textproduct: Burlington

SYNOPSIS

Gradually warming weather is expected over the next few days. Light rain will unfold Friday and Friday evening as temperatures reach their peak. Gusty southwest winds are also expected, followed by briefly colder conditions on Saturday. After mostly quiet conditions much of the day, snow and a wintry mix will lift back northwards late Saturday evening into early Sunday morning. A breezy day on Sunday will precede a cold front with showers during the afternoon. Then, more seasonable to somewhat above normal temperatures will return with snow showers opening the new work week.

NEAR TERM /THROUGH FRIDAY NIGHT/

As of 132 PM EST Thursday...For the rest of today, ever so slowly decreasing cloud cover will give way to some breaks with temperatures generally above freezing. Guidance insists on enough clearing to radiate out, but HREF cloud cover progs keeps me skeptical. Continued the theme of using raw, hourly data against the typical diurnal curve. Sheltered hollows of the Adirondacks and the Upper Valley that clear out still have the potential to fall into the teens to lower 20s, but most will remain near freezing under clouds before south winds initiate the more noticeable warm up. Increasingly dry low-level conditions embedded in the upper ridge axis will settle in as surface high pressure slides off the Mid- Atlantic.

Friday will be warm and windy. Guidance has trended upwards with regards to the strength of the LLJ, with values bumping up towards 65-70 knots. The core of highest winds remains in the inversion, but there still looks to be about southwest winds of 45-50 knots at 925mb beneath an inversion around 2000 ft. It's not necessarily ideal for strong mixing, but HREF and REFS guidance probabilities of gusts greater than 50 knots are highlight the common trouble spots for southwest winds - the Route 11 corridor and the immediate shores of Lake Champlain. So a Wind Advisory has been issues 10 AM Fri to 1 AM Saturday with gusts early in the afternoon likely in the 35-45 mph range within the Advisory area.

Rain will quickly shift east with a sharp, narrow plume of moisture, and is still expected to make a hasty departure after dropping 0.10- 0.25" of rain. Snow will efficiently get eaten up by the winds and the warm temperatures, but rainfall amounts of this quantity are not likely enough to cause significant issues. Cold air quickly rushes in, and unfortunately, it appears that it does so while fast mid- level flow remains in place. Post-frontal height rises and increasingly mixed low-level conditions will produce a second bout of strong gusts. This should result in one last push of very gusty winds immediately following the front, with values likely reaching 50 mph, perhaps approaching 55 mph from Malone through Ellenburg, NY depending on the strength of the boundary. This post frontal air mass will bring cool air rushing in, but by Saturday morning, it will still probably range from the mid 20s to mid 30s.

SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/

As of 132 PM EST Thursday...Much of Saturday is expected to be dry. Northwest flow will quickly break down, and so however cold we get Saturday morning will be how cold we'll likely be for whatever comes next. Temperatures will rise a few degrees into the mid to upper 30s with very dry air in the region owing to a broad, stretched out 1028-1030mb surface high building across eastern Canada. Precipitation will lift north Saturday evening after facing some initial resistance from dry air, but it will help provide some wet- bulb cooling. P-Type should be snow at onset. A double barrel low situation will evolve with low pressure developing off Mid-Atlantic tracking towards the New England Coastline. So warm advection will decrease some, but eventually by Saturday night, it will be far enough that some of the warmer mid-level conditions associated with the parent low will entrain. We'll see how much, but a mix will likely develop over portions of the region heading into Sunday morning.

LONG TERM /SUNDAY THROUGH THURSDAY/

As of 132 PM EST Thursday...Key Points: * Key Point: Frozen precipitation areawide, likely in the form of snow, anticipated Sunday, with accumulating snow possible.

A classic double barrel system will continue into the day Sunday with an occluding parent low and a developing coastal low off southern New England. It continues to look more likely that the coastal low will become the dominant feature of the two overall, which will continue the trend of a more colder solution for Sunday in terms of precipitation types. Precipitation is likely to fall as snow Sunday with a split snow consistency across Vermont and New York. New York will largely continue to be influenced by the parent low with more of a dry fluffier snow and higher snow ratios towards 10-15:1. However in Vermont and the CPV, southeasterly flow from the dominating coastal low will lead to lower snow ratios (8-10:1) and a wetter snow in the morning before winds become west/northwest with colder and drier air helping to increase snow ratios by Sunday evening. Although temperatures will reach highs in the mid 30s Sunday, wet-bulbing should be able to allow for most of the region to see mainly snow. However, locations near Lake Champlain, such as Grand Isle, St. Albans. and downtown Burlington, could see a mix of rain and snow at times, mainly near midday Sunday. As the coastal low departs east, the parent upper low will shift east as well leading to prevailing westerly flow areawide. Winds increase in the downslope regions of the eastern Adirondacks and eastern Greens as the parent low upper level jet traverses the region. Gusty winds up to 20 to 30 mph will be possible. With the parent low passage, an associated vort max continues to look promising in terms of available lift with the potential for isolated snow squalls Sunday night. The NAM12 solution depicts up to 100J/kg of CAPE Sunday afternoon into the evening across northern New York and central and northern Vermont before weakening into the Northeast Kingdom. There should be some moisture around with mild enough temperatures to support showers and embedded squalls Sunday evening with the potential for additional travel impacts.

