given the supplementation of shallow low-level moisture under the light northeast flow. Fog likely expands from the Thumb and Tri- Cities before pushing into the interior of SE MI before lifting by daybreak. Temperatures then return back into the mid 60s for a high under sunny skies. Outside of radiational fog concerns in the mornings, above normal temperatures under mostly clear skies persists into the weekend.

The upper level ridge will flatten Monday into Tuesday over the Great Lakes with a cold front pushing over the state. Limited moisture under a weaker temperature gradient will not bring any concrete rain chances thus PoP values will remain sub 15%, however, flattening of the upper-level will direct better moisture and cloud coverage downstream. Temperatures moderate back towards seasonal normals through at least the early week period. ML-models are much more progressive with the forecasted Pacific trough by the middle of next week relative to the deterministic counterparts, which would again bring about above normal temperatures by the middle of next week if they verify, as the warmer air across the Plains streams into the Great Lakes.

MARINE...

High pressure builds into the Great Lakes today behind a departing weak surface trough. Northeast wind becomes established this afternoon, peaking around 10 to 15 kt. Light flow veers around to southeast on Friday, then becomes more southerly on Saturday as the center of high pressure sinks southward from Quebec toward New England. A slight uptick in wind speeds will be possible this weekend in advance of the next weak trough set to arrive from the northwest.

DTX WATCHES/WARNINGS/ADVISORIES

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