textproduct: Binghamton

WHAT HAS CHANGED

No significant changes were made to the forecast.

KEY MESSAGES

1)Upper level low will spin over the area this afternoon gradually shifting to the east this evening. This will keep scattered showers and a few thunderstorms in the forecast.

2) Drier weather returns to the area Friday and Saturday as weak ridging and high pressure move overhead.

3) The weather pattern turns more active and wetter heading into the second half of the weekend. Expect a warming trend next week.

DISCUSSION

KEY MESSAGE 1...

Mid and upper level low pressure system slowly rotates over the northeast coast this afternoon gradually shifting east this evening with drier air pushing in behind it. Isolated to scattered showers and thunderstorms are expected to linger into the afternoon before tapering off. Instability also increases towards the afternoon hours allowing additional showers and thunderstorms to develop over the area. Instability parameters are modest with ML CAPE values up to 500 J/Kg at most, along with 20 knots of shear. It remains humid with dew points in the mid to upper 60s and pwats around 1.3 inches. We can't rule out some brief locally heavy rainfall with the storms this afternoon, but overall severe weather is not expected today. Highest PoPs are over the Catskills of east-central NY. The rain showers end tonight and skies partially clear. Winds turn light as high pressure gradually builds in from the west. This will be a good setup to see valley fog development. Lows dip down into the mid-50s and low 60s.

KEY MESSAGE 2...

With high pressure in place Friday through Saturday conditions remain generally dry. There is a slight chance for a late day shower or thunderstorm to pop up over the Catskills where the slow departing trough will still hold some influence. Otherwise temperatures warm into the upper 70s to mid-80s, with generally comfortable humidity levels. Similar conditions are expected Saturday with mostly dry conditions in the morning and afternoon hours. As an upper level ridge moves in on Saturday, southwesterly flow settles into the region. As a result, temperatures trend slightly warmer with highs in the upper 70s to mid 80s over the region. Dry conditions will be short lived as another frontal system approaches the region in the evening and overnight hours increasing precipitation chances.

KEY MESSAGE 3...

By Sunday, the next deep trough, front and low pressure center will be moving into the area from the midwest. With southwesterly flow out ahead of it, abundant moisture gets advected into the region increasing PWATs 1.8 to 2.0 inches. Model consensus is good on the arrival timing and position of these features. It is too early for specific details on exactly how much instability will be present, as that will certainly depend on day time surface heating. The main concern is the risk for excessive heavy rainfall as this system moves through. Model guidance does show some timing differences in when the system will exit. GFS keeps the upper level low rotating over the east coast through Wednesday, while the ECMWF and Canadian show it moving east sometime Monday with an upper level ridge building in behind. Beyond this, expect a warming trend for the middle of next week with chances for afternoon and evening thunderstorms also in the forecast.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Spotty showers and intermittent MVFR ceilings will occur for just a few hours after 18Z Wednesday on the back end of departing low pressure. After clouds scatter out into this evening, KELM appears very likely to experience restrictive valley fog during the pre-dawn hours Thursday. Ground moisture from recent rainfall may lead to fog development at several other terminals as well but there is uncertainty for how thick and whether it will reach terminal levels. Regardless, VFR conditions are anticipated during the daytime Friday after any fog burns off.

Outlook:

Late Friday through Saturday evening...Mainly VFR.

Late Saturday Night through Sunday night...Rain and restrictions likely, with a chance of thunderstorms, as a moist frontal system passes through the region.

Monday through Tuesday...Lingering chance of scattered showers and isolated thunder; associated restrictions. Mainly Monday.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...None.