textproduct: Burlington

SYNOPSIS

Periods of snow showers will continue across portions of northern New York and Vermont through Sunday as a weak trough moves through the region. Then, frigid conditions are expected Sunday night bringing wind chill values as low as -10 to -20 degrees for much of northern New York and Vermont. Conditions are expected to trend warmer by the middle of next week with potential for sharper warming and some mixed wintry precipitation by late week.

NEAR TERM /THROUGH SUNDAY NIGHT/

* Frigid temperatures and wind chills are expected Sunday night into Monday. Many locations will range -10 to -15F while portions of northern New York and northeastern Vermont dip -15 to -22F. These conditions will increase chances of frost bite for those unprepared.

As of 108 PM EST Saturday...Light snow showers are beginning to tapering down as drier air works into the region out of Canada this afternoon. However, another weak trough will sweep west to east overnight bringing more scattered showers before becoming relegated to higher terrain by late Sunday.

Focus remains on high pressure Sunday night moving into the region allowing for some radiational cooling to drop temperatures. Some locations, especially in the Adirondacks to near Malone and in northeastern Vermont, could see hazardous wind chill values below -20F. The caveat here will be winds which remain marginal and cloud cover. Should cloud cover linger slightly longer, wind chill values will stay above -20F. Also, if clouds clear out, then nocturnal subsidence and what promises to be a very strong radiation inversion would decouple winds. Still, a light downslope wind of 2 to 5 mph could push wind chill values low enough to warrant a marginal Advisory. Best advice for now is to plan for frigid conditions to prevent frost bite.

SHORT TERM /MONDAY THROUGH MONDAY NIGHT/

As of 108 PM EST Saturday...Flow is favored to turn southerly Monday heralding a relative warming trend with temperatures continuing to run below seasonal averages. A fast moving, but consolidated at 850-700mb, trough is expected to move through the region bringing isolated to scattered snow showers. Speed and limited moisture content (dendritic growth zone nearly on the ground with little appreciable moisture advection) will keep snow amounts on the lighter side with a trace to 2 inches generally possible; highest amounts favored towards the St Lawrence Valley, higher terrain of southern Vermont, and higher terrain of the Adirondacks. Thermal packing and gradient to not appear strong in mostly depictions, so temperatures will actually be warmer than Sunday night with lows likely ranging from the single digits above 0F to around 12F.

LONG TERM /TUESDAY THROUGH SATURDAY/

As of 139 PM EST Saturday...Above normal temperatures and an weather active pattern will dominate the long term for mid to late next week. Tuesday will be the coldest day of the long term, though mild compared to current temperatures. Tuesday will begin a warming trend with highs in the mid to upper 20s to near 30 as a warm front lifts north through the region. The warm front, and associated low over eastern Ontario, will slide northeast during the evening to overnight Tuesday with precipitation chances increase from southwest to northeast Tuesday night. The system is expected to slide eastward into Wednesday morning and exit by Wednesday evening. Thermal profiles support all snow to start with surface temperatures in the mid to upper 20s and below 0 925- 850mb thicknesses. However, as the system shifts east/northeast overnight, winds aloft will turn to the southwest drawing in warmer air with progged 850mb temps to 1-3C, with the GEFS the more aggressive solution with the warming aloft as compared to the EPS. There have been some subtle trends towards a cooler surface, especially across the eastern Greens due to cad, and across the northern St. Lawrence Valley from cooler drainage winds as the system slides east. These could lock in colder surface air longer, and coupled with warming aloft, could lead to period of wintry mix. While still some uncertainty, with anecdotal evidence and a typical pattern for brief freezing rain, supported by model soundings, have introduced a mention of freezing rain for portions of southern Vermont, and the St. Lawrence Valley where confidence is higher for a period of freezing rain. This wintry mix looks to possibly impact the Wednesday morning commute. By midday Wednesday, thermal profiles will continue to warm towards highs in the mid 30s with mostly rain outside of the higher terrain and eastern Greens. In addition to the wintry mix potential, winds will become gusty with the system as a 40-50 kt 850mb jet overhead. With any northerly jog to the system, more efficient mixing could lead to gusty surface winds, particularly across the St. Lawrence Valley, Champlain Valley, and northern Vermont. Have continued to trend gusts towards the NBM 90th percentile. As the system departs, wrap around moisture with northwest flow will switch any lingering precipitation to mountain snow confined to the northern Greens, and Adirondacks briefly Wednesday night.

Subtle cooling Wednesday night will be short lived with continued warming Thursday into Friday as ridging builds in ahead of a full latitude mid/upper level trough. A mature northern hemisphere cyclone looks to develop across the lee of the Rockies Thursday and track up the Ohio Valley into New England by late Thursday night into Friday morning. Ensemble low to mid level temperatures show good agreement in moderate warming with a 60-80% chance of reaching 40 degrees on Friday and Saturday. There is still a lot of uncertainty with the track of the system which will heavily impact the magnitude of warm air aloft and ultimately the precipitation types associated with the system. However, with probabilistic guidance noting a strong chance of above freezing temperatures, there is increasing potential for a mostly rain event by late week. Ice movement and snow melt could be a concern by mid to late next week. One good thing is that dewpoints look to struggle to reach at or above freezing for much of the period which should limit widespread efficient melting.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Through 00Z Monday...Scattered light snow showers will persist at mainly KSLK/KMPV through 04z, with visibility generally 3-5SM though occasionally 2SM during that time. Otherwise, anticipate VFR to prevail at most terminals through the evening hours. An area of light snow will try to make its way into southwestern parts of the region after 06z, and while most of it should miss the terminals, have included some MVFR/IFR visibilities and MVFR ceilings at KRUT/KSLK through 12z. The other terminals should see continuing VFR conditions overnight and through much of the day tomorrow, though can't rule out occasional MVFR ceilings through the period. Winds will generally N 3-8 kt during this period.

Outlook...

Sunday Night: VFR. NO SIG WX. Monday: Mainly VFR, with local MVFR possible. Chance SHSN. Monday Night: Mainly MVFR, with areas VFR possible. Chance SN. Tuesday: Mainly VFR, with areas MVFR possible. Slight chance SHSN. Tuesday Night: Mainly MVFR, with areas VFR possible. Chance SHSN. Wednesday: MVFR. Chance SHRA, Chance SHSN. Wednesday Night: Mainly IFR, with areas MVFR possible. NO SIG WX. Thursday: Mainly MVFR, with local IFR possible. NO SIG WX.

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...None.