textproduct: Burlington

WHAT HAS CHANGED

As of 206 AM EST Saturday...

No significant changes.

KEY MESSAGES

As of 206 AM EST Saturday...

1. Widespread upslope snow showers today, gradually tapering off Sunday.

2. A warm, dry and mostly sunny week is in store.

DISCUSSION

As of 206 AM EST Saturday...

KEY MESSAGE 1: Cyclonic northwest flow will prevail under an upper- level low this weekend. A potent embedded shortwave will pass south today and tonight, bringing widespread showers. While they will be most concentrated in the typical northwest flow upslope areas, very marginal instability will develop in the lowest 10,000 ft in the atmosphere due to cold air aloft and solar heating. This will cause the precipitation to trend more convective, especially this afternoon. Therefore, snow showers will be able to survive crossing the terrain and should pass through the downslope areas like the Connecticut River Valley, though likely in a lighter form. While temperatures will rise above freezing below 2,000 ft and likely reach 40 in the lowest points, temperatures will drop significantly in any of the showers. Therefore, even though consistent snow levels will likely only be down to around 1,000-1,500 ft, a period of graupel or even brief wet snow will be possible all the way down into the valleys. However, any continuous accumulations should generally be limited to above 2,000 ft. The showers will gradually become less and less widespread heading into Sunday, and they should be done by Sunday evening. Accumulations by the end should be in the 1-4 inch range above 2,000 ft, with mostly brief coatings that melt below that. The lowest accumulating snow levels will be tonight. Moisture off Lake Champlain will enhance the showers in parts of the Champlain Valley and Greens, but the more convective nature may prevent the formation of distinct bands at times.

KEY MESSAGE 2: A potent ridge and associated area of surface high pressure will dominate the weather next week, making it feel as if it were still mid-October. In a classic El Nino pattern, deep troughing and strong surface lows over the Pacific have caused continuous southwest to westerly flow out west, flooding the Great Plains and western Canada with warm Pacific air. This has caused temperature anomalies in the 20-30+ degree range. This airmass will begin to arrive Monday, but clouds will likely remain stuck under the inversion, so it will likely take until Tuesday to warm up. From then through the end of the week, and potentially through the weekend, highs in the 50s will prevail, though 60 will be possible in some of the warmest areas. There will be a strong, persistent subsidence inversion, and it will aided by the fact that significantly more surface heat will be lost at night than will be able to be replenished by the sun during the day. Radiational cooling will help lows drop to the 20s and 30s, around climatological normals. Weak troughs will gradually erode the ridge from the north, but it will take until at least next weekend for it to get pushed to the south and east and for cooler conditions and chances for precipitation to return.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

Through 12Z Sunday...A mix of flight categories currently exist due to low ceilings and they will generally hold steady for the next few hours. Heading into the late morning and afternoon, ceilings should increase a bit but they will likely remain a mix of MVFR and VFR. Ceilings will mostly decrease into the MVFR range tonight. Scattered showers will continue through the evening, falling mostly as snow, but some rain should mix in at BTV and PBG. During the day, some intervals of MVFR or IFR visibility will occur at every terminal, with the most at SLK and EFK. At those terminals, it should be relatively steady. Temperatures above freezing during the day should prevent much accumulation on runways. While lingering snow showers are possible tonight, they should be mostly restricted to SLK and EFK. Northwest Wind gusts in the 5-15 KT range are expected during the day and they should generally drop under 10 KT at night.

Outlook...

Sunday: Mainly MVFR, with areas VFR possible. Slight chance SHSN. Sunday Night: Mainly MVFR, with areas VFR possible. NO SIG WX. Monday: Mainly MVFR, with areas VFR possible. NO SIG WX. Monday Night: VFR. 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.