textproduct: Burlington

WHAT HAS CHANGED

As of 145 AM EST Tuesday...

No significant changes have been made to the forecast.

KEY MESSAGES

As of 145 AM EST Tuesday...

1. Light snow showers, along with the chance for some light drizzle or freezing drizzle, will be possible through this morning into the afternoon.

2. Some snow will likely impact southern portions of the region on Wednesday and Wednesday night. Northward extent of this precipitation remains highly uncertain.

3. Snow is possible on midday Friday into Saturday, but the timing is uncertain. Snow showers will linger into next week.

DISCUSSION

As of 145 AM EST Tuesday...

KEY MESSAGE 1: A weak shortwave continues to move across the region this morning, bringing some light precipitation chances along with it with limited moisture to work with. As the morning progresses, mid-level drying is expected, resulting in a loss of cloud ice and the potential for patchy drizzle/freezing drizzle. This particular set up is a bit tricky in regards to the freezing drizzle, as there is uncertainty in regards to how quickly the drier air moves in as well as how quickly temperatures warm this afternoon. Overall, little to no ice accumulation is expected for the region, although some slick spots may be possible so be sure to use caution this morning. By this afternoon, temperatures are expected to warm above freezing, generally the mid to upper 30s.

KEY MESSAGE 2: Our next chances for precipitation arrive Wednesday as a frontal boundary drapes across the region. As of now, it looks like our forecast region will likely remain on the cold side, with precipitation type primarily falling as snow across the region. There continues to remain a large amount on uncertainty as to the northward extent of the snowfall associated with this system Wednesday night and where the axis of heaviest precipitation sets up. The current forecast keeps the more impactful snowfall south of our region, although there are a few models showing a more northerly extent, so these trends will still need to be monitored as we get closer. The timing of the precipitation looks to align with the Wednesday evening commute, so hazardous travel may be possible, especially across southern Vermont where impacts are more likely.

Following the snowy weather Wednesday, a rather quiet day is expected for Thursday as high pressure builds into the region, bringing seasonable temperatures.

KEY MESSAGE 3: NBM indicates chances of precipitation on Friday morning. However, most guidance is dry. Given we're several days away, left the forecast untouched. The later range of forecast scenarios indicate precipitation is more likely to advance during the middle of Friday afternoon or maybe even the overnight hours. Probability of 4" of snow is about 20-40%. The overall pattern features blocked low pressure still going around the Great Lakes region with a new surface low developing from the south, and eventually taking over. As it matures over the Great Lakes, a triple point low may try to develop over Lake Ontario, but vorticity advection alongside model projected pressure falls suggest a coastal low will dominate and carry better moisture and forcing away. This is likely why model prognoses are not very high. Upper divergence will be favorable over the region, though, and warm advection will be sufficient for some overrunning precipitation. We'll have to monitor how much warming takes place given we'll be flirting close to the freezing point at 850mb. Several pinwheeling upper vorts rotating through a deep upper trough should keep chances for snow showers present into next week under moist, northwest flow. Seasonable temperatures will be present at the surface, but it will be cool aloft (~33rd percentile from LREF) with thicknesses near or below 530 dam. So even if we manage to warm into the mid 30s, precipitation will likely remain snow.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

Through 06Z Wednesday...Snow will be possible through about 15z Tuesday with potential mixing at KMSS and KPBG, followed by patchy drizzle (freezing drizzle if below 32 F) or mist. Terminals are mostly VFR right now, and given dry air, noted PROB30s with a slow stair-step down to MVFR and then IFR over the next 6-9 hours while gradually showing the potential for transitioning precipitation types. Very light snowfall rates will be present overnight, and with dry air in place, it may do little to reduce visibility. Ceilings are expected to gradually lower throughout the period. The combination of low-level moisture and a slow moving boundary with above freezing temperatures over a relatively deep snow pack could allow for fog over snow. It's hard to pinpoint how low visibilities will drop this early, but 2-5SM seems likely, with ceilings ranging from 500-1500 ft agl the remainder of the day, and then slowly improve beyond 00z Wednesday. Winds will mainly be south to southwest at 4-9 knots, and trend towards 5 knots and become westerly after 00z Wednesday.

Outlook...

Wednesday: VFR. Chance SN. Wednesday Night: VFR. Chance SN, Slight chance FZRA. Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. Chance SN. Friday Night: VFR. Likely SN. Saturday: Mainly VFR, with areas MVFR possible. Chance SN.

EQUIPMENT

The KMPV ASOS has suffered a communications failure. The issue has been diagnosed, but there is currently no estimated time of return to service. Terminal Aerodrome Forecasts will continue, but amendments to those forecasts will be suspended.

NOAA Weather Radio station WXM-44, transmitting from Mt. Ascutney, Vermont, on frequency 162.475 MHz is non- operational at this time. NWS technicians have diagnosed the problem, but repairs will likely not be able to occur for quite some time due to circumstances beyond our control. Therefore, the time of return to service is currently unknown. The following NOAA Weather Radio transmitters may be able to provide service during this outage: WWG 50 from Burke Mtn, VT at 162.425 MHz and WNG 546 from Hanover, NH at 162.525 MHz.

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...None. NY...None.