Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
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036 FXUS63 KDTX 151949 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 349 PM EDT Sun Sep 15 2024 .KEY MESSAGES... - Seasonably warm and dry conditions prevail through mid-week with patchy morning fog Sunday through Tuesday. - Spotty light rain becomes possible Wednesday. && .DISCUSSION... A longwave blocking ridge over much of eastern North America will continue to dominate the weather through the midweek period at minimum. A strong anticyclonic vorticity advection signal is progged on Monday as a remnant dipole high maximum aloft retrogrades back into the area from the east. Ridge reinforcement is then advertised for Tuesday and Wednesday as right exit region dynamics from the center of the country spread northeastward with time. Just a remarkable stretch of persistence weather continuing with daytime highs in the lower 80s and nighttime lows dropping into the 50s. Again, the preference has been to side with EC-AIFS for temperatures since blended gridded guidance continues to run high. Patchy morning ground fog each of the days will give way to clear skies. The blocking ridge will slowly evolve into a pseudo rex feature this week with heights lowering and a coalescing of deeper moisture content over the Southeast United States. Models differ on the details and timing of the moisture advection to the northwest with time. Latest thoughts are a lobe of absolute vorticity will push into the area increasing high cloud Tuesday with 850-600mb thetae then arriving over the far southeastern CWA sometime Wednesday. Forecast soundings show moist adiabatic lapse rates at moist adiabatic above 10.0 kft but a fair amount of high static stability lingering between 2.5 and 7.5 kft agl. Slight chance PoPs at 20% or less are sufficient for now. A strong ridging max of the rex block is then expected to be in close proximity of the area and will likely perpetuate quiet weather into next weekend. && .MARINE... High pressure continues to dominate conditions across the central Great Lakes through the first half of the week. Light (aob 15kts) southerly flow holds through Monday before turning back to more easterly midweek. && .PREV DISCUSSION... Issued at 100 PM EDT Sun Sep 15 2024 AVIATION... Large-scale pattern remains locked-in again through the TAF period based on sprawling surface high pressure centered near Cape Cod. This provides generally clear skies and light southeasterly winds AOB 10 knots through the daylight hours. Wildfire smoke continues to stream in aloft with negligible impact on overall sky fraction. Persistence forecast warrants continuation of MVFR fog restrictions Monday morning from PTK south with lower potential for brief visibility drops to IFR. Based on previous observational trends, IFR development is more likely for YIP and/or DET. For DTW/D21 Convection...Thunderstorms are not forecast this week. DTW THRESHOLD PROBABILITIES... * None. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...CB MARINE.......KDK AVIATION.....KGK You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.