textproduct: Detroit/Pontiac

KEY MESSAGES

- Widespread accumulating snow peaks in coverage midday and this afternoon with accumulations of 1 to 3 inches. Scattered lake effect snow showers tonight.

- Becoming colder Saturday and Sunday with additional scattered lake effect snow showers. Widespread light snowfall likely Sunday night into Monday morning.

- Frigid and blustery conditions Monday through Wednesday with wind chills holding near or below 0F and additional snow showers. Dangerously cold wind chills near -15F will be possible Tuesday morning.

AVIATION

Area of low pressure will drop into the northern Great Lakes this morning and then across northern Lower MI through the day and overnight. This system will cause conditions to deteriorate through the day with varying CIGS early as some lead bands of light snow push through, but a cold front will sweep through this afternoon/evening bringing a short window, around 4 hours, of IFR and potentially LIFR CIGS and VSBYS as a band of heavier snow passes through. Though light snow will exist through much of the day, this period will result in 1-3 inches of accumulation across the area. Should temporarily dry out immediately behind the front this evening, but then cold southwesterly winds will initiate lake effect snow showers across lower MI. The bulk of the showers should favor PTK, FNT and possibly MBS, with lower chances for the Detroit taf sites. Will keep the prob30s going for those sites as a placeholder for the potential lake effect activity.

For DTW... Light snow or flurries ongoing should taper off around 13Z before the better organized snow band works across the state this afternoon. Trends have been to push back the heaviest snow slightly so will drop it back an hour to 18-21Z. Scattered lake effect showers are possible overnight but coverage and confidence will be better to the north of PTK so will hold off on any mention at this time.

DTW THRESHOLD PROBABILITIES...

* High for ceiling 5000 ft through the forecast.

* High for precipitation type of snow today and tonight.

* Medium confidence in visibility restrictions to 1/2sm in falling snow this afternoon.

PREV DISCUSSION

Issued at 409 AM EST Fri Jan 16 2026

DISCUSSION...

An upper low dropping into the Midwest is driving the region of light snowfall working in from the west early this morning. Modest isentropic ascent ahead of the low will continue to spread overhead through mid morning which will gradually displace low-level dry air to allow flurries and light snow to increase in coverage over the next few hours. There has been a trend toward slightly lower amounts this morning and just a dusting is most likely through the morning commute. A peak in snowfall rates is still anticipated midday and this afternoon as forcing ramps up in response to height falls/PVA with an amplified shortwave tracking directly overhead, coincident with upper divergence within the left exit region of the upper jet. This period of stronger ascent will be centered between 11AM and 5PM with rates becoming briefly moderate before the dry slot arrives and provides a transition into a more scattered/lake effect character this evening into tonight.

Soundings show the DGZ initially positioned around 8-10 kft AGL with a relatively deep isothermal layer around -9 to -10C beneath. Meanwhile surface temps rise from the teens this morning to the lower 30s by this afternoon. Omega is generally focused near or just above the DGZ, suggesting some dendrite production as well as some riming on the way down. SLRs are expected to be a bit higher than climo, around 15:1. Signal among ensembles offers high confidence in QPF between 0.05 and 0.20" through 7PM, supportive of widespread snow totals of 1 to 3 inches. Did weigh issuing a Winter Weather Advisory considering snowfall timing with the evening commute, but prefer to handle with SPSs given the brief nature and generally minor impacts suggested by model data. Hi-res ensemble QPF LPMM targets the northern Saginaw Valley to receive near or over 0.20" with this initial round which favors the higher end of the snowfall range in this area and the potential to exceed 3 inches.

Widespread accumulating snowfall ends by this evening with the arrival of the dry slot, but then lake effect snow showers will affect parts of the area through the night. Low-level wind convergence within the prevailing SW flow directs the best banding along and north of the I-69 corridor where additional accumulations of a dusting up to around 1 inch will be likely overnight. Persistent cyclonic flow aloft with arctic air wrapping around the system and engaging Lake Michigan moisture flux brings additional chances for lake effect snow showers through the day Saturday with relatively low confidence on placement of minor accumulation, but again the SW flow would favor areas north of Metro Detroit. Higher confidence in an uptick in snow shower coverage exists Saturday night into Sunday morning as passage of a surface trough offers a more defined signal for shower activity. A general half inch to 1 inch accumulation is most likely through this period.

The next wave embedded in the persistent longwave troughing pattern arrives Sunday night, ushering in a reinforcement of arctic air with 850mb temps progged to drop to near -25C by late Monday. Widespread light accumulating snow will be likely late Sunday into Monday with blustery/squally conditions following during the day Monday as the arctic air mass surges in. Frigid conditions Monday last through Wednesday morning with wind chill holding below 0F for most of this period. Monday night/Tuesday morning will be a target for potential Cold Weather Advisory headlines as wind chill bottoms out near -15F. Snow showers will also remain pervasive through the mid-week as the DGZ resides within the boundary layer and lake moisture continues to wash over the state.

MARINE...

Two main low pressure systems affect the Great Lakes over the next few days. The first moves in from central Canada early this morning and through the day bringing a pattern of snow across the region. Increasing south wind ahead of this system helps displace arctic air while still remaining cold enough for snow. Wind speed remains below gales as the center of low pressure moves slowly across Upper Michigan and northern Lake Huron through Saturday. This is followed by a brief period of high pressure Sunday and then the next low Sunday night into Monday. This system brings a strong surge of arctic air, and the next potential round of gales, that dominate conditions across Lake Huron and Lower Michigan through early next week.

DTX WATCHES/WARNINGS/ADVISORIES

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