Area Forecast Discussion
Issued by NWS Burlington, VT
Issued by NWS Burlington, VT
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688 FXUS61 KBTV 120528 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 1228 AM EST Tue Nov 12 2024 .SYNOPSIS... A strong cold front arrives tonight, sweeping from northwest to southeast across the region bringing gusty northwesterly winds up to 40 mph and a rapid drop in temperatures. A light snow accumulation is expected early tomorrow morning across the higher terrain, and some locally icy roads are possible for the Tuesday morning commute. Thereafter, the weather trends drier and quieter for the remainder of the work week, with chilly nights and daytime highs primarily in the 40s. && .NEAR TERM /THROUGH WEDNESDAY/... As of 934 PM EST Monday...The cold front is currently situated just north of Montreal and will continue to make steady progress south and eastward through the overnight hours. Showers have begun to overspread the region already and period of showers will continue to be likely through the overnight period as well. Temperatures are remaining steady while we await the frontal passage which is slower than previously forecasted. This will delay the onset of colder air, especially at the higher summits, which will likely reduce snow totals a bit from what we had earlier. We have updated the forecast to account for the anticipated temperature trend and the subsequent precipitation types and totals. Previous Discussion...The main feature heading into the overnight hours will be a strong cold front set to sweep through the forecast area moving northwest to southeast. This front will help produce gusty northwesterly winds 20-40 knots with potentially even up to 50 knots at summits. The front will also bring with it rapidly falling temperatures as low as 30-40 degrees. For some, this will mean below freezing temperatures arriving to produce icy road conditions, particularly on elevated surfaces like bridges as well as mountainous areas where roads have not been treated. Precipitation associated with this frontal boundary may freeze with the colder temperatures, and some minor snow accumulations are also possible. Snow accumulations into tomorrow morning could reach up to 2-3 inches at the peaks of the Greens, but around 0.5-2.0" are is expected elsewhere above 1000 feet. The wider valleys of St. Lawrence, Champlain, and Connecticut River valleys should have no or trace snow accumulate. Efficient atmospheric mixing and strong cold air advection will produce continued N/NW wind gusts 20-40 knots and again up to 50 knots possible on highest peaks tomorrow. These strong NW winds contribute to concern for wildfire spread. Precipitation will cut off by the afternoon hours as sunny skies make their way through our forecast area. This, however, won`t be enough to counteract the cold air flowing into the area on the backs of the brisk winds. Despite very cold temperatures producing moderate relative humidity values, fire behavior in the drought area of southern Vermont has proven to thrive in these very dry, windy conditions. Highs will struggle to reach above the mid 30s to lower 40s on Tuesday, putting us about 5- 10 degrees below seasonal averages. Apparent temperatures are forecast to remain below freezing from late tonight through the end of the day Tuesday. Tuesday night will be even chillier under upper level ridging and surface high pressure, which will result in clear skies and decreasing winds. Temperatures are expected to fall into the mid teens to mid 20s, again 5-10 degrees below climatological normals. Though temperatures should be too dry and winds just too elevated/mixed for radiational fog to be a concern, some models are indicating the potential for low level stratus developing. && .SHORT TERM /WEDNESDAY NIGHT/... As of 334 PM EST Monday...High pressure will continue to build over the North Country with some northerly breezes lingering Wednesday morning. This flow pattern and cool temperature advection will promote highs and low lower than seasonal averages. Temperatures will warm into the upper 30s to low/mid 40s and cool overnight into the teens to lower 20s; mid/upper 20s are expected around Lake Champlain with influence of warmer lake water. While skies will be mainly clear, can`t rule out some low clouds over and adjacent to Lake Champlain from a strong upward moisture flux resulting from thermal contrast between water and air temperatures. It wouldn`t be surprising to see some flurries along the lake shore early Thursday. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 334 PM EST Monday...There is a strong model consensus that high pressure will remain over the region through early Friday keeping conditions dry with temperatures slowly warming, but still a few degrees below seasonal averages. Models begin to diverge from a common solution late Friday into the weekend with various depictions of how far low pressure off the New England coast retrogrades northwestward. While the degree of retrogression is uncertain, consensus is promoting increased shower chances as moisture wraps around the low and as low level flow upslopes along the Adirondacks and northern Green Mountains late Friday and Saturday. Uncertainty in the upper level pattern increases Sunday onward. Blended guidance and ensembles favor briefly drier conditions and increasing southerly flow early next week before the next system can move into the region. Other deterministic runs are much less amplified in the Sunday/Monday upper level ridge and would promote continued shower chances before a front moves through. The current forecast leans more towards the blended guidance and ensembles which have verified better recently over the single deterministic solutions. The result is cautiously optimistic increase in temperatures Sunday into Monday to around/slightly above seasonal averages in the upper 40s to around 50 degrees and milder overnight lows with shower chances increasing again Monday. . && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... Through 06Z Wednesday...A sweeping cold front will provide a resurgence in winds just after 06Z onward with gusts as high as 20-35 knots through at least 18Z. Wind direction will be out of the northwest following the frontal passage. Ceiling heights will be on the decrease throughout this 24 hour period as the cold front comes in, making most sites MVFR around 03Z-06Z Tuesday due to ceilings 1000-3000 feet above ground level. One exception will be SLK, which may see IFR ceilings from current time through 12z. Showers are also expected to increase in coverage overnight, with best chances for precipitation around 07Z-12Z, depending on the site. Most sites have the potential for some snow mixing in with rain around 10Z-14Z when temperatures dip the lowest. This increases the chance for visibilities to lower to IFR in showers, especially at SLK and MPV, where snow is most likely. From 12z onward ceilings will be improving as precipitation comes to an end and high pressure begins to ridge into the area bringing VFR conditions after 18Z. Outlook... Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. Slight chance SHRA, Slight chance SHSN. Friday Night: Mainly VFR, with areas MVFR possible. Chance SHSN, Chance SHRA. Saturday: Mainly MVFR, with local IFR possible. Chance SHRA, Chance SHSN. && .FIRE WEATHER... Strong northwesterly winds 15-25 mph with gusts 30-40 mph are expected Tuesday behind a cold front. Cool temperatures are expected to keep RH values above critical thresholds, but fine fuels remain very dry across portions of southern and central Vermont. This, combined with the gusty winds, will have an impact on fire weather conditions Tuesday. If any fires were to start, the weather and fuel conditions could cause fires to quickly get out of control and be difficult to contain. && .MARINE... A Lake Wind Advisory has been issued for Lake Champlain tonight for westerly turning northwesterly winds 15-25 knots sustained and gusts 35-40 knots across all three sections of the lake. Wave heights will be in the 3 to 5 feet range tonight into tomorrow. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Storm NEAR TERM...Clay/Storm SHORT TERM...Boyd LONG TERM...Boyd AVIATION...Neiles/Verasamy FIRE WEATHER...Team BTV MARINE...Team BTV