textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry weather persists tonight.

- Slightly cooler than normal temperatures continue through mid to late week.

- The next chance of rain arrives Wednesday afternoon and night then lasts through Thursday. There is a low chance for thunderstorms Thursday afternoon.

- Warming temperatures this weekend with additional rain chances.

DISCUSSION

Northerly flow off of Lake Huron has led to diurnal cumulus development this afternoon underneath transient cirrus aloft. Comfortable evening is in store for SE Michigan with temperatures in the low-mid 70s and clearing skies overnight.

Lead edge of the height fall center moves into lower Michigan Wednesday morning, followed by a steady influx of moisture and thickening high level cirrus throughout the day. Isentropic arm of this system then supplies moist ascent into the lowest 700mb of the column beginning early Wednesday evening and continuing overnight, creating the next opportunity for rain across SE Michigan. Standard concerns as to how upstream convection over southern CONUS will impact moisture transport into this northern stream system, which caps qpf to a half inch or less Wednesday night. Cannot completely rule out a rumble of thunder with this activity, although mid level lapse rates generally remain aob 6.0 C/km in the warm advective regime.

Dry slot arrives Thursday morning, but with additional perturbations rippling around the mid-level circulation that could overcome some of the ongoing subsidence. This keeps lower PoPs in play for the morning hours, until instability builds Thursday afternoon as the boundary layer destabilizes. Mid level lapse rates improve to 6.5 C/km as the main trough axis moves across northern Lower, which also adds broader synoptic support to the environment and reinvigorates shower and thunderstorm chances for the afternoon. This is especially true for the Saginaw Valley/Thumb which are in closer proximity to the synoptic forcing and moisture. Varying degrees of subsidence in the model suite, with capping potential increasing south of I-69. If the more bullish solutions were to verify (e.g. NAM), the environment could support a stronger cell or two across the north, although severe weather is unlikely at this time.

PoPs then decrease Thursday night once the front completely slides through in favor of dry weather Friday. Temperatures through the week remain seasonably cool, in the mid to upper 70s before a warm up is expected this weekend into early next week in which a hot and humid pattern is forecast to emerge. Remnant baroclinic axis is forecast to settle across the Ohio Valley this weekend, keeping rain chances south of the state line through the weekend, although there are still many points in the forecast cycle where this could trend north. Roughly a third of ensemble members generate measurable qpf this weekend.

MARINE

High pressure anchored over the region will maintain quiet conditions across all waterways through Tuesday. Modest winds prevailing generally from the north to northwest tonight will become southerly Tuesday. A low pressure system will gradually advance across the region Wednesday and Thursday. This will bring intermittent potential for showers and thunderstorms through this period. Limited wind and wave action expected overall given a weak gradient, but with any stronger storms being capable of producing locally higher gusts.

PREV DISCUSSION

Issued at 150 PM EDT Tue Jun 23 2026

AVIATION...

VFR conditions through the forecast as high pressure drifts across the region to the south. The northerly flow today will flip around to southwesterly on Wednesday as the center of the high moves to the south and east of the area. There will be a developing warm front west of the area which will nose into the area in the afternoon that will introduce increasing clouds. Otherwise, the rest of the day will have patches of high cloud with diurnal cu that will dissipate this evening.

D21/DTW Convection...No thunderstorms expected today and tonight.

DTW THRESHOLD PROBABILITIES...

* Low for ceiling at or below 5000 ft Wednesday afternoon.

DTX WATCHES/WARNINGS/ADVISORIES

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