textproduct: Burlington

WHAT HAS CHANGED

As of 136 AM EST Wednesday... While very cold temperatures and low wind chills are still expected this weekend, forecast values are trending less extreme than previously forecast.

KEY MESSAGES

As of 136 AM EST Wednesday...

1. Light snowfall this morning, but with minimal road impacts.

2. Hazardous travel is possible late Friday and Friday night due to snow showers spreading over the region.

3. Dangerous cold with wind chills of 20 to 30 below zero likely over the weekend.

DISCUSSION

As of 136 AM EST Wednesday... KEY MESSAGE 1: Early morning GOES-19 IR imagery reveals well the compact mid-level vort progressing ewd along the International Border of NY. This system will continue slowly ewd and cross nrn VT between 12-15Z. With PW values of only 0.15-0.20" across the region, feature has a skeletal appearance in IR imagery due to limited moisture availability. Dynamical forcing remains moderately strong and will be sufficient to produce continued light snowfall across nrn NY and central/nrn VT through mid-morning (PoPs 60-80% for most nrn areas). Snowfall amounts will generally range from a coating to 1", except locally 1-2" across Franklin VT county and into the far nrn Greens. With a fluffy character to the snowfall and SLRs around 20:1, impacts for this morning's commute should be minor. Skies will trend partly sunny this afternoon once mid-level system translates ewd into NH/ME. Winds will trend light NW, but with little overall change in low-level air mass. Looking for afternoon highs similar to yesterday...generally in the low-mid 20s.

KEY MESSAGE 2: Scattered to numerous show showers are expected to spread over the region from west to east late Friday and Friday night as a clipper low pressure system and its associated upper trough scoot across northern New England. A strong cold front will be dragged along in the clipper's wake, and this will help to serve as a focus for snow shower activity. Timing for this feature has slowed about 6 hours compared to this time yesterday, so while a few scattered showers will be possible during the daylight hours Friday afternoon, the bulk will occur Friday night into Saturday morning. There will be ample frontogenetical forcing with this front, but moisture will be scarce (PWATs only 0.25 inch). This along with the unfavorable timing of the frontal passage will greatly limit available instability as well. So while there could be a few heavier showers as the front moves through, don't anticipate true squalls at this point. Flow turns around to the west/northwest behind the front, so some wrap around showers may persist into Saturday afternoon in the favored upslope areas of the northern Adirondacks/Greens. Snow/liquid ratios will be high, resulting in a fairly light and fluffy snow. Guidance still points at most places seeing 2 inches or less, with perhaps 2-4 inches along the spine of the northern Greens and portions of the western Adirondacks.

KEY MESSAGE 3: The aforementioned cold front will usher in a very cold and dry airmass for the weekend. With the slower timing, northern NY will see temperatures fall sharply late Friday night into Saturday morning. Meanwhile, much of VT, particularly east of the Greens, will likely hold steady or only cool slightly into the teens by Saturday morning, then fall through the single digits Saturday afternoon. Latest guidance has backed off on the extreme cold of this incoming airmass, with 850mb temperatures now expected to be closer to -25C rather than -30C. Winds have also backed off just a bit as well, though it will still be pretty breezy Saturday into Saturday night when gusts around 30 mph possible. The pressure gradient will relax on Sunday as ridging noses into New England, allowing gusts to slacken though sustained winds will remain 5-10 mph. With all this, it's still going to be dangerously cold; note the 01z NBM shows 50-85% chance of Saturday's highs remaining below +5F west of the Champlain Valley. This expands across the vast majority of our northern and central regions on Sunday. Saturday and Sunday night lows, meanwhile, will be well below zero, with many locations dropping into the -10 to -20F range. Given this, it won't take much wind for wind chills to reach dangerous levels; expect widespread -10F to -20F during the day Saturday and Sunday, with - 20F to -30F likely Saturday night into Sunday morning. Even though these wind chills/cold aren't quite as extreme as what we were looking at this time yesterday, it will still be very dangerous for anyone outdoors, especially if they are not dressed for the cold. We'll continue to refine the forecast going forward, but at this point, anticipate that at least Cold Weather Advisories will be needed across the entire area this weekend. Anyone with outdoor plans should keep a close eye on future forecasts.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

Through 06Z Wednesday...A mix of MVFR/VFR conditions prevails at the start of this TAF period, but expect ceilings to lower to MVFR areawide as snow showers spread from west to east through the early morning hours. Snow will be light and will move through quickly, generally affecting the terminals for 3-6 hours, ending at all sites by 15z. KMSS/KSLK/KEFK have the best chances for IFR visibility, but elsewhere anticipate visibilities to remain 3-5SM in showers. Once these exit to the east, ceilings will still remain 1500-2500 ft, with only KRUT to remain VFR and snow-free, and these trends will continue through the remainder of the TAF period. Winds will be light and variable through early Wednesday morning, trending toward W/NW at 4-9kt after 13z.

Outlook...

Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: Mainly VFR, with local MVFR possible. Chance SHSN. Friday Night: Mainly MVFR and IFR, with local VFR possible. Definite SN, Likely SHSN. Saturday: Mainly VFR, with local MVFR possible. Chance SHSN. Saturday Night: VFR. NO SIG WX. Sunday: VFR. 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.