textproduct: Detroit/Pontiac

KEY MESSAGES

- Precipitation chances end this morning with mostly dry conditions through remainder of the day.

- Shower chances return Wednesday morning to early afternoon.

- Much colder air arrives by late week and holds through the weekend resulting in frost/freezing potential.

DTW THRESHOLD PROBABILITIES

* High for ceilings aob 5000 feet this morning. Moderate this afternoon.

PREV DISCUSSION

Issued at 329 AM EDT Tue Apr 28 2026

DISCUSSION...

Scattered showers are ongoing early this morning with ascent along the warm front driven by an impressive 50-60 knot lower level jet. Lack of strong instability still precludes severe weather, but any thunderstorm may still have at least some low potential to bring down isolated strong wind gusts and brief heavy rainfall. Wake low winds may also lead to isolated gusty winds early this morning. Relatively brief time spent in the warm sector before the systems cold front sweeps through southeast Michigan later this morning as the main surface low lifts north of Lake Superior. This maintains the scattered shower and thunderstorm chances through about 12Z before dry air starts to push into the area. Post frontal west winds will be a gusty to 25-30 mph this afternoon as weak cold advection supports mixing into around 30 knots of flow. Gusts weaken this evening as lower level flow drops significantly with time. Lingering clouds cover helps keep overnight lows tonight in the 40s.

Canadian troughing takes over the region mid-week marking the beginning to a stretch of below normal temperatures which will carry into the month May. Tomorrow morning will see a deepening surface low lift through the Ohio Valley along existing frontal zone. Favorable placement of deformation north of the the low develops over southeast Michigan leading to increasing chance for showers starting around 09Z Wednesday morning and lingering into the early afternoon. Highest PoPs are focused mainly across southern and eastern southeast Michigan.

The main item to note for the late week period into the weekend will be the frost/freeze potential for a few nights as polar troughing settles across the Great Lakes. North-northwest flow will usher in 850mb temperatures down to around -5C by Thursday morning, which will persist around that temperature through Saturday night. Currently, Thursday night and Friday night look to be the coldest nights given the cloud forecast and the better radiational cooling potential. Outgoing forecast has overnight lows these nights at 32 degrees to 2-3 degrees below. Of lesser impact during this time, will be the potential for periodic isolated lake induced light precipitation in the form of rain, graupel, and/or wet snowflakes each day as overlake instability produces higher coverage of clouds and steepening lapse rates supports this activity. Daily high temperatures Thursday through Saturday will mostly reside around the 50 degree mark.

MARINE...

A low pressure system exits Lake Superior and moves into central Ontario this morning as its expansive low-level wind field migrates across the central Great Lakes. A Gale Warning remains in effect for the open waters of Lake Huron, north of Sturgeon Point. Winds within the lowest levels will decrease through the morning hours causing lingering occasional gusts to gales to diminish. Meanwhile, inbound/ongoing convection persists until midday as the system's warm front surges across the eastern UP. The elevated thunderstorms should augment stability profiles, even as the strongest lower column flow exits. Small Craft Advisories also remain in effect for all nearshore waters until at least this afternoon due to persistent elevated winds/waves. The system's cold front then crosses through the waterways late this morning and into the midday period leading to calmer weather and a shift to northwest flow. High pressure eventually builds in mid-week.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until 4 PM EDT this afternoon for LHZ441>443.

Gale Warning until 8 AM EDT this morning for LHZ361>363.

Small Craft Advisory until 10 PM EDT this evening for LHZ421-422.

Lake St Clair...Small Craft Advisory until 4 PM EDT this afternoon for LCZ460.

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