textproduct: Binghamton

WHAT HAS CHANGED

Increased coverage of precipitation chances today through tomorrow. Also added plentiful valley fog for the next few nights.

KEY MESSAGES

1) Active weather pattern returns today as we end up on the Northeast edge of a large ridge in the South Central US.

2) A stronger shortwave looks to pass around the northeast edge of the ridge mid next week with potential for stronger thunderstorms and heavy rain.

DISCUSSION

KEY MESSAGE 1...

A strengthening ridge of high pressure is building over the Southern Plains today with a trough sitting just off the east coast of Northern New England. This puts us in the "Ring of Fire" around the ridge helping to keep our daily precipitation chances elevated. Given that we are starting to get later in the year and our days getting shorter with a lower sun angle, we will not build up a lot of instability most afternoons despite good shear in place, with 0-6 km shear between 30 and 50 knots over the next week. Clouds will also help in lowering the amount of solar heating we get so most days, we only see a few hundred joules of CAPE develop. Subtle shortwaves today and tomorrow will lead to widely scattered rain showers and isolated thunderstorms. Surface based CAPE will be limited through Tuesday and mid level lapse rates are between 5C/km and 6C/km will greatly limit the severe thunderstorm potential today and tomorrow. Tuesday and Wednesday have more sun and a more potent shortwave in the models currently, though these days will be focused on in key message 2. Beyond Wednesday, troughing may build back in, but daily showers may still pop up in the afternoons under the cooler air aloft.

With the increase in moisture and likely some rainfall daily, valley fog will be prevalent most mornings if there is any clearing of the clouds in the overnight hours. Locally dense fog will form in the typical spots, the valleys of the Chemung, Susquehanna, and Delaware Rivers. The Wyoming and Mohawk Valleys may even get some dense fog if clearing overnight could last more than a few hours Monday night and Tuesday night.

KEY MESSAGE 2...

Tuesday and Wendesday this week look to have late season severe potential. The ridge builds a little bit more into the Northeast, with warmer, more humid conditions pushing in helping to build better Surface Based CAPE. Looking at Ensemble probabilities of greater than 1000 J/kg of surface CAPE and bulk shear greater than 30 knots, both Tuesday and Wednesday afternoons have a greater than 50% chance of meeting those requirements. Lowering CAPE to 500 J/kg, probabilities get over 80% Tuesday and 70% Wednesday. Deterministic models vary more but there is good consistency in Tuesday having between 30 and 40 knots of shear with CAPE closer to 1000 in the model means. Wednesday has better shear, with models consistent with shear closer to 50 knots. Wednesday also has the stronger shortwave passage.

Putting it all together, Tuesday's potential is a little lower with less synoptic support for triggers, but still could be some isolated to scattered thunderstorms in the afternoon. With hodographs mostly strait and NW flow, hail and damaging wind gusts would be the main concern. Wednesday, hodographs are more curved with the passage of the shortwave and have longer tails. Its tough to figure out what the storm evolution may be, as there is plenty of synoptic lift. This could cause it to me cloudy and limit surface CAPE and keep storms more elevated with hail and localized downburst being a concern. If it does end up being warmer and sunny with surface based CAPE, all hazards are possible. Storms may upscale quick into an MCS as well with the strength of the shortwave so flash flooding will likely become a concern especially later in the day and overnight Wednesday. A low level jet and plenty of heat and moisture in the ridge feeding into the shortwave may help sustain storms and upstream redevelopment well into the night.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Rain showers will move into the area later this morning, moving from NW to SE across the region with conditions remaining mostly VFR into the evening hours. A few showers may be heavy enough to reduce conditions to MVFR but these restrictions should not last. Scattered rain shower chances will remain into the overnight hours.

Widespread fog is expected across the region tonight with IFR and lower restrictions possible at BGM/ELM/RME/ITH.

Outlook...

Monday through Thursday... Scattered showers and thunderstorms possible with associated restrictions, especially each afternoon/evening.

BGM WATCHES/WARNINGS/ADVISORIES

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