Mont Garceau Snow Report

741 FXUS61 KBTV 010620 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 220 AM EDT Tue Sep 1 2026 .WHAT HAS CHANGED... As of 220 AM EDT Tuesday... A Marginal Risk (level 1 out of 5) for severe thunderstorms has been introduced to southwestern St. Lawrence County for Wednesday. && .KEY MESSAGES... As of 220 AM EDT Tuesday... 1. Rain along a stationary boundary will push through the region this morning into early this afternoon, tapering off this evening for most. Some isolated areas of drizzle will be possible overnight mainly in eastern Vermont and the Adirondacks. 2. Heavier, more widespread, rain is expected Wednesday into Wednesday night with some embedded thunderstorms. Isolated showers will continue Thursday, mainly across Vermont. 3. A few showers linger into late-week, trending drier through the weekend. && .DISCUSSION... As of 220 AM EDT Tuesday... KEY MESSAGE 1: Confluent flow driven by departing high pressure to the southeast, and a stalled stationary boundary over the Great Lakes and south into the Mid-Atlantic will push showers through the region this morning into the early afternoon. Radar depicts a broad area of light to moderate showers extending from the St. Lawrence Valley into northeastern Ontario. This area of showers will ride along a stationary boundary into northern New York with good isentropic lift, before diving south into the Hudson Valley, following the synoptic flow of the departing area of high pressure. Stratiform rain is expected across much of northern New York and areas south of I-89 in Vermont. The Northeast Kingdom may be able to stay dry through much of the day today. Rainfall rates will be fairly light with a thin warm cloud depth, in association with decently dry mid levels. Rainfall may resemble light rain or drizzle intermittently between showers. Most of the more persistent shower activity should move south and east of the region by this afternoon, with just some lingering light showers. Trends have kept the better instability and thunder chances to our southwest in the quasi warm sector and along the stationary boundary. Rainfall amounts through this evening are expected to be less than half and inch with a quarter to a half an inch southwest of a line from Massena, NY to the Orange/Caledonia County border in Vermont. As showers depart this afternoon, low level moisture will linger, though mid levels will remain fairly dry. Thus, some drizzle may still linger into the overnight hours, particularly in eastern Vermont where damed cold air will reside under the approaching warm air from the west leading to further isentropic lift. While it will not be a total washout today, with likely breaks between showers, especially this afternoon, it will likely be dreary. With the added cloud cover temperatures today temperatures will struggle to get out of the 60s in our south and western regions, with some warmer temperatures on the northern edge of the shower activity near the International Border where mid 70s will be possible. KEY MESSAGE 2: A more dynamic system will push into the area Wednesday into Wednesday night as the stationary boundary to our southwest, drifts northeast closer to our region. A surface low over the Great Lakes associated with a parent low in northeast Ontario will track east from eastern Ontario. Showers are expected to move into the St. Lawrence Valley by the early afternoon on Wednesday, though with limited instability due to likely convective blowoff preceding these showers. However by the mid to late afternoon models depict good elevated instability above an inversion layer which could help sustain some thunderstorm activity primarily in the later afternoon and evening hours in the St. Lawrence Valley. 1000-1500J/kg of MLCAPE associated with 30-40kts of 0-6km bulk shear would be ample to support embedded thunderstorms towards the later afternoon. Any stronger storms Wednesday afternoon, would be tied to northwestern New York, and conditional on the amount of cloud cover and antecedent convection. Temperature profiles likely will not be of much help with surface temperatures in the mid to upper 70s Wednesday afternoon. Should convection become self-sustaining in Canada, it likely would be able to continue due to the available MUCAPE to 1500-2000J/kg modeled across the St. Lawrence Valley. As a result of this slight upward trend, the Storm Prediction Center has added southwestern St. Lawrence County in a Marginal Risk (level 1 out of 5) for Severe thunderstorms Wednesday afternoon-Wednesday night. As the showers and embedded thunderstorms continue to track east Wednesday evening, a developing nocturnal inversion will help decrease the threat of any stronger storms in addition to the overall thunder chances. However, showers will still retain the potential for heavier downpours into Vermont beyond sunset. Rainfall rates in the HREF through Wednesday evening denote pockets of 0.25- 0.5"/hour rates across northern New York. A good wetting rain is anticipated Wednesday night areawide with most areas expected to see three-quarters of an inch to an inch of rain, with perhaps an inch to 1.5 inches in the higher terrain of the Greens. Ensembles still show a 20-50% chance of receiving an inch or more, with 2 inch probabilities unchanged and less than 10%. While most of the area is still in a Marginal Risk (level 1 out of 4) for the potential for isolated Flash Flooding, the threat remains low and conditional upon the heavy rain axis becoming colocated with the rain axis today. Regardless, there will be several hours between rain events today and Wednesdays in addition to marginal rainfall totals. The bulk of the rain is expected to fall overnight Wednesday into Thursday morning. The heaviest showers should depart early Thursday morning to our east, though some lingering showers will still be possible in eastern Vermont as a trailing cold front shifts east. Within this thin warm sector a few pop up showers and isolated thunderstorms will be possible Thursday afternoon, mainly in southern Vermont where chances for any clearing will be highest. No severe storms are expected at this time Thursday. Unsettled weather will finally trend towards more quiet conditions as we near Friday and the weekend. KEY MESSAGE 3: The upper-level low centered over central Quebec will shift southeastward through Saturday. Multiple shortwaves rotating around the low will keep some scattered showers around, interspersed with drier periods in between shortwaves. Friday`s showers look mainly focused over northwestern slopes of higher terrain with northwesterly flow in place. As the low further shifts away on Saturday, flow will become northeasterly and thus favor showers on the northeastern slopes. Sunday will trend drier as the low moves out to sea and high pressure builds in from the west. Given the lingering upper-level low, temperatures will remain on the cooler side of seasonal normals. Highs through the weekend will generally be in the 70s, with lows in the 40s and 50s. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... Through 06Z Wednesday...An area of showers to our west will spread into portions of our forecast area this morning. The steadiest rain will remain over the southern Saint Lawrence Valley, southern Adirondacks, and into southern Vermont. This includes KRUT and KSLK. KMPV is a little more tricky...they look to remain right on the northern periphery of the line of steadier rain. Thinking showers at times for KMPV, but also some fog could develop at both KMPV and KEFK toward sunrise if we get breaks in showers and clouds. Otherwise, KMSS, KPBG, and KBTV are forecast to remain predominantly VFR, except may briefly drop visibilities to MVFR levels within heavier showers. Looking towards the end of the TAF period, forecast soundings are suggesting ceilings areawide lower towards and after 06Z Wednesday. Outlook... Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA, Slight chance TSRA. Wednesday Night: Mainly MVFR, with local IFR possible. Definite SHRA, Slight chance TSRA. Thursday: Mainly MVFR, with areas IFR possible. Chance SHRA. Thursday Night: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Friday: MVFR. Chance SHRA. Friday Night: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Saturday: Mainly MVFR, with local IFR possible. Slight chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ WHAT HAS CHANGED...Danzig DISCUSSION...Danzig/Duell AVIATION...Duell