947 FXUS61 KBTV 222332 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 732 PM EDT Sun Sep 22 2019 .SYNOPSIS... An upper trough moving east from the Great Lakes will bring numerous showers Monday and Tuesday, along with the chance for a few rumbles of thunder. For Wednesday onward through the weekend, every other day will feature chances for rain, starting with high pressure and dry conditions Wednesday, and scattered showers Thursday. && .NEAR TERM /THROUGH MONDAY NIGHT/... As of 722 PM EDT Sunday...Deep southwesterly flow is developing over the region this evening with VAD wind profiles indicating winds of 25 to 35 kts between 850 and 700 mb. Consequently, dewpoints are rising through the evening into the low to mid 60s. Tweaked temperatures to match observations, otherwise on track for a warm, sultry night to close out summer. Previous discussion..High pressure will continue to move off the East Coast tonight while an upper trough approaches from the Great Lakes. Southwest flow will increase through this evening with a 40+kt low-level jet to cross the region late tonight into early Monday. This flow is already ushering moisture into the region as evidenced by dewpoints already in the 60s in most locations. This increasing moisture along with winds remaining 10-20 mph overnight will keep temperatures in the 60s, making the last night of summer a bit on the muggy side. For Monday and Monday night...The aforementioned upper trough will continue to shift eastward, drawing its associated frontal boundary across the forecast area later Monday into Monday evening. Scattered showers will develop out ahead of this boundary from roughly mid- morning on. Weak instability will exist as we'll remain under gusty southwest flow; CAPE values in the 250-600 J/kg range will allow for a few rumbles of thunder. Not much moisture or forcing with this front, so don't anticipate more than perhaps a tenth or two of rainfall from these showers, especially in the Champlain Valley due to downsloping of the southwest winds. Highs will range from the mid 70s in the higher elevations to the lower 80s in the southern Champlain and CT River Valleys. The front will move to our east Monday evening as the upper trough closes off to our west. A dry slot looks to work in behind the front, and expect we'll see a break in the precipitation for a few hours around midnight or so. However, expect we'll see redevelopment, especially in the northern mountains, as moisture and lift increase with the approach of the upper low. Lows will mainly be in the mid to upper 50s, though some upper 40s will be possible in the favored cold spots in the Adirondacks. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... As of 334 PM EDT Sunday...As the closed upper level low moves overhead on Tuesday, rain chances will increase once again across the North Country. Steep low- level and mid-level lapse rates will exist underneath the cold core low which will make shower activity likely by the afternoon hours on Tuesday. A few rumbles of thunder cannot be ruled out but the low equilibrium level capped by a strong inversion above the mixed layer makes any deep convection unlikely and should limit overall thunder potential. Rain chances will taper off Tuesday evening and Tuesday night as the upper level low shifts eastward and deep layer ridging quickly builds behind the departing low. Temperatures will noticeably cooler on Tuesday with the low directly overhead with afternoon highs struggling to climb into the lower mid to upper 60s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... As of 334 PM EDT Sunday...Deep layer ridging will build back into the region on Wednesday but will be short-lived as an upper level trough over the western US begins to strengthen. This should yield a nice day across the region with skies becoming mostly clear as subsidence and dry air will likely win out. Temps will also remain near normal with afternoon highs in the mid 60s to lower 70s. The amplifying upper level trough will drive yet another cold front into the region on Thursday but there are some distinct similarities and differences amongst the deterministic guidance. While the timing from the ECMWF, GFS and Canadian all are very close together, the strength of the front and associated dynamics remains up in the air. The GFS is by far the most aggressive with rainfall associated with the front but seems to suffer from some convective feedback and also depicts impressive frontogenesis and Q-vector convergence over the region. However, the ECMWF and Canadian are both a bit less optimistic on rainfall but still puts a decent bit of convection with the frontal passage. Have trended away from the GFS with this forecast package as the convective feedback seems to contaminate the PWAT and QPF fields significantly on Thursday. The front on Thursday will be very progressive with rainfall likely to end just after sunset across the North Country. At this point, the trough will exit to the west with a strong 595dm ridge beginning to build northward across the region. This will result in a warming trend late this week into the early weekend when models suggest a weak shortwave will rotate around the periphery of the upper level ridge and bring another round of showers to the region. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... Through 00z Tuesday...Southwest flow aloft continues ahead of approaching system with increasing mid/upper level clouds developing from west to east. These clouds, along with 925mb to 850mb winds of 25 to 40 knots will prevent fog/br from developing at taf sites overnight, as all sites experience vfr conditions. Sfc winds generally in the 5 to 10 knot range, but with some periodic gusts up to 15 to 18 knots possible, at btv/mss. Clouds continue to lower on Monday with some scattered showers arriving mid to late morning from west to east. Thinking generally vfr conditions with some brief periods of mvfr cigs/vis in the stronger active during the aftn hours. Winds continue at 5 to 15 knots with some localized higher gusts possible, along with some turbulence and shear likely near the higher trrn of the dacks and green mtns. Outlook... Monday Night: VFR. Chance SHRA, Slight chance TSRA. Tuesday: Mainly VFR, with areas MVFR possible. Chance SHRA. Tuesday Night: Mainly VFR, with local IFR possible. Slight chance SHRA. Wednesday: Mainly VFR, with local MVFR possible. NO SIG WX. Wednesday Night: VFR. Slight chance SHRA. Thursday: VFR. Likely SHRA. Thursday Night: Mainly VFR, with local MVFR possible. NO SIG WX. Friday: VFR. NO SIG WX. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Hastings NEAR TERM...Duell/Hastings SHORT TERM...Clay LONG TERM...Clay AVIATION...Taber