textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry weather today and 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.

- Warming temperatures this weekend with additional rain chances.

DTW THRESHOLD PROBABILITIES

* None.

PREV DISCUSSION

Issued at 357 AM EDT Tue Jun 23 2026

DISCUSSION...

A broad area of surface high pressure extends from northern Ontario nearly to the MS/LA Gulf coast today. The north/south ridge axis holds along or just west of Lake Michigan to maintain a light northerly wind into SE Mi. It continues the slightly cooler than normal temperature regime that has been in place for several days, however surface Td remains in or returns the 50s as daytime heating peaks this afternoon. A generous field of cumulus coverage is the result but little else given the adequate mid level subsidence inversion shown in a survey of model soundings. Another day of highs in the mid to upper 70s looks very reasonable in temperature guidance, except cooler near the Lake Huron shoreline.

Cumulus transitions to increasing cirrus coverage tonight, especially after midnight, as the next low pressure system arrives in the upper Midwest toward sunrise. Satellite imagery early this morning shows the mid/upper level circulation moving out of the Canadian Rockies with respectable intensity and easily able to organize at the surface today. Consensus of 00Z deterministic models then has the surface low on schedule to reach the MB/ND border this afternoon and the MN arrowhead by Wednesday morning. The system sets up a standard pattern of moisture transport from the central Plains, although without full access to Gulf moisture given the front stalled along the coast. More typical, rather than excessive, PW in the 1.0 to 1.5 inch range is shown building into Lower Mi with the warm sector theta-e ridge during Wednesday. Scattered showers gradually increase coverage while spreading from the Tri Cities toward Flint and Thumb Wednesday afternoon and then southward toward metro Detroit by evening. The associated cold front provides an assist to coverage as it moves through Lower Mi Wednesday night and early Thursday while intensity fights against nocturnal timing. The GFS parameter space can be sneaky good at capturing nocturnal convection, both surface based and elevated, and even it struggles to maintain MUCAPE above 500 J/kg in the 1000-850 mb layer through sunrise. Showers and storms then remain in the forecast for the daytime Thursday as the 00Z model cycle agrees on slower eastward timing/progress of the low and cold front not settling into Ontario and Ohio until Thursday night.

Heading into the weekend, diffuse surface high pressure settles into the central Great Lakes as the Thursday front stalls in the Ohio valley. The front becomes the focus for a very active convective pattern judging by model QPF fields, but which remains south of Lower Mi in this forecast cycle. Weak high pressure holds over the central Great Lakes through Saturday while larger scale changes begin in the long wave pattern. This is centered around the large closed low shown in extended time range models developing over the Pacific NW into the northern Rockies by Sunday. The long wave amplification points to a temperature trend shifting above normal in the Great Lakes by Sunday into early next week.

MARINE...

Wind direction will continue to back north to northwest through the early week period as high pressure builds in. Lighter winds are expected today and Wednesday. Winds will then increase to around 10 knots from the south and southwest late Wednesday and into Thursday ahead of the next low pressure and frontal system. This system will also bring numerous showers and a chance of thunderstorms late Wednesday into Thursday.

DTX WATCHES/WARNINGS/ADVISORIES

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