Mad River Glen Snow Report

351 FXUS61 KBTV 210655 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 255 AM EDT Tue Jul 21 2026 .WHAT HAS CHANGED... As of 249 AM EDT Tuesday... No significant changes. && .KEY MESSAGES... As of 249 AM EDT Tuesday... 1. Multiple rounds of showers and storms today and tomorrow. 2. Blue sky conditions to end the week with cool and crisp air. 3. Quiet and hot weather is expected this weekend before another storm system brings showers and thunderstorms to the region early next week. && .DISCUSSION... As of 249 AM EDT Tuesday... KEY MESSAGE 1: An occluding low will track well to the north today into Wednesday, bringing several rounds of showers. A few showers will move through this morning, but more widespread showers and thunderstorms will move through in the afternoon and evening. They will mostly dissipate and move out tonight, before another round of showers and thunderstorms develops on Wednesday, though mostly for Vermont. Right now, the severe threat is relatively low. There does not look to be a well-defined boundary; instead several rounds of showers with plenty of clouds will move through. There is very little time for solar heating and instability to form, and the airmass will be relatively cool to start with. With the low tracking well to the north, the best synoptic forcing will be well to the north, though there will be adequate wind shear. Overall, the region is in an SPC marginal risk which seems representative. While an isolated strong to severe storm is possible, that currently looks to be the extent of it, though the amount of heating will still be watched as more sun than expected could increase storm coverage a little. The system does not look to provide much of a flooding threat either. HREF probabilities of receiving more than an inch of rain are generally between 10-40 percent. While there will be areas of convective enhancement, the storms will be quick-moving and there will be gaps between the showers. PWATs should rise into the 1.5- 1.75 inch range but with the expected setup, that should not pose too much of a problem. While limited wildfire smoke may return today, its concentration will be significantly less than on Saturday and it will likely not have much of an effect on the convection. KEY MESSAGE 2: A seasonably cool air mass, with minimal high altitude smoke, should make for outstanding weather for outdoor activities on Thursday and Friday as an upper level trough pushes to our northeast. Westerly flow in the morning will probably support some rough conditions on Lake Champlain that should improve during the day as anomalous low level temperatures moderate along with decreasing wind speeds. Winds decrease significantly for Friday. Expect high temperatures not too far off of seasonable norms due to abundant sunshine, currently projected to range through the 70s and into the lower 80s. Lows at night will be in the 40s and 50s. KEY MESSAGE 3: High pressure will dominate this weekend, resulting in dry weather Friday night into Sunday. This is also allow for above seasonable temperatures with highs in the 80s and lows in the 50s to mid 60s as southwesterly flow aloft increases, advecting in warmer air ahead of our next system. This next system is expected to swing through early next week featuring a trough and cold front. This far out, models show significant differences from each other as well as from run to run, but most likely period of showers and thunderstorms would be Monday. This should also knock temperatures back down towards normal in the 70s to mid 80 and lows in the upper 40s to lower 60s. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... Through 06Z Wednesday...VFR conditions will likely prevail at all sites early this morning with some light south-southwesterly flow limiting fog potential. Still, fog is not out of the question, particularly at SLK where their dew point depression is suspiciously low. Overall low confidence in anything occurring and how long it may last. A warm front may produce some light, isolated showers this morning, but most impactful showers and storms are expected to wait until this afternoon and evening. The first wave will move through southern Vermont around 15Z-16Z Tuesday, just showers and potentially some MVFR ceilings, then another round of showers/lower ceilings plus thunderstorms is anticipated at northern New York sites beginning 18Z-20Z, moving east to Vermont sites by 20Z-22Z. Strong wind gusts are possible with a few storms, especially in southern St. Lawrence County. Outside of storms, we expect wind gusts as high as 15-35 knots out of the south and southeast from 12Z- 18Z Tuesday onwards. A strong low level jet, fluctuating wind direction from southerly to southwesterly, will likely make for some periods of LLWS at all TAFs throughout the day Tuesday. Outlook... Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA, Slight chance TSRA. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX. Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX. && .MARINE... A Lake Wind Advisory is expected to be in effect through tonight. Southerly winds will quickly increase in the latter portion of the night and by morning, sustained winds are expected to be in the 20-30 KT range. These winds stay elevated for the rest of the day and the evening. Winds will eventually become westerly and decrease for late tonight and tomorrow, dropping into the 10-20 KT range. Multiple rounds of showers and thunderstorms are expected today, with stronger and erratic winds possible in any of those. The highest coverage of showers and storms will be in the afternoon and evening. Waves will quickly build into the 2-4 FT range for today and this evening, before eventually dropping into the 1-2 FT range late in the night. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ WHAT HAS CHANGED...Myskowski DISCUSSION...Myskowski/Storm AVIATION...Storm MARINE...NWS BTV