textproduct: Detroit/Pontiac

KEY MESSAGES

- Rain showers with embedded thunderstorms Sunday afternoon.

- Summer-like temperatures Monday through Wednesday with low rain chances.

DISCUSSION

Center of low pressure near the mouth of the Detroit River lifts NE along the MI/ON border through the rest of the day. Mid-level moisture gradually strips out but sub-700mb moisture lingers around beneath additional PVA to continue to grind out more light showers, drizzle, and mist into this evening - especially east of I-75. Abundant cloud cover and northeast wind maintain a rather raw afternoon for late May standards. Precip tapers off and wind backs to westerly as the low passes north this evening, leading into a mostly cloudy night with lows 40s and 50s and some patchy fog.

Deep layer but modest southwest flow emerges on Sunday ahead of an amplified trough working in from the Midwest. This drives a warm front into southern Lower MI, allowing temps to rebound into the 60s and lower 70s later in the day. The front also provides the focus for convective initiation as PVA spreads in aloft, and a cluster of showers and embedded thunderstorms are likely during the afternoon to early evening. Lightning, heavy downpours, and gusty winds may interrupt some holiday weekend plans tomorrow. Weak boundary layer flow and instability will be limiting factors for strong to severe storms as cloud cover looks to be fairly widespread and lapse rates through the column are meager. Still, bulk wind shear creeping up to 35 to 45 kt, low LCLs, and slightly backed low-level flow near the front may support a sneaky severe setup if instability overachieves the current forecast. Precip chances taper off during the evening as any remaining instability wanes and high pressure develops overhead.

The high pressures eases toward Lake Erie on Monday with southwest flow advecting in much warmer air from the Midwest. The strongest warm air advection will set up in the Saginaw Valley where highs in the mid 80s are forecast and there may be enough instability for an afternoon shower or storm. Elsewhere, capped profiles and shallower warm air keep highs in the upper 70s to around 80. A similar setup will exist Tuesday and Wednesday with a 20-30% chance for showers and storms on Wednesday as a backdoor cold front provides some surface convergence within an otherwise nebulous forcing regime. A cool down to more seasonable temps ensues late week as Canadian high pressure builds in.

MARINE

Small craft advisories continue for all nearshore waters with the exception of Lake Erie with strong onshore flow. Easterly winds gusting 25 to 30 knots will persist much of the day as surface low slow tracks north from the northern Ohio Valley. Widespread light rain showers and drizzle will also persist through this evening. The low will weaken and dissipate this evening into tonight over Lake Huron, leading to lighter winds for the second half of the weekend. However, another upper-level disturbance will bring a good chance of showers and isolated thunderstorms over the region on Sunday. High pressure returns Monday and slips east into the Mid-Atlantic States on Tuesday, maintaining generally light winds.

HYDROLOGY

A cluster of showers and thunderstorms is forecast to track west to east across the area Sunday afternoon. Most areas will receive a quarter inch of rainfall or less, but there will be the potential for some areas to see up to 1 inch. This would be most likely to occur south of M-59. Overall dry conditions over the past 30 days suggests the potential for flooding is low, aside from typical isolated flood prone locations in urban areas.

PREV DISCUSSION

Issued at 157 PM EDT Sat May 23 2026

AVIATION...

Lingering showers across the area will wane as the main surface low lifts north across the region this afternoon and evening. Gusty easterly winds will also diminish in speed as the low departs, becoming northerly and eventually westerly by late evening. While showers depart, MVFR ceilings will linger into the overnight hours. With lingering low-level moisture in place and light winds expected overnight, ceilings may gradually lower. There will be a window for patchy BR/FG development, mainly between 08-13Z Sunday.

Attention then focuses on a window for showers and a few thunderstorms on Sunday. The main window of concern for thunderstorm activity is currently between 18-22Z.

D21/DTW Convection...A broken line of showers, with a few embedded thunderstorm, is expected to move across the D21 airspace on Sunday afternoon. At this time, the potential for any strong or severe thunderstorms is very low. Brief heavy downpours may result in a narrow windows of reduced visibilities.

DTW THRESHOLD PROBABILITIES...

* High for ceilings at or below 5000ft into Sunday morning.

* Low for ceilings and visibilities to fall to 200ft or 1/2SM Tonight into Sunday Morning.

* Low to medium thunderstorms Sunday afternoon.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Beach Hazards Statement until midnight EDT tonight for MIZ048-049- 055-063.

Beach Hazards Statement until 4 PM EDT this afternoon for MIZ070- 076-083.

Lake Huron...Small Craft Advisory until 10 PM EDT this evening for LHZ422.

Small Craft Advisory until 4 AM EDT Sunday for LHZ421-441>443.

Lake St Clair...Small Craft Advisory until 10 PM EDT this evening for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory until 4 PM EDT this afternoon for LEZ444.