textproduct: Detroit/Pontiac

KEY MESSAGES

- Steady warming trend this weekend into early next week with dry conditions. Lower 70s will be possible by Tuesday.

- Shower chances arrive by Monday night with showers and thunderstorms then likely Tuesday. A couple stronger storms could be possible.

- Cooler midweek with slightly below average temperatures favored.

DISCUSSION

A large midlevel anticyclone will track from the central Great Lakes this afternoon to portions of the eastern seaboard and Mid Atlantic tonight. Northeasterly flow trajectories along the eastern periphery of the high will maintain system relative isentropic downglide the remainder of today ensuring very quiet weather. The cool, resident airmass and dry dewpoints will keep for chilly conditions soon after sundown with windchills quickly falling into the lower 30s.

Southwesterly return flow will begin to build into Southeast Michigan late tonight resulting in a steady moderation of temperatures the next couple of days. NBM percentile data suggests low variance for daytime highs in the 50s Sunday and low variance for 60s on Monday. The exception will likely be the far northern Thumb where temperatures will be cooler by Lake Huron.

Focus then shifts to the Monday night through Tuesday as a shortwave ejects out of the Rockies, inducing cyclogenesis across the upper Midwest. Strengthening southwesterly flow will result in large scale warm advection over the Great Lakes with 850mb temperatures progged to climb into the 13-15C range over Southeast Michigan. This will push Tuesday afternoon temperatures into the upper 60s to lower 70s, some 20 degrees above late March averages.

Convective potential remains the primary forecast concern as the region resides firmly within the warm sector. Initial elevated showers and thunderstorms are likely late Monday/early Tuesday, driven by strong thetae advection along a 50-55kt low level jet. While morning activity could limit destabilization, particularly over the northern cwa, deterministic guidance suggests surface based CAPE reaching 500-1000 J/kg Tuesday afternoon ahead of the approaching cold front. Given a strong kinematic profile, organized deep convection including severe thunderstorm may be possible. Swody3 from SPC has a Marginal Risk for Severe weather for late Monday upstream across portions of Lake Michigan and western Lower Michigan. Will continue to monitor the northward progression of the warm front/stationary front in addition to the timing of the cold front since these features are sure to impact the potential for severe weather at any one location.

Troughing in the wake of the Tuesday system appears to be relatively muted as global deterministic data suggests upper level ridging will build rapidly back into the region. Dry and stable conditions are anticipated during the midweek period due to a dry air mass and very low dewpoints. Morning temperatures will likely begin in the 20s to lower 30s before warming into the 40s during the afternoons on both Wednesday and Thursday.

MARINE

High pressure drifts across the Ohio Valley through the rest of the day, maintaining west-southwest flow and dry conditions across the Great Lakes region. Surface pressure then gradually falls across the region Sunday with flow organizing out of the southwest at 10-15 knots. Offshore flow pushes elevated waves into the open waters, preventing marine headline concerns through the weekend. A warmer and less stable airmass arrives early next week, introducing shower and thunderstorm chances Monday night as the warm front lifts through and again Tuesday afternoon-evening as a strong cold front sweeps across the region. Gusts on Tuesday peak around 30 knots for most of the waters, but more localized gusts to 34 knots or above are plausible primarily in any thunderstorm activity. The front sweeps through Tuesday night, bringing a colder airmass and rain- snow mix potential back into the forecast.

PREV DISCUSSION

Issued at 159 PM EDT Sat Mar 28 2026

AVIATION...

Prevailing VFR conditions this afternoon into tomorrow with increasing coverage of mid to high clouds this evening into tomorrow. Passage of the high pressure across the Ohio Valley brings winds out of the west to southwest to around 10 knots this afternoon while holding out of the southwest tonight. The typical drop in winds will occur this evening before eventually picking back up towards 10 knots tomorrow morning.

DTW THRESHOLD PROBABILITIES...

* None.

DTX WATCHES/WARNINGS/ADVISORIES

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