textproduct: Burlington

WHAT HAS CHANGED

As of 222 PM EDT Sunday...

No significant changes to the current forecast.

KEY MESSAGES

As of 222 PM EDT Sunday...

1. A mix of snow and rain will lighten into the early evening with a change to freezing drizzle tonight into Monday morning, with potential impacts to the Monday morning commute.

2. Afternoon snow showers expected on Monday will trend towards more seasonally cool and dry conditions for Tuesday and Wednesday.

3. Several weather disturbances are projected to traverse Vermont and northern New York for the rest of the week.

DISCUSSION

As of 222 PM EDT Sunday...

KEY MESSAGE 1: A clipper system is moving overhead this afternoon with temperatures, outside of northeastern Vermont, rising above freezing with all precipitation types present areawide. Snow will linger across the Northeast Kingdom into this evening as colder air will be harder to scour out. However, across the rest of Vermont, and northern New York, a mix of sleet and rain is widespread, but should lighten into this evening as the center of the low drifts eastward. A cold front associated with the low is expected to become quasi- stationary this evening into tonight across southern Vermont leading to pooling and blocked deep low level moisture areawide. Mid to upper level moisture will begin to dry out by this evening as dry cooler air entrains with upper level northerly flow. This drying will cause the DGZ to become unsaturated, and with lingering low level blocked moisture, a forecast of drizzle and freezing drizzle remains on track. Temperatures will begin to fall back to and below freezing by this evening. Freezing drizzle will be patchy than widespread as light northwest surface flow should be enough to create scattered shallow dry pockets in the wider valleys of the region, though cannot be ruled out entirely. Sheltered locations and locations above 1000ft, have a higher potential for freezing drizzle and reduced visibilities as the drizzle may be suspended in fog rather than acting like falling rain which could cause some slippery conditions on untreated surfaces. With the low level moisture, elevations above 2000ft will likely experience some rime ice development tonight. We are expecting a light glaze up to 0.05 inches of ice accumulation through tomorrow morning. It is likely that travel conditions may be hazardous for the Monday morning commute.

KEY MESSAGE 2: While the bulk of the winter precipitation will taper off Monday morning, an inverted trough extending northeast from the departing surface low on Monday will drive some wrap around scattered snow showers Monday afternoon. These showers will be aided by lingering low level moisture in a DGZ between 3-6kft and relatively steep lapse rates as the mid to upper levels continue to dry. These showers wont have a lot of instability as an inversion around 6000ft will limit the retention time of any snowflakes. Furthermore, surface temperatures will warm to the mid 30s, which would support more graupel like showers than full snow showers. Snow showers will be more likely across the Northeast Kingdom which will be closer to the center of the departing low and within colder temperatures and a bit detached from the best mid to upper level dry air. Overall, these showers look to be more popcorn-esque and transient which will only support light accumulations between a dusting to an inch, locally two inches, mainly across the northern Greens and Northeast Kingdom.

Showers will quickly taper off by Monday evening as temperatures sink into the teens to near 20 degrees. Deep layer ridging is expected to build into the region as an area of high pressure lifts north from the Ohio Valley. Drier conditions with at or just below average temperatures will persist into mid week. However, we will still be under the influence of a synoptic scale longwave trough to our northwest which will keep temperatures seasonably cool with some light rain/snow shower chances by Wednesday.

KEY MESSAGE 3: A warm front will advance ahead of a very weak 1013mb surface low quickly ejecting northeast. Early morning snow will transition to elevation dependent rain or snow as snow levels rise to about 1500-2000 ft agl. The progress of this system will impact conditions on Thursday into Friday with the next system. Yesterday, guidance was fairly 50-50 split on the timing and location of the track, but the trend has been a low track north of the international border. This will likely result in warmer conditions with more widespread rain across Vermont and northern New York. There could be some snow showers on the backside, but the air mass coming in with the cold will also be dry as a 1040+ mb surface high builds over Canada and descends into the Northern Plains of the USA. Again, there is some spread on how the rest of the weekend plays out. Some guidance continues to spit out some snow showers with an upper trough late Saturday into Sunday, but it's hard to envision with so much dry air and such a weak surface reflection. We'll see how it goes, but cool weather will be likely over the weekend.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Through 18Z Monday...Surface low pressure is moving through the Mohawk Valley with temperatures near the freezing mark while we're in the process of losing cloud ice. So we're slowly transitioning from snow to drizzle or freezing drizzle. Convergence near the low is resulting in gradually falling ceilings. There could be some in and out of IFR until lower ceilings settle in between 20z-06z. Most terminals will experience some ceilings around 300-800 ft agl before improving conditions spread west to east with some terrain influences keeping areas like KSLK in lower ceilings for a longer duration. During this period of IFR to LIFR ceilings, drizzle will be possible, and after 22z, cool air from increasing north to northwest winds at 5-10 knots will result in some freezing drizzle. Little or slow improvement will take place around 06-09z Monday, and steadier improvements will begin about 15z-18z Monday, along with a transition out of drizzle towards isolated to scattered snow showers during the day on Monday.

Outlook...

Monday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: VFR. Slight chance SN. Wednesday: VFR. Chance SN, Chance RA. Wednesday Night: Mainly VFR, with areas MVFR possible. Chance SN. Thursday: Mainly VFR, with areas MVFR possible. Likely RA, Chance SN. Thursday Night: Mainly MVFR, with local IFR possible. Chance RA, Chance SN. Friday: Mainly VFR, with areas MVFR possible. Slight chance SN.

EQUIPMENT

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. Please contact us if you observe winds significantly deviating from the recreational forecast.

BTV WATCHES/WARNINGS/ADVISORIES

VT...Winter Weather Advisory until 8 AM EDT Monday for VTZ003-004- 006>008-010-017>021. NY...Winter Weather Advisory until 8 AM EDT Monday for NYZ027-030- 031-034.