Apple Mountain Snow Report

977 FXUS63 KDTX 250821 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 421 AM EDT Fri Sep 25 2026 .KEY MESSAGES... - Dry weather with cool to seasonable temperatures lasts through the weekend and the first half of next week. - The next chance of rain arrives with a low pressure system and cold front projected to reach the region by Wednesday. && .DISCUSSION... The large-scale pattern will be governed by varying forms of vicinity ridging through the weekend, and into the first half of next week. At present, the prior Rex Block has unlocked and is being replaced by a weak mid-level shortwave trough getting pushed downstream of Upper Midwest ridging. This should provide ambient ascent over Lower Michigan, generating healthy coverage of clouds aloft. Thermal fields remain intact, with 850 mb temperatures holding near 10C which keeps highs at least 5F below climatological normals. Strong stability within the lower half of the column, positioned within a well-established anticyclone ensures subsidence and limited boundary-layer cloud. Rain-free weather extends through the weekend with a warming trend lifting readings toward early Fall averages. An elongated ridge axis extending from the Gulf into Ontario, subdivided by southern and northern stream components, will move eastward by Saturday. The northern stream shorter wavelength feature displaces the residual troughing, and centers over the western Great Lakes. High pressure will lock in at the surface, centering between southwest Lower and Quebec, offering light winds from the northeast quadrant. Meanwhile, a strong Atlantic coast quasi-tropical system/nor`easter will meander between Chesapeake Bay and Cape Cod over the next 3+ days. The upper levels of this system and the stationary mature low are what will prevent much movement from the composite ridge axis over the Great Lakes region. A strong positively-tilted Pacific longwave trough eventually digs across CONUS mid-week, kicking out the Atlantic wave. High confidence in a dry forecast prior to the arrival of this system, once pre-frontal winds flip southerly and top-down column saturation gets underway closer to Wednesday. && .MARINE... The expansion of a strong Canadian high pressure system derived from Quebec and Ontario into the Great Lakes will provide an extended period of light winds and dry weather through early next week. Some periodic wind gust potential around 20 knots will be possible across southern Lake Huron through this extended time frame, but otherwise, wind gust potential at or below 15 knots is expected. Wind direction will mainly hold from the northeast as high pressure fills in across Michigan. && .PREV DISCUSSION... Issued at 1213 AM EDT Fri Sep 25 2026 AVIATION... Strengthening mid to upper level low pressure over the Mid Atlantic region will cause the Rex Block to readjust during the next 24 hours. The change will help the center of surface high pressure to retrograde from Quebec into the central Great Lakes by mid afternoon Friday. Persistent easterly flow and moisture fluxing off of Lake Ontario and Lake Erie will bring the potential for some VFR or MVFR cloud Friday morning. Low confidence exists in ocarinas and will leave out of the taf forecast. D21/DTW Convection...Thunderstorms are not forecast through the forecast period. DTW THRESHOLD PROBABILITIES... * Low in ceilings aob 5000 feet through the TAF period. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...KGK MARINE.......AM AVIATION.....CB You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.