textproduct: Detroit/Pontiac

KEY MESSAGES

- Strong winds develop late this afternoon and continue intermittently tonight. A Wind Advisory is in effect for all of SE Michigan.

- A band of showers with scattered thunderstorms moves through Lower Michigan tonight. An isolated storm could approach severe intensity and a Marginal Risk is in place for all of southeast Michigan for mainly a damaging wind threat.

- Hazardous wind gusts continue Monday as arctic air sends temperatures from the 50s Monday morning into the 20s by Monday evening. Arctic air also brings increasing chances for lake effect snow showers and possible snow squalls Monday afternoon.

- Wind chills bottom out around zero Tuesday morning with highs only in the mid to upper 20s Tuesday afternoon.

DISCUSSION

The Wind Advisory is expanded across all of SE Mi and extended through Monday evening with this afternoon's forecast update. Satellite and surface observations so far today are tracking the well-mixed warm sector from the Ohio valley into Lower Mi this afternoon and evening. Peak gusts in the 40 to 50 mph range have been prevalent across IL/IN and reached the Ohio border stations as of 3 PM. Similar gust conditions are expected to push farther north into SE Mi during late afternoon and evening. The northward elongation of the deepening low pressure center is the key in this case to overcome the customary influence of the eastern Great Lakes to delay northward progress of the warm front, although it still has a stabilizing influence closer to the shorelines and with northward extent. Advisory level gusts become more intermittent after sunset as model soundings indicate some perishable boundary layer stability. Gust frequency increases again after midnight as thermal profiles become more neutral, as the low level jet peaks overhead, and as showers increase across the area. This is followed by a wind surge with the cold front and then hazardous gusts that continue through Monday as cold air surges into the region and the primary surface low drops to near 980 mb depth in northern Lower Mi Monday afternoon.

Showers become widespread across the area during the evening with isolated to scattered stronger thunderstorms still to evaluate going through the night. Taking cues from afternoon observations and hourly mesoanalysis shows a few lightning strikes now in far SW Lower Mi feeding into deeper convection along the cold front trailing off into the mid MS valley. MUCAPE is still sub 500 J/kg at mid afternoon which is captured well by the 12Z HREF that shows the surface based instability axis moving into and then collapsing over southern Lower Mi. Various hi-res models seem to acknowledge the instability trends with solutions that show convection in a more organized linear mode to the west and south this afternoon tending to become more cellular to the north into Lower Mi while maintaining some structure toward the Ohio valley. The wind profile remains worthy of respect for any surface based cell that can survive the shear, and a Marginal Risk for severe intensity remains in place for the area until the cold front sweeps through toward sunrise Monday morning.

Monday carries a return to winter for the Great Lakes as cold air surges into the region. The Wind Advisory highlights 45 to 50 mph wind gusts, however the parent low pressure system is increasingly supportive of lake enhanced snow showers/squalls during the afternoon into Monday evening. Model soundings indicate convective depth approaching 10 kft by mid afternoon aided by the 500 mb trough and cold core reaching down to near -35 C. Mid March daytime heating also contributes to the steep lapse rate below cloud base and the strong wind field adds a component to the snow squall equation while direction shifts SW to NW by evening. The forecast is leaned toward greater coverage making it into SE Mi from the Lake Michigan shoreline, and a localized quick inch of accumulation is in reach where any location gets more than one snow shower.

Cold air is then rooted in the Great Lakes for the mid week period highlighted by wind chill around zero Tuesday morning. The next round of snow still looks light in mid week model data and marks the beginning of a late week warming trend.

MARINE

An anomalously strong low pressure system will travel from southern Lake Michigan late this evening, strengthening as it moves in across northern Lake Huron by tomorrow morning and afternoon. This will bring a wide array of unsettled conditions, including extended windows for gust to gales, rain showers, snow showers, and highly localized freezing rain/sleet chances.

For this afternoon... A warm front and associated strong low-level jet now over southern Michigan will continue to push north, stalling around north-central Lake Huron by this evening. Stability has quickly increased across the southern Great Lakes with the advent of warmer temperatures which hold gust potential to below gales. The exception remains across north and north central Lake Huron as a more neutral thermal profiles have allowed for strong winds aloft to mix down.

For this evening... The approaching low pressure system will rapidly increase the strength of the pressure gradient over the eastern Great Lakes. The strength of the pressure gradient alone will likely still support elevated gusts around 25 to 30 knots despite southern locations being in the warm sector. For locations north across north- central and northern Lake Huron, a lull in gust to gales will be possible favored in the late evening and early morning hours Monday as the center of the low arrives overhead. In this window, freezing rain to sleet will be possible across northern Lake Huron, with rain and some isolated thunderstorm chances holding for locations south.

As the low departs the region late tomorrow into Tuesday morning, a strong cold front delivering arctic air arrives over the Great Lakes. This will produce a well mixed environment and will bring the most favorable conditions to see gust to gales for all locations, down through Lake St. Clair and Lake Erie. The intrusion of cold air will also convert any rain showers back over to snow showers and will bring the likely chance for heavy freezing spray. A Heavy Freezing Spray Warning has been issued for all of Lake Huron. Additionally, isolated squalls will be possible Monday afternoon and evening, favored across the southern Lake Huron basin, Lake St. Clair, and Lake Erie. Gale potential lasts through at least Tuesday morning before a brief ridge of high pressure fills in by Tuesday afternoon, ending gales. Gale Warnings are in effect for all marine zones.

PREV DISCUSSION

Issued at 118 PM EDT Sun Mar 15 2026

AVIATION...

Surface warm front is slowly lifting out of northern OH into SE MI this afternoon, clearing the southern terminals by late afternoon and eventually the northern ones by early evening. Behind the front, VFR conditions are maintained with limited low cloud (<5kft) though southerly winds quickly strengthen with peak gusts into early tonight around 40kts. System's cold front eventually arrives over southern lower MI tonight supporting a preceding line of gusty showers and thunderstorms pushing over SE MI late tonight (~5-10Z). Given the late arrival window, decaying convection/convective remnants are likely so have opted to maintain prob30 thunder groups for this forecast update.

For DTW...Dry and windy this afternoon into the evening once the warm front lifts north of the airport. A line of gusty showers and some thunderstorms work through from the west late tonight. Convective gusts possibly approach 50 knots.

DTW THRESHOLD PROBABILITIES...

* Low in ceilings at or below 5000 through this evening, moderate to high tonight.

* Low in thunder late tonight into Monday.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Wind Advisory until midnight EDT Monday night for MIZ047>049- 053>055-060>063-068>070-075-076-082-083.

Lake Huron...Gale Warning until 11 AM EDT Tuesday for LHZ361-362.

Heavy Freezing Spray Warning from 2 PM Monday to 5 PM EDT Tuesday for LHZ361>363-421-441>443-462>464.

Gale Warning from 8 PM this evening to 11 AM EDT Tuesday for LHZ363- 441>443-462>464.

Small Craft Advisory until 8 AM EDT Monday for LHZ421-422.

Gale Warning from 8 AM Monday to 11 AM EDT Tuesday for LHZ421-422.

Small Craft Advisory until 8 PM EDT this evening for LHZ441>443.

Lake St Clair...Small Craft Advisory until 5 AM EDT Monday for LCZ460.

Gale Warning from 5 AM Monday to 11 AM EDT Tuesday for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory until 5 AM EDT Monday for LEZ444.

Gale Warning from 5 AM Monday to 11 AM EDT Tuesday for LEZ444.

Low Water Advisory from 8 AM Monday to 8 AM EDT Tuesday for LEZ444.