Area Forecast Discussion

WHAT HAS CHANGED

As of 257 PM EDT Sunday...

No major changes have been made to the forecast. Widespread precipitation will become more showery towards this evening. Unseasonable cold and additional snow showers chances are expected for tomorrow, some of which may impact the morning commute.

KEY MESSAGES

As of 257 PM EDT Sunday...

1. Widespread precipitation will continue across the region this afternoon in the wake of a cold front, with most locations observing at least a period of snowfall. Minor snow accumulations will be possible, especially at higher elevations, with slippery travel conditions possible as the day continues.

2. Unseasonably cold conditions are expected to start the work week. Additional chances for snow showers are possible, especially Monday morning which may impact the morning commute.

3. Temperatures will likely be fairly steady near seasonable normals from Thursday into the weekend associated with a blocking pattern. There is a chance of rain over the weekend but details are unclear at this time.

DISCUSSION

As of 257 PM EDT Sunday...

KEY MESSAGE 1: Widespread precipitation continues across the region this afternoon in the wake of the cold front that exited the region this morning. Colder air continues to move into the region, with current temperatures generally between low to mid 30s for most locations, which has allowed for snowfall to be the dominant precipitation type across the area this afternoon. Despite the widespread snow, accumulations have been a different story, with little to no accumulations occurring in the valleys due to warmer ground temperatures, especially after hitting the 70s yesterday. Meanwhile higher elevations have seem more measurable snowfall, with some higher summits receiving a few inches of snow by the time precipitation is over, with snowfall amounts very similar to the previous forecast. The main impact associated with the snow will be travel related, as visibilities have been less than a mile at times within steadier precipitation. Slick roads are also possible, especially at higher elevations. Given the late season snowfall, motorists should use caution and be prepared for changing conditions. Precipitation will become less widespread as the evening progresses, but a few chances for rain and snow showers will still be possible.

KEY MESSAGE 2: Unseasonably cold weather will start off the work week as cold air continues to move into the region. By Monday morning, temperatures are expected to be in the 20s to low 30s. With these temperatures, some patches of black ice may be possible in areas with standing water from the recent precipitation. Additionally, another shortwave looks to pass through the region tonight into tomorrow morning, which will bring some additional chances for snow showers. Depending on what guidance you look at, some of these showers could be on the heavier side and may impact the morning commute tomorrow morning. Despite shower chances, accumulations should be minimal given limited moisture available, with decreasing shower chances towards the afternoon. High temperatures tomorrow will be quite frigid for this time of year, with highs only reaching the 30s to low 40s, well below normal for this time of year with temperatures typically in the low to upper 50s. Monday night looks to be the coldest night with ideal radiational coolings, with temperatures plummeting into the teens and mid 20s overnight. Another cold front looks to bring additional shower chances Tuesday night, but at this time the front looks to be fairly week as it moves through the region. Temperatures will start to moderate as we head towards the middle of the week.

KEY MESSAGE 3: A closed low over the western Atlantic will become established late in the week. Following a dry Thursday and Friday, precipitation chances do increase over the weekend. As a shortwave trough makes a run at us from the west, some complex interactions within the steering patterns will develop. Generally this trough should encounter convergent flow aloft that would lead to a weakening trend in precipitation, but overall rain chances especially Friday night into Saturday, are fairly uncertain. Think the ensemble guidance may be overly dispersive in this period with a lot of members showing widespread rainfall. Generally the pattern suggests highest chances of rain throughout this period are in southern and western areas of the forecast area, and primarily in central New York, consistent with several deterministic model runs. Based on global ensemble data, probabilities of a soaking rain are somewhat high (rainfall exceeds 0.25" in about 30 to 60% of models within the scenarios with lower 500 millibar heights/greater troughing upstream). To give an idea of the uncertainty, another ensemble cluster with good multi-model agreement shows measurable precipitation chances only reaching 25 to 60% range, and with a preference for rain to occur on Sunday rather than Saturday. Therefore, the general idea of a chance of showers throughout the weekend still looks reasonable, given the spread in model output and the low predictability this many days out within a blocked pattern. Temperatures will be modulated by any precipitation and cloudy periods, but generally look near normal with highs in the mid 50s to low 60s and lows in the mid 30s to low 40s.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Through 18Z Monday...An area of snow is gradually shifting eastward through the airspace today, associated with a wave of low pressure riding along a slow moving cold front. Temperatures have cooled just cold enough for wet snow, with greatest chances for accumulations at MPV, through 21Z when the bulk of the precipitation will occur. Snow will wind down steadily from west to east in Vermont by 22Z. Winds will remain light at about 5 knots or less, except at MSS where west-southwest winds near 10 knots will continue through about 00Z. Overnight a secondary cold front will work its way southeastward and bring chances for snow showers, primarily from 09Z through 15Z, with greatest confidence in IFR conditions at EFK. This boundary will help winds increase somewhat out of the northwest, with gusts upwards of 20 knots possible, with greatest likelihood at MPV and especially after 12Z.

Outlook...

Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: VFR. Slight chance SHRA, Slight chance SHSN. Wednesday: Mainly VFR, with areas MVFR possible. NO SIG WX. Wednesday Night: Mainly VFR, with local MVFR possible. Slight chance SHRA. Thursday: Mainly VFR, with local MVFR possible. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. Slight chance SHRA.

BTV WATCHES / WARNINGS / ADVISORIES

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