textproduct: Detroit/Pontiac

KEY MESSAGES

- Wind chills minimize in the 10 to 15 degrees below zero range Friday and Saturday mornings; wind chills near 20 below possible for The Thumb and Tri-Cities Friday morning.

- Intervals of flurries or light snow showers possible at times today through Saturday with minimal accumulation expected.

AVIATION

Upper level confluence is expected to weaken lake aggregate surface troughing over the Great Lakes today. Predominate VFR conditions throughout the day for much of the area. Cold air mass will bring the potential for passing flurries or light snow but no significant accumulations is anticipated. Shortwave energy pushing due southward from Canada will sharpen another arctic front or dewpoint gradient late tonight. There is some signal that surface convergence will develop ahead of this front and lead to some better chances for snow showers between 23-05z this evening. Included prevailing groups at all sites for MVFR snow. The better potential appears at KFNT and KMBS but no significant accumulation is anticipated.

DTW THRESHOLD PROBABILITIES...

* High in ceilings around or below 5000 feet today.

* High in precipitation type of snow

* Low in visibilities of 1/2sm or ceilings of 200 ft.

PREV DISCUSSION

Issued at 355 AM EST Thu Jan 29 2026

DISCUSSION...

Large-scale geopotential height adjustments are underway this morning over the eastern half of CONUS as a 500 mb low gets dislodged and sheared by a retrograding inverted shortwave polar trough and a 150+ knot unified jet core. This allows the cold air reservoir from Ontario and Quebec to spill southward this morning. Even though the center of the cold airmass features a minimum 850 mb temperature of minus 30C, the northern Great Lakes will moderate the coldest air upon arrival in Southeast Michigan, generally between minus 23C to minus 20C. Slight moistening and cooling within the boundary layer allows for a diurnal response in lake effect snow showers. Expect limited coverage today, likely in isolated to widely scattered fashion later in the day as northwesterly low-level wind field decreases. Better potential resides over the southern half of the forecast area this evening for brief light snowfall, after the southern Lake Michigan ThetaE plume releases southeastward. Little to no accumulation expected.

Another very cold night develops, although lake stratocumulus will affect how chilly temperatures and wind chills get. Model data has continued to trend cloudier for most of the area, with the main exception being The Thumb, and possibly the Tri-Cities. Further south, the potential to approach/exceed Cold Weather Advisory criteria will be lower. A few additional flurries are possible early tonight, with a lower column perturbation, but accumulations will be light, if any.

Similar thermodynamic profiles should be in place Friday as the inverted mid-level circulation carves through The Plains. The zonally oriented collapsing upper trough axis translates through Lower Michigan causing flow to turn northerly. Yet another opportunity for pockets of light snow/flurries on Friday as steep surface-based lapse rates activate a shallow supersaturated cloud layer (wrt ice). Highs stay parked near the 10F mark, supported by flow trajectories arcing back into the Canadian Prairies. This upstream ridge takes an abrupt southward turn Friday night into Saturday morning as the 1050 mb surface high builds into the southern Plains. This continues the advection of arctic air into the Great Lakes with minus double digit wind chills again late Friday night into Saturday morning. The axis of coldest air should reside just southeast of Lower Michigan, therefore cold headlines are not anticipated. LLJ winds increase, out of the northeast, on Saturday with lake effect snow potential off the Huron basin for The Thumb, and possibly further inland. Higher likelihood for flow-parallel bands during the daylight hours Saturday. The lake-modified air should also help moderate temperatures, slightly, with highs in the mid-upper teens. Height rises arrive early next week, although southern Lower will reside INVOF the baroclinic zone.

MARINE...

The Great Lakes remain under broad upper troughing allowing arctic air to hold across the waters. Winds hold from the northwest at 10- 20kts with gusts up to 25kts through Friday. Trough influence keeps lake effect snow showers active though directed at the Canadian waters and southern Ontario. Some areas of freezing spray are possible through this timeframe in the ice-free waters however lack of strong winds prevent any widespread heavy freezing spray from developing. Slowly moderating airmass and slightly lighter winds continue to look to be in store for the weekend.

DTX WATCHES/WARNINGS/ADVISORIES

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