Area Forecast Discussion
Issued by NWS Burlington, VT

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBTV 281058 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 658 AM EDT Fri Oct 28 2016 .SYNOPSIS... Developing coastal low pressure over southern New England will produce occasional rain and snow across most of Vermont today with scattered precipitation over northern New York. Additional wet snow accumulation of an inch or so is possible below 2000 feet. The precipitation will taper off this afternoon with mostly cloudy skies and cool temperatures prevailing. Our next weather system arrives on Saturday with breezy conditions and mainly rain showers as temperatures climb to near normal levels. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 652 AM EDT Friday...Overall forecast on track with only minor update to capture latest radar trends....which show precip redeveloping across the champlain valley associated with developing blocked flow. The combination of easterly mid level flow and developing northerly winds will continue to produce areas of light precipitation across vt...including the champlain valley through this morning. Have mention areas of drizzle this deeper moisture is limited...thinking some patchy freezing drizzle is possible near the summits associated with temps near 32f. Otherwise...any snow accumulations will be above 2000 feet as temps have warmed into at least the mid 30s most locations. Water vapor shows potent 5h energy moving across eastern NY this morning as closing 5h/7h circulation drops southeast toward southern New England. This energy aloft is helping to deepen coastal low pres near the eastern tip of Long Island with 3 hr pres falls of 4 to 5 mb...along with some lightning activity. This developing area of low pres will be captured by upper air system and track north toward the Gulf of Maine mid/upper level flow advects Atlantic moisture back into most of VT. NAM/GFS/ECMWF shows a sharp 850 to 500mb west to east moisture gradient across our region...along with associated qpf fields. Based on track of surface low pres and developing northwest winds on backside...thinking additional qpf will range between 0.25 to 0.50 for most of vt...with <0.25 northern NY mountains. The progged 850mb flow is not all that strong so upslope component for enhanced precip will be limited as winds are only 15 to 25 knots. Thermal profiles continue to be challenging this morning with pockets of near freezing temps continuing associated with the higher precip rates. For example MPV warmed to 34f earlier this evening with light precip...but steadier precip has redeveloped and temp has dropped back to 32 with light snow. Thinking during heavier precip rates this morning bursts of snow are possible above 1500 feet across eastern/central vt...with an additional slushy inch or so possible. Given the marginal bl temps not expecting any major impacts...maybe a few slick spots on untreated secondary roads across the higher terrain. Also...given the heavy wet nature of the snow...cannot rule out additional isolated power outage. As surface low pres deepens our winds will change to the northwest and progged 850mb temps cool several degrees...while boundary layer to 925mb continue to warm. Snow levels will increase above 2000 feet by 15z today. Thinking this supports the summits staying mostly snow for the entire event with storm total snow amounts up to 6 inches likely...with localized higher amounts possible near Killington. By this afternoon precip will slowly taper off with areas of drizzle and freezing drizzle possible near the moisture quickly decreases in the favorable snow growth region and best upper forcing shifts to our east. Any ice accumulation will be confined to above 3500 feet. High temps with plenty of clouds will range from the mid 30s mountain towns to mid 40s champlain and saint lawrence valleys. Tonight...depth of moisture continues to slowly decrease with winds becoming light terrain driven. Some areas of br/fog are possible given the lighter winds and saturated low levels...especially during the evening hours...before winds increase again ahead of our next system. Have mention some chance pops toward morning with thermal profiles supporting mostly rain showers...except near the summits. Temps mainly in the 30s to near 40 overnight.
-- End Changed Discussion --
&& .SHORT TERM /SATURDAY THROUGH SUNDAY/... As of 336 AM EDT Friday...Little overall change in the forecast from previous versions as we head into the weekend with the main feature being weak low pressure passing north of the Canadian border on Saturday. Latest models continue to indicate abundant low/mid level moisture with this system, but synoptic forcing is rather weak so while we continue to highlight likely PoPs for rain showers(mainly north), QPF will be light with temps pushing well above seasonal normals into the mid/upper 40s east to mid 50s west. By nightfall, the deepest low level moisture begins to shift east as the low tracks off into the Canadian maritimes and thus precipitation will gradually taper off by Sunday morning. Sunday`s forecast has become a little more tricky though as high pressure begins to build over the Great Lake region, but aloft weak shortwave energy looks to intensify and dig out a trough over southern Ontario. Models are showing some light QPF possible along a washed out boundary draped across our central/southern zones from Saturdays low, but I`m hesitant to go with more than chance pops with surface high pressure trying to build in. Temps will be tricky as well depending on where the boundary sets up, but thinking across central/northern areas highs will be slightly below seasonal normals in the mid/upper 40s, with upper 40s to possibly lower 50s south. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... As of 336 AM EDT Friday...Aforementioned high pressure over the Great Lakes Sunday shifts east across the northeast for Sunday night and Monday offering a dry and seasonally cool end to the weekend and start of the work week. Thereafter, this mornings runs of the GFS/CMC/ECMWF are in a little disagreement with our next potential system developing out of northern plains Monday afternoon. ECMWF and CMC stayed consistent to previous run tracks taking the low north of Lake Superior Monday night to the tip of James Bay by Tuesday night, while the GFS has trended a little further south. All push a warm front through the area Tuesday with the North Country firmly in the warm sector through Wednesday night, but the more southerly track of the GFS would offer higher precipitation chances. Have stuck close to consistency from our previous forecast highlighting some low chance PoPs with highs Tuesday/Wednesday pushing back into the 50s area- wide as mean 925mb temps jump to +5-10C. && .AVIATION /12Z Friday THROUGH Tuesday/...
-- Changed Discussion --
Through 12z Saturday...The aviation challenge is lowering cigs/vis associated with low level moisture and potential ifr conditions. Current obs show a mix of ifr at rutland to mvfr at mpv/slk/mss/btv and vfr at pbg. Current radar shows precip redeveloping across the champlain valley with lowering cigs toward ifr at btv. Expecting ifr cigs to prevail most of the morning before lifting between 16-18z today at rut/btv/mpv/ northwest winds develop at 5 to 10 knots. Tonight...soundings show additional moisture developing...especially slk/mpv with ifr conditions possible...but these low clouds lift as winds increase toward morning. Expect higher terrain to be obscured. Outlook 12z Saturday through Tuesday...Low clouds with ifr conditions are possible through Saturday morning...before warm front produces additional showers on Saturday across our northern taf sites. Periods of mvfr cigs are possible. South to southwest winds will increase with localized gusts to 30 knots possible at slk/mss/btv. Surface cold front with a wind shift to the northwest occurs on Sunday morning with mainly vfr conditions expected for early next week.
-- End Changed Discussion --
&& .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Taber NEAR TERM...Taber SHORT TERM...Lahiff LONG TERM...Lahiff AVIATION...Taber is the U.S. government's official web portal to all federal, state and local government web resources and services.