Mont Ste-Marie Snow Report

392 FXUS61 KBTV 250655 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 255 AM EDT Tue Aug 25 2026 .WHAT HAS CHANGED... As of 253 AM EDT Tuesday... No significant changes to the current forecast. && .KEY MESSAGES... As of 253 AM EDT Tuesday... 1. Additional showers expected today as surface and upper level troughs move across the area. 2. A dry and seasonable weekend will trend showery and more humid by early next week. && .DISCUSSION... As of 253 AM EDT Tuesday... KEY MESSAGE 1: More shower activity is expected today as a surface trough and upper level trough both cross our area. Not expecting any thunderstorms or severe weather. Coverage and intensity should be less than yesterday. Winds will become more northwesterly as the day goes on as trough axis pushes east of our forecast area. Drier air will then work into the region, and remain through Wednesday night with surface and upper level ridges building over the area. More shower activity is expected on Thursday into Thursday night, and lingering into Friday as well. A surface cold front along with some upper level shortwave energy will cross the region. KEY MESSAGE 2: Following a frontal passage and parent low departure Thursday and Friday, the weekend looks to trend drier as our flow pattern becomes more zonal. There still looks to be some signs of subtle cyclonic flow as the upper low lifts north and east, which may spur some isolated shower activity in eastern Ontario. Some of which could bring some increase cloud cover and an isolated shower to the St. Lawrence Valley (though PoPs are still below 20%). Temperatures will generally be seasonable in the 70s, though a few spot low 80s will be possible in the southern, wider valleys by Sunday. Humidity will also gradually increase through the weekend from the upper 40s on Saturday to the upper 50s by Monday. The increase in humidity will be a result of a trough swinging through the area to start next week. Models diverge on the strength of this trough with the GFS ensembles denoting a continue more zonal pattern, whereas the Euro ensembles depict a slightly more amplified trough, which is in line with the CMC as well. The forecast will likely change in the coming days as models resolve this feature better in the days to come. As of right now, most of the area has a 30-40% chance for showers Monday, with temperatures in the upper 70s which does seem to be on the warmer side of most guidance. There is a good chance for conditions to be quite a bit cooler early next week should the pattern become more amplified with additional cloud cover and daytime precipitation. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... Through 06Z Wednesday...Showers associated with an eastward moving trough are moving through the region with MVFR cigs on the leading edge and IFR cigs across the St. Lawrence Valley. Most terminal reductions tonight will be due to low stratus and not fog, with the exception of MSS/MPV where fog in the Ottawa River Valley bodes confidence for some intermittent IFR fog at MSS from 06-11Z, and low trapped moisture in eastern Vermont may lead to intermittent fog at MPV from 09-12Z. Have used TEMPO groups as cigs will likely bounce between IFR/low MVFR. Outside of the fog, low stratus will trend most sites outside of PBG towards MVFR cigs at least between 2000-3000 ft agl. Low stratus will likely trend ceilings lower to 1000-2000ft agl at MSS/SLK, as the base of the trough moves over northern New York through 13-15Z. With diurnal mixing, ceilings may lift to 2500- 3500ft agl by 18Z, then perhaps all VFR beyond 21-23Z. Isolated to scattered showers will accompany these low ceilings, with only PROB30 confidence at this time for showers at a terminal. All sites will see VCSH this afternoon, but confidence of a shower moving over a terminal is only 30-40% at this time. As the trough moves through this morning, light and variable winds will turn to the west-northwest under 10 knots for all terminals. Winds shifts will occur between 12-15Z from west to east. Models denote the potential for a brief winds shift to the east at PBG due to a lake breeze during the late morning hours, however, the shift looks to be short lived and quickly overtaken by the prevailing northwesterlies. Winds trend calm and variable with a return of low stratus and potential fog towards 06Z tomorrow night at the climatologically favored terminals. Outlook... Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. Chance SHRA, Chance TSRA. Thursday Night: Mainly VFR, with areas MVFR possible. Chance SHRA, Slight chance TSRA. Friday: Mainly MVFR, with local IFR possible. Chance SHRA, Slight chance TSRA. Friday Night: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Saturday: VFR. NO SIG WX. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ WHAT HAS CHANGED...Neiles DISCUSSION...Neiles/Danzig AVIATION...Danzig