textproduct: Detroit/Pontiac

KEY MESSAGES

- Warmer and breezy Friday - southwest wind gusts to 30 to 40 mph in the afternoon.

- A 40 to 60 percent chance of snow late Saturday with minor accumulations where snow occurs.

- Colder Sunday, then a warming trend through next week.

DISCUSSION

Surface anticyclone is spreading into the eastern Great Lakes, with burgeoning southwest flow advecting in milder conditions this afternoon. Temperatures peak in the upper 30s south to around 30 north, up from morning lows in the single digits and teens. Spotty light snow showers associated with a weakening northern stream wave are spreading into northern Lower this afternoon, with a very low chance for some of these to move across the Saginaw Valley or northern Thumb tonight. Model soundings continue to indicate too much dry air for the weak forcing this far south to overcome, so will keep the forecast dry. The milder air, higher dew points, and increased cloud cover will keep low temps relatively milder in the 20s Friday morning.

Southwest flow strengthens on Friday as a stronger wave moves across northern Ontario. This system will be deepening through the day with its LLJ increasing to 50 to 60 kt over SE MI by the evening. Gusty winds can be expected by afternoon but much of the momentum will be trapped above the developing inversion - gusts are most likely to peak in the 30 to 40 mph range at the surface. Warm and dry air will advect in to result in highs in the lower 50s across much of the area, though the Thumb and Saginaw Valley are more likely to reach the mid to upper 40s. Weak low-level moisture advection precludes a PoP mention but should see some intervals of mid/high cloud. The associated dry cold front passes through overnight into early Saturday to produce a cooling trend through the weekend.

As the front settles south on Saturday, a shortwave will pass over the elevated frontal slope draped over the area to trigger a period of fgen forced snowfall during the afternoon and evening. 12z guidance has come into better agreement for placement of the west- east oriented QPF axis south of I-69, which could be relatively narrow given the nature of forcing. However, there is still an appreciable spread in QPF amounts within the ensemble space with NBM QMD fields showing 25th percentile amounts at 0.00" and 75th at nearly 0.25". Despite the cold air advection, daytime heating will provide a slight boost in temps to around 40 for Metro Detroit and areas south. To the north, highs peak in the 30s. There will also be a fair amount of remnant low-level dry air to contend with during the afternoon, and with the mild temps confidence is low on accumulation during the afternoon. Temps then trend below freezing during the evening bringing higher confidence for minor accumulations of around a half inch to inch. Should the higher end of QPF be realized, snow totals of 2 to 3 inches would be plausible in a narrow swath.

The cooler air fully settles in for the late weekend as arctic high pressure passes through the northern Great Lakes. Temps are currently favored to be on the cool side of normal, with highs Sunday in the 20s and lower 30s and lows Sunday/Monday morning in the teens. Monday will be a period to watch for another round of elevated fgen snowfall across the south as roughly 30 to 40% of grand ensemble members (mainly ENS and GEPS) clip the southern CWA with accumulating snow. Growing confidence then exists for a warming trend through the late week as a trough digs into the western CONUS. Mild and moist southwest flow becomes directed toward the Great Lakes with potential for several rounds of rainfall from late Wednesday into the weekend.

MARINE

A weak system slides across the northern Great Lakes tonight bringing a modest uptick in southwesterly winds towards 20-25kts. Associated snow showers will be confined to the northern half of Lake Huron and generally light. After a brief relaxation in the wind early Friday morning, southwest winds restrengthen through the day as strong low pressure works across northern Ontario. Despite 45- 55kt winds developing aloft during this timeframe, milder airmass still expected to greatly limit overlake mixing capping potential peak wind gusts near 30kts. An arctic cold front quickly follows Friday night ushering in a much colder airmass as well supporting a 5-8hr window for northwest gusts to exceed 34kts over the northern third of Lake Huron (currently 80% probability to reach gales) with lower potential (~30%) to exceed 40kts for a few hours. Freezing spray will accompany these stronger winds including potential for some areas of heaving freezing spray particularly in the northernmost portions of the Lake Huron open waters. A Gale Watch remains in effect north of Sturgeon Point Friday night through early Saturday morning. Strong high pressure then builds over the central Great Lakes Sunday supporting lighter winds and dry conditions to close out the weekend.

PREV DISCUSSION

Issued at 1237 PM EST Thu Feb 26 2026

AVIATION...

Surface high pressure positioned overhead this afternoon drifts eastward while maintaining control of conditions across SE Mi through this evening. It keeps the low levels free of clouds while varying amounts of mid and high coverage move across the Great Lakes from low pressure in central Canada. As this low approaches northern Ontario, cloud layer wind increases from the SW tonight which carries in borderline VFR/MVFR clouds from the Midwest on the leading edge of milder air. These clouds track across Lower Mi from about midnight into sunrise Friday and then clear eastward during the morning. Precipitation struggles to reach this far south leaving VFR above 5000 ft and increasingly gusty SW wind as the weather highlights for the remainder of Friday.

DTW THRESHOLD PROBABILITIES...

* Moderate for ceiling 5000 ft or less late tonight.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Gale Watch from Friday evening through Saturday morning for LHZ361- 362.

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