Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 270721 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 321 AM EDT Mon Mar 27 2017 .SYNOPSIS... Unsettled and warmer weather moves into the North Country for tonight and Monday as developing low pressure over the central U.S. pushes a warm front northward through the region. Periods of freezing rain tonight into Monday will transition to all rain by Monday afternoon, briefly tapering off Monday night before returning for Tuesday and ending as snow Tuesday night. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... As of 1021 PM EDT Sunday...Have increased pops along and north of a potsdam to Burlington to white river junction line thru 06z...for mainly light rain with pockets of freezing rain. Surface temps continue to be several degrees warmer than expected have bumped hourly temps up and decreased overall areal coverage of freezing rain thru 06z. Still expect some pockets of freezing rain to develop as temps drop btwn 29-32 across the deeper valleys of central/eastern vt...including the northeast kingdom. Temps continue to be challenging as Whiteface is 39F while Mansfield is 25f with BTV 36F and 1V4 is 35F. Most of central/southern Vt remains dry this evening...but additional moisture will advect back into this region after 06z...based on upstream radar trends. Also...have trimmed back total qpf grids with amounts generally between 0.33 and 0.66 expected by Monday Afternoon. Previous discussion below: Better slug of moisture with deeper saturation will move into the area after 6z. Warm air aloft continues to push into the area and temperatures have risen into the mid to upper 30s across our area. Temperatures will not drop too far overnight with clouds and precipitation moving into the area, as well as warm air advection with warm front lifting across the area. Still concerns across the Eastern Dacks and Eastern Vermont for freezing rain and headlines for freezing rain advisory remains in place. For tonight into Monday, concerns remain from the previous forecast thinking in regards to freezing rain potential as deep low pressure pushes a warm front across the area. Thermal profiles are as such that freezing rain will be the dominant ptype across Essex County of New York and from the western slopes of the Green Mountains eastward where surface temps will hover a freezing or just below as warmer air aloft moves over the area. In the deeper Champlain and St. Lawrence Valleys surface temps remain in the low/mid 30s overnight so while pockets of freezing rain are certainly possible, the overall impacts will be minimal. On the impact side of things, under the advisory area, there is some concern that impacts will be on the low side through much of the event as modeled road temperatures show surfaces warming well above freezing during the day, and only right to freezing during the overnight. The expected ice accumulations won`t have an impact on powerlines as only up to a tenth of an inch is expected at the lower elevations, and even though higher up on the mid-slopes increased amounts could accumulate onto the larger transmission lines, they can usually handle a little more without failing. Freezing rain will be falling during the Monday morning commute though so any ice on area roadways will be a concern. By mid-day Monday the warm front pushes closer to the Canadian border allowing surface temps to warm into the mid-30s east to upper 40s west transitioning ptype to plain rain and ending the threat of ice accumulation. Rain will be ending by about 00z across our entire forecast area. && .SHORT TERM /7 PM THIS EVENING THROUGH WEDNESDAY/... As of 321 AM EDT Monday....Background flow trends bodily to the northwest in all areas by Tuesday night as northern stream upper trough builds southward into the area. This will drive a cold front through the region and with boundary layer temperatures cooling a transition to scattered snow showers is expected as coverage gradually wanes. Some minor accumulations possible across elevated terrain to perhaps an inch or two. By Wednesday main push of upper trough swings through the region as surface high pressure builds south and east from central Ontario. A continued threat for scattered rain/snow shower activity will exist, mainly across the northern high terrain as temperatures top out in the upper 30s to lower 40s for most. A fairly deep boundary layer to 850 mb under modest cold thermal advection aloft should ensure a breezy day with northwesterly gusts in the 15 to 25 mph range as skies trend partly sunny for all but the northern Green Mountains by the afternoon hours. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... As of 321 AM EDT Monday...Any lingering northern mountain snow showers end Wednesday evening with dry weather expected Thursday into Thursday night as southern nose of Canadian high pressure traverses the area. Low temperatures on both nights mainly in the 20s with a few upper teens in favored northern mountain hollows. Highs on Thursday similar to Wednesday - upper 30s to mid 40s. Next precipitation maker then arrives by Friday into Friday night as additional energy tracks northeast from the Ohio Valley/Great Lakes area. Global models have trended toward taking this system further northward than prior indications and as such have raised precipitation probabilities accordingly - especially during the Friday afternoon to Saturday morning time frame. Boundary layer thermal profiles suggest this will mainly fall as a rain event for lower elevations, though with 850 mb temps hovering around 0C some mix with snow or even all snow may occur across the higher terrain above 1500 feet or so, especially Friday night when a mix may even reach the valley floors. Time will tell. By Saturday steadier precipitation exits east during the morning hours as skies remain variably cloudy. Temperatures average near late March norms with highs Friday/Saturday generally in the lower to mid 40s with Friday night lows from the upper 20s to mid 30s. Looking further out a gradual drying trend is expected by the latter half of the weekend as surface high pressure is bridged aloft by modest upper troughing. Temperatures should remain within 5 degrees of typical early April values with highs ranging through the 40s and overnight lows from 25 to 35. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... Through 06Z Tuesday...MVFR conditions to persist through the next 24 hours with IFR possible towards the tail end. Warm frontal precipitation moves into the region in the next few hours predominantly as rain except for FZRA at KMPV through 15Z. Precip clears the area to the east after 18Z. For winds, mainly south/southeast except northeast at KMSS at 5-10kts. Some gusts up to 20-24kts in the Champlain Valley at KRUT/KBTV through mid-day. Outlook 06Z Tuesday through Friday... 00Z Tuesday through 00Z Thursday...MVFR/IFR in scattered rain showers Monday night, becoming prevailing rain Tuesday, and rain/snow Tuesday night and Wednesday. Moderately gusty NW winds likely Wednesday. 00Z Thursday through 00Z Saturday...Mainly VFR, except for some scattered MVFR snow showers over the Adirondacks and Green Mountains, mainly 00Z Thursday until 00Z Friday. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...Freezing Rain Advisory until 11 AM EDT this morning for VTZ003- 004-006>008-010-012-018-019. NY...Freezing Rain Advisory until 11 AM EDT this morning for NYZ034. && $$ SYNOPSIS...Neiles NEAR TERM...Neiles/Taber SHORT TERM...JMG LONG TERM...JMG AVIATION...Lahiff is the U.S. government's official web portal to all federal, state and local government web resources and services.