textproduct: Detroit/Pontiac

KEY MESSAGES

- Summer-like temperatures expected through Wednesday. These conditions will bring a low chance of showers and thunderstorms late Wednesday.

- A return to more seasonable temperatures Thursday through next weekend. No rain currently expected during this time.

DISCUSSION

Western extension of high pressure anchored over the eastern great lakes will maintain influence over the next 48 hours. Modest south to southwest low level flow held on the backside of the surface high lending to a moderating thermal profile to finish the holiday weekend, as latest surface obs show temps pushing toward the upper 70s to lower 80s /warmest across the Saginaw valley/. Higher degree of stability maintained across much of the area given the capped profile. A weak shortwave evident on water vapor ejecting across northern lake Mi will pass by to the north this evening. There remains some model support for a lower coverage of convection to emerge across mainly northeast lower mi as this wave engages a narrow axis of meaningful instability. The probability for any activity to drift into the outer Saginaw Bay/Tip of the thumb region remains at less than 10 percent. Much lower potential for fog development tonight with notable drying ongoing under full insolation and likelihood for a light southwest gradient to persist tonight for many locales. With that, a more localized dip in visibility plausible generally between I-94 and the Ohio border given closer proximity to high pressure influence with flow off lake Erie. An introductory patchy fog mention appropriate for this area. Lows tonight broadly distributed in the 50s.

Dry and seasonably warm conditions entrenched Tuesday, as an improving mean thickness field within the background of lingering low-mid level ridging affords an additional upward trend in daylight temperature. Highs in the 80s, warmest again across the Saginaw valley. Governing upper ridge will retrograde with time to the west as modest height falls commence along the front flank. This will allow an initially shallow backdoor cold front to sag into the region Tuesday night and Wednesday. Little disruption to the diurnal heating process evident for Wednesday again lends to highs in the 80s except along the immediate lake Huron shoreline. Greatest inbound height falls currently noted for Wednesday evening and overnight tied to the passage of a lower amplitude wave. Depending on the southward pace of associated forced ascent/better mid level lapse rates relative to the peak heating cycle, this may offer some convective potential during this time. Outgoing forecast appropriately maintains modest chances at this stage.

A high amplitude pattern featuring a pseudo-rex block configuration will dictate conditions throughout much of the conus late this week and through next weekend. Southeast Michigan will hold position just downstream of the higher magnitude ridge axis, leaving a resident airmass characterized as generally seasonable within deeper, prevailing northerly flow. This pattern will maintain manageable humidity level with dewpoints generally in the 40s, while afternoon temperature peaks mainly in the 70s during this time. Forecast continues to highlight a stretch of dry weather as high pressure anchors to the north.

MARINE

High pressure built into the area overnight and remains in place today. Flow has become southwesterly across the central Great Lakes as a result. Southwest winds may increase across the Saginaw Bay area today, with speeds increasing to around 20 knots. By Wednesday, high pressure becomes quite elongated, stretching across the Ohio Valley and into the Northeast. A cold front then drops south across the area late Wednesday, with the next chance for showers and thunderstorms. The mid-week cold front is not expected to be particularly strong, so currently not anticipating any significant ramp up of winds behind the front. Another area of high pressure builds into the region behind the front and will lead to varying winds throughout the end of the week. There may be periods with enhanced onshore northeast winds, which may elevate wave activity in nearshore zones at times.

PREV DISCUSSION

Issued at 1258 PM EDT Mon May 25 2026

AVIATION...

Light and variable winds and clear skies in place over southeast Michigan early this afternoon, but scattered mid clouds (10-20 kft) likely move through northern tafs (MBS) as an upper level disturbance tracks near/through the Straights early this evening. Otherwise, there is a low concern for fog development tonight if surface dew pts fail to mix down from the current values in the mid to upper 50s. With a very light onshore wind coming from Lake Erie, southern tafs have the best chance for fog, but will include just a modest visibility reduction at this time as confidence remains low.

D21/DTW Convection...No thunderstorms anticipated.

DTW THRESHOLD PROBABILITIES...

* None.

* Very low for visibilities of 1/2sm or ceilings at less than 300 ft late tonight.

DTX WATCHES/WARNINGS/ADVISORIES

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