textproduct: Detroit/Pontiac

KEY MESSAGES

- A dusting to half inch of snow accumulation will be focused south of I-69 this afternoon and evening.

- Cold weather will persist through the weekend. Wind chills are forecast to fluctuate between the single digits and teens above zero.

- There will be an additional chance for light snow Saturday afternoon and evening.

UPDATE

Morning forecast update includes an upward revision of PoP and snowfall amounts across the southern CWA this afternoon and evening. Upper jet left exit region nudges in late afternoon and induces a modest isentropic ascent response within the saturated and deep DGZ positioned between 2000 and 12000 ft AGL. The upper moisture will quickly strip out this evening, but GEFS, ECMWF, and CMC ensemble data offer moderate confidence in a couple hundredths of QPF from this forcing. With cold conditions and expected SLRs on the higher end of climo, this would be able to produce up to around a half inch of accumulation for areas south of I-69 and mainly flurries north. Latest hi-res weighted guidance offer 80 to 100% probability for 0.1", 30 to 50% chance for 0.5", and up to 10% chance for 1.0". Peak coverage is expected 4pm to 9pm with accumulating snow tapering off before midnight. Flurries may continue overnight as the Lake Michigan moisture plume advects across the state.

PREV DISCUSSION

Issued at 534 AM EST Thu Jan 1 2026

AVIATION...

Skies have largely cleared this morning within post frontal dry arctic air advection under northwest winds. The northwest winds will back toward the west this morning, driving some of the Lake Michigan moisture plume into Se Mi. Available guidance suggests a mix of MVFR and VFR based strato cu. A region of mid level moisture will move across srn Lake Mi and Lower Mi this afternoon/evening. This will allow some enhancement of the Lake Mi response, likely leading to some flurries and/or light snow showers from KFNT south across the metro Detroit terminals.

DTW THRESHOLD PROBABILITIES...

* Low for ceiling aob 5000 feet this morning. High this afternoon and tonight.

PREV DISCUSSION... Issued at 347 AM EST Thu Jan 1 2026

DISCUSSION...

A very cold start to the morning with temperatures in the single digits to low teens and wind chills to zero and below. This is the result of the arctic airmass now entrenched across SE MI in the wake of yesterday's frontal passage, with 850 mb temperatures holding around -17C to -20C. Dry advection behind the front scoured out cloud cover and has allowed for efficient radiational cooling. The cold persists this afternoon with highs holding in the low 20s. There will be a brief window for some sunshine this morning until the low-level wind field backs to the west, which will release Lake Michigan moisture inland late this morning, while clouds expand in coverage due to daytime heating.

For tonight, a fast moving clipper from the northern Plains will translate into southern Lake Michigan and northern Ohio Valley late tonight. This will mostly result in flurries for the northern third of the cwa, but a low chance for a light dusting will be possible for I-69 south given some very weak lake moisture enhancement from the southern basin of Lake Huron. In general though, the progressive nature of the wave is a limiting factor for accumulation. A second clipper is then favored to target the northern Great Lakes late Saturday. At present time the track of the low and strong vort max looks to hold across northern lower Michigan which would limit snow accumulations to around a dusting, this time favored north of M59, however, any southward progression of forecasted track could creep totals closer to an inch, especially through the Tri-Cities and Thumb. Outside of this, dry conditions and below normal temperatures are favored to end the week.

For next week, the axis of the thermal trough pivots towards the continental NE, allowing a more zonal flow regime to develop and support moderation from the Plains into the Great Lakes. This allows temperatures to return back to near or slightly above normal values by Monday. There is increasing chances for an additional clipper system to target SE MI Monday morning with additive forcing along an elevated warm front. While too early to get into specifics on snow amounts, this setup does present better chances for accumulating snowfall. Primary uncertainties revolve around exact track of the upper wave and attendant frontogenetical forcing, but current signal favors northern lower Michigan into the northern half of the cwa as the most likely corridor for potential snow accumulation in excess of one inch.

MARINE...

Moderate NW winds of 25-30kts, strongest in northernmost portions of Lake Huron, shift to more westerly through the day while largely maintaining strength as the region remains under the edge of broad troughing. While heavier freezing spray potential diminishes over the course of the morning, areas of freezing spray continue for the open waters through Friday as an arctic airmass holds overhead. Winds WNW winds begin weakening into Saturday as the gradient finally begins to slacken. Additional weak clippers round the trough into the region this weekend bringing light snow chances however a still fairly diffuse gradient keeps winds sub 25kts.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until 10 PM EST this evening for LHZ421-441.

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