textproduct: Detroit/Pontiac

KEY MESSAGES

- Sunny, breezy, and less humid today.

- Warmer on Saturday with scattered to numerous showers and thunderstorms Saturday night into early Sunday. Isolated storms may be strong to severe.

- Dry and relatively cooler conditions early next week before another active, stormy pattern commences midweek.

DTW THRESHOLD PROBABILITIES

* Low in ceilings aob 5000 feet today.

PREV DISCUSSION

Issued at 340 AM EDT Fri Jun 12 2026

DISCUSSION...

A cold front is working across the central Lower Peninsula at press time, driven by a potent shortwave taking on a negative tilt as it races across the northern Great Lakes. Deeper convection has been ushered east of the area and remaining showers will remain light and spotty through the early morning. Cold advection ensues through the rest of the morning with 850mb temp falling to 9 to 11 C by this afternoon and sfc dew points lowering to a more comfortable level in the 50s. Morning post-frontal lower clouds give way to a good amount of insolation today with the mid June sun angle boosting temps to around 80 degrees. Breezy west wind will peak in the 25 to 30 mph range then diminish tonight.

A closed upper low takes shape over northern Ontario this weekend, directing a zonally oriented jet streak across the Great Lakes on Saturday. Subsidence on the anticyclonically sheared side produces a broad ridge of high pressure over the Ohio Valley which provides a cap over SE MI and keeps conditions dry and warm through the day. Southwest return flow wrapping around the high advects in higher boundary layer moisture with steep mid-level lapse rates contributing to increasing instability into the evening. A weakly forced cold front will migrate southward across northern lower MI through the evening before reaching the Saginaw Valley close to midnight. Availability of surface based instability is not guaranteed given unfavorable diurnal timing, but bears monitoring as a 35 to 40 kt LLJ works in ahead of the front. Isolated strong to severe storms will be possible overnight given the favorable sfc-1km and sfc-6km shear profiles, with highest probability directed over the Saginaw Valley and Thumb. Otherwise, rain showers with embedded thunderstorms will be likely for most of the area overnight into Sunday morning.

The front clears Metro Detroit by midday Sunday with much cooler and drier air filtering in through the day. High static stability and zonal flow at the base of the northern Ontario upper trough maintain seasonable and benign conditions through early week. Southwest flow emerges Tuesday to bring in the next bout of warm/moist advection ahead of a cold front slated to pass through between late Tuesday and early Wednesday. This will be the next window for showers and storms. A deeper, compact low is then advertised to track through the Great Lakes Wednesday night into Thursday with additional showers and storms.

MARINE...

A cold front will finish pushing east of the area this morning allowing for high pressure to build in across the southern Lakes. Another cold front will start moving toward the north western Lakes which will help keep a fairly tight pressure gradient across the region today. Winds will increase from the southwest, turning more westerly, behind the front offering a period of gusts to near 30 knots for Saginaw Bay and the tip of the Thumb through this morning so a Small Craft Advisory is in effect. The second cold front will help keep elevated southwesterly winds across the lakes through much of Saturday before the front then sweeps east by Sunday morning. Winds will stay elevated around 20 knots, but out of the northwest Sunday.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Beach Hazards Statement until noon EDT today for MIZ049.

Lake Huron...Small Craft Advisory until noon EDT today for LHZ421-422-441.

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