439 FXUS61 KBGM 252316 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 716 PM EDT Thu Jul 25 2019 .SYNOPSIS... High pressure will bring sunny skies and warmer temperatures to NY and PA through the weekend. An isolated thunderstorm will be possible on any given day, but the majority of the area will experience fair weather. && .NEAR TERM /THROUGH FRIDAY NIGHT/... 700 PM update... Only minor changes needed with the early evening update as the previous forecast was in good shape. Isolated pop-up showers have been confined to the far western (Finger Lakes, Central- Southern Tier of NY, and Northern Tier of PA) and eastern (Catskills) zones of the forecast area. Any lingering convection in these locations will dissipate toward sunset owing to the loss of daytime heating. The earlier decision to keep showers and storms out of the forecast for our far northern zones (southern Tug Hill and western Mohawk Valley) still seems like a good one as the once organized and robust upstream convection over southern Ontario this afternoon has fallen apart as it progressed southward toward Lake Ontario. The most notable affect from this decaying MCC will be mid- to high-level debris clouds spreading southward over the CNY I-90 corridor early this evening. Patchy river valley fog will form again early Friday morning. Temperatures will fall to between 55 and 60 degrees. The weather pattern remains the same for Friday. Ridging will usher in slightly warmer temperatures and dew points. Again, we can't rule out an isolated thunderstorm, but the vast majority of the region will experience quiet weather and plenty of sunshine. Another night with a favorable radiational cooling setup under the high. The weak return flow that sets up late in the day Friday will yield a slight uptick in temperatures and dewpoints Friday night compared to the previous two nights. Fog will once again be confined primarily to the river valleys just before daybreak Saturday. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... Saturday through Sunday night...Fairly typical, generally benign summer pattern expected in the short term period. Temperatures are forecast to be slightly above average (about 5 degrees) over the weekend. A very weak wave will be moving east across the area on Saturday which could allow an isolated thunderstorm to develop during the afternoon or early evening hours; especially across the western Catskills region. Otherwise, it will be partly sunny, warm and a little humid with highs 82-87. A zonal pattern Saturday night will allow for more quiet weather, with mainly dry conditions expected. Partly cloudy and mild with lows in the 60s. Another weak shortwave moves through on Sunday....while at the same time low and mid level moisture builds. Mixed layer instability is forecast to also increase, between 600-1200 J/Kg. This will bring a slightly higher chance for afternoon or evening thunderstorms; but coverage still looks limited, with higher probabilities from Binghamton north and west. Very similar temperatures continue, with highs in the mid- 80s for most locations. Perhaps a lingering shower or storm into Sunday night, otherwise mild with lows 65-70. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Monday through Thursday...Warm and humid with scattered showers and thunderstorms around for much of the extended period. A long wave upper level trough begins to amplify across the central Great Lakes during the day Monday. This will put central NY and northeast PA under a warm southwest flow. At this point Monday is forecast to be the warmest day of the week; with highs 85-90 and dew points reaching the mid to upper 60s. There will be a chance for late day Thunderstorms, especially across our Central NY zones. A slow moving frontal boundary then moves through Tuesday into Wednesday as more upper level energy dives into the long wave trough. Latest guidance shows plenty of instability over the region and modest amounts of moisture, as PWATS rise to around 1.5-1.6 inches. Overall, this should lead to more cloud cover and higher chances for showers and thunderstorms on these two days. These factors should also knock down temperatures a few degrees, especially by Wednesday. By the end of next week, there are, as expected some minor differnces in timing/position of features in the models. In general it seems the upper trough and front slow and nearly stall over the Northeast and Mid-Atlantic. The ECMWF allows a pocket of drier air in a NW flow regime and a surface high to build over our area. Meanwhile, the GFS is slower, leaving behind additional weak PVA, moisture and instability. Took a blend of the guidance for now on days 7-8, which gives slight chance to low end chance PoPs for a few showers/thunderstorms. Temperatures should fall back closer to the seasonal average, with highs in the upper 70s to low 80s and lows around 60. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... Patchy river valley fog is forecast to affect KELM early Friday morning. Ceilings will drop to 100-200 feet toward sunrise, and visibilities could fall below 2SM. Otherwise, VFR conditions and light winds are expected across the entire region through Friday afternoon. Outlook... Friday afternoon through Saturday night...VFR other than possible predawn valley fog at KELM each morning. Sunday and Monday...Chance of afternoon showers and storms with associated brief restrictions. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...DJP NEAR TERM...DJP/JRK SHORT TERM...MJM LONG TERM...MJM AVIATION...DJP/RRM