Area Forecast Discussion
Issued by NWS Burlington, VT

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000 FXUS61 KBTV 142327 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 727 PM EDT Thu Sep 14 2017 .SYNOPSIS... Remnant moisture from Irma will slowly move east through Friday, so scattered showers and isolated thunderstorm are possible. Beginning Saturday, a large area of high pressure will build over the region, resulting in an extended stretch of warm and dry weather into the middle of next week. && .NEAR TERM /THROUGH FRIDAY NIGHT/... As of 315 PM EDT Thursday...12z suite of hi-res models are all in pretty good agreement. We`ve got the remnants of Irma, tied up with a weakening mid/upper level trough, that is centered well off to the southwest. That trough is starting to get elonganted and sheared out, so it`s a sign there isn`t much in the way of dynamics to really trigger any widespread precipitation. Given increased moisture (dewpoints into the mid 60s and precipitable water values of 1.2-1.4 inches -- though it`s noted the moisture quickly drops off near and just north of the Canadian border), and daytime heating, we do have some surface instability with 1000-1500 J/kg of CAPE, especially southern half of the area. So the only trigger we have is just that heating and terrain effects. Net result, not looking for much in the way of shower/t-storm activity. HRRR, BTV4km, NAM3 all support this idea that any convection will tend to be in the south the next few hours. So used a combo of their outputs to drive the PoPs. Any shower activity fades away this evening. Expecting patchy fog late tonight, especially given the rather humid airmass. Lows will remain quite mild for this time of year, lots of 50s to lower 60s. For Friday, that trough/Irma remnants will be centered southeast of our area. However enough low level moisture and instability will be in place for another round of afternoon showers, and perhaps an isolated t-storm, especially southern & eastern sections. Should be sunny and dry across the St Lawrence Valley and the northern Champlain Valley since those areas will be removed from the moisture. One thing of note, with any showers we do get Friday, they will tend to move from east to west. That`s because with the weak low to the southeast, we`ll be in a light easterly flow across the region. 925mb temperatures will again be 19-20C, and that should support highs well into the 70s to lower 80s. The warmest temperatures will be across the St Lawrence Valley and northern Champlain Valley where there will be the most amount of sunshine. Friday night, should be similar to tonight. Any showers fade away early, and with clearing skies we`ll see patchy fog again develop overnight. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... As of 318 PM EDT Thursday...Can`t complain about the forecast for the weekend as surface high pressure and a building ridge aloft will dominate the North Country`s weather. The result will be dry conditions, an abundance of sunshine and temperatures well above normal, Indian summer conditions for sure! Normal temperatures this time of year are typically in the low 70s for highs and upper 40s to low 50s for lows. This weekend will feature temps about 10 degrees warmer on average with highs in the upper 70s to low 80s, and lows in the mid 50s to low 60s. Make plans now to get out and enjoy! && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 318 PM EDT Thursday...No major changes in the forecast from the previous forecaster thinking with the long range forecast largely hinging on the track of hurricane Jose along with a northern stream shortwave trough moving over James Bay mid-week. Latest trends haven`t changed in regard to Jose with the GFS/ECMWF/GEM all in general agreement tracking the storm to around the benchmark by 12Z Wednesday, then taking a turn east thereafter. Slight change in the track of the northern stream trough which now looks to be further north than previous runs. The result is a drier forecast for the Monday/Tuesday timeframe, and just a low chance for some showers associated with Jose across east-central to southeastern Vermont Wednesday. Thereafter, a strong highly amplified ridge builds back over the Northeast, keeping the dry stretch going into the later part of the week. In general temps remain above normal to start the week, but trend more towards climo by Thursday. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/...
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Through 00Z Saturday...Mostly VFR for the period with with an overnight strech of MVFR/IFR for a few hours before sunrise. Have added in fog for the overnight hours at most TAF sites. Much of the available guidance suggests that fog will develop across the region, including here at BTV. Fog will dissipate by 14z, and most of the region will go back to VFR. Could see a few showers across eastern and southern Vermont by 18z. Outlook... Friday Night: VFR. Patchy FG. Saturday: VFR. NO SIG WX. Saturday Night: VFR. NO SIG WX. Sunday: VFR. NO SIG WX. Sunday Night: VFR. NO SIG WX. Monday: VFR. Slight Chance SHRA. Monday Night: VFR. Slight Chance SHRA. Tuesday: VFR. Slight Chance SHRA.
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&& .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Nash NEAR TERM...Nash SHORT TERM...Lahiff LONG TERM...Lahiff AVIATION...Nash/Verasamy

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