textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry and seasonable conditions through tonight.

- Warming trend tomorrow with dry conditions during the day.

- Showers and thunderstorms expected tomorrow night into Tuesday.

- Stretch of below average temperatures latter half of the week.

DISCUSSION

Deep layer stability held within existing low-mid level ridging maintains benign weather conditions to wrap up the weekend. Late day temperatures arriving in the vicinity of average under a high degree of insolation. Upper ridge axis slides east tonight, affording an increase in magnitude of upper level southwest flow with time. This will initiate a respectable window of 850-500 mb warm air advection. A dearth in available moisture ensures this process remains inconsequential in terms of rainfall potential, but will work to moderate the thermal profile. Lows in the low to mid 40s.

Substantial corridor of higher magnitude warm air advection ongoing upstream ahead of an inbound mid level wave expected to maintain some degree of elevated convection over the midwest Monday morning. This activity will spill eastward with time through the day, but likely arrives locally as little more than some thicker high based cloud and perhaps a brief shower/sprinkle, owing to unsupportive lower level thermodynamics still held within dry/stable southeast boundary layer flow. The advective process will lead to a meaningful warming trend to start the week. Given the projected increase noted at 925 mb within a modestly mixed profile, highs of low to mid 70s on target except within the immediate proximity of the colder lake waters where temperatures will hold in the 60s.

Aforementioned mid-level wave and associated cold front are projected to sweep through the region early Tuesday. Organized convective development and expansion expected throughout the midwest by Monday evening. Evolution from there becomes increasingly uncertain, but there remains a higher probability for some degree of this activity to anchor along the warm front and arrive locally during the early morning hours Tuesday /02z-08z/. Low level instability remains virtually non-existent by this time, leaving any remnant convective clusters as elevated and possibly diminishing in coverage with time. While the thermodynamics are capped by the early morning timing, magnitude of forcing as precipitable water values near 1.25 inches suggest heavy downpours are possible. Projected rainfall generally within the .25-.50" range, locally up to .75" possible. Very brief warm sector intrusion /mid-upper 50s dewpoints/ mid-late morning Tuesday before the cold front lifts through. Some model evidence exists for a secondary window for a lower coverage of convection to develop with the frontal passage. Expect a drying trend in the wake of the front, with some clearing possible by late afternoon. Highs will hover in the low-to-mid 60s.

Trailing mid level wave lifts across the Ohio valley Tuesday night into Wednesday. Given projected trajectory at this stage, southeast Michigan could become favorably positioned for a period of stronger mid level forcing along the northwest flank. Outgoing forecast still maintains a more conservative stance, highlighting a modest chance of rain across mainly southern/eastern sections this period. Otherwise, broad longwave troughing to become established over Central Canada, placing Southeast Michigan in a persistent west-to- northwest flow pattern for the remainder of the week. Occasional bouts of pva rotating around the base of the Canadian low may trigger a stray light shower, but most areas will remain dry. Mid- level heights will gradually decline through Friday. This ensures below average temperatures will exist heading into the first weekend of May.

MARINE

High pressure 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. Local probabilistic guidance continues to hold chances around 30% to reach 34kts so have held off on a Gale Watch. 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.

PREV DISCUSSION

Issued at 1234 PM EDT Sun Apr 26 2026

AVIATION...

MVFR ceilings developed near DTW this morning, but as boundary layer depths continue to increase, dry air is expected to prevail and support clear to mostly clear skies through this evening. Light easterly flow continues through this evening, veering southeasterly tonight. Low chance of MVFR clouds developing 7-13z as low level moisture slowly increases. Otherwise, just mid-to-high clouds increasing late tonight and Monday as an elevated warm front lifts across the region. No showers are expected through at least early Monday afternoon. Winds will then strengthen on Monday, with gusts of 20-30 knots expected by the afternoon.

D21/DTW Convection...No thunderstorms expected through this TAF period.

DTW THRESHOLD PROBABILITIES...

* None.

DTX WATCHES/WARNINGS/ADVISORIES

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