textproduct: Detroit/Pontiac

KEY MESSAGES

- Mild temperatures will persist through Thursday.

- The next round of precipitation is on schedule for Tuesday night and Wednesday. All rain is expected with a low chance for freezing rain north of M 46.

- A rain/snow mix moves in by Friday followed by a temperature drop back toward mid/late February normals this weekend.

DISCUSSION

A cluster of showers and thunderstorms traversed northern Lower Mi today, associated with a compact mid level short wave. Current observational trends indicate the rain remaining north of the thumb late this afternoon. South of this feature, southerly flow has driven an axis of warm low level air across Se Mi. Enough diurnal mixing has occurred today to drive temps into the 50s over much of the forecast area. Weak sfc low pressure trailing the precipitation across the northern lakes will track east of Lake Huron tonight and will drive a weak cold front into Se Mi. Weakening of the sfc flow, nocturnal cooling and ample boundary layer moisture will provide favorable conditions for fog and low stratus development. Sfc high pressure will expand across Lake Huron on Tuesday, allowing an easterly component to the surface winds. This will suppress Tuesday highs a bit in relation to today, with forecast highs in the 40s (30s near the Lake Huron shore).

An upper wave will translate across the Midwest Tues night and across Lower Mi Wednesday. Excellent deep layer moist isentropic ascent will proceed this wave, aided by the ageostrophic response within the exit region of a 160 knot upper jet. The ascent will be focused overnight Tuesday into Wednesday morning. This combined with efficient Gulf moisture transport will support widespread rain. Wet bulb cooling within the easterly flow may allow temps to drop below freezing for a time across portions of Midland/Bay/Huron Counties Tues night. This will warrant a mention of freezing rain in these areas. Given the surge of warm air, the risk for anything more than a glaze of icing looks minimal. Steepening mid level lapse rates within the ascent will also support a slight chance of thunderstorms. The passage of the mid level trough will allow mid level drying to take hold during the latter half of the day Wednesday. The upper wave is forecast to become more elongated across the northern lakes Wednesday. This and the icy waters of the Great Lakes will limit the northward progress of the associated warm front into Se Mi Wednesday. Model guidance is supportive of highs reaching the upper 50s/lower 60s south and upper 30s/lower 40s across the northern Saginaw Valley and thumb.

There is reasonable model agreement showing a secondary wave emerging in the lee of the central Rockies and rotating into the Great Lakes Thurs night into Friday, proving the next chance for precipitation, mainly rain. Seasonally cold air is forecast to circulate around this system and into Se Mi Friday/Saturday.

MARINE

Widespread rain and isolated thunderstorms exit into Ontario over the next hour or so, driven by the surface low that is currently tracking across northern Michigan. This low pushes into Lake Huron this evening while a strong inversion just off the deck caps gusts around 20 knots. The system's cold front sags across lower Michigan overnight, eventually setting up a deformation axis that splits flow from northwest across Lake Huron to southwest across Lake Erie. Meanwhile, the next low pressure system deepens upstream causing winds to organize out of the east-southeast locally by Tuesday night. Elevated portions of the warm front expand across the waterways Wednesday, but enough depth to the cold air remains in place across northern Lake Huron to mix down enhanced low level jet winds. A Gale Watch has been issued north of Sturgeon Point as easterly gusts reach 35 to 40 knots for most of the daytime hours Wednesday. Marine areas south of Sturgeon Point likely see rain with this system, with increasing chances for wintry mix to the north. Next round of elevated wind potential comes Friday as another low pressure system impacts the Great Lakes region.

HYDROLOGY

Widespread rain will precede an upper wave and associated warm front Tuesday night into Wednesday. There has been a slight reduction in forecast rainfall totals in the latest probabilistic guidance, suggesting low to moderate probabilities for one quarter to one half inch of rain south of I-95 and low to moderate probabilities for a half to three quarters inch north. The rain will occur on top of a melting snowpack that has a Snow Water Equivalent analysis ranging between 0.5" to 1". The combination of rain and snow melt on frozen ground may lead to rises on area streams and rivers. Ponding of water on roads is also possible, especially where drains could be blocked by snow and/or winter debris.

PREV DISCUSSION

Issued at 1204 PM EST Mon Feb 16 2026

AVIATION...

Morning fog has mixed out, as south-southwest winds increase this afternoon (aoa 10 knots) with low pressure moving over northern lower Michigan. A few gusts aoa 20 knots are possible late this afternoon, particularly over northern sites. Winds diminish this evening and tonight as the weak cold front from the departing low sinks south. The weak low level convergence, continued snow melt today, and elevated dew pts (above 32 degrees) will once again bring fog potential tonight. However, high degree of uncertainty if we get down to IFR/LIFR or hold mainly in MVFR, as there looks to be a mid deck of clouds over southern Lower Michigan overnight, which argues against dense fog. However, there are even a few solutions indicating enough saturation down low to produce light drizzle/sprinkles across the southern TAFS. Across the north/MBS, there is modest low level dry air working in behind the front, but that still may not be enough to prevent low clouds/fog. Went with low MVFR visibilities at the very least and allowed for the potential borderline IFR/LIFR across the southern tafs.

DTW THRESHOLD PROBABILITIES...

* Low for cig/vsby below 200ft and/or 1/2SM tonight into Tuesday morning.

* Low for cig aoa 5000 feet tonight into Tuesday morning.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Gale Watch from late Tuesday night through Wednesday afternoon for LHZ361-362.

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