textproduct: Detroit/Pontiac

KEY MESSAGES

- Next chance of widespread accumulating snow showers will be tonight into Monday, when 1-3" inches is expected.

- Frigid and blustery conditions Monday with potential for snow squalls and winds gusting 30-40 mph.

- Dangerously cold wind chills of -5 to -15F Monday night into Tuesday morning.

- Another light round of snow likely on Wednesday.

AVIATION

Subtle veering of wind in the cloud bearing layer has caused stratus to expand across much of the area this morning. Prevailing MVFR ceiling today, particularly north of Metro Detroit where lake moisture is most plentiful via low-level southwest flow. A few flurries possible in this plume but accumulating snow is not anticipated during the day. Model soundings show occasional lapses in low-level saturation for the Detroit terminals, so fluctuations to VFR may be possible at times. A clipper system is on track to move into the area from the Midwest this evening, bringing widespread light snowfall to all terminals into tonight. A strong arctic front follows this system Monday morning with snow/cloud character shifting to more localized lake effect streamers through Monday.

For DTW...Intervals between MVFR and VFR are most likely through the morning and early afternoon. Light snowfall favored to start around 00Z this evening and begin to taper off around 07Z. Snow showers then become more prevalent Monday morning with the arctic front passing through around 12Z, shifting wind to the west with gusts quickly ramping up to 30 knots.

DTW THRESHOLD PROBABILITIES...

* Medium in ceilings aob 5000 feet through the day. High tonight.

* Medium to exceed crosswind thresholds Monday morning.

PREV DISCUSSION

Issued at 342 AM EST Sun Jan 18 2026

DISCUSSION...

First wave of arctic air has arrived overnight after dropping into the Ohio Valley with the cyclonic flow then drawing it back northward into far southern MI. This has lead to falling dewpoints into the single digits lifting up across the Ohio border. Lingering band of moisture and snow showers up through Mid MI continues to lose intensity into the early morning with mainly flurries persisting but still some fine lines of convergence helping bring some 2-4SM snow at times. Dry southwesterly flow will continue into the day further scouring out the moisture depth ahead of the next clipper that will slide through tonight. Still with a trough axis in the vicinity and subsidence inversion aloft trapping the low level moisture, it's looking likely that we'll stay overcast today with highs only in the low to mid 20s.

Next chance of widespread snow comes tonight as a clipper dives through the longwave trough encompassing the region. Though the leading mid level vort max digs south of the area, the surface low sets up well to our north over Lake Superior, deepening as it phases with the lingering lake trough over the waters and additional mid level support moves in. Initial prefrontal trough and leading theta e push comes through soon after 00Z this evening. Some additional mid level deformation support slides through on the north side of the mid level wave skirting through Ohio as well. Moisture depth once saturated will rise to over 15kft with the arctic air steepening low level lapse rates through the DGZ which will be between 2-5kft. QPF amounts still reside around 0.1 inch and with the decent forcing and high snow to liquid ratios in excess 20:1 with the arctic airmass, 1 to 2 inches should be possible overnight. Main arctic front then sweeps through prior to 12Z Monday. In addition to the continues strong frontal forcing and low level lapse rates, this front will drag the SW to NE oriented lake convergence axis eastward across lower MI. Mixing depths get a big boost up to around 8-9kft which is all lining up for a decent lake effect day across southern MI. Though initially getting pushed toward the I94 corridor, the westerly flow looks to organize it between I94 and M59 into the afternoon before mid level moisture gets stripped out with weak ridging trying to slide through the area. So the lake convergence axis will be offset somewhat by the arctic air cooling the airmass below the DGZ leading to smaller flakes. Wind gusts will possibly reach 30-40 mph with the high mixing depths accessing 40 knots aloft which will lead to blowing and drifting snow in addition to potential snow squalls. Snow totals for the day Monday will be difficult to pinpoint due to the dependency on the location of the lake band. Would expect a broad footprint of totals of 0.5-1.0 inches with locally higher totals in the vicinity of the band.

Temperatures will be another issue through the front half of the week with the arctic airmass in the negative teens today, dipping further to below -20C on Monday and Monday night. With temps in the teens during the day Monday and Tuesday and dropping to around 0F Monday night with the winds present, Wind chill values will be at or below 0F for the most part these days. Monday night remains the focus for the coldest wind chill potential with negative teens noted in the Thumb and near the Ohio border, but lingering lake effect clouds centered around M59 will lead to slightly warmer values in the -10 to -5F range.

Longwave trough flattens Tuesday into Wednesday with heights increasing and a strong surface high to the south bringing warmer air back to the region with highs back around 30 on Wednesday. Any break in the active weather post arctic outbreak looks short as the next system is already targeting the area for Wednesday bringing another round of snow.

MARINE...

A partial slackening of the gradient this morning allows southwest winds to edge down slightly, toward the 20-25kt range. Next clipper quickly arrives over the northern Great Lakes latter part of today deepening as it slides into eastern Ontario. Associated arctic front is then set to drop across the central Great Lakes Monday afternoon ushering in the coldest airmass of the winter season thus far and widespread snow showers/squalls. Gradient looks to respond most over the southern Great Lakes, given the low center near Manitoulin Island, with west-southwest gale potential developing by Monday morning before the arrival of the actual cold front. For Lake Huron, a roughly 3-5hr window for gales comes immediately along/following the arctic front Monday afternoon-evening with post frontal mixing partially mixing down a 40-45kt LLJ forecast to develop at the base of the low. Gale Watches remain in effect from the central waters of Lake Huron down to Lake Erie as a result. Areas of moderate to heavy freezing spray also likely in this timeframe.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Gale Watch from Monday morning through Monday evening for LHZ362- 363-421-422-441>443-462>464.

Lake St Clair...Gale Watch from Monday morning through Monday evening for LCZ460.

Michigan waters of Lake Erie...Gale Watch from Monday morning through Monday evening for LEZ444.