textproduct: Burlington

WHAT HAS CHANGED

As of 128 AM EST Thursday...

No significant changes.

KEY MESSAGES

As of 128 AM EST Thursday...

1. Snow showers end early today, with mainly quiet weather through tomorrow under influence of high pressure.

2. A brief windy warm up Friday night into Saturday. Then colder Saturday night into Sunday with light snow possible.

3. Sharply colder temperatures early next week, then turning warmer and more active with several chances for precipitation for the middle of the week.

DISCUSSION

As of 128 AM EST Thursday...

KEY MESSAGE 1: Early this morning a trough of low pressure is exiting to our east, with pressure rises gradually slowing as high pressure builds in during the day today. Modest cold air advection continues behind the cold front while scattered snow showers wind down. As a result, it will be a slightly cooler day today than yesterday, especially towards the International Border from northwestern Vermont and points west. A north to south thermal gradient will linger through tonight ahead of a warm front as high pressure moves to our east. This front will mainly stay to our west, but very light, spotty snow will be possible as a weak trough translates northeastward over southern Canada. Saturation of the snow growth layer is uncertain, limiting chances of anything more than a trace of snow at this time. Any precipitation will probably be across the northern Adirondacks and northern St. Lawrence Valley, as early as Friday morning and possibly into the daytime hours, although cannot rule out flurries farther east into northern Vermont. Compared to Thursday, we'll see an increase in clouds and some light south winds helping boost temperatures after a cold start into the mid and upper 30s.

KEY MESSAGE 2: Gusty winds with a typical channeled valley flow setup is on tap for early Saturday ahead of a cold front. Maximum wind gust potential per model soundings and NBM QMD data shows 35 to 42 MPH in typical spots that do well with these southerly winds, such as near Malone and in the vicinity of Lake Champlain. The winds will peak prior to clouds thickening with the arrival of a band of showers. These showers will be the first of two chances for light precipitation over the weekend. Showers Saturday morning will be tied to a moisture starved, but thermally strong cold front. Have bumped up PoPs a bit compared to the National Blend of Models for early Saturday morning in northern New York, based on depiction of the front in various deterministic model guidance. There is somewhat better upper level diffluence than over areas farther east, as the system's surface low tracks towards the northeast well into northern portions of Quebec. However, future forecasts may also increase precipitation chances into Vermont. Generally precipitation should more favored in the higher terrain given dry low level air, a narrow zone of deep moisture, and strong southwesterly low level flow unfavorable for surface convergence ahead of the front. Precipitation type looks elevationally dependent and mainly rain, with perhaps wet bulbing effects changing rain to snow as clouds lower. Temperatures will be steady or fall during the day Saturday depending on location; areas farther west are more likely to see sharply lowering temperatures during the day, but hourly temperatures are fairly uncertain at this point. That being said, high temperatures are on track to be mild on Saturday areawide, in the 40s for most locations. As much colder air spills into the region, a lingering thermal gradient and a broad trough to our west will support an area of snow pushing eastward across the Midwest and into the Northeast Saturday night into Sunday. While most global model ensemble data shows chances for snow, the snowiest scenario for Vermont and northern New York would be if ridging to our northeast is a little stronger than the consensus idea. Regardless, this will probably be a light snowfall. Early estimates are in the 0.5-3" inch range at this time, with highest amounts slightly favored in the western Adirondack and central to southern Green Mountain regions.

KEY MESSAGE 3: High pressure will settle over the region to start the work week, bringing cold but dry conditions through Monday night. Highs will only be in the teens to perhaps low 20s, while overnights will drop into the single digits above and below zero. This cold spell will be short lived, however, as the ridge shifts east and brings increasing south flow to our region by Tuesday. The high will serve to keep precipitation shunted to our south Monday and Tuesday, though there are some indications that precipitation may push far enough north to bring some light snow to our central and southern regions. The GFS continues to be the most aggressive with the high pressure and amount of dry air, while the ECMWF bring a quick shot of snow to the southern 2/3 of our area. Better chances for precipitation look to be Tuesday night into Wednesday. There remains considerable spread in the deterministic and ensemble members as to where low pressure will track, which would in turn have considerable impact on our precipitation type and temperatures. The GFS is the most aggressive with this system, and would be cold enough for mainly snow, while the other deterministic models aren't even sure there will be anything there, with high pressure holding firm. Needless to say, lots of uncertainty for the latter half of next week.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Through 12Z Friday...Primarily VFR conditions across the region through the TAF period, with local MVFR in isolated snow showers early this morning. KSLK/KEFK have the best chances for reduced visibility and lower ceilings due to snow showers through 15z, but otherwise expect little more than flurries, if anything, at the remainder of the TAF sites. Ceilings 3500-5000 ft will erode through afternoon and evening hours, giving way to FEW by 00z Fri. W/NW winds 5 to 10 kt through the daylight hours with localized gusts to around 20 kt, becoming light and variable after 00z Fri.

Outlook...

Friday: VFR. NO SIG WX. Friday Night: VFR. Windy with gusts to 30 kt. Chance SHRA. Saturday: Mainly VFR, with local MVFR possible. Windy with gusts to 30 kt. NO SIG WX. Saturday Night: VFR. Chance SN. Sunday: VFR. Chance SN. Sunday Night: VFR. NO SIG WX. Monday: VFR. NO SIG WX.

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. This communications line is not serviced by the NWS. 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...None. NY...None.