Mad River Mountain Snow Report

876 FXUS63 KDTX 010752 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 352 AM EDT Tue Sep 1 2026 .KEY MESSAGES... - Very warm or hot and humid conditions today and tomorrow. - Favorable conditions for potential severe weather exist today through tomorrow. A Marginal Risk for severe weather is in place today with Wednesday a Marginal to Slight Risk for tomorrow. - More rain and thunderstorm chances during the late week. && .DISCUSSION... Southeast Michigan will reside on the northern periphery of a high pressure ridge slowly migrating east across the OH/TN Valleys to the Atlantic Coast over the next several days. A warm and humid airmass will settle into the area and persist and support chances for multiple rounds of showers and thunderstorms with some storms possibly becoming strong to severe. Models struggling to come to a consensus with this pattern and predictability remains low over the next 2-3 days. For today, an 850-500 mb theta-e ridge axis containing deep moisture will hover around lower Michigan today and pivot northward later in the day. Surface dewpoints have already climbed to the 70 marks in parts of the area this morning. The 00Z RAOB from last evening observed PWAT at 1.60 inches with PWATS approaching 2.00 inches expected to pivot northward with the theta-e ridge. Temperatures at 850 mb have also climbed to 20C and are forecast to hold around there over the next couple days, which would support high temperatures up to around 90 degrees. Presence of a cap with warming mid-levels along with some drying aloft is bringing some confidence that any widespread convection is becoming less likely today. This leans the forecast towards the higher temperature outcome putting heat indices up toward 100 degrees in parts of Lower Michigan. It still looks borderline for prolonged heat indices to 100 degrees or greater, so will hold off on any headlines for now. Regardless, a warm and muggy day will be in store. While widespread convection looks unlikely during much of the day, the underlying environment will be supportive of strong to severe thunderstorms if any cells are able to overcome any capping via local boundaries. SBCAPE values will be up to 2000+ J/kg with the NAM advertising 4000-5000 j/kg by late afternoon. Effective shear will be up to 40+ knots and mid-level lapse rates will be up to 6-7 C/km. Late this afternoon into the early half of tonight appears to be the best opportunity for potential convection to develop while a shortwave also rounds the ridge across Lake Michigan. Confidence remains low on where convection may develop, but the parts of the Saginaw Valley close to Saginaw Bay looks favored by some of the latest guidance. Will also need to keep an eye on any upstream development that may try and roll into the forecast area. Any cells or clusters of cells that can develop will be capable of strong to severe winds and hail along with heavy downpours that could lead to localized flooding, thus the entire CWA is in a Marginal Risk for severe weather. For tomorrow, a shortwave within a belt of strong mid-level westerly along with a potential nearby cold frontal boundary will be the items of interest for another round of potential strong to severe thunderstorm development. Models again not offering much consensus on how Wednesday may play out, as some point to an early afternoon uptick in convection while others point toward convection not occuring until late in the day into Wednesday night. Timing of convection ultimately will determine overall severe weather threat. Parameter space though bulk of the day will again be supportive of isolated to scattered severe weather if timed well in the diurnal cycle (MLCAPEs to 1000-3000 J/kg, effective shear to 40+ knots, and mid-level lapse rates 6-7 C/km). Severe wind and hail with locally heavy rain will again be the main threats with a low end tornado potential. The other item of note for Wednesday will be the heat and humidity bringing heat index values back up to around 100 degrees, which will be dependent on how convection eventually plays out. Headlines may be possible if early day convection does not pan out and less cloud cover allows for max heat index values to be realized. Aforementioned cold front will eventually be pushed southward keeping shower and thunderstorm chances in the forecast late Wednesday night into Thursday morning. Though, instability will be decreasing throughout the night. The frontal boundary hanging around lower Michigan Thursday morning/afternoon will again provide a focus for additional isolated strong to possibly severe convection as another shortwave is advertised to crest the building ridge axis. Post frontal airmass does look to cool daytime temperatures back down into the 80s for the late week period. && .MARINE... A low pressure system over southern Manitoba will track through Ontario today resulting in periods of active weather locally. There is an occluded front reaching down into northern Minnesota with a warm front then extending east through the straits and northern Lake Huron. A series of mid level disturbances have been initiating rounds of showers and thunderstorms which will continue to occur through Wednesday until the cold front drops through the region. Any break in the rain will be short lived as the front lifts back north on Thursday providing additional chances of storms. Winds will be fluctuating alot this week with the frequency of frontal passages. The weak gradient will keep speeds down through the week though with max wind gusts rarely touching 20 knots. The slightly cooler air over the waters brings chances of waterspouts with any of the storms over the lakes this week. && .PREV DISCUSSION... Issued at 1251 AM EDT Tue Sep 1 2026 AVIATION... Overnight clearing trends may allow some fog development prior to daybreak given the abundant low level moisture. Otherwise outside of a low chance for a stray isolated shower, mostly dry conditions expected through the morning. Low predictability regarding shower and thunderstorm chances for the afternoon and evening hours. A capped environment is expected to limit coverage potential through the day. However, a small subset of hi-res model output show the cap weakening just enough to aid in development of isolated to scattered shower and thunderstorms. In this highly conditional setup, thunderstorms would have the ability to rapidly intensify given the high instability in place across SE MI. This conditional setup will be most favorable closer to the Metro terminals, represented by a PROB30 group. D21/DTW Convection...There will be a low chance for isolated to scattered thunderstorm development in the afternoon and evening. DTW THRESHOLD PROBABILITIES... * Low this afternoon and evening. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Dense Fog Advisory until 2 PM EDT this afternoon for LHZ361. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...AA MARINE.......DRK AVIATION.....AM You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.