648 FXUS61 KBTV 190516 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 116 AM EDT Thu Jun 19 2025 .SYNOPSIS... Warm and humid conditions will continue across the region for the next few days, with some isolated showers possible this evening. A cold front moving through the region tomorrow will bring increased chances of stronger storms that could produce damaging winds and downpours potentially leading to localized flash flooding. Unsettled conditions will linger into the weekend before high pressure builds over the eastern U.S. bringing the potential for dangerous heat next week. && .NEAR TERM /THROUGH FRIDAY/... As of 101 AM EDT Thursday...Lowered PoPs throughout the day Thursday to better depict the more scattered nature of convective thunderstorms expected. Otherwise, forecast is on track. Previous discussion below: Another warm and humid afternoon across the region this afternoon, with most locations in the upper 70s to mid 80s and dewpoints generally in the 60s to almost 70 in some locations. It`s been relatively dry this afternoon, although with enough instability present, a few pop-up thunderstorms cannot be ruled out through the evening hours, especially near the international border where conditions have been clearer this afternoon. Overnight lows tonight will continue to be on the mild side, with temperatures only dropping into the 60s, and parts of the Champlain Valley barely dropping below 70. A fairly active weather day looks to be in store for tomorrow as trough looks to push across the region. Compared to previous forecasts, the environment for tomorrow afternoon looks a little less favorable for the severe potential based on the overall forcing and timing of the boundary pushing through. Regardless, all of the ingredients for severe weather are there, with plenty of CAPE, shear, and moisture with PWATS in excess of 1.5 inches. The best timing for thunderstorms look to be in the mid to late afternoon, although guidance continues to slow down the timing of the trough. SPC continues to maintain the Slight Risk (2 of 5) of severe weather across our region for tomorrow. Additionally, with so much moisture and the potential for heavy rain, isolated flash flooding cannot be ruled out and WPC maintains the Marginal Risk (1 of 4) for excessive rainfall. The front looks to exit the region tomorrow night, with winds becoming more westerly. Overnight lows will still be on the mild side, but cooler than previous nights, with temperatures in the 50s to low 60s. && .SHORT TERM /FRIDAY NIGHT/... As of 401 PM EDT Wednesday...Friday morning looks fairly eventful with regards to gusty winds. We will have a brief period of cold- season like weather as steep low level lapse rates and upslope westerly flow develops behind the departing unseasonably strong low pressure system. For those with interests on Lake Champlain, please monitor the latest forecasts with potential for unusually strong westerly winds (possibly in excess of 30 knots) for several hours. Higher elevations in Vermont and the western slopes will see scattered showers early taper off by afternoon. Along with the breezes, temperatures will be dramatically cooler with temperatures struggling to warm out of the 60s. Think the cool air advection will relax early enough in the day and enough sunshine should develop during the afternoon to see highs eventually top out in the mid and upper 70s for most locations. We could see isolated thunderstorms late in the day as a weaker upper level wave moves across the region and flow begins to shift back towards the south, especially in northern New York. This wind shift will support seasonably mild temperatures overnight (although the coolest for awhile), especially in the wider valleys; more sheltered locations could see decent radiational cooling and chillier lows into the lower to mid 50s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 401 PM EDT Wednesday...Over the weekend, the general trend will be for increasing heat and humidity following a break on Friday. Saturday looks like the more comfortable day of the two days. The main hazard of note during the period will probably be related to nocturnal convection. We continue to see evidence for a ridge rolling, large cluster of thunderstorms to zip southeastward across the region. These storms will be capable of torrential rain and frequent lightning, with greatest probabilities over western portions of northern New York at this time. Stay tuned as the track of these thunderstorms become more predictable in the coming days. The heat for early next week, particularly on Monday and Tuesday, does look impressive, even for this time of year. Some record daily high temperatures will probably be broken based on the latest deterministic blended guidance, which has trended a bit warmer while continuing to be a bit less hot than the median of the probabilistic blend. The ECMWF Extreme Forecast Index suggests that across the entire region, and especially the Champlain Valley, unusually hot conditions can be expected. The heat is supported by 850 and 700 millibar anomalies of 2 to 3 standard deviations above normal per NAEFS mean. Both days look similarly hot and humid with maximum heat index values (feels like temperatures) in the lower valleys between 95 and 100 with localized values exceeding 100 possible at times. As such, expect heat stress and increased risk of heat related illnesses, especially for sensitive and vulnerable populations. The large upper level ridge, or heat dome, centered to our south will sink southward a bit on Tuesday. That may support more westerly flow and possible thunderstorms (about 20-25% chance between 2 PM and 8 PM) late in the day as a backdoor cold front slips in from the north. As such, the extreme heat will probably break, with even the warmest scenarios showing highs mainly in the 80s on Wednesday. The likely persistence of the ridge however will probably keep this boundary near the region. This pattern will promote unsettled weather mid-week, with additional chances for showers and thunderstorms especially if the front moves back northward. && .AVIATION /05Z THURSDAY THROUGH MONDAY/... Through 06Z Friday...Mostly VFR conditions across the forecast area early this morning except at RUT where low level moisture has begun to approach from the south and southeast, leaving ceilings there at about 2000-2500 feet above ground level. This moisture is expected to continue its northward progression into other sites throughout the early morning, producing MVFR or lower cigs at the rest of the sites by about 08Z-15Z. Some sites could even have ceilings dip as low as 500-1000 feet. This is most likely at MPV from 10Z-13Z, but could occur briefly across the rest of Vermont. Winds will be southerly to southeasterly during this time frame, light overnight but increasing as we head into the daylight hours Thursday, which is also what could help mix out some of the lower ceilings. We`ll see a return of VFR conditions by about 15Z except at MSS, which could lag behind the others to about 19Z. A broken line of showers and thunderstorms is expected between 18z and 23z on Thursday. The stronger storms will be capable of localized strong and gusty outflow winds up to 40 mph, brief heavy rainfall, and frequent lighting. Have continued to utilize PROB30 groups for this potential with VFR and MVFR flight categories, but a brief 15 to 20 minute window of IFR vis or cigs are possible if a terminal gets a direct hit by a stronger storm in the afternoon. Outside of thunderstorms, southwesterly winds will gust 15-25 knots throughout the afternoon but should lower again in the evening. Outlook... Friday: Mainly VFR, with local MVFR possible. Windy with gusts to 30 kt. Slight chance SHRA. Friday Night: VFR. Slight chance SHRA. Saturday: VFR. Slight chance SHRA, Slight chance TSRA. Saturday Night: VFR. Likely SHRA, Slight chance TSRA. Sunday: VFR. Slight chance SHRA, Slight chance TSRA. Sunday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Monday: Mainly VFR, with areas MVFR possible. NO SIG WX. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Kremer NEAR TERM...Kremer/Taber/Storm SHORT TERM...Kutikoff LONG TERM...Kutikoff AVIATION...Storm