textproduct: Binghamton

WHAT HAS CHANGED

No significant changes to the forecast. Still anticipating an area of thunderstorms to move through this evening and again Thursday afternoon.

KEY MESSAGES

1) There is a threat for severe thunderstorms this evening and into the early overnight hours. Damaging winds and locally heavy rain are the main threats.

2) Another round of thunderstorms is expected Thursday afternoon and evening. Strong wind gusts and heavy rain are the primary threats.

3) A dramatic pattern shift will begin Sunday with a round of showers and storms followed by falling temperatures Sunday night and Monday, along with light snow showers and gusty northwest winds early next week.

DISCUSSION

KEY MESSAGE 1...

The near term concerns are focused around the threat for strong to possibly severe thunderstorms later today.

The environment continues to destabilize this afternoon with surface temperatures climbing into the mid to upper 70s, as of 1 PM, but will jump into the upper 70s and lower 80s in the next couple hours. Surface dew points in the lower 60s will contribute to SB CAPE values ranging from 1000-2000 J/kg, along with steepening low level lapse rates. The combination of a plume of deep available moisture, 25 to 35 kt of deep shear and mid level lapse rates around 6.7 degC/km should provide enough ingredients for deep convection and strong to possibly severe storms. Convective initiation could end up being the challenge. There really isn't any well-defined feature to provide the support for strong ascent, unless the remnants of a propagating, relatively small MCS/MCV coming out of the southern Great Lakes make it to the western NY/PA border. This potential feature could provide the support for the storms to persistent farther to the east and also maintain intensity.

The primary threats within any of these storms will be damaging wind gusts between the hours of 6 PM and 12 AM. However, given the amount of deep layer moisture and PWs around 1.5 inches, and if heavy rain falls over the same area or on locations with moist antecedent surface conditions, the threat for localized flash flooding could be enhanced.

The convection is expected to diminish in intensity and coverage after 1 AM Thu with fog likely late tonight and early Thu morning.

KEY MESSAGE 2...

The potential for another round of thunderstorms exists late in the day Thursday as well.

An east-west oriented boundary across the region will lift to the north during the morning and afternoon Thursday and allow for temperatures to climb into the upper 70s and lower 80s once again. Plenty of low level moisture and increasing instability will create favorable conditions for strong to possibly severe convection later in the afternoon Thursday, and into the evening hours.

An upper short wave to the west will help provide the necessary forcing for large scale ascent, and when combined with building instability should be sufficient for scattered areas of strong to possibly severe storms. The SPC Day 2 Convective Outlook is highlighting a good portion of central NY in the Slight Risk for severe storms. Convective initiation looks to be between 3-5 PM across the Finger Lakes or just to the north. These storms will push eastward quickly, initially in discrete mode, but then potentially becoming more linear with time. The primary threats are likely hail and damaging winds, but a secondary threat of a few tornadoes cannot be ruled out given the amount of shear with backed surface winds along the boundary across central NY.

The threat for heavy rain leading to excessive runoff and flash flooding cannot be overlooked either. With multiple previous days of rain and wet surface conditions, any heavy rain exceeding approximately 1.5 inches in an hour could potentially cause issues.

Again, after a loss of heating Thursday evening, most of the intense convection should diminish and end close to/around midnight.

KEY MESSAGE 3...

Confidence continues to increase in the onset of a relatively cold air mass early next week.

On Saturday a deepening trough over the central US will cause a downstream ridge to amplify over the Northeast and allow for a brief warm up into the low to mid 70s. The leading edge of this cold air mass will push in from the west/sw in the form of showers and thunderstorms Sat night and early Sunday. Brief heavy rain will be followed by falling temperatures Sunday during the afternoon and Sunday night.

Temperatures on Sunday midday will range from the upper 40s to mid 50s, but drop into the mid to upper 20s Sunday night. Winds will start to really increase out of the northwest Sunday night and continue through the day Monday and Mon night. Highs on Monday will only reach into the upper 30s and lower 40s...and a few lake enhanced snow showers cannot be ruled out anywhere across central NY and northeast PA. Gusty northwest winds around 20 to 30 mph will make it feel even colder at times.

Drier air settles in Mon night but with mid to upper 20s once again. Temperatures recover back into the 50s and 60s going into the middle of next week.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Mainly VFR conditions are expected for most of this afternoon. However, another batch of showers and thunderstorms is expected to move through the area this evening, which will likely result in occasional restrictions. These restrictions will be mainly MVFR, but brief IFR restrictions cannot be completely ruled out. Following these showers and thunderstorms, lingering low ceilings and patchy fog/mist will likely keep restrictions around at least until 06Z, before a gradual return to VFR.

Outlook:

Thursday afternoon through Friday...Restrictions possible from scattered showers and thunderstorms.

Saturday...Occasional restrictions possible in scattered showers and thunderstorms late in the day. Otherwise, mainly VFR.

Sunday...Restrictions possible from rain showers.

Sunday night through Monday...Occasional restrictions possible in scattered rain and snow showers.

BGM WATCHES/WARNINGS/ADVISORIES

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