textproduct: Binghamton

WHAT HAS CHANGED

Just minor adjustments to precipitation chances, temperatures and cloud cover based on the latest observational trends and forecast models. No significant changes were made at this time.

KEY MESSAGES

1) It will be warm and humid with scattered showers and thunderstorms this afternoon through Saturday evening. A few storms could contain gusty winds and heavy rainfall.

2) A brief dry period is expected on Sunday with lower humidity and mostly sunny skies.

3) Scattered showers and thunderstorms return to the forecast early next week. Temperatures will be on a gradual cooling trend through the upcoming week and into next weekend.

DISCUSSION

KEY MESSAGE 1...

The area remains locked in a broad southwest flow pattern between the offshore ridge and a trough over the Midwest to Great Lakes region. The upper level trough will slowly move east heading into the weekend, pushing the ridge further offshore. A west-southwest flow of deep moisture will persist over the area, with PWATs around 1.9 inches today, 1.8 inches Friday and falling slightly to 1.6 inches on Saturday. Surface dew points will remain elevated in the upper 60s to low 70s, locally mid 70s, through Saturday as well. Each afternoon and evening instability will build due to the day time heating. MLCAPE is progged to be 1000-1500 J/kg this afternoon, and again on Friday and Saturday afternoon as well. Shear will be 20-30 kts each afternoon and evening, which may be enough for a few clusters of thunderstorms to develop. There will be the potential for isolated gusty to damaging winds and torrential downpours with these storms. There will be a little more forcing heading into the area for Friday and Saturday as the broad trough approaches, this may also help to better organize the convection at times.

Otherwise, outside of the showers and thunderstorms expect conditions to be very warm and humid under partly cloudy skies. Daytime highs will be generally in the 80s, with a few areas around 90 in the urban valley locations. Heat indices could reach the low to mid-90s this afternoon for locations that see more sunshine and miss out on the showers/storms. Did not have enough confidence or coverage of mid 90s heat indices to issue any heat advisories at this time. The heat index should be slightly lower Friday and Saturday afternoons, mainly in the upper 80s to low 90s, except mid 90s in the Wyoming Valley. Overnight lows will be mild and muggy, in the mid to upper 60s with areas of fog possible.

KEY MESSAGE 2...

Most of the latest deterministic and ensemble guidance swings a front through and east of the area later Saturday night, bringing a drier air mass in behind it. The 12z NAM seems to be an outlier, with a slower frontal passage on Sunday. The official forecast follows the majority of the ensembles which brings sunny skies, falling dew points and dry weather areawide. Temperatures remain seasonably warm in the upper 70s to mid-80s, with steady NW winds between 6-12 mph expected. It will be a little cooler Sunday night and less humid, with lows in the upper 50s to mid-60s.

KEY MESSAGE 3...

After the brief, flat ridge exits Sunday night, the next fast moving shortwave disturbance will approach from the west on Monday. Moisture levels will increase, with surface dew points rising back into the upper 60s. Chances for showers and thunderstorms increase Monday afternoon and evening as this disturbance rolls through. Temperatures warm up a few degrees compared to Sunday. The overall flow then looks to remain fairly zonal Tuesday and Wednesday, before a deeper trough digs into the Central Great Lakes midweek. This will keep fast moving shortwave moving into our area at times. Tuesday has the highest chance for showers and thunderstorms, with chances fading a bit by Wednesday if current timing and placement of weather systems hold. Temperatures start a gradual cooling trend Tuesday, Wednesday and Thursday next week; falling back to near average levels for the middle of August. A deeper, more amplified upper level trough looks to approach the area for the end of next week; this could act to increase showers and storms along with brining even cooler temperatures behind it for next weekend.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

VFR conditions are present across much of the region, with some isolated rain showers and storms continuing along and east of I-81. With the humid conditions, light winds and high pressure overhead, fog is expected to develop, especially where it rained this afternoon and evening. Highest confidence for fog is at ELM, where around 0.3 inches of rain fell this afternoon. The rain has also dropped temps into the mid 70s with dewpoints in the upper 60s, so we are not going to need much cooling to get the temp to hit the dewpoint. These figures point to a strong case for fog development. Went a little earlier than guidance suggested and introduced tempo fog from 05-07z. This could be a little late and fog may start forming around 04z, but confidence in pushing fog up that early was not high enough to include in the TAF. Fog should settle in between 2 and 3 am and last into the morning hours.

ITH also had some rain this afternoon and with temps and dewpoints behaving like ELM, fog is expected to develop here tonight as well. BGM did not see rain today, but with high humidity and calm winds expected, fog should form for a few hours tonight. Guidance is showing some hints for fog at AVP, but with no rain today, confidence was not high enough to include IFR in the TAFs. TEMPO MVFR fog will be possible late tonight into the morning.

SYR and RME should be VFR through the TAF period.

Outlook:

Friday night through Tuesday...Unsettled with repeating times of showers and scattered thunderstorms and associated restrictions. Overnight fog/mist restrictions are also possible.

BGM WATCHES/WARNINGS/ADVISORIES

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