textproduct: Burlington

SYNOPSIS

Surface high pressure will bring several days of quiet weather to Vermont and the North Country. Dry air will help produce cold mornings, but daytime temperatures will trend milder and then above normal by the weekend. A pattern change to unsettled weather then will unfold with chances of rain and areas of freezing rain possible beginning on Sunday.

NEAR TERM /THROUGH FRIDAY/

As of 634 AM EST Thursday...No significant changes were needed with this update. Cold temperatures across the region this morning, ranging from the teens in the St Lawrence Valley to the single digits below zero in eastern VT. We continue to see variable sky conditions, along with some patchy fog and scattered flurries. Still anticipate clearing late this morning into the afternoon. The forecast has this covered, so only adjustments were some minor tweaks to sky cover and temperatures to match the latest trends.

Previous discussion...High pressure will remain positioned across the region through this period, keeping the weather fairly benign. We're starting out cold with a wide range of sky cover conditions this morning. Low clouds blanket the northern/western Adirondacks into the St Lawrence Valley due to low-level moisture becoming trapped under the subsidence inversion. Locations along Lake Champlain are cloudy as well as the relative warm waters of Lake Champlain steam into the cold air mass overhead. Flurries have been noted with this lake-enhanced cloud cover as well, with visibility here at KBTV going as low as 2SM at times. Elsewhere, skies are clear, though expect patchy valley fog will develop through daybreak.

Like yesterday, expect clouds to slowly dissipate through mid/late morning, with most areas seeing sunshine by this afternoon. Highs will be below normal, generally from 20F to around 30F. Tonight should be very similar to what we're seeing this morning, with clouds spreading into the St Lawrence and Champlain Valleys, and some light flurries possible near Lake Champlain. Valley fog will be possible as well. Temperatures will be quite variable due to the differences in cloud cover, ranging from the single digits below zero in the cold valleys in the Northeast Kingdom to around 10F above in the cloudier locations.

Friday will be another dry day, though don't expect quite so much sunshine in the afternoon as high clouds stream overhead. Still, we'll warm up a little more than today, with highs in the low 20s to low/mid 30s.

SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/

As of 308 AM EST Thursday...This will be the quiet before the storm(s) period with ridging at all levels exiting east allowing for broad southwest flow to develop, especially Saturday into the first half of the long term period.

High clouds advancing across the area Friday night but still one more seasonable cold night with lows primarily in the teens which helps lay the framework to a messy Saturday night-Sunday forecast.

On Saturday...broad southwest flow and healthy warm air advection aloft will cause 0C isotherm at all critical levels to move into Canada.

For the most part...precipitation holds off until later Saturday evening-Saturday night but some spotty light pcpn may reach the St. Lawrence Vly where low-level drainage flow will likely keep surface temperatures AOB 32F from KOGS northward through KMSS and Malone, NY for some possible spotty FZRA.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

As of 308 AM EST Thursday...Spotty, light precipitation will continue to advance across the CWA from SW to NE Saturday night. Air temperatures will drop a few degrees after sunset to near 32F but more importantly surface road temperatures will fall due to recent snow and very cold temperatures, thus sub-surface temperatures will take awhile to rebound when temperatures due warm up.

Therefore...expect chance to likely -ZR to develop across most locales Saturday night and linger the longest east of the Green mountains to possibly early afternoon. Although SFC temps may be M30s in the Champlain Vly at onset I think -ZR even possible due to very cold sub-surface and road treatment has been several days since last event so not much residual assistance.

This is all precursor to the main event which the trend has been toward the more amplified, stronger ECMWF solution which WPC surface fronts show. Despite some discrepancies in the deterministic solutions...most model ensemble solutions (and WPC) bring a general 1/2 to 1+ QPF across our CWA but we'll need to watch to see if the ECMWF deterministic solution suggesting 1-2 inches is an indicator of something more. There will be some snowmelt with SFC temps rising into the 40s during the Sun-Mon and overnight lows staying above freezing. Snowpacks are far from ripe with the cold temperatures and it will take awhile to warm and ripen them but there will be some snowmelt loss. At this time...long range ensemble river forecasts have most of our main stem below action stage with a hint of possibly something to watch in the Mad, Otter Creek and Ausable watersheds as model snowmelt of approximately 1 inch combined with ensemble rainfall of one inch. ATTM...not overly concerned of a flooding event but will need to watch closely to see if the ECMWF solution pans out with higher QPF. Heaviest rainfall and greatest snowmelt Monday-Monday evening.

Tuesday (New Years eve)...will be primarily dry during the daylight hours with temperatures in the U30s-L40s. Currently...still a decent divergence in solutions, especially as we get into New Years Day and beyond.

General consensus is light precipitation is likely to move into NY between 00-06z Wed with Champlain vly east as 2025 arrives. Temperature profiles are generally mild enough for rain showers with some higher elevation snow showers but not looking at any freezing rain.

New Years...this is where the models truly diverge although the Canadian is morphing to the ECMWF solution. Attm, temperature profiles call for a valley rain/mountain snow-rain mix and will need to monitor closely about a coastal low forming in favorable SE MA/Cape area that would allow for greater precipitation and colder air working into the system. Another possible messy solution...Stay tuned.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Through 12z Friday...A wide variety of flight conditions across the region this morning. Low clouds and patchy fog have resulted in persistent IFR/LIFR conditions at KBTV/KSLK/KMPV, while KMSS and KRUT are slightly better with ceilings around 1500 ft. KEFK/KPBG remain VFR. This trend will continue through 14z, then clouds will lift/dissipate and all terminals should be VFR by 16z. Tonight will be a repeat from last night, with clouds once again developing at KMSS/KSLK/KBTV and patchy fog possible elsewhere. VFR should prevail through 02z Fri, then conditions will start to lower. Winds will remain light and variable through the entire TAF period.

Outlook...

Friday: VFR. NO SIG WX. Friday Night: VFR. NO SIG WX. Saturday: Mainly VFR, with areas MVFR possible. Slight chance FZRA. Saturday Night: Mainly MVFR, with local IFR possible. Chance RA, Chance FZRA. Sunday: Mainly MVFR, with areas IFR possible. Likely RA. Sunday Night: Mainly IFR, with areas MVFR possible. Definite RA. Monday: Mainly IFR, with areas MVFR possible. Definite RA.

BTV WATCHES/WARNINGS/ADVISORIES

VT...None. NY...None.