textproduct: Binghamton

WHAT HAS CHANGED

Expanded valley fog coverage tonight across the Twin Tiers and Catskills. PoPs have trended lower during the day on Wednesday. Lowered PoPs into the likely category Thursday and Friday afternoon, as the atmosphere is lacking strong forcing these days.

KEY MESSAGES

1) Wonderful summer weather continues the rest of today into Wednesday. Dry and seasonably warm weather is expected.

2) Increasing moisture and instability bring scattered to numerous showers and thunderstorms Thursday through Saturday.

3) Typical summer weather pattern expected for Sunday into early next week, with a few chances for showers or thunderstorms.

DISCUSSION

KEY MESSAGE 1...

High pressure remains in control of our weather into tonight. Expect sunny skies into the evening hours, with highs in the upper 70s to low 80s along with low humidity. Winds remain light and skies remain clear this evening. This will allow for areas of fog to develop in the typical valley locations. Some mid and high level clouds will arrive from the south overnight. It will be mild, with lows in the mid 50s to low 60s.

Wednesday features partly to mostly sunny skies across the majority of the forecast area. Moisture begins to increase through the day from south to north. In fact, PWATs reach 2.0 inches by late afternoon over NE PA, and dew points rise into the mid/upper 60s. Model guidance has still be consistent showing a minima of CAPE and instability over most of the CWA Wednesday afternoon. The higher end CAPE looks confined to western NY and southeast PA. With that said, we can't rule out a late day shower or storm, mainly across the Poconos, Wyoming Valley and/or Steuben County. Otherwise, it will be another seasonably warm day with highs in the 80s areawide.

KEY MESSAGE 2...

Moisture advection increases along the western periphery of the Bermuda high heading into Thursday. PWATs increase between 1.75 to 2.0 inches across the region. Surface dew points also rise into the lower 70s. Soundings show substantial CAPE, between 1000-2000 J/kg or even locally higher. However, with that said, heights will be steady or even subtly rising around the offshore ridge. There will be only very minor perturbations and shortwaves approaching from the south. Therefore, in collaboration with surrounding NWS offices, decided to cap PoPs at the likely/numerous level (as opposed to categorical/widespread level suggested by the NBM). Coverage of showers and storms is expected to be scattered to perhaps numerous based on the overall setup, lack of strong forcing and the latest CAMS as it comes into time range. So overall, do not expect a washout Thursday or Friday. It is forecast to be partly sunny, very humid with occasional showers or storms possible. Any storms that do form could be strong, with gusty winds, frequent lightning and torrential downpours. WPC is indicating a marginal risk for excessive rainfall Thursday through Saturday over the area. Deep layer wind shear is expected to remain generally below 25 kts in the 0-6km layer, this would indicate a better chance for pulse, pop up storms. However, as a weak front and better height falls approach on Friday and Saturday, some more organized convection would be possible.

KEY MESSAGE 3...

A zonal or slight northwest flow pattern looks to remain in place Sunday and early next week. Occasional rounds of showers and storms may arrive from the west-northwest in this regime. Otherwise, heights and thicknesses remain elevated, and 850mb temperatures remain around +16C through Monday, suggesting continued warm and humid weather conditions. A front looks to approach and potentially move through the area by next Tuesday or Wednesday. This could bring a bit of a cool down, with close to, or slightly below average temperatures for the middle and end of next week.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

VFR is expected at all sites through most of the period. Fog with airport minimum restrictions is again likely at KELM shortly before sunrise although may be in and out as early as 05Z-06Z. A sheared out upper level wave will move north out of the Carolinas and spread lowering clouds into the region toward the end of the period. Ceilings should remain VFR but can't completely rule out MVFR sneaking into KAVP right at end of period.

Outlook:

Wednesday through Sunday...Repeat showers and scattered thunderstorms with VFR ceilings consistently at or below FL050 with intermittent worse cig/vsby restrictions associated with rain/storms.

BGM WATCHES/WARNINGS/ADVISORIES

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