textproduct: Detroit/Pontiac

KEY MESSAGES

- Isolated to scattered chances for showers and thunderstorms today through the weekend. Better coverage of showers and storms possible Monday.

- Temperatures remain seasonable through the weekend, with highs mainly in the 80s.

DTW THRESHOLD PROBABILITIES

* Medium for ceiling aob 5000 ft today. Low tonight.

* Low for thunderstorms this afternoon and evening.

PREV DISCUSSION

Issued at 317 AM EDT Fri Aug 7 2026

DISCUSSION...

Patchy fog, locally dense in spots, will remain possible through the early morning hours, especially closer to south-central MI where upstream observations highlight the region of reduced visibility. Any fog development will dissipate quickly after sunrise with daytime heating and boundary-layer mixing.

Broad troughing remains in place across the Great Lakes today with relatively weak large-scale forcing overall. A subtle shortwave is progged to track across southern Michigan during the afternoon and combined with weaker boundary layer convergence, will provide sufficient ascent for isolated or scattered shower and thunderstorm development as diurnal instability builds towards 1000 - 1500 J/kg. Deep-layer shear remains modest, generally 20-25 knots through 6km, with very weak low-level flow. This will favor isolated or loosely organized multicell convection with limited thunderstorm longevity. The severe weather threat remains very low, although steep low-level lapse rates and elevated DCAPE values could support a highly localized strong wet microbursts with any robust development.

Isolated shower chances continue overnight as another shortwave traverses the region, but loss of daytime heating should limit coverage and intensity.

A weak cold front will be the focus for additional shower and thunderstorm development tomorrow afternoon and evening. Under a similar environment with CAPE values around 1000-1300 K/kg and modest deep layer shear, this will again favor disorganized convection and a very low severe weather threat. Additional shower and thunderstorm chances may persist Sunday, but forcing will be much more ill- defined, bringing low confidence for shower chances.

A better signal exists for thunderstorms Monday as strengthening southern flow across the Plains establishes a more pronounced moisture transport regime. Moisture convergence with the elevated instability brings higher end chances for MCS development across the Plains that will be capable of progressing into portions of the Great Lakes. Uncertainty remains regarding eventual timing, track and degree of maintenance.

Temperatures through the forecast period will remain seasonable with highs around the mid 80s through the weekend, settling into the low 80s by the midweek period.

MARINE...

A series of frontal boundaries will bring the continuation of showers and some thunderstorms to round out the week and into the weekend. Most of the activity will be mainly confined south of the northern Lake Huron zone, aligned with the frontal boundary. Winds generally remain light and variable outside of any thunderstorm activity. High pressure building in over northern portions of the area will keep things dry through the morning, before another cold front moves through Friday into Saturday. This will bring yet another chance for showers and thunderstorms Friday afternoon and evening. Winds on Friday will remain lighter as the flow becomes more southerly. Periods of unsettled weather will continue to be possible going through the weekend.

DTX WATCHES/WARNINGS/ADVISORIES

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