textproduct: Binghamton

WHAT HAS CHANGED

Severe thunderstorm watch has been canceled across all of our Central NY counties and the northern tier of NE PA. The heat advisory has been allowed to expire. Chances for rain and thunderstorms have been significantly lowered to just a slight chance for a shower this evening across Central NY.

KEY MESSAGES

1) A few lingering thunderstorms this evening and steady rain for the Wyoming Valley region of NE PA. Otherwise, drying out overnight with patchy fog possible.

2) A weak, but deepening surface low passes south of the region Sunday evening into Monday, with widespread rain and cooler conditions expected to start the week.

3) Upper level ridge moves west, with more seasonable temperatures this week into next weekend along with several chances of showers and thunderstorms.

DISCUSSION

KEY MESSAGE 1...

Partly to mostly cloudy conditions persist across central NY late this evening, with just a few brief, spotty showers around. Instability is quickly decreasing and CIN increasing across NE PA at this time. Therefore the severe threat has significantly decreased and will be ending shortly in this area. Expect a period of steady rain, with a few embedded thunderstorms for the Wyoming Valley and areas south of I-84 in NE PA through the late evening hours.

KEY MESSAGE 2...

The evolution of storms and rainfall today will help set the stage for potential flash flood risk Sunday evening into Monday. A broad, weak low moves slowly through the region with scattered showers and thunderstorms accompanying it. With the upper level ridge retrograding and surface high pressure across New England, an axis of stronger convergence is likely across portions of southern NY or Northern PA. HREF Probability Matched Means are indicating some higher end rainfall of 3 to 4 inches in 12 to 24 hours. This seems reasonable given forecast soundings show favorable winds for training (especially along that axis of convergence), and warm cloud depths 11K to 13K feet.

Heavy rain today, especially in areas that could get 1 to 2 inches of rain, would be more susceptible to the flash flood risk so a flood watch may be issued if the rain is widespread enough.

KEY MESSAGE 3...

The upper level ridge retrogrades to the west later this weekend and builds out west. Temperatures will be closer to average to slightly above, with surface dew points falling back into the 60s. This time of year, we do need to watch this northwest flow pattern. We are still close to the edge of the ridge, with decent low level moisture/instability each afternoon. Shear will be higher being closer to the jet stream so any shortwave that passes through could bring a threat for severe weather. Also, potential ridge riding MCSs would be possible under this flow.

AVIATION /01Z SUNDAY THROUGH THURSDAY/

Lingering showers and storms will be possible at AVP with restrictions possible. Those should come to an end by 04z but then low ceilings and fog will begin to develop at all terminals. Late tonight/early Sunday morning, IFR to LIFR restrictions will be possible at most terminals. There is uncertainty at ELM and BGM where no rain fell today. However, clear skies and light winds will be favorable for fog and/or low ceilings. Fog should lift by 12z Sunday with conditions improving throughout the morning. Rain showers and isolated thunderstorms will be possible at AVP tomorrow, which then may lead to additional restrictions. After this evening, winds become calm and stay light throughout this TAF period.

Outlook:

Sunday Night through Monday...Restrictions possible due to showers and possibly thunderstorms.

Tuesday...Mainly VFR with a chance for showers and isolated thunderstorms.

Wednesday through Thursday...Mainly VFR; showers and isolated thunderstorms possible late Thursday.

BGM WATCHES/WARNINGS/ADVISORIES

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