Marine Weather and Tide Forecast for West Rutland, VT

KEY MESSAGES
As of 204 PM EST Friday...

1. A cooler and unsettled weather pattern is expected this weekend with some summit level wet snow possible on Sunday morning.

2. Continued unsettled flow with temperatures falling towards the end of next week.

DISCUSSION
As of 204 PM EST Friday...

KEY MESSAGE 1: The forecast challenge this weekend is evolution of closed mid/upper lvl cyclonic circulation and track of sfc low pres and associated pops and qpf placement. Sfc analysis shows stationary boundary draped along the Eastern Seaboard with axis of showers and embedded thunderstorms. Meanwhile, GOES-19 water vapor imagery shows a potent/compact closed cyclonic circulation over the central Great Lakes this aftn with north side deformation/moisture over the northern Lakes. This circulation is progged to move southeast toward the Southern Tier of NY by 00z Sunday, while north side deformation and mid lvl moisture axis lifting from southwest to northeast acrs our cwa on Sat aftn. The mid/upper lvl circulation tries to capture sfc low pres by late Sat into Sunday with weak inverted sfc trof developing acrs our cwa. The combination of weak sfc convergence and mid lvl deformation on north/northwest side of closed 850-700mb cyclonic circulation supports high categorical (85-100%) Sat aft into Sunday acrs most of our cwa. As 1000mb sfc low pres lifts acrs eastern Maine on Sunday brisk/northwest upslope flow develops under modest low level caa. It should be noted the airmass behind this system is only marginally cool enough to support summit lvls snow, given progged 850mb temps near 0C and 925mb of 1C to 3C. Any snow accumulations wl be above 3000 ft and generally a dusting to 1 inch, maybe 1 to 3 inches above 4000 ft acrs the High Peaks in Essex County, NY. Rainfall amounts will be 0.30" to 0.60" with localized higher amounts possible in favorable upslope areas of the northern Dacks and central/northern Greens. This general idea of higher pops and qpf is supported by the latest AI-GFS/AI-ECWMF 12z/06z runs respectively. Much cooler temps wl be expected this weekend, especially on Sunday with brisk northwest winds/damp conditions and highs only in the 40s.

Next potent s/w energy in the progressive northwest flow aloft arrives on Monday with additional widespread precip likely, especially favorable upslope areas. Progged thickness values are cooler for this system, along with progged 850mb temps btwn -1C and - 3C, supporting slightly lower snow levels. However, still some uncertainty on amount of moisture in nw flow aloft with pw values in the 0.30 and 0.40 range and limited pocket of mid lvl moisture. For now have kept close to NBM pops/qpf and thermal profiles, but expect changes to occur as it becomes a near term forecast focus. Highs Monday wl range from the mid 30s to upper 40s acrs our region.

KEY MESSAGE 2: The large scale cyclonic gyre over the Hudson Bay will continue to eject several shortwaves through mid to late next week.
Tuesday and Wednesday will see shower chances focused in the higher terrain, with perhaps some blocking against the Greens pushing moisture into the Champlain Valley either day. The most robust of the two days looks to be Tuesday, with a more defined vort max tracking near the International Border. Thermal profiles Tuesday into Wednesday would be supportive of some nighttime snow potential in the higher terrain upslope favored regions above 2500ft, with light accumulations possible given the prolonged period of 925-850mb temperatures at or below 0 through mid week. Below 2500ft, mainly rain is to be expected, with little in the way of impacts. Should Mount Mansfield still be holding onto the latest 1" snowfall, of which the record is November 9th, it appears currently that we will have a high chance to reach 1" at the latest by Wednesday morning.
By the late week, ensembles are coming into better agreement that a mid/upper level closed low will develop and swing through the area.
This would point towards sharply cooler daytime highs as 850mb temperatures will fall to near -5C, supporting highs in the upper 30s to low 40s across the area Thursday, and especially Friday, with some chances for some light shower activity.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
Through 00Z Sunday...VFR conditions are expected to prevail through the evening. In the second half of the night, ceilings are expected to quickly lower. They will likely go from VFR to low MVFR and IFR within a few hours at most terminals, generally between 07-13Z. Low ceilings will prevail for the rest of the day, though rises of several hundred feet are likely. Areas of mist and drizzle will also accompany these ceilings, especially at BTV, SLK and EFK. Scattered showers will move through tomorrow morning, with more organized rain possible in the afternoon. While this rain by itself will likely not be enough to significantly reduce the visibility, it will likely combine with the mist/drizzle and there will be periods of MVFR visibility. Winds will generally be under 10 KT and northerly/northeasterly, or light and variable.

Outlook...

Saturday Night: Mainly IFR, with local MVFR possible. Definite RA, Likely SN.
Sunday: Mainly MVFR, with areas VFR possible. Chance RA, Chance SHRA.
Sunday Night: Mainly VFR, with areas MVFR possible. Chance SHRA.
Monday: Mainly MVFR, with local IFR possible. Chance SHRA.
Monday Night: Mainly MVFR, with local IFR possible. NO SIG WX.
Tuesday: Mainly MVFR, with areas VFR possible. Chance SHRA.
Tuesday Night: Mainly MVFR, with local IFR possible. Chance SHRA.
Veterans Day: Mainly MVFR, with local IFR possible. Chance SHRA.

BTV WATCHES/WARNINGS/ADVISORIES
VT...None.
NY...None.