Area forecast discussion National Weather Service Binghamton New York 1014 am EDT Thursday may 23 2013 Synopsis... a cold front will approach the region by this evening...then slowly cross the area late tonight or early Friday. Showers and thunderstorms will likely precede and accompany the front through this evening...with showers then continuing behind the front later tonight and Friday...along with much cooler temperatures. && Near term /until 6 PM this evening/... 1010 am update... forecast in fairly good shape this morning...only minor changes needed at the present time. Regional radars showing an area of light showers working northeast through the bgm forecast area on the heels of a weak shortwave trough now lifting north through central New York with latest water vapor imagery showing a notable dry slot now entering western New York. So far current activity has displayed no convective trends and as a result...have backed off thunder mention until early afternoon. Main concern going into the afternoon remains possible severe weather development as long advertised cold front approaches from the northwest. That said...forecast models continue to indicate only weakly unstable conditions by this afternoon/evening which may be a result of current cloud cover aloft. That said...the potential does exist for model underestimation of this afternoon/S instability as periodic breaks are expected to move into the region later today. That said...RUC and local WRF BUFKIT and AWIPS plan view forecasts show nearly 800 j/kg of MLCAPE by this afternoon which may not be too far off if some clearing does move into the area. The other thing that today/S setup has going for it is decent dynamics aloft as upper divergence will be increasing through the day as a jetstreak strengthens over the region in confluent flow aloft. Considering 0-6km bulk shear vectors are oriented nearly parallel to the arriving cold front...main development will likely be linear in fashion with strong winds likely being the biggest threats. Obviously a lot to monitor and updates will be made as needed. Current thinking is today/S activity will hold off until middle to late afternoon at the earliest. Remainder of near term forecast looks to be in good shape with middle to upper 70s expected for daytime highs. 545 am update... a band of -shra/isolated thunderstorms and rain continues to March across the County Warning Area at this time...likely associated with an upper-level wave. We expect showers to impact much of the region through 14-15z...followed by a lull in precipitation for most of this afternoon. Although a fair amount of cloud debris should be resident today over the northestern states...ahead of the surface cold front...a few breaks of sun are not out of the question during the early and middle-afternoon hours. This will likely provide enough heating/destabilization to fuel another round of rain showers/thunderstorms and rain late in the day...and especially this evening...as the front itself apprchs. The latest rap/WRF/GFS consensus suggests the potential for 500-1000 j/kg of cape this afternoon...along with improving deep-layered shear...and some height falls aloft. Thus...organized linear features seem plausible...with damaging winds the primary threat. && Short term /6 PM this evening through Saturday night/... 555 am update... our model suite continues to trend slower/less progressive...with the amplified upper-level trough to impact the region through at least the first half of the Holiday weekend. Post-frontal showers have been well advertised in our forecast for Friday...along with much cooler temperatures...and nothing has changed in this regard. In fact...readings Friday likely will hold about steady in the Lower-Middle 50s...and may even edge downward a bit as the day GOES on. We've nudged probability of precipitation upward a bit for Friday ngt/Sat...mainly in our eastern zones...to account for the likelihood of a slower departure of moisture/forced lift...as it now appears that a closer upper-level system will linger along the coast at least into Sat. Although drying/clearing skies now looks slower to occur...we still anticipate that some clearing will make it into our western zones by Sat/Sat evening. Thus...present indications are are that the best shot for frost/freeze conds will be in the western half of the forecast area Sat night/early sun am. && Long term /Sunday through Wednesday/... period begins with a large and cool Canadian hp building into the area in the wake of a deep low over new eng. 800 mb temperatures drop to near 0c by Sun morning with the possiblity of some leftover precipitation in the eastern zones. Latest GFS and European model (ecmwf) are a bit slower lifting the upper low north into eastern Canada on Sunday indicating the potential for a cloudier cooler day on Sunday than previous forecast. Otherwise still expect steady improvement next week as the upper low finally lifts north into the Maritimes. Have lowered temperatures slightly on Sunday to account for latest GFS/European model (ecmwf) cooler trend... otherwise no significant changes. && Aviation /14z Thursday through Monday/... heaviest showers and thunderstorms have ended across the taf sites early this morning but occasional showers will continue through today in moist flow ahead of an approaching cold front. Isolated to scattered thunder could occur through the day but coverage and duration not enough to include in the tafs at this time. The cold front will cross the area from west to east tonight with occasional showers continuing. Again there could be some thunder but coverage and duration not enough to include in the tafs at this time. Winds will be southwest at 5 to 15 kts today shifting to northwest at 5 to 15 kts tonight. Outlook... Friday - Sat...possible lingering restrictions in lower cigs/-shra. Sun - Monday...VFR. Breezy. && Bgm watches/warnings/advisories... PA...none. New York...none. && $$ Synopsis...mlj near term...cmg/mlj short term...mlj long term...dgm/mse aviation...mse