Area Forecast Discussion
Issued by NWS Burlington, VT

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187 FXUS61 KBTV 130729 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 329 AM EDT Sun Jul 13 2025 .SYNOPSIS... A couple of rounds of showers and thunderstorms are on tap for today and Monday as a slow-moving frontal boundary drifts across southern Canada and into the Northeast United States. Heavy rainfall will be possible with any thunderstorms, and localized flooding cannot be ruled out. Drier weather resumes by Tuesday, but it will still be hot and humid for the rest of the week. && .NEAR TERM /THROUGH MONDAY/... As of 236 AM EDT Sunday...The main focus for the near term will be a slow moving frontal boundary which will bring a couple of rounds of showers and thunderstorms to the region. Ample moisture will pool along and ahead of the front, with PWATs approaching 2 inches, which is 2 to 3 standard deviations more than normal. Given this, the biggest concern will be torrential rainfall with localized flooding; note that we are in a Marginal Risk in WPC`s Excessive Rainfall Outlook both Sunday and Monday, which is indicative of a 5% risk of exceeding flash flood guidance. Read on for details. The front currently lies well to our west early this morning, stretching from its parent low near Hudson Bay south/southwestward through the Great Lakes and into the Midwest. This boundary will gradually drift eastward through the day, eventually approaching the St Lawrence Valley by this evening. In the meantime, heat and humidity will build, and expect we`ll see SB CAPE values of 1000+ J/kg by this afternoon. This may be enough to allow a few showers/storms to bubble up over the higher terrain or perhaps along lake breeze boundaries through early afternoon, until better forcing arrives with the approaching front later in the day. The bulk of the activity will be from the Champlain Valley westward as eastern VT looks to stay more capped with an inversion around 850mb. Scattered to numerous showers/thunderstorms will cross northern NY into the northern Champlain Valley through the evening, waning in coverage and intensity as we lose daytime heating. Flow parallel to the incoming front will allow for training of storms, and warm cloud depths of 10 kft or more will enhance efficient rainfall processes. Brief rainfall rates of 1 in/hr will be be possible, and we`ll have to watch for training closely to see if cumulative amounts approach/exceed FFG. Note that 6-hr FFG is 2+ inches; indeed, 3-hr FFG is as well, except in those areas that received flooding rainfall a couple of days ago (especially the NEK - more on that below), and probabilities of 2+ in in 6 hours are 10% or less. Still, isolated instances of flooding will be possible. Some of the stronger storms may be capable of producing gusty winds as well, perhaps approaching severe levels. Much of the area from the northern Champlain Valley westward is included in a Marginal Risk from SPC. It`ll be another hot and humid day, though increased cloud cover should keep us a little cooler than yesterday. Highs will generally be in the 80s with some spots in the wider valleys approaching 90F. After a muggy night tonight, Monday will be a near repeat of today; the main difference will be that showers and thunderstorms will have shifted further south and east along with the frontal boundary. The focus will mainly be over VT, particularly northern and central areas. As with today, all the same ingredients will result in efficient rain makers, with rainfall rates of 1 in/hr at times. Note that probabilities of greater than 1 in/hr have a bit more coverage than today, with even a small area of 10% chance of more than 3 inches in 3 hours over portions of the Northeast Kingdom. Obviously this area is of greater concern given the recent flooding; 3-hr FFG is generally 1.5 to 2.5 inches in those locations. Please watch for forecast updates as hopefully trends will become more clear with subsequent forecast packages. Please remain weather aware over the next couple of days. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/... As of 236 AM EDT Sunday...The front should finally make its exit to our southeast Monday night, bringing showers and thunderstorms to an end by midnight. A drier airmass will follow in its wake as ridging briefly builds over the region. The result will be lots of sunshine on Tuesday. We`ll also see a return to warmer temperatures Tuesday as highs are expected to climb back into the mid 80s to low 90s. Dewpoints will be in the 60s, so it`ll feel muggy, but we should stay just below heat advisory levels. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 236 AM EDT Sunday...Eastern CONUS Heat ridge will nose across CWA Tuesday night- Wednesday peaking wednesday with 925mb temps reaching 24-26C at its peak. Dewpoints likely in the 60s to around 70F to put heat indices in the advisory range for most of our wider valleys. During the transition Tuesday night...higher and medium resolution models suggest decent shortwave riding along the backside of the upper ridge with strong moisture pooling and potential MCS development across Great Lakes riding along the periphery of the ridge so at this time it looks like it will be across Ontario-Quebec but will need to monitor. It looks like the the earlier timing difference from the GFS the last few days has come around as expected to the ECMWF/Canadian solutions as northern stream shortwave lifts more NE thus front slows in parallel SW upper flow. Therefore...warmer than yesterday`s runs but cooler than Wednesday`s forecast highs and rich moisture sending dewpoints into the lower 70s bringing heat indices just under Wednesday`s reading but with a very warm Wednesday night...can see needing an advisory as well, especially CVly into VT. The front in parallel WSW flow will slowly move into and through CWA Thu aftn through early Friday morning with rich PWATS of 1.75-2 inches, thus potential for heavy rain producers so we`ll need to monitor closely. By 12z Friday...front is likely across eastern New England with surface high across the Great Lakes. Upper flow is still WSW across the northeast and Great Lakes so the front brings some dewpoint relief but temperatures are still AOB seasonable levels for Friday and the weekend. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/...
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Through 06Z Monday... VFR conditions will prevail for most sites early this morning but ceilings are likely to drop aft 08z at SLK and EFK will likely see them fall to MVFR. Ceilings at MPV may go IFR for a couple hours as well. Ceilings will rise tomorrow morning and they should mostly be VFR for the rest of the day. There will be isolated showers around the Champlain Vly ard 12z, otherwise dry until Scattered showers and thunderstorms develop aft 18-20z timeframe. Brief MVFR or IFR visibilities will occur in the heaviest storms. Winds will increase from the SSW with gusts between 10 and 20 KTs are generally expected. Aft 00z...winds will subside with lower ceilings developing and possible fog where it rained earlier and continuing Sunday night. Outlook... Monday: Mainly VFR, with local MVFR possible. Likely SHRA, Chance TSRA. Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. Slight chance SHRA, Slight chance TSRA. Wednesday Night: VFR. Chance SHRA. Thursday: Mainly VFR, with local MVFR possible. Chance SHRA, Slight chance TSRA.
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&& .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Hastings NEAR TERM...Hastings SHORT TERM...Hastings LONG TERM...SLW AVIATION...SLW