textproduct: Burlington

WHAT HAS CHANGED

As of 838 AM EST Sunday...

Made some morning adjustments to the PoPs, temperatures, dew points, weather, and sky cover today. Snow has been making it into northern New York this morning, so have adjusted PoPs upwards and tweaked weather to better match these observations of snow showers. Also increased sky cover outside of the Greens/Northeast Kingdom due to this. Temperatures and dew points needed some slight adjustments as many locations across the Northeast Kingdom fell lower in temperature than previously anticipated.

KEY MESSAGES

As of 156 AM EST Sunday...

1. A strong nor'easter developing off the Mid-Atlantic coast will bring snowfall and breezy conditions to the region, with the greatest snowfall amounts expected across southern and central Vermont.

2. Cold weather is expected Monday night through Tuesday night. With the combination of lingering strong northwest gusts, wind chills of -5 to -15 are possible over northern New York through Tuesday afternoon.

3. Active weather expected over the latter half of next week with several rounds of widespread precipitation in the forecast.

DISCUSSION

As of 156 AM EST Sunday...

KEY MESSAGE 1: A strong Nor'easter looks to develop off the Mid- Atlantic coast today, with the center of the low tracking southeast of Cape Cod tonight into Monday. While this system will bring heavy snow and blizzard conditions to southern New England, our region will remain on the northern periphery of the system with a fairly sharp snowfall gradient expected, as typical with these systems. As of now, the current forecast shows 3 to 5 inches across south central Vermont, with 1 to 3 across central Vermont, while more northern locations and most of northern New York will miss out. As of now, the bulk of the snowfall looks to fall Monday morning, before gradually winding down Monday afternoon and evening as the coastal low pulls away. Due to increased confidence of higher snow amounts, a Winter Weather Advisory has been issued for Rutland and Windsor counties from 1 AM Monday to 7 PM Monday. In addition to the snowfall, gusty winds are also expected with this system, with gusts in the 30 to 40 mph range increasingly likely across southern Vermont. These winds could lead to blowing snow, making for even more hazardous travel conditions and reduced visibilities, especially in any mountain passes so be sure be alert and use caution if traveling through southern Vermont Monday.

KEY MESSAGE 2: Even as powerful, deep low pressure shifts east of the region, we'll still feel some impacts Monday night into Tuesday. Isobars remain tightly packed as arctic high pressure noses down across James Bay. Temperatures will sink towards 0 F across northern New York while winds remain around 10-20 mph with gusts up to 25. Temperatures will feel more like -5 to -15 across the region. Vermont is likely to remain a bit warmer, as the core of coldest air doesn't arrive in Vermont until midday, and the depth of cold is also somewhat shallow with an inversion around 2000 ft agl meaning that cold air will have a harder time making it over mountain ridges. Highs on Tuesday will creep into the 10s over northern New York and far northern Vermont, while the lower Champlain Valley and Upper Valley warm into the 20s. A few lingering snow showers will be possible as an incoming shortwave gets absorbed within deep, stacked low pressure and arctic maritime moisture wraps around. The forecast for temperatures on Tuesday night is somewhat tricky when high pressure settles in and winds go calm. We may radiate initially, but cloud cover from the next system will already be approaching, and it may cap things off early. The current forecast is about -5 to 5 F. If there's less cloud cover, perennial cold spot Saranac Lake, New York may make a break for it and drop to the teens below zero.

KEY MESSAGE 3: The second half of next week will observe moderating temperatures behind the brief cold, with very seasonable conditions. The range of model scenarios is a bit less, and it appears they have a better handle of the two systems translating east across the region. The first seems less impactful. During the day Tuesday, a surface low will develop off the Rockies as a vort is ejected out of British Columbia and skirt the international border over the course of its life. The cyclone will mature over Lake Superior and be on the decline upon reaching Vermont and northern New York. The system will be somewhat lacking in moisture (PWATS 0.15-0.25), but enough forcing should exist as the trough acquires a negative tilt with low- level speed convergence due to the positioning of a LLJ across the Mid-Atlantic that we should be able to manage about 0.05-0.25" of liquid. Upper air temperatures will stay very cold in the wake of the early week coastal. So even as surface temperatures warm near freezing to the mid 30s, the warm air is very shallow, and so precipitation will likely remain entirely snow.

The Thursday night into Friday morning feature appears more likely to have some impact. It's a fast moving system, with precipitation likely confined to a 18 hour window, but several ingredients for synoptic forcing will be present. Unfortunately, one of those is a fairly strong southerly jet in the 850-700mb level at 50-55 knots, maybe even approaching 60 kts depending on which model scenario you're looking at. Some guidance keeps us cool enough that everything is all snow, but a handful allows a warm nose aloft that causes mixed p-types in the forecast area. There is some latitude spread, with some keeping activity suppressed far enough south that we see little, but the majority indicate widespread precipitation will be headed our way.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Through 12Z Monday...Conditions are currently a mix of VFR and MVFR, mainly as a result of a status deck persisting around 2000-6000 ft agl. Very light snow is being observed, mainly over northern New York, and the expectation is any visibility restrictions in snow will mainly be with 3-8SM. Winds will be mostly light and variable with a preference for southeasterly flow, and this will shift MVFR ceilings and snow out, and then winds will become more east to northeast, and finally northerly in response to a developing coastal low. On the northwest side of it, very dry air will likely result in ceilings rising towards 6000-12000 ft agl with wind speeds increasing to 5 to 10 knots. At KRUT and KMPV, some LLWS is possible as northeast to east winds at 2000 ft agl increase to 35-40 knots. Between 06z and 12z Monday, snow will begin to reach KRUT.

Outlook...

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

EQUIPMENT

The KMPV ASOS has suffered a communications failure. The issue has been diagnosed, but there is currently no estimated time of return to service. Terminal Aerodrome Forecasts will continue, but amendments to those forecasts will be suspended.

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. Please contact us if you observe winds significantly deviating from the recreational forecast.

BTV WATCHES/WARNINGS/ADVISORIES

VT...Winter Weather Advisory from 1 AM to 7 PM EST Monday for VTZ011-019>021. NY...None.