textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry weather and cooler but seasonable temperatures this weekend.

- Showers and thunderstorms return Monday night into Tuesday.

DTW THRESHOLD PROBABILITIES

* High in ceilings aob 5000 feet today.

PREV DISCUSSION

Issued at 408 AM EDT Sat Apr 25 2026

DISCUSSION...

Early morning sfc analysis shows an occluded front bisecting southeast MI, extending southeast from stalled parent low pressure over southern SK. This front connects to weak low pressure migrating from Metro Detroit into the upper Ohio Valley, with patchy fog and stratus wrapping around this system. Eventually the front becomes orphaned off into a remnant trough as mid-level shortwave ridging builds overhead today. The result will be a strengthening inversion that traps abundant low-level moisture, with morning fog mixing out into the thick stratus layer which holds in place through the day. Persistent north wind feeds cooler air beneath the inversion and limits highs to the 50s for most of the area, or near the seasonal average. Low 60s will still be achievable for the I-94 corridor and areas south, while the Lake Huron shoreline stays cooler in the upper 40s. The stratus shows some potential for scattering in the Saginaw Valley and Thumb by late afternoon as drier air with origins over southern Ontario spreads across Lake Huron.

The mid-level ridge crests overhead tonight into Sunday, ensuring stable and dry conditions prevail through the weekend. The drier air from Ontario gains more ground which favors a lower cloud fraction by Sunday morning, but easterly flow off western Lake Erie likely holds some stratus in the south - at least early before daytime mixing helps erode this cloud too. The boost in insolation helps temperatures take a step up into the lower to mid 60s.

The dry and stable weather continues into Monday with temperatures taking another another step toward the upper 60s and lower 70s. Upstream, a potent shortwave will pass over the Rockies and induce cyclogenesis over the central Plains. This low tracks from the Midwest into the northern Great Lakes Monday night with deep layer southerly flow advecting an arc of elevated moisture in overnight into Tuesday morning to fuel a round of convection. The peak in synoptic ascent looks to occur after daybreak Tuesday morning as the negatively tilted trough passes overhead. A narrow warm sector passing through the region brings a window for storms to become surface-based with enough balance between marginal instability and wind shear to support a low chance of isolated strong to severe storms before the cold front sweeps through early afternoon.

Longwave troughing progresses across central Canada and descends into the Great Lakes midweek. Low confidence exists on timing of individual systems as there will be several shorter wavelength perturbations undergoing interactions during this period, but the synoptic setup supports a period of cooler and occasionally unsettled weather through late week.

MARINE...

Departing low pressure early this morning sets up modest northeasterly flow in its wake. While most of the region holds at or below 20kts for peak wind, the long fetch and now 'mild' water temperatures likely support enhancement of winds funneling into the Saginaw Bay. Gusts look capable to peak in the mid to upper 20kt range warranting a Small Craft Advisory through the evening. High pressure then expands over the Great Lakes this evening/overnight gradually weakening winds. Influence of said high holds through early Monday maintaining light winds and dry conditions to close out the weekend.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until 10 PM EDT this evening for LHZ421-422.

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