748 FXUS61 KBGM 190756 AFDBGM AREA FORECAST DISCUSSION National Weather Service Binghamton NY 356 AM EDT Wed Jun 19 2019 .SYNOPSIS... Scattered showers and a few thunderstorms are possible across the area on Wednesday. Another stronger low will bring more showers and storms Thursday and Thursday night. A period of dry weather settles in Friday into early Sunday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 pm update...Forecast soundings showing some weak elevated instability through midnight now, with about 100 J/kg of CAPE. Dry air finally comes in around midnight or just after and showers should diminish. Kept scattered showers in the forecast for our western counties for a few more hours and then just isolated/slight chance for showers thereafter. 7 pm update... Made only minor changes to PoP based on latest Radar, with showers more scattered across Steuben County and very limited shower activity elsewhere. After sunset, should see showers diminish rather quickly, but with the very wet conditions, fog could become rather thick in some locations overnight. 340 pm update... Main concerns in the near term remain focused on the potential for scattered showers and a few weak storms this afternoon and early evening...the development of low clouds and fog tonight...and more scattered showers and storms on Wednesday. Weak upper wave and associated surface front will continue to track to the east late this afternoon with a few lingering rain showers passing through the Poconos and far srn Catskills. A post-frontal air mass is currently moving into central NY with a few very weak showers and storms popping up...which should continue through sunset. The air mass will stabilize tonight and allow for the development of low clouds and fog. Atmosphere will remain unsettled tonight...and cannot rule out a stray light rain shower...so have kept with a slight chance of rain through tonight. The potential for rain increases during the late morning on Wednesday as the air mass destabilizes. ML CAPE values around 1000 J/kg and weak to moderate deep layer shear will promote convective initiation, but the combination of weak upper level forcing...shallow low level lapse rates and the presence of an ill- defined surface boundary should keep the storms in check for the most part. The threat for showers and storms peaks during the afternoon and early evening, and then starts to diminish after sunset and through the overnight hours. The main concern with any storms that do form will likely be hail and strong wind gusts. The threat for heavy rain and flash flooding is on the lower end of the scale given the presence of a relatively deep layer of dry air aloft. Isolated rainfall amounts around a half inch are not out of the question, but widespread amounts will likely be a quarter inch or less. Temperatures tonight will remain fairly mild with lows dropping into the upper 50s and lower 60s. On Wednesday, temperatures will warm into the lower to mid 70s in the Catskills and Poconos...and into the mid 70s to lower 80s along and west of I-81. Another mild night Wednesday night with lows bottoming out in the lower 60s. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... 330 pm update... Thursday into Thursday night will be the main issue for the week. An upper level trough will move through with a surface low and cold front tracking through PA. Models very similar the last few days on the scenario. Heavy rain will be ahead of with the surface low Thursday into Thursday evening. Pwats will be 1.5" to almost 2". The individual cells will be moving but the entire duration of the rain will be long. Models are showing stripes of heavy rain just about anywhere in the CWA. Widespread average amounts of 1 inch is likely. Thunderstorms with heavy rain could up the amounts to a few inches. Too far out to say where the heaviest rain will be. The most prone area will be where the flash flooding was today in NEPA. The severe threat will be best in NEPA to the Catskills in the afternoon to early evening. SPC has the area in a marginal risk. With a saturated sounding, CAPE is tall and skinny and mostly around 500. Bulk deep shear is around 35 kts. Temperatures rise only a little into the low and mid 70s Thursday. Clouds and rain will hinder the rise. Rain will push east late Thursday night. Lows from the mid 50s north to around 60 south. Friday a few lingering showers will be around in the morning and quickly push east. The afternoon will be mostly dry with skies becoming mostly sunny. Highs in the upper 60s to lower 70s. && .LONG TERM /FRIDAY THROUGH TUESDAY/... 350 AM Update... A welcome dry period will take shape as we head into the weekend, before the pattern turns wetter again early next week. Post-frontal clouds will linger over the area early Friday, and even spotty morning showers. However, cool dry air advection will scatter clouds out while ending showers, with gusty northwesterly winds. A ridge of high pressure will then drift over the area Friday night through midday Sunday, with temperatures trending back up. Highs by Sunday will be mainly upper 70s-lower 80s. Upper ridge will start to have smaller waves attempting to flatten it by late Sunday onward, increasing moisture and thus also chances of showers. At this point, model consensus indicates a frontal system moving through during the Monday- Tuesday time frame. Warm air ahead of the wave, and orientation of the frontal system, suggest some instability being present as well. Thus showers will probably include some thunder. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... Tricky aviation forecast for several of the terminals this TAF period. For the remainder of overnight, amorphous deck of clouds will compete with attempts at fog formation. Confidence has dropped for more restrictive conditions, but IFR-fuel alternate visibility is still expected at times in the hours leading up to dawn for KITH and especially KELM. While a fuel alternate ceiling will develop for a period this morning at KBGM, downsloping flow should hold KAVP from dropping below higher end MVFR. Further north, VFR is most likely to continue to prevail for KSYR-KRME, though there is a small chance of brief lower ceiling at KRME early this morning; watch for amendments. Clouds generally will lift to high end MVFR or VFR for much of today. However, by mid to late afternoon a wave of low pressure along with ample moisture and instability will cause scattered showers and thunderstorms to develop for parts of the area. Confidence now high enough to have a window of thunder at KAVP late today, but too low at the other terminals to include in TAFs. Weak flow will allow light and variable winds at all sites throughout the TAF period. In the wake of showers and thunder, moist atmosphere could again lead to ceiling and/or visibility restrictions developing later tonight. Outlook... Late Wednesday night through Thursday night...Periods of restrictions likely from showers and chance of thunderstorms as a low pressure system moves through the region. Friday through Saturday night...VFR as high pressure takes charge; but early morning fog possible KELM especially Saturday morning. Sunday through Sunday night...VFR during the day, but chance of showers and restrictions moving in Sunday night. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Flash Flood Watch from noon EDT today through late tonight for PAZ038>040-043-044-047-048-072. NY...Flash Flood Watch from noon EDT today through late tonight for NYZ055-056. && $$ SYNOPSIS...BJT NEAR TERM...BJT/MPK SHORT TERM...TAC LONG TERM...MDP AVIATION...MDP