Area Discussion |
SYNOPSIS ... Heat will increase through Thursday with daily chances of afternoon thunderstorms and periods of moderate to heavy rain showers. A cold front moving through the region on Thursday will bring increased chances of stronger storms that could produce damaging winds and downpours potentially leading to localized flash flooding. Unsettled conditions will linger into the weekend before high pressure builds over the eastern U.S. bringing the potential for dangerous heat next week.NEAR TERM /THROUGH WEDNESDAY/... As of 725 AM EDT Tuesday...Minimal changes were necessary with the forecast verifying well. Clouds will increase south to north this morning with rain chances spreading northward as well. Previous Discussion...A quasi- stationary frontal boundary remains draped over portions of the Northeast. This will provide the focal point for rain today, especially across southern and eastern Vermont as a trough moves along the boundary. A few thunderstorms will be possible mainly across northern New York and the northern Champlain Valley this afternoon and evening. Behind the trough the surface boundary will linger and become the focal point for more showers and thunderstorms on Wednesday. PWATs will be rising over 1" with some areas exceeding 1.5-2 inches suggesting potential for moderate to heavy rainfall with any thunderstorms Wednesday. Stronger storms are not out of the question Wednesday with CAPE ranging 500-1250J/kg, especially over northern New York as a trough drops out of Canada over the afternoon hours. This could be a decent trigger for multicellular clusters and possibly a line of storms to develop. Apparent temperatures will be climbing with dewpoints rising Wednesday displacing recent dry air. Highs will be rising from the mid/upper 70s to near 80 today into the low/mid 80s for Wednesday pushing apparent temperatures close to 90 degrees by Wednesday afternoon.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/... As of 338 AM EDT Tuesday...Warm and humid conditions will persist Wednesday night as 850mb temperatures increase by a couple degrees C throughout the course of the night. Precipitable water values of 1.40-2.00 inches are expected across the forecast area as well. This will result in increased cloud cover by early Thursday morning as well as additional showers and thunderstorms, potentially heavy at times, riding the upper level ridge into northern New York and eventually northern Vermont. Any heavier shower or thunderstorm will prime the soil for additional precipitation Thursday to be potentially hazardous. These warm, humid conditions will also result in one of the warmest nights of the week as lows hover around the 60s and lower 70s and dew points in the 60s. An upper level trough and associated cold front are expected to impact the region on Thursday, meeting an air mass that`s primed with heat, humidity, and instability. 925mb temperatures are modeled in the 20-27 C range while surface highs are forecast in the upper 70s and 80s F and models project Pwats approaching two inches for some. Surface CAPE values are expected to be around 1500-2000 J/kg (isolated up to 2500 J/kg) and 6km bulk shear around 40-60 knots. Some areas could even have 60-80 knots of bulk shear, though the main caveat is that shear seems to manifest after the period of most favorable instability, arriving slightly late to the event for maximum severe potential to develop. Regardless, warm cloud layers are projected around 10,500 feet, paired with a low level jet 30-40 knots paired with the aforementioned pwat values could indicate any showers or thunderstorms will be heavy raining in nature. The Weather Prediction Center continues to place our entire forecast area in a Marginal Risk area for excessive rainfall, indicating there`s at least a 5% chance of rainfall exceeding flash flood guidance in or around a given location.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 338 AM EDT Tuesday...Temperatures and humidity will take a brief dip following Thursday`s activity with Friday`s highs in the 70s and lows both Thursday night and Friday night in the upper 40s to lower 60s. A shortwave could trigger some scattered showers and thunderstorms Friday, then again Saturday night. Next week, strong ridging still looks good to build across the mid-Atlantic buoying temperatures into the upper 80s and lower 90s by Monday. With lows in the mid 60s to lower 70s returning as well, the potential for heat stress and heat related illnesses will be increasing. .AVIATION /12Z TUESDAY THROUGH SATURDAY/... Through 12Z Wednesday...Mostly VFR conditions continue until isentropic lift/moisture increases across a quasi-stationary front draped over portions of the NE with MVFR CIGs chances increasing south to north through 18Z. IFR CIG chances increase after 18Z with a wave progressing along the boundary. A trough approaching out of Canada could cause a few isolated thunderstorms mainly over northern New York with some lower potential in the Champlain Valley. Gradient winds are now expected to channel in the northern Champlain Valley with some gusts anticipated around 20kts for PBG/BTV; PBG could see a period of gusts 25kts with favored wind directions off of Lake Champlain 18-00Z. Finally, the trough sharpens a little after 00Z resulting in some LLWS potential for BTV/EFK/MPV, but PBG may also see a brief period of LLWS should SFC winds decrease. CIGs will sag overnight keeping most terminals MVFR or lower. Outlook... Wednesday: Mainly VFR, with local IFR possible. Chance SHRA, Chance TSRA. Wednesday Night: Mainly VFR, with local IFR possible. Chance SHRA, Chance TSRA. Thursday: Mainly VFR, with local IFR possible. Definite SHRA, Chance TSRA. Thursday Night: Mainly VFR, with areas MVFR possible. Chance SHRA, Slight chance TSRA. Friday: Mainly VFR, with areas MVFR possible. Chance SHRA. Friday Night: VFR. Slight chance SHRA, Slight chance TSRA. Saturday: VFR. Chance SHRA, Slight chance TSRA. . |
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