textproduct: Burlington

WHAT HAS CHANGED

As of 104 AM EST Monday...Snowfall amounts have been decreased by 2 to 4 inches across the region. Widespread 8 to 12 inches remains expected and no changes to the ongoing Winter Storm Warning were made.

KEY MESSAGES

As of 104 AM EST Monday...

1. Light to moderate snow will yield an additional 3 to 7 inches of snow, with storm totals ranging between 7 to 16 inches, with the highest values in Essex County, New York and portions of southern and central Vermont.

2. Below normal temperatures are expected for the mid to late week time frame, with just a few periodic chances for light snow showers, mainly in the Lake Ontario snowbelts and in the northern mountains. In particular, Thursday night into Friday morning will need to be monitored for potential Cold Weather headlines.

DISCUSSION

As of 104 AM EST Monday...

KEY MESSAGE 1: IR satellite imagery depicts colder cloud tops shifting away from Vermont and northern New York. This is an indication of more shallow moisture. Radar reflectivities have collapsed in southern Vermont. A subtle trough is keeping activity going across the northern half of Vermont and northern New York, but this will shift out of the region momentarily, with a regional lull in activity overnight and early this morning.

Between the fine crystals and some needles at the event onset, as well as what looks to be a longer duration of drier, more subsident air this morning and early this afternoon, snowfall totals have been reduced about 2-4" areawide. It seems guidance was too warm in the low-levels, and so the colder conditions had several areas cooler than favorable temperatures for dendritic growth. The liquid equivalent aspect of the forecast is in excellent shape, though. So the expectation of additional 3-7" of snow associated with a mid-level trough that will close off and produce some low-level FGEN and better upward motions is on track, even if the gap between little snow and this feature is somewhat larger. Storm totals are at least 8-12" for much of the region, with 10-16" in southern-central Vermont. Portions of the St. Lawrence Valley may struggle to reach 7", but we'll see how they do as this subtle trough reaches that area momentarily.

For those waking in the St. Lawrence Valley, northeasterly drainage winds have maintained cool wind chills of -5 to -15, locally down to -20. This will likely continue through mid- morning. Fortunately, the amount of snow will be relatively lower there, but bundle up clearing snow given the cool conditions. Snowfall quickly drops after 8 PM tonight. As winds shift to the northwest 5 to 10 mph, we'll see temperatures fall into the single digits above and below zero overnight. So very cold wind chills of -5 to -15 are likely.

.KEY MESSAGE 2: A large-scale upper polar trough will influence weather conditions the rest of the week and maintain below normal temperatures. Mean daily averages around -8 to -12 degrees will be the rule during these periods. Several perturbations will drift into the region, but nothing significant is anticipated with limited moisture sources. A transient lake effect band will develop Tuesday afternoon ahead of one of those troughs. Portions of southern St. Lawrence County could pick up about 3" of snow as this band drifts south. As far as cold temperatures go, Thursday night into Friday may need to be watched. Winds will pick up in advance of a surface trough while reinforcing cold air. Apparent temperatures based on the latest NBM forecast already indicate values around -10 to -20 F, with a few batches of -25 in the Adirondacks and Northeast Kingdom.

AVIATION /06Z MONDAY THROUGH FRIDAY/

Through 06Z Tuesday...Widespread snow continues through this evening. The steadiest and heaviest snow will be through about 9Z, where visibilities most places will be IFR. Between around 9Z and mid afternoon, the snow will become lighter and more scattered. There will likely be intervals of MVFR or even VFR visibilities at times. During the late afternoon and evening, the snow looks to become heavier and steadier, and visibilities should return to IFR for most places. The snow exits tonight and visibilities return to VFR. Ceilings will be mostly MVFR during the next 24 hours, though they look to be briefly IFR at MPV and SLK during the steadiest snow. Winds will generally be light and northerly, except at RUT where southeast gusts in the 10 to 20 KT range are expected and MSS where 10 to 20 KT gusts from the northeast are expected. LLWS will be present at times this morning, especially at RUT.

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...Winter Storm Warning until 1 AM EST Tuesday for VTZ001>011- 016>021. NY...Winter Storm Warning until 1 AM EST Tuesday for NYZ026>031-034- 035-087.