Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 181830 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 230 PM EDT Tue Oct 18 2016 .SYNOPSIS... A warm front will lift north of the area today with unseasonably warm temperatures expected. A weak cold front with scattered showers will cross the area this evening and tonight. Mild and increasingly unsettled weather is expected across the area by Thursday into Friday, followed by much cooler, showery weather next weekend. && .NEAR TERM /UNTIL 11 PM THIS EVENING/...
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As of 220 PM EDT Tuesday...Complex hourly surface temperatures across our region this afternoon as warm front pushes from southwest to northeast. The biggest challenge has been the marine layer over eastern Vermont which is leading to nearly a 30 degree temperature fluctuation from Massena NY to Springfield VT. Guidance is struggling to put it nicely with this low clouds although with the last couple of visible satellite scans there is some evidence of the clouds beginning to erode. If we break out for even an hour or so temps will jump up by 5-10 degrees. However I`m not sure we will so I`ve trended eastern and southern Vermont`s temperatures down quite a bit. Expecting gusty south/southwest winds to continue this afternoon...with bottom of the mixed layer off RAP13 sounding supporting gusts between 45 and 50 mph. Wind advisory looks good for the Saint Lawrence Valley with the strongest winds occurring between 1 PM and 5 PM. Several record high temps will be approached this afternoon...especially at MSS. Any rain associated with surface boundary arrives in the western cwa around sunset. Prior discussion... An interesting day weatherwise across our area as a strong warm front lifts northeast through the area with very warm temperatures expected in many locales. Other than a scattered showers/isolated storms far north and east this morning, much of the day should trend very mild and dry as skies trend partly sunny in all but far northeastern counties. 24-hour back trajectory analysis at 21Z suggests source air arrives from southern Ohio in the Champlain Valley, and from near the KY/TN border across our northern NY counties. Values in these areas were in the lower to mid-80s yesterday, so readings in the upper 70s to lower 80s seem quite plausible from the Champlain Valley west this afternoon. Further east and north, the warm front will begin to slow as it encounters a more stubborn maritime airmass across eastern New England. In these northeastern counties clouds will likely linger a good portion of the day and keep resultant temperatures somewhat cooler (upper 60s to lower 70s). These values are still some 10 to 15 degrees above normal however. In addition to the mild temperatures, south/southwesterly winds will trend quite breezy to windy from the Champlain Valley west by this afternoon. Indeed, gusts into the 25-35 mph range will be likely in the Champlain Valley and Adirondacks with channeled flow boosting gusts into the 40-50 mph range in the SLV where a Wind Advisory is in effect from noon to 800 pm local time. By later this afternoon/early evening a weak cold front will approach from the northwest with scattered shower activity developing along an associated pre-frontal trough across northern NY counties. Given some nominal boundary layer instability and latest 3-hrly SREF/MOS t- progs have offered an outside shot of an isolated storm or two in these areas as well. Front then sinks through the area tonight with scattered showers/isolated storms as winds abate fairly quickly. Precipitation coverage should wane in coverage after midnight as front clears south. Larger-scale background flow remains deep southwesterly across and behind the boundary however, so an appreciable airmass change is not expected with lows generally holding on the mild side in the 50s to around 60.
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&& .SHORT TERM /11 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... As of 415 AM EDT Tuesday...Cold front continues to depart to the east with the North Country. Westerly flow with cooler temperatures and dry conditions prevail for Wednesday and Wednesday night with brief period of surface high pressure over the region. Temperatures will remain above normal with maxes in the 60s and mins in the 40s. Clouds increase Wednesday night ahead of approaching low pressure system. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 502 AM EDT Tuesday...Pattern changes with potential long duration rain event. Mid-upper level trough will dig south and east from south central Canada, towards the Mississippi into the southern Ohio Valley late Thursday. At the surface, a low pressure system will gradually strengthen and bring a warm front into the North Country late Thursday. This low track up to Ohio River valley, continuing NEwd over PA by Friday morning. GFS and NAM depict strong area of frontogenetic forcing over portions of the North Country Friday. Mid level trough becomes negatively tilted late Friday as it interacts with coastal low followed by rapid strengthening of the surface low come Saturday morning. As the the surface low moves east into Maine, cold air filters in on NW flow. 540 thickness line moves into the area, indicating possibility for some snow showers Saturday morning, mainly in the higher elevations. Rain continues with possible breaks as dry slot may develop on Saturday. The low becomes closed and stacked during the day, with several pieces of vorticity embedded in cyclonic flow keeping a chance for precipitation through at least Sunday. Storm total QPF may vary widely based on where deformation zone develops Friday. && .AVIATION /19Z Tuesday THROUGH Sunday/...
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...Strong/gusty winds expected at KMSS today... Through 18Z Wednesday...Largest concern is remains the gusty south/southwesterly winds and enhanced low level turbulence this afternoon/early evening. Mean boundary layer flow of 20-30kts will continue for KRUT/KBTV/KPBG/KSLK with surface gusts for 25 to 35kts at least through 22-00z. At MSS expect Stronger gusts in the 35 to 50 mph range as a low level jet peaks over the Saint Lawrence Valley. These winds will create moderate low level turbulence though directions are within climatological norms so no large- scale crosswind concerns are expected. A cold front with showers will arrive later today/tonight skies will trend BKN/OVC in the 040-090 AGL range, trending MVFR at KSLK/KMPV for a short period. Winds to generally abate after 00Z, veering to west/northwesterly behind the front after 06Z. Outlook 18Z Wednesday through Sunday... 18z Wednesday - 12z Thursday: VFR under weak high pressure. 12z Thursday through Saturday: Trending MVFR/IFR by 00Z Friday as frontal zone and developing low pressure bring widespread showers/rainfall to the area.
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&& .MARINE... A warm front lifting northward across the area this morning will allow increasingly strong southerly flow to develop on Lake Champlain by late morning into the afternoon hours. Sustained winds of 20 to 30 kts are expected with gusts to near 35 kts. This will create choppy to rough conditions on open waters and in bays/inlets with open southerly exposures. These conditions may pose a hazard to small craft and inexperienced mariners. A cold front will cross the area tonight with scattered showers as winds abate and veer to west/northwesterly over time. && .CLIMATE... Max Temp Records for 10/18/2016 KBTV 84/1947 KMPV 78/1968 K1V4 82/1947 KMSS 81/1998 && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...Wind Advisory until 8 PM EDT this evening for NYZ026-027-087. && $$ SYNOPSIS...JMG NEAR TERM...JMG/Taber SHORT TERM...KGM LONG TERM...KGM AVIATION...JMG/Deal MARINE...JMG CLIMATE...Taber is the U.S. government's official web portal to all federal, state and local government web resources and services.