textproduct: Detroit/Pontiac

KEY MESSAGES

- Seasonably cool temperatures persist this week.

- Dry Monday, but showers and storms return Tuesday afternoon/evening and again Wednesday afternoon into Wednesday night.

- Heaviest rainfall is expected Wednesday night, with widespread amounts in excess of 1 inch possible.

- Windy conditions arrive on Thursday, with wind gusts potentially reaching or exceeding 40 mph.

DTW THRESHOLD PROBABILITIES

* Moderate for ceiling at or below 5000 ft this evening.

* Low for a rumble of thunder this evening.

PREV DISCUSSION

Issued at 331 PM EDT Sun Jun 14 2026

DISCUSSION...

Thunderstorms and showers are exiting the Central Great Lakes, as Mlcapes did end up exceeding 1000 J/kg over Wayne/Monroe counties earlier, allowing for a few strong to marginally severe thunderstorms. Much quieter weather will settle in for the next 24 hours as northwest upper-level confluent flow takes hold. A strong shortwave will track through the Ohio Valley on Monday, but will miss southern Lower Michigan entirely as a dry airmass prevails.

A deep upper-level low anchored over/near Hudson will dominate the atmospheric pattern through the upcoming week. This setup will maintain a persistent northwesterly flow aloft, keeping the temperatures seasonably cool across Southeast Michigan. The primary forecast challenges revolve around the timing of distinct shortwave troughs pivoting around the main upper-level low.

Medium range models remain in pretty good agreement indicating a good 1-2 punch of upper level support late Tuesday/evening, and then again Wednesday evening/night. The Wednesday night system looks to be the stronger of the two, bringing a heavy rain threat (with totals potentially exceeding 1 inch) and strong to severe thunderstorms. The 12z Euro indicates a seasonably strong surface low tracking through central/northwest Lower Michigan, which raises concerns for severe weather given exceptional 0-6 KM bulk shear on the order of 65-75 knots. Fortunately, the clean warm sector and deeper instability should have difficult time pushing past the southern Michigan border, with more of an occluded structure setting up.

This strong system slowly exits Thursday, leaving residual troughing and cool northwest flow to keep low shower chances and below-normal A temperatures through Friday. A tight pressure gradient and deeper boundary-layer mixing on Thursday will support a windy day, with the potential to reach or exceed 40 MPH per the Euro ensemble mean.

MARINE...

Showers and thunderstorms have exited into southern Ontario and the eastern Great Lakes this afternoon as low pressure continues eastward. The post-frontal airmass has also veered weakening gradient winds north/northwesterly. This current lull in winds/gusts fades tonight as slightly stronger lower column flow moves over the waterways. This should mainly impact portions of Saginaw Bay and The Thumb nearshores, with gusts approaching 25 knots. A Small Craft Advisory remains in place through Monday morning. Drier conditions take hold tonight and Monday as high pressure migrates across The Southeast. This causes flow to flip southwesterly Monday night into Tuesday, ahead of the next low and cold front. Expect showers and storms to reach the central waterways by Tuesday afternoon with the next wave. A brief break in activity ensues Wednesday, followed by a secondary stronger system Wednesday night into Thursday. A higher likelihood exists for more intense convection with the Wednesday night system. Seasonably strong gradient winds will also accompany the low, with gusts to gales possible Thursday, after mixing profiles improve featuring 45-60 knot flow within the lowest 1-5 kft layer.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None.

Lake Huron...Small Craft Advisory until noon EDT Monday for LHZ421-422-441.

Lake St Clair...None.

Michigan waters of Lake Erie...None.