textproduct: Burlington

WHAT HAS CHANGED

As of 202 PM EST Friday...

No significant changes to the current forecast.

KEY MESSAGES

As of 202 PM EST Friday...

1. Upslope snow showers will develop late tonight for the northwest facing slopes of the Adirondacks and Greens, with some possible Lake Champlain enhanced precipitation in the Champlain Valley late Saturday into Sunday.

2. Conditions are expected to remain dry with a warming trend next week.

DISCUSSION

As of 202 PM EST Friday...

KEY MESSAGE 1: Snow showers across southern Vermont will end this afternoon with a brief lull in precipitation for this evening. Clouds will remain as a reinforcing shortwave will shift south from Quebec later tonight into tomorrow. Wrap around moisture associated with the large upper level trough centered across our region will provide enough moisture to sustain upslope snow showers by tomorrow morning. As the shortwave dips into our area by tomorrow morning, blocked flow and orographic lift will lead to stratiform snow showers along our northwestern facing slopes in the northern Adirondacks and central and northern Greens. As the core of the shortwave passes through tomorrow early afternoon, our showery activity will turn more convective as marginal instability develops, allowing shower activity to survive the spine of the Greens into the eastern Greens, and survive the northwest slopes of the Adirondacks into the central northern Adirondacks. Snow showers will be strongest along the spine of the Greens with 3 to 5 inches of more powdery snow due to snow ratios around 10-15:1. Into the Adirondacks 2 to 4 inches is expected, with the highest amounts in the High Peaks and northern Franklin County in New York between US-11 and Saranac Lake. Snow levels look to initially hover around 1200ft agl, but dynamical cooling could lead to snow level lowering down towards 500ft, especially by tomorrow night in coordination with diurnal cooling. This could push some flakes into the eastern Champlain Valley where a few tenths of an inch of wet snow are possible. While snow amounts will be localized to the higher terrain, mountain passes, and untreated roads may become slick at times. Moreover, some localized power outages may be possible, but due to the drier character of the snow, impacts will be limited.

As our snow turns more convective tomorrow afternoon into Saturday night, Lake Champlain streamers downstream of Lake Champlain look to develop as cold air aloft will be 10 degrees cooler than the current lake temperatures. Precipitation enhancement will be possible in the downstream regions of southern Chittenden and north and central Addison Counties. Precipitation types along this corridor will be mainly rain closest to the lake, with snow closer to the western slopes of the Greens, but dynamical cooling could push precipitation towards more snow closer to the lake at times. Accumulations look to be light as precipitable water will only be around 3 to 4 tenths of an inch. The position of any lake streamers are still somewhat uncertain, and will be dependent on the prevailing wind at the time, but it looks to be focused in an area between VT-22A and the spine of the Greens.

Snow showers will lighten into Sunday, and taper off by Sunday evening, departing the highest summits of the Greens and NEK last. Solar heating, and gradual clearing will help to melt any snow in the lower elevations by Monday, with a warming and drying trend beginning early next week.

KEY MESSAGE 2: Confidence remains high that pervasive ridging will remain over the region next week keeping local weather dry and promoting a warming trend. High temperatures are favored in the 50s from Tuesday through Friday with lows ranging in the 20s to low 30s through mid week, climbing to around 30 to upper 30s by the end of the work week. Conditions for radiational cooling will be near ideal, so typically colder hollows will be running several degrees colder each morning.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

Through 00Z Sunday...Mainly overcast skies continue, especially north and west. With a few exceptions, like KRUT, most locations have ceilings around 2500-4000 ft agl. Winds range from light and variable to north or northwest around 4-9 knots. Ceilings may lower some in the next few hours, but the main impacts will come as a secondary trough to our north approaches the region around 06z-14z, and then an upper low shifts south across the area about 16z-04z Sunday. This will result in intervals of showers across the area, with a few terminals cold enough for snow to mix in or precipitation to be all snow. Some convective elements are possible. Some graupel may be observed, as well as heavier some briefly heavy rates that could result in sharper drops in visibility. The greatest confidence of these impacts are at KSLK after about 16z. Otherwise, kept visibility impacts generally around 4-6SM.

Outlook...

Saturday Night: Mainly MVFR, with local IFR possible. Chance SHSN, Chance SHRA. Sunday: Mainly MVFR, with areas VFR possible. Chance SHSN, Slight chance SHRA. Sunday Night: Mainly MVFR, with areas VFR possible. NO SIG WX. Monday: Mainly MVFR, with areas VFR possible. NO SIG WX. Monday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. NO SIG WX.

BTV WATCHES/WARNINGS/ADVISORIES

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