891 FXUS61 KBGM 292353 AFDBGM AREA FORECAST DISCUSSION National Weather Service Binghamton NY 753 PM EDT Mon Apr 29 2019 .SYNOPSIS... A low pressure system over the Ohio valley will push east this evening spreading showers into the area. High pressure from Ontario will build into the area behind the storm on Tuesday bringing cool but drier air. && .NEAR TERM /THROUGH TUESDAY NIGHT/... Rather flat surface wave with an associated low pushes into the area tonight. Surface low slowly fills as the upper jet structure weakens over the area. This results in a broad area of rather light rain into the evening hours. Very light rain or drizzle with continue into the morning as the surface low moves by but overall amounts should be light. Surface boundary drops through Tuesday morning followed by a freshening northwest flow of cool air. This should keep the area precip free with some afternoon clearing. High pressure builds overhead Tuesday evening allowing for a chilly night, especially in the Catskills and Mohawk valley. Further west over the Finger Lakes, return flow will develop toward morning modifying the overnight temperatures a bit. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... 350 PM Update... Wednesday, the warm frontal boundary will press northward for much of the area, yet there will also be east to southeast low level flow against the terrain east of Interstate 81 especially Poconos-Catskills. To the west, temperatures will rise well into the 60s Wednesday, but eastern areas will be stuck in the 50s. Ridging will be occurring aloft, with a lack of jet support. Thus while showers will be possible, amounts will be light. Late Wednesday through Thursday, a wave of low pressure will ride through the ridge with some forced ascent/jet support as well as a pool of ample moisture and some modest instability aloft. This will produce a better likelihood for showers and embedded thunder - mostly not surface-based - initially mainly in Central NY but pressing into Northeast PA as well with time Wednesday night. Though the frontal boundary will somewhat sag into the area during this period, most of the time we will be in warm and humid air which will keep temperatures from dropping below the 50s for much of the area Wednesday night. Thursday starts off mainly dry across the area, but a few lingering showers are still possible in the morning as the frontal boundary washes out near the NY/PA border. Ridging aloft occurs out ahead of the next low pressure system near the Great Lakes. Instability builds along and south of the warm front, basically from the Twin Tiers south...therefore there will be a chance for thunderstorm development here by Thursday afternoon. Bumped temperatures up several degrees Thursday afternoon in line with the latest guidance. So now looking for highs in the mid to upper 60s from Penn Yan--Cortland--Norwich north....70-75 for the Twin Tiers and mid to upper 70s for the Wyoming Valley. Dew points will be in the lower 60s south of the front, so it will be humid and unstable. MLCAPE values are now forecast to range between 500-1000 J/Kg from the southern tier south, along with deep layer shear values between 30-40 kts...so a few better organized thunderstorms are possible. As the front lifts north, a wave of low pressure rides along it near Lake Ontario Thursday night. This will bring our highest chance for rain showers and embedded thunderstorms to the area. Remaining warm with lows only in the 50s. && .LONG TERM /FRIDAY THROUGH MONDAY/... 400 PM Update Friday: Above mentioned low pressure center moves up the St. Lawrence valley, bringing a frontal boundary through our area. There will still be plenty of instability to work with by late morning and afternoon, so will keep showers likely with a chance of thunderstorms in the forecast. A slower moving front look to allow for more daytime heating on Friday, with highs now expected to be in the mid 60s north, with upper 60s to mid-70s south. The frontal boundary stalls out in our area once again as it runs into the offshore ridge. Another wave could approach the area later Friday night, keeping shower chances in the forecast. Saturday: The frontal boundary lingers near our southern zones, and a weak shortwave tries to ride northeast along it. The latest blended guidance is trending up with PoPs and shower chances even during the day Saturday night, so trended the official forecast in this direction. The highest PoPs are from the Twin Tiers south into NE PA; closer to the boundary. Temperatures are also trending up for Saturday, with much of the area in the mid-60s to lower 70s. Model guidance diverges for Sunday and Monday, with some of the guidance indicating a dry period late Saturday night through Sunday as high pressure moves nearby. However, the 12z ECMWF would not give much of a dry period, as it wants to keep showers going south of the NY/PA border Sunday, then bring another trough in from the Great lakes Sunday night and Monday with a period of rain. For now used a blend of the latest guidance to account for these timing difference. Held PoPs at slight chance for Sunday, as odds are still favoring a mainly dry day. Went with chance PoPs by Monday as there was somewhat better agreement on the next frontal system pushing through. Staying seasonably mild, with highs well into the 60s or around 70 and overnight lows in the 40s. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... A low pressure system will move through New York State overnight bringing showers and restrictions. Conditions will lower into the MVFR then Alternate Required category late tonight with IFR likely at KBGM/KAVP. Showers will taper off after midnight but restrictions will continue due to ceilings. Northwest flow on back side of system will bring slow improvement on Tuesday with ceilings lifting into the low VFR category during the afternoon. Southeast winds this evening around 5-10 knots shifting to the southwest late tonight or light and variable. Winds becoming northwest Tuesday morning and increasing to 8-12 knots by afternoon. Outlook... Tuesday night and Wednesday...Occasional restrictions possible in periods of rain showers. Wednesday night through Saturday...Periodic restrictions with additional showers around. Isolated thunderstorms possible. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...MJM/MDP LONG TERM...DAB/MJM AVIATION...RRM