935 FXUS61 KBGM 241745 AFDBGM AREA FORECAST DISCUSSION National Weather Service Binghamton NY 145 PM EDT Mon Jun 24 2019 .SYNOPSIS... High pressure will gradually move east of the area today, allowing a weak system to pass through tonight into early Tuesday with periods of showers and possible thunderstorms. While dry much of the time for the rest of the week, other weak disturbances will skim by the area yielding isolated to scattered showers and thunderstorms. && .NEAR TERM /THROUGH TUESDAY/... 1130 AM Update...Only minor changes to reduce PoPs later this afternoon; also tweaked cloud cover and temperatures based on the latest trends and near term guidance. Highs still on track to reach the upper 70s to lower 80s. There could still be a few light showers or sprinkles west of I-81 late this afternoon... then a break in the shower activity and even cloud cover arrives early this evening. The main front, with best lift and instability does not arrive until after midnight, with the highest probability of rain and embedded thunderstorms from about 3 to 10 am Tuesday. Moisture increases quite a bit tonight; with pwats nearing 2 inches and dew points rising into the low to mid-60s. Humid and much warmer overnight with lows 62 to 68 areawide. Previous Discussion Below 400 AM update... Main concern this period is for isolated heavy rain overnight tonight into early Tuesday as a brief frontal system moves through with a narrow axis of high precipitable water values. Things are all quiet for now, with high pressure still in charge even though it is heading east. Dewpoints are creeping up slowly in its return flow. Combined with much lighter boundary layer winds compared to prior mornings, and continued mostly clear sky, radiational cooling is allowing bit more valley fog to form. This will burn off quickly after dawn. A weak wave, effectively a warm front, will run into initially dry air and upper ridge this afternoon. We will probably see some reflectivity echoes on the radar but much of it will be virga, with just a slight to low chance of actual showers. Overall, today will be mostly a dry day with increasing clouds and dewpoints, and high temperatures will be near climatology in the upper 70s to lower 80s. The warm front will slow down this evening, while upstream a negatively-tilted wave aloft will force a cold front into the region overnight. Thus we will have either a quick warm front- cold front progression, or occluding front. Despite the initially dry retreating air mass, models are in agreement that the upper wave is successfully tapping Gulf moisture and it will pool together a narrow axis of anomalously high precipitable water (Pwat) values around 2 inches. The good thing is that we have had a few dry days, and the occluding front/high Pwat values will carry through late tonight into early Tuesday morning when diurnal energy is at a minimum. Most areas will have no problem handling the average of a few to several tenths of an inch of rain. However, for a brief time things may line up for a possible small window of training-backbuilding of embedded convective cells somewhere within our area. Rainfall will be very efficient in the nearly moist-adiabatic air mass and warm cloud depths will get to around 12 kft agl. Thus we cannot rule out isolated heavy rain and localized flooding, even though the vast majority of the area will be fine. There are some pockets of our area that if receiving more than three- quarters of an inch of rain in a short period, could experience minor issues. With the ample cloud cover and moisture, it will be a humid night with lows in the 60s. By shortly after dawn most rain will start heading east of I-81, though there could still be lingering spotty showers. Westerly winds will pick up a bit, though being an occluding front there will be very little if any shallow cool air advection behind it. Highs will thus again be right around climatology, and clouds will generally decrease as the day carries on. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... Surface ridge builds into the area Tuesday night, however, dry conditions will be short-lived as next short wave pushes in from the west Wednesday afternoon. Models are in pretty good agreement at this time, with wave coming in around period of max heating. CAPE values of 500 - 1000 J/kg appear likely, especially across the northern forecast area, where thunderstorms will be most likely. Does not appear at this time we will see severe storms, as shear is somewhat weak and also the flood threat will be minimal as forecast soundings only have PWATs climbing to 1.3" and the wave is pretty progressive. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Main changes made to the long term from the previous forecast was to introduce likely PoP this Saturday as upper low drops south out of Ontario and into the area. Ensembles and and deterministic guidance is now in fairly good agreement with this feature, so with a decent consensus with the guidance, forecast confidence for showers and storms has increased. Thursday and Friday look drier now, with brief ridging building in. Scattered showers and storms expected Saturday afternoon/evening, and the upper low looks to remain in our vicinity through the weekend and into next week. This means unsettled conditions, especially during the max heating hours. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions are expected at all terminals this afternoon and evening. SCT-BKN high clouds 12-20k ft agl are expected through the afternoon and early evening, with a few mid level clouds 5-8k ft agl also possible. A few light showers will try to move across the terminals this evening, but likelihood of rain will be much higher 08Z-13Z Tuesday with MVFR and even fuel alternate restrictions developing. Embedded thunder will be possible as well but confidence is still too low to include in TAFs at this time. For surface winds in general; becoming S/SE 5-9 kts this afternoon and tonight. Winds turn west-southwest, then westerly behind the front Tuesday morning; 6-12 kts. Outlook... Tuesday afternoon through Wednesday morning...Mainly VFR. Wednesday afternoon and Wednesday evening...Another passing disturbance with chance of showers-thunder/brief restrictions. Wednesday night through midday Friday...Mainly VFR. Friday afternoon through Saturday...Increasing chances for showers-thunderstorms and restrictions as a wave approaches. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MDP/MJM NEAR TERM...MJM/MDP SHORT TERM...MPK LONG TERM...MPK AVIATION...MJM/MDP