textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry and seasonable conditions will exist to finish the weekend.

- Warming trend Monday as dry conditiosn persist, before showers and thunderstorms return Monday night into Tuesday.

DTW THRESHOLD PROBABILITIES

* Moderate in ceilings below 5000 feet tonight.

PREV DISCUSSION

Issued at 248 PM EDT Sat Apr 25 2026

DISCUSSION...

Notably cooler conditions entrenched locally within a persistent area of stratus late this afternoon, as the resident thermal profile now governed by prevailing northerly flow south of influential high pressure. Secondary period of cold air advection this evening as flow veers and increases depth to northeast wind, with the thermal flux augmented by onshore flow off the cold lake Huron waters. This process will also work to erode remaining saturation beneath the inversion, affording a gradual clearing trend with time. Lows Sunday morning arriving in the uppe 30s to lowe 40s most locatins.

Deep layer stability held within prevailing low to mid level ridging affords dry and seasonable conditions to finish the weekend period. A standard moderation of the existing airmass occurs under a high degree of insolation and increasing upper height field, but still lacking in meaningful warm air advection. Highs in the lower 60s in most locations, except near the shorelines. Lingering influence of upper ridging ensures dry and stable conditions persist throughout the daylight period Monday. Resident airmass continues to moderate given the elevated mean thickness readings, but still capped by a low level gradient that remains modified by a southeasterly component. Highs arriving above average - readings mid to upper 60s.

Mid level wave noted on water vapor this afternoon off the coast of California projected to eject northeast over the next 72 hours, with the main height fall center reaching the great lakes by Tuesday morning. A narrow plume of deeper moisture will align parallel to the inbound associated cold front, as the parent surface low tracks toward lake Superior. A sizable convective episode likely to emerge upstream by Monday evening within a favored corridor of higher magnitude instability and supportive kinematics. Influx of higher quality moisture coincident with an increase in frontal forcing will likely sustain this activity to some degree into lower Michigan Mon night-Tue morning. Expectation for limited instability to exist as consolidated activity funnels downstream and arrives locally within the diurnal minimum precludes a greater concern for organized convection at this stage. Forecast will continue to call for a high likelihood of showers and thunderstorms within the AM hours.

Broad mid level troughing south of a closed low meandering across central Canada will take control through the latter half of next week. Generally benign conditions favored within this pattern, absent of meaningful areas of greater forced ascent and moisture quality/depth. Trending cooler with time Wed to Fri as mid level heights gradually decline atop prevailing low level northwest flow. Below average temperatures expected to wrap up the month of April.

MARINE...

Gradual establishment of high pressure maintains a slow weakening trend in winds through the evening. High holds over the region through early Monday maintaining benign marine conditions. Southeasterly winds strength latter half of Monday as the next low lifts out of the central Plains towards the northern Great Lakes. While a 45-60kt LLJ develops over the central Great Lakes Monday night, accompanying warm advection should promote a stable overlake thermal profile limiting mixing potential. Currently local probabilistic guidance is advertising a ~35% chance to reach 34kts. Arrival of showers and storms late night-early Tuesday does offer potential for profiles to turn more neutral, however this set-up would warrant short-fused special marine warnings over gale headlines. System's cold front crosses daytime Tuesday ending storm chances as well as flipping winds to the northwest. Rapidly weakening pressure gradient on the backedge of the low keeps these winds under 30kts.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory until 10 PM EDT this evening for LHZ421-422.

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