Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
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913 FXUS63 KDTX 282248 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 648 PM EDT Fri Aug 28 2026 .KEY MESSAGES... - Seasonable temperatures with dry weather tonight through Saturday. - Increasing chances for showers and storms Saturday night and Sunday continuing through early next week. - A new round of heat and humidity builds for the early to mid week period. && .AVIATION... Subtle mid level moisture advection this afternoon contributed to some expansion of mid level clouds (based above 6k feet). The easing and departure of this mid level moisture combined with the loss of diurnal heating will contribute to a decrease in cloud cover during the evening hours. The influence of a weak gradient flow as a result of sfc high pressure anchored over the eastern Great Lakes will sustain light winds through daybreak Saturday. An increasing south gradient on Friday will lead to light winds. Upstream warm air advection will drive ample mid and high clouds into the region in the afternoon. While there may be some diurnal cloud development, available guidance strongly supports VFR conditions through the day Saturday. D21/DTW Convection...No convection is forecast through the TAF period. .DTW THRESHOLD PROBABILITIES... * None. && .PREV DISCUSSION... Issued at 348 PM EDT Fri Aug 28 2026 DISCUSSION... Afternoon cumulus is mixed with a mid level cloud component tied to moisture transport aloft while surface high pressure is otherwise the primary weather influence across Lower Mi today. The high pressure air mass combined with the mix of clouds and sun are producing pleasant conditions across the region that continue tonight. Cloud production will be variable as mid level flow remains weak and theta-e disorganized, however periods of clear sky have adequate duration for enough cooling to reach low temperatures in the mid to upper 50s outside of metro Detroit. Beside the clouds, an uptick in south wind occurs before sunrise which is just enough to keep readings a few degrees warmer than this morning, which even saw some 40s in the typically cooler locations around the region. High pressure departs to the Atlantic coast while the next low pressure system organizes across the high Plains during Saturday. These are the primary surface weather elements connected by the upper jet spanning the Canadian border from Montana to the northern Great Lakes. It`s the upper jet that boosts moisture transport with much farther eastward reach into Lower Mi compared to the warm front from late Saturday through Saturday night. This results in a renewed cloud increase during the afternoon and an increasing chance of showers and thunderstorms Saturday night into Sunday morning. Convective potential ramps up considerably on low level jet strength in the northern Plains and upper Midwest tonight and again Saturday night as the 850-700 mb theta-e ridge builds west to east into Lower Mi. The inbound moisture axis helps improve prospects that convective remnants survive into SE Mi by Sunday morning. Clouds and showers then linger during the day as the warm front moves in ahead of the Plains to Midwest low pressure system. The preferred forecast leans toward higher POPs and lower temperatures compared to NBM to finish the weekend. Today`s 12Z deterministic/AI/ensemble means show the northward progress of the surface warm front is still a forecast focus for Monday. Consensus slightly favors the front moving into the northern Great Lakes followed by a new round of heat and humidity that builds into at least the southern part of Lower Mi for the early week period. MARINE... High pressure in place through the day maintaining light winds and dry weather. Influence of said high wanes Saturday as it shifts to the Northeast with the central Great Lakes holding on its westernmost fringe. This allows for modest southwest winds to develop during the day with gusts holding aob 20kts, save for central Lake Huron where favorable fetch could allow for up to 25kts. Active pattern returns by Sunday as developing low pressure over the northern Plains lifts a warm front through the area ushering in a more humid airmass leading numerous shower/storm chances into the new work week. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....SC DISCUSSION...BT MARINE.......KDK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.