Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 201156 AFDBTV AREA FORECAST DISCUSSION National Weather Service Burlington VT 756 AM EDT Mon May 20 2019 .SYNOPSIS... A pre frontal trough and surface cold front crossing the area today will interact with heat and moisture to bring another round of strong to locally severe thunderstorms. The primary threats will be isolated damaging winds and brief heavy downpours. Cooler and drier weather returns for midweek. && .NEAR TERM /THROUGH TUESDAY/... As of 726 AM EDT Monday...Showers have pushed east of the region this morning. Seeing some breaks in the clouds this morning, which should increase surface based instability today. Still looks like a pretty small window for the convection today, roughly 15-21z. Previous discussion follows. Pre frontal trough pushes across our forecast area this morning and will bring a round of showers and thunderstorms. Additional showers and thunderstorms are expected this afternoon as surface cold front approaches and crosses the area this evening. Strong to possibly severe thunderstorms are expected, with main threat being strong winds with perhaps some small hail. Ongoing convection this morning may damper the surface based instability a bit. But, should see enough clearing after morning convection moves out for some destabilization and stronger storms this afternoon. Across Vermont, maximum temperatures should reach the upper 70s to lower 80s, and with dewpoints nearing 60 will see CAPE values surpass 1000 J/kg from the Champlain valley eastward. Window is a bit small though, mainly 15-21z. Good upper level support as well with strong jet moving overhead today. Additional brief heavy rainfall is possible, and some areas have already had heavy rainfall in the past 24 hours, so will need to monitor for possible flash flooding concerns. After showers move east of the region this morning, looks like convection will fire between about 11 and noon. As cold front pushes through during the evening hours, bulk of the stronger storms will be pushed off to our east as well. SPC has parts of our area in Slight risk for today, mainly eastern and southern Vermont. Overnight as flow turns northwesterly behind the departing cold front, will have some orographically enhanced showers during the overnight hours. Showers may even linger into Tuesday a bit as upper trough and upper level shortwave cross the area. Tuesday will also be much cooler than today, highs will be in the upper 40s to lower 60s, about 20 degrees cooler. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 408 AM EDT Monday...Quieter weather returns for the short-term period as vertically stacked low pressure exits thru the Canadian Maritimes, and a dry nwly flow develops across northern NY and New England. Resulting air mass will be relatively cool/crisp, as 850mb temperatures fall to - 1C to +1C across the North Country by 12Z Wednesday. Any lingering rain showers should end before midnight Tuesday night, with gradual clearing expected throughout the overnight period. Should see Tuesday night lows in the low-mid 40s, with highs on Wednesday in the mid 60s following MOS-based consensus. Continued NW winds on Wednesday at 10-15 mph with gusts up to 25 mph will contribute to dewpoints falling into the 30s with PBL mixing/deepening throughout the day. High pressure moves in from the west late in the day and crests across the region Wednesday night, resulting in lessening wind speeds toward early evening. Wednesday night will continue dry with low temperatures again mainly in the 40s. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 408 AM EDT Monday...Relatively good consistency noted between the operational 00Z GFS/ECMWF this cycle. Two precipitation events are anticipated across the North Country. A mid-level shortwave trough embedded in WNWLY flow with 80-90kt 500mb jet will traverse the region Thursday afternoon into Thursday night. With sfc low moving eswd along 850mb frontal zone, appears mesoscale and synoptic-setting will be favorable for showers and possible embedded thunderstorms. Carried a slight chance of thunder at this point, and we`ll need to monitor for possible strong thunderstorms if low-level moisture return is adequate for higher instability than presently indicated. Valley highs on Thursday presently expected in the lower 70s. Should see a period of dry weather for Friday and Friday night with seasonable temperatures. Next shortwave trough arrives Saturday/Saturday night with periods of showers and PoPs 60-70%. Early indications suggest drier weather returns for the latter half of the weekend. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... Through 12Z Monday...Showers and thunderstorms have pushed east of our area this morning. Further convection is expected from 15-21z Monday across Southern and Central Vermont especially. Some storms will be strong to severe this afternoon. Strong turbulence and gusty winds to 35 kts near any convection. Winds will trend southwesterly later this morning and gusty. Outlook... Tuesday: Mainly VFR, with local MVFR possible. Slight chance SHRA. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. Chance SHRA, Slight chance TSRA. Thursday Night: Mainly MVFR, with areas IFR possible. Chance SHRA, Slight chance TSRA. Friday: Mainly MVFR, with local IFR possible. Slight chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Neiles NEAR TERM...Neiles SHORT TERM...Banacos LONG TERM...Banacos AVIATION...Neiles is the U.S. government's official web portal to all federal, state and local government web resources and services.