textproduct: Detroit/Pontiac

KEY MESSAGES

- Cooler temperatures can be expected Tuesday.

- Mild weather will then prevail through the rest of the week.

- There is a chance for light rain Thursday and Thursday night.

DTW THRESHOLD PROBABILITIES

* Low for cigs at or below 5000 ft through Tuesday.

PREV DISCUSSION

Issued at 348 PM EDT Mon Oct 26 2026

DISCUSSION...

The surface cold front will exit south of the state by late afternoon. The shallow low level frontal circulation and lack of upper level forcing has maintained a dry fropa across Se Mi today. The cold front has been driven southward as a 1035mb sfc high expands across northern Ontario. This high will sustain low level anticyclonic flow across Se Mi through Tuesday as it drifts toward srn Quebec, resulting in continued dry weather across Se Mi. Post frontal cold air advection will drop 925mb temps down into the single digits tonight. A light gradient flow and occasional mid/high clouds will offer some limit to radiational cooling tonight, supporting lows from the upper 30s in the thumb to mid 40s in Detroit. Residual shallow cold air within east-southeasterly sfc winds will limit daytime mixing on Tuesday, supporting daytime highs of mid 50s in the thumb to low 60s across metro Detroit south.

Occasional mid/high clouds will persist into Wednesday as a broad mid level warm air advection regime envelops the region within emerging deep layer southwest flow. An embedded short wave impulse is forecast to lift into the Great Lakes region from the southwest Wednesday. Model cross sections indicate elevated and shallow moist isentropic ascent associated with this feature, not supportive of rain. Veering of the surface winds toward the south on Wednesday with the continued eastward departure of the surface high will drive 925mb temps into the teens. Probabilistic guidance is well clustered on highs into the low 70s Wednesday within the pattern, roughly 15 degree above seasonal norms.

A northern stream short wave will drive a sfc cold front into Lower Mi on Thursday. There are indications that the deep layer frontal structure will weaken/become frontolytic as it tracks across Se Mi Thurs/Thurs night. Nonetheless, a narrow axis of deep layer moisture with some steeper mid level lapse rates will warrant a chance of showers. Probabilistic guidance suggests the better chances will be across the Tri Cities and thumb. Strong indications within the data indicate that if it were to rain, QPF amounts will be a few hundredths of an inch at best. Strengthening southwest flow in advance of the front will set the stage for a mild day Thursday as model soundings and prob guidance support highs in the low to mid 70s. Any semblance of post frontal cold air advection looks brief as the northern stream jet retreats to the north allowing mild air to remain entrenched across the Great Lakes region.

MARINE...

Ongoing post frontal cold air advection is boosting northerly wind gusts into the 15 to 20 knot range across Southern Lake Huron. Recent runs of the wave model are suggesting significant waves across the southern basin and portions of outer Saginaw reaching 3 feet this evening, with max wave heights in the 4 to 5 foot range. While somewhat borderline, a short fused small craft advisory has been issued for this evening.

Winds and waves will decrease overnight and will veer more easterly associated with strong high pressure expanding to the north of Lake Huron. The high will become centered over New England by Wednesday. This and an approaching cold front from the northwest will result in south-southwesterly winds across the lakes. An increase in the southwest gradient immediately ahead of the front on Thursday will boost wind gusts to 20 to 25 knots. While the wind response may be tempered a bit by the warm air advection across the lakes, the southwest flow may lead to another round of hazardous conditions to small craft on Saginaw Bay.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until 4 AM EDT Tuesday for LHZ442-443.

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