textproduct: Detroit/Pontiac

KEY MESSAGES

- Warming trend today and Friday with highs in the mid to upper 80s.

- Scattered to numerous showers and isolated thunderstorms expected Friday evening through Saturday.

- Dry weather returns early next week with warming temperatures approaching 90 degrees by mid week.

DTW THRESHOLD PROBABILITIES

* None.

PREV DISCUSSION

Issued at 309 AM EDT Thu Jul 30 2026

DISCUSSION...

Satellite imagery this morning shows clear skies stretching from the Mississippi River Valley to the Appalachians as high pressure stays in control. 00z upper air observations have started to show the thermal ridge folding over into northern Michigan (h8 of 15 C at APX) while NW flow will continue to advect this warmer air south. This brings highs into the mid to upper 80s today and Friday. Hi-res guidance produces a speckling of showers later this afternoon near the Saginaw Bay/northern Lake Huron lake breezes. Considering the strong cap aloft and dry/well mixed boundary layer this afternoon, thinking this will mostly just result in an uptick in diurnal cu. Overall dry conditions persist through Friday, although the next system will send high cloud into the region Friday afternoon.

Next opportunity for showers and a few thunderstorms arrives Friday night into the weekend as a synoptic wave rounds the central CONUS ridge. The best chance to see rain Friday evening will be north of I- 69, closest to the lead vort max. The Euro shows the most bullish solution where the strength of the wave cools the mid-levels enough to erode the strong subsidence bubble that will be in place. Moisture then fills in more broadly overnight into Saturday, in which PoPs fluctuate in the 40-70% range through the day. Majority of soundings show issues with moisture depth, particularly in the low levels as most of the moisture transport occurs over the Ohio Valley. While this does not prevent rain chances entirely, it does look to cut down on QPF as ensemble medians are still coming in below 0.5". A concentrated footprint of higher rainfall totals will be possible given the presence of the deformation axis overhead, although absence of instability (< 500 J/kg MUCAPE) will also be a limiting factor for rainfall intensity/amounts Saturday. Much of the instability is concentrated in the drier low levels, meaning shallow equilibrium levels between 0 and -10 C and limited ice production. This affords only low end thunder chances. All of this culminates to a cool and cloudy Saturday with periods of at least light-moderate rain. The thick cloud cover and cooler NE flow caps highs in the mid- upper 70s.

Aggressive isentropic downglide then takes hold Saturday night, stripping out the mid and upper level column moisture. This brings an end to the steady rain we see Saturday although some lingering low-topped shower activity may spill into Sunday, especially given the cool NE flow off of Lake Huron. Gradual warming trend is then expected Sunday onward as mid-level heights build back into the region and cloud cover diminishes. Highs in the low 80s Sunday climb into the upper 80s by mid-week.

MARINE...

Light north winds this morning become easterly later today, and eventually southerly on Friday as high pressure drops south through the region. Late Friday and through the weekend, the surface wind field across the region responds to a surface low progged to track east across the Ohio Valley. Locally, winds across the central Great Lakes will become north-northeast Saturday. As this low approaches, the likelihood of showers and a few thunderstorms increase late Friday and on Saturday.

On Sunday, north winds will briefly become reinforced and lingering chances for showers and storms remain in the forecast as a cold front drops south across the region. High pressure follows for early next week.

DTX WATCHES/WARNINGS/ADVISORIES

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