textproduct: Detroit/Pontiac

KEY MESSAGES

- Light snow returns for the end of the workweek, with accumulations generally 1-3 inches. The bulk of the snow will fall late Friday morning.

- Temperatures reach or exceed freezing on Friday; however, strong northwest winds at the end of the day (gusting 30-40 MPH) will drive much colder air back into southeast Michigan.

- Wind chills of 10 to 15 degrees below zero are likely Saturday morning before a modest warming trend occurs over the weekend.

DISCUSSION

Despite northwest-north low level flow over Lower Michigan, A Lake Superior-northern Lake Michigan connection is still proving sufficient to lock in clouds (some breaks) and even flurries with the surface temps in the teens. Tough call on the sky cover today, as there will be additional subsidence and subsequent warming/drying at the 850 MB level, as temps warm into the negative upper single numbers. Still, there may be sufficient moisture trapped/lingering at the 925 MB level to support continued mostly cloudy, which is the direction this forecast will lean. That's not to say there will not be a period of sunshine before clouds redevelop in any breaks. With the elevated temps this morning, breaks in the clouds should support maxes in the lower 20 (see warmer NAM mos).

Exceptional upper level ridge over the Great Basin, with 500 MB heights (585-586 DAM) at or near record daily record values for early February. This leads to strong upper level northwest jet over Western Canada tracking into the Western-Central Great Lakes region, which leads to fast moving upper level waves translating through. Two discrete upper level waves/500 MB height fall centers to move through to close our the workweek, one on Thursday and the second Friday morning.

Should see some light snow with the lead wave Thursday afternoon, and utilized the SREF pops for the most part during this period. Although, thermal profiles are less than ideal (have to get to 700 MB level to reach temps around the -10 C), thus southwest flow off Lake Michigan should not contribute much to the moisture profile. As such, would not expect much more than a dusting to one inch through Thursday evening.

The wave/jet on Friday looks to be the stronger one of the two, and will gives us the majority of our snowfall. Euro/Canadian ensembles both indicating 80-100 percent probability of 24 hr QPF to be aoa a tenth of an inch. A 1-3" snowfall seems reasonable based on 850-700 MB specific humidity of 2-2.75 g/kg tracking through. Better moisture progged to track through the Western Ohio Valley Friday morning, but good lift rolls through southeast Michigan. Short duration is expected to limit totals, as strong northwest winds, gusting 30-40 mph late in the day (per local probabilistic guidance) ushers in much colder and drier air. Bulk of the arctic air (-25 C at 850 MB) looks to be tracking through the Eastern Great Lakes and moves east fairly quickly, per 00z Euro.

Slow warm advection pattern for the Weekend, and an elevated warm front may become active for the second half of the weekend and produce a little light snow. However, with the strong high pressure holding at the surface, NBM pops are just indicating slight chance for now. If the upstream warm front does not produce mid-high clouds Saturday night, good chance for min temps to be colder than outgoing forecast (single numbers).

MARINE

Moderate northwesterly winds and colder air will continue as a clipper system pushes away from the Great Lakes region. High pressure dropping out of Canada will expand over the Great Lakes region on Wednesday bringing drier weather and lighter (<15kt) winds. Another clipper swinging out of northern Ontario is expected to draw an arctic cold front over the central Great Lakes late Thursday though Saturday. Strong trailing cold advection looks to offer the next shot at gales and heavy freezing spray (for whatever ice-free waters are still there by that point) over Lake Huron.

PREV DISCUSSION

Issued at 1207 AM EST Wed Feb 4 2026

AVIATION...

Late evening observations indicate considerable coverage of MVFR ceiling still over Lower Mi leading up to midnight. The Great Lakes aggregate is the primary contributor to the cloud supply which is locked into the boundary layer as weak Midwest high pressure builds into the region. NW surface wind and northerly cloud layer wind occur ahead of this weak high pressure extension which also promotes larger breaks of clear sky at times, especially toward the MBS area where a downslope wind component is most pronounced. Cloud layer wind remains from the N-NW during the day which keeps Lake Michigan involved in cloud development while the presence of surface high pressure adds some uncertainty on the eastward extent of ceiling coverage. There is potential for larger breaks to occur and then fill in with a daytime "heating" component and an eventual improvement of ceiling into the lower range of VFR into Wednesday evening.

For DTW... Ceiling near the VFR/MVFR threshold is expected to hold during the late night and morning, and then build higher into VFR with some breaks developing in the afternoon.

DTW THRESHOLD PROBABILITIES...

* High for ceiling at or below 5000 feet late tonight and in the morning, moderate wednesday afternoon.

DTX WATCHES/WARNINGS/ADVISORIES

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