Subtle northwesterly flow late Sunday night into Monday morning across the northern Greens could lead to some localized upslope showers with enhancement from some weak orographic lift. Into parts of New York, however, southwesterly flow will be favorable for a lake effect band to form off Lake Ontario, leading to localized light to moderate snow in south/southeastern St. Lawrence County Sunday into Sunday night. However, the bulk of the moisture will be dragged along with the upper low, so expect only a few inches across the upslope higher terrain and in regions under the lake effect snow band. The pattern beyond the weekend looks to be a bit unsettled, but on the mild side with a series of weak ridges and troughs. Temperatures will be mild with highs into the low to mid 30s for much of early next week. The bulk of the weekend precipitation should taper off Monday, but linger in the St. Lawrence Valley. Locations that could see the best chances for precipitation in the extended will be across the St. Lawrence Valley and northern Greens as a long wave trough will eject several shortwaves along the St. Lawrence Valley and International Border. Shadowing and a dry slot across the CPV and Vermont could limit the overall spatial extent of these shower chances, but expect broken to overcast skies to continue through next week. It is January in northern New York and Vermont after all, but the sun will return someday.

AVIATION /19Z THURSDAY THROUGH TUESDAY/

Through 18Z Friday...Main terminal impacts through this afternoon will be continued MVFR ceilings with intermittent BR leading to some visibility reductions. High pressure is attempting to scour out some clouds from the south with clearing evident on satellite in the eastern Adirondacks and western Champlain Valley. However, persistent low level moisture across much of Vermont and the rest of New York is keeping some low clouds in place, generally 2000-3000ft agl, outside of the mountain sites at SLK/EFK where ceilings are 1500-2000ft agl. Looking upstream on the other side of the clearing are some additional MVFR cigs, however, the expectation is that by 22Z, this clearing should arrive at most terminals. SLK/EFK/MSS could hold on to some low level moisture through the overnight, but should also see improvements to VFR by 12Z. One other wrinkle to this forecast is with increasing temperatures and dewpoints rising above freezing, snowmelt is continuing to lead to intermittent 3-5SM BR. Unlike yesterday, light flow should reduce the chance of any LIFR and fog, but there is a non-zero chance of IFR visibilities if snowmelt becomes more vigorous, especially once winds increase overnight. Model soundings suggest that at PBG tonight between 03Z and 09Z, a low lake cloud off of Lake Champlain, coupled with light south/southeast flow, could drift into PBG leading to localized IFR/LIFR conditions. Have only mentioned a sct003 for now due to some uncertainty, but persistence with this pattern setup suggests an increased confidence.

While winds are generally light and variable right now, they will become prevailing southerly overnight with increasing magnitude towards sunrise and beyond. Winds will increase towards 10-15kts, especially in the wider valleys, with gusts up to 20-30 kts by 12- 15Z, and increase further towards 30-40kts at BTV and the New York terminals by the end of this TAF period. These winds are associated with a moderately strong 850mb jet which could lead to widespread turbulence, as well as widespread LLWS areawide.

Outlook...

Friday Night: Mainly VFR, with areas MVFR possible. Chance RA, Slight chance SHRA. Saturday: VFR. Chance RA, Chance SN, Slight chance PL. Saturday Night: Mainly MVFR, with local IFR possible. Definite FZRA, Definite RA, Chance SN. Sunday: Mainly MVFR, with local IFR possible. Chance SN, Chance RA, Chance FZRA. Sunday Night: Mainly MVFR, with areas VFR possible. Chance SN. Monday: Mainly VFR, with areas MVFR possible. NO SIG WX. Monday Night: MVFR. Chance SN. Tuesday: MVFR. Slight chance SN.

EQUIPMENT

NOAA Weather Radio station WXM-44, transmitting from Mt. Ascutney, Vermont, on frequency 162.475 MHz is non-operational at this time. NWS technicians have diagnosed the problem, but repairs will likely not be able to occur for quite some time due to circumstances beyond our control. Therefore, the time of return to service is currently unknown. The following NOAA Weather Radio transmitters may be able to provide service during this outage: WWG 50 from Burke Mtn, VT at 162.425 MHz and WNG 546 from Hanover, NH at 162.525 MHz.

The Colchester Reef meteorological station is out of service. This site is not serviced by the NWS and there isn't an estimated return to service at present. Use extra caution when navigating the broad waters of Lake Champlain. Please contact us if you observe winds significantly deviating from the recreational forecast.

BTV WATCHES/WARNINGS/ADVISORIES

VT...None. NY...Wind Advisory from 10 AM Friday to 1 AM EST Saturday for NYZ027-030-031.