textproduct: Binghamton

WHAT HAS CHANGED

No significant change with the latest forecast.

KEY MESSAGES

1) Warmer temperatures and increasing humidity are expected across Central New York and Northeast Pennsylvania today and tomorrow.

2) Scattered afternoon showers and thunderstorms return to the region Thursday and Friday before quiet weather and high pressure build back in for the weekend.

DISCUSSION

KEY MESSAGE 1...

Upper level low has shifted east with weak high pressure building in behind it. This will allow skies to gradually clear with winds becoming light and variable. Morning patchy fog is expected to burn off soon after sunrise. A cool start to the day will quickly give way to warming afternoon temperatures as abundant sunshine and the strong July sun angle help temperatures climb into the 80s across much of the region. Overall, a quiet and pleasant day is in store. Attention then turns to a weak shortwave approaching later this evening, bringing a small chance for showers across portions of the Southern Tier, otherwise mostly dry conditions are expected elsewhere.

KEY MESSAGE 2...

Southwesterly flow develops Thursday as 850 mb temperatures rise into the +16 to +18 degrees C range. Surface temperatures should climb well into the 80s, with a few lower 90s not out of the question. Heat indices in the 90 to 95 degree range will be possible, especially across the Lake Ontario Plain and interior valleys. As temperatures and dew points increase, so too will the threat for scattered showers and thunderstorms. A southern wave moving east across portions of the northern Mid-Atlantic during the early afternoon will trigger isolated showers and storms from the Southern Tier of NY south into northeast PA. Later in the day a northern wave approaching from the northwest will generate a broader area if convection that progresses northwest to southeast through the evening and overnight hours.

Model guidance continues to indicate favorable instability, with ML CAPE values around 800-1000 J/Kg and steep low level lapse rates. Forecast soundings suggest the cap may weaken enough for storm development, though shear remains on the weaker side and may limit sustained or mature convection. The early afternoon activity over northeast PA should remain relatively weak, with greater concern for strong to locally severe storms accompanying the incoming front from the northwest. Western and central NY will have more time to erode the inversion and tap into slightly stronger deep layer shear. Sounding profiles also support a localized flash flood threat, with long skinny CAPE, PWATS of 1.5 to 2 inches, and warm cloud depths around 11-12 kft. This threat appears greatest from Thursday afternoon through the overnight period, particularly across northeast PA.

Temperatures Friday will be slightly cooler, with highs ranging from the mid 70s to mid 80s, though dew points remain elevated in the 60s and lower 70s. A lingering boundary may serve as a focus for additional convection Friday afternoon and evening. The threat for stronger storms Friday into Friday night will need to be monitored as deep layer shear increases in response to a modest jet streak aloft and embedded shortwave. By Friday night a longwave trough will move through the region, ushering in a cooler and less humid air mass for the weekend with highs mainly in the 70s and lower 80s. Rain chances will also diminish considerably as a drier pattern settles over the area.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

A mix of fog and low ceilings have brought LIFR restrictions to KBGM. It will slowly lift and dissipate through around 13z. The current MVFR/Fuel Alt deck over KELM is also expected to last until 13z. Otherwise, VFR conditions expected for all terminals after 13z.

Outlook:

Wednesday night through Thursday...Mainly VFR; High pressure building in, morning fog likely, mainly at ELM.

Friday into Saturday...Cold front could move in and stall, leading to persistent showers and thunderstorms with associated restrictions.

Sunday...VFR likely with high pressure building in, morning fog potential at ELM.

BGM WATCHES/WARNINGS/ADVISORIES

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