Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 282322 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 722 PM EDT SAT MAY 28 2016 .SYNOPSIS... The Memorial Day weekend will continue to see well above normal temperatures with daytime max temps between 10 to 20 degrees above normal. Increasing low level moisture will allow for higher relative humidities and an increasing chance for widespread showers with scattered thunderstorms possible on Sunday and Memorial Day. && .NEAR TERM /THROUGH SUNDAY/... As of 344 PM EDT Saturday... With the 2pm observation in Burlington we reached 90 degrees for the second day in a row putting us two thirds of a way to a local heat wave. Expect warm and muggy (relative to normal for the North Country) conditions through the rest of the afternoon and early evening. The scattered cumulus field has continued to develop across both northern New York and Vermont, however the lack of any significant forcing has prevented any showers from developing as of this discussion. The lake breeze on the western edge of Lake Champlain may end up being the trigger for some late afternoon early evening convection depending on how inland it moves. Additionally, the western edge of the Champlain Valley has been considerable cooler with light to moderate onshore flow from the much colder lake water temps. With the area somewhat unstable 150-200 J/kg of MUCAPE any showers that do develop will have the potential to cause an isolated lightning strike or two. As the upper level ridge continues to build this evening expect another evening with some potential for patchy fog development. The best chance will be over northern New York where we are still drying out from the light rain that fell overnight Thursday. Across Vermont where we`ve gone with consecutive drys days we may not have enough boundary layer moisture to see widespread fog. Tomorrow, as mentioned by the midnight crew, becomes quite the active period. The upper level ridge overnight gives way to an advancing upper level trough. There will be a large influx of precipitable water with values rising to 1.6-1.8 by location. 925mb temps are elevated again Sunday and the 21-23C 925mb temps will support max temps tomorrow once again in the upper 80s to low 90s. Currently the forecast for Burlington reaches heat wave criteria with a max temps of 90 expected. Unlike today however there will be a few piece of shortwave energy the ride along the longwave trough providing the necessary trigger for convection to occur. So I`ve continue to offer high chance to likely pops for most of the forecast area. MUCAPE values are expected to exceed 500-1000 J/kg and K-index values also are indicated of thunderstorm development. With the chance for thunderstorm development, slow storm motions, and abnormally high pwat, I continued to mention the chance for heavy rain in any thunderstorms that develop. We should be safe with regards to flash flooding due to how dry we`ve been in May but caution should be taken with any shower producing heavy rainfall. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... As of 427 PM EDT Saturday...precipitable water values early Sunday night will be 1.5 to 2 inches. Will mention showers and thunderstorms for Sunday night, and will include some heavy rainfall possible with any thunderstorms. Conditions quite dry across the region in May, so do not expect any flash flood issues at this time. ECMWF and GFS models now showing frontal system will move through the region earlier in the day on Monday with showers mainly Monday morning, as both models showing a mid level dry slot will move into the region by 18z Monday. Thus, have decreased pops for Monday afternoon, and will go with a dry forecast for Monday night. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 427 PM EDT Saturday...Fair and dry weather will be over the north country from Tuesday through Thursday night, as a ridge of high pressure at the surface and aloft builds east from the Great Lakes. ECMWF and GFS models in fairly good agreement with bring a cold front from the Great Lakes into the region with showers expected Friday and Friday night. ECMWF and GFS models differ on forecast for Saturday, with the ECMWF model more progressive than the GFS and has a mainly dry forecast for Saturday, while the GFS model has the front stalled across the region on Saturday as it will be parallel to the upper flow. Thus, forecaster confidence for the Saturday forecast is low at this time. Have stuck with super-blend pops for Saturday and will have a chance of showers in the forecast for Saturday. && .AVIATION /23Z Saturday THROUGH Thursday/...
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Through 00z Monday... Generally VFR with overnight IFR/LIFR mist at SLK and possibly at MPV. Increasing risk for sct SHRA/TSRA particularly after 16z Sunday. All-in-all pretty similar to last night with some leftover high clouds. Areas of mist likely starting at 06z at SLK. Boundary- layer flow is slightly higher enough at mpv to keep any mist that may develop there temporary. Winds initially light/terrain driven becoming calm. Any mist/light fog burns off early in the morning under strong sunshine. Additional heating and increasing depth of moisture should support at least scattered showers/possible storms. Latest short-term guidance points to a start time around 16z off the Adirondacks and then advancing eastward. Any thunderstorm capable of heavy rain and associated brief IFR visibilities. Maintained VCSH for this period with prevailing VFR conditions. Winds becoming south/southwest 5-8 kts. Outlook 00z Monday through Wednesday... Mainly VFR with daily chances for showers and thunderstorms each afternoon and evening. Greatest coverage/threat appears to occur in the Sunday early evening and Monday time frame. Best chance for a dry day will be Wednesday.
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&& .CLIMATE... Record maximum temperatures for Saturday 5/28 and Sunday 5/29 are as follows: 5/28 5/29 BTV - Burlington 92 in 1978 89 in 1978 MPV - Montpelier 88 in 1978 87 in 1978 MSS - Massena 89 in 1978 90 in 1978 St Johnsbury 93 in 1978 92 in 1978 Mt Mansfield 77 in 1978 77 in 1978 && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Deal NEAR TERM...Deal SHORT TERM...WGH LONG TERM...WGH AVIATION...Deal/Loconto CLIMATE...BTV is the U.S. government's official web portal to all federal, state and local government web resources and services.