textproduct: Detroit/Pontiac

KEY MESSAGES

- Intervals of light snow today and tonight, with additional accumulation between a half inch and 2 inches most areas. Localized amounts in excess of 2 inches are possible.

- Brisk on Monday with temps below freezing and morning wind chill in the single digits, only rising to the teens in the afternoon.

- Widespread accumulating snow late Tuesday into Tuesday night, with several inches possible for parts of SE MI.

AVIATION

Deep layer moisture within broad mid level troughing will linger across Se Mi into the evening hours. Steepening lapse rates through diurnal heating will continue to supportive intervals of light snow showers within the broad region of light snow/flurries. This will result in fluctuations between MVFR and IFR based conditions during at least the afternoon. While there will be some departure of the deep layer moisture tonight, northerly flow may drive some residual flurries and low clouds into the metro Detroit terminals. A more notable push of subsidence/drying will then take hold on Monday, offering the potential for improved flight conditions during the day.

For DTW...Periods of light snow will persist through the afternoon. Surface temperatures will rise into the lower 30s. Light snow chances will decrease during the late evening/overnight.

DTW THRESHOLD PROBABILITIES...

* High for ceiling at or below 5000 feet today and tonight. Moderate on Monday.

* High for precipitation type as snow.

PREV DISCUSSION

Issued at 327 AM EST Sun Feb 22 2026

DISCUSSION...

A broader, loosely organized region of lower mid level heights will continue to govern conditions thru the latter half of the weekend. Bouts of more organized upward vertical motion tied to a combination of periodic cva and smaller scale convergence engaging a steep low level lapse rate environment will contribute to periodic light snow or snow shower development thru this time. A more focused region of ascent anchored along an eastward propagating vort max evident tracking across southern lower Mi early this morning. Corresponding increase in coverage of light accumulating snow particularly along/south of M-59 with this feature. Supportive background environment going forward today throughout the area as intervals of super saturation with respect to ice within a weakly unstable profile contribute to generally light intensity snow production, with the main uncertainty being duration of meaningful activity at any one location. There remains a signal for a brief increase in forcing this evening as the upper low/trough currently fixated over northern lake Huron shears back southward. Given the underlying profile, this would offer an opportunity for pockets of higher intensity snow showers to materialize within any enhanced regions of convergence. More efficient accumulation in spots this morning across metro Detroit where a more fluffy character of snow exists. Efficiency may prove more lackluster on paved surfaces as daytime heating works to lift temperatures to/just above freezing into the afternoon, while snowfall rate remains manageable. Greater accum potential again post-sunset as temperatures settle back below freezing and snowfall rate briefly increases. As low level flow veers to north-northeast with time tonight, expectation for at least modest moisture flux to occur off the remaining open water over lake Huron, affording an additive component of lake effect for the northern thumb region through Monday morning. Outgoing forecast will continue to highlight 24 hour accumulation ranging from half an inch /mainly Saginaw valley/ to an inch or two elsewhere. There remains potential for a smaller footprint to exceed 2 inches, with the highest probability between portions of northern metro Detroit to Flint to the thumb region.

Deep layer northerly flow entrenched to start the work week. Notable period of cold air advection overnight into Monday will drag temperatures back below average for late February, with daylight readings mainly in the 20s. Some areas of light snow showers and flurries likely throughout the daylight period as adequate depth to the moisture remains with the cloud layer fixated within the dgz. Any additional accumulation would remain minor. Coldest conditions noted Monday night. Actual low temperature and accompanying wind chill minimum carries dependence on degree of clearing, but any open sky certainly encourages a dip in temperatures to the single digits for some areas by Tuesday morning. This would translate into a minimum wind chill in the vicinity of zero degrees.

Clipper system forecast to lift across the great lakes late Tuesday into Tuesday night. Unsettled model solution space evident in differences in system trajectory and placement/quality of moisture relative to both the system warm frontal passage late Tuesday and with the parent low arrival overnight. This will dictate both accumulation potential and timing across this time horizon. Outgoing forecast currently outlining a broader 1 to 3 inches range for possible accumulation /highest north/, but worth noting a subset of solutions offer a much sharper gradient in qpf along the southern edge acknowledging the variability yet noted with this smaller scale system. Influx of hi res solutions in the coming periods will offer more clarity. Benign conditions Wednesday, before another progressive system provides the next opportunity for snow Thursday.

MARINE...

Cyclonic flow persists across the Great Lakes region with surface low pressure continuing to weaken over Lake Huron. Lingering convergence axis to the north and arrival of a mid level disturbance to the south has allowed broad coverage of snow showers to develop. Snow showers driven in part by the lake aggregate will persist through the evening until the surface low fully phases with a much stronger coastal Atlantic low. This process establishes an expansive pressure gradient that extends into western portions of the Great Lakes, leading to sustained northerly flow around 25 to 30 knots. Combination of ice cover and disorganized low level wind field generally cap frequent gusts below gale force. Potential does exist for nearshore zones to reach advisory thresholds however, as gusts reach 30 knots and wave heights exceed 5 feet in ice-free waters. High pressure then briefly builds in Tuesday to relax the gradient before the next clipper arrives mid-week.

DTX WATCHES/WARNINGS/ADVISORIES

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