textproduct: Binghamton

WHAT HAS CHANGED

Cloud cover was increased for all of CNY into the Southern Tier as the clouds have been slow to scatter out. SPC's marginal risk was expanded northward to near the NY/PA border Sunday with a sliver of slight risk introduced in far southern Luzerne county.

KEY MESSAGES

1) A clipper system moving through Sunday brings steady rain in Central New York and potential thunderstorms to Northeast Pennsylvania, some of which could contain gusty winds.

2) An active pattern with frequent clipper systems next week, bringing light precipitation chances and frequent temperature swings.

DISCUSSION

KEY MESSAGE 1... A clipper system moves through late tonight into Sunday with a warm front lifting into CNY. Temperatures overnight with the warm front lifting in will be above freezing region wide, forecast soundings also showing warm air aloft so the precipitation type is expected to be rain for the area overnight. The Southern Tier and southward is in the warm sector of the low. Forecast soundings and mid and upper level RH fields show that there will be plenty of clouds. This will limit the heating for most of the area but the best chance for clearing will be in southern NEPA. It will be hard to overcome the low level inversion in the warm sector for our area but elevated instability will still lead to thunderstorms for most of NEPA in the late afternoon. Mid level lapse rates are around 6.5 C/km and 7.5 C/km. With the 0-6 km shear around 55 to 60 knots, some larger hail is possible in the stronger storms with elevated CAPE getting up around 500-1000 J/kg. Wind threat is uncertain as that would be dependent on the size of the cold pool that forms in the storm to break through the stable layer or if there could be enough sun for storms to be more surface based. Current SPC outlook is for a marginal risk across far southern Luzerne county.

KEY MESSAGE 2... With the strong ridge of high pressure over the Desert Southwest slowly building into the high plains next week, we will be on the NE edge of the ridge with frequent 500 mb shortwaves propagating around the northern edge of the ridge. Given the cooler temperatures in New England under a trough, we could see a few snow flakes mix in at times, especially in the higher elevations of CNY and Catskills during the overnight hours with any of these shortwaves. For the most part, given the higher sun angle and most of the precipitation with these shortwaves falling on the warm air advection side of the lows, precipitation types should be mostly rain. There is low potential for lake effect snow Monday night with 850 mb temps falling to <-10C, and then again Friday into Saturday as GEFS and EPS ensemble probabilities of less than -10C at 850 get over 50 to 75% for CNY into the Tug Hill.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

MVFR cigs have been slow to scatter out but as the winds become more southerly tonight with a low level jet forming, VFR conditions should briefly return before 6Z. LLWS is likely at most terminals with the low level jet strengthening. There is some light rain moving in from the NW this evening but VFR conditions have been mostly observed with it so far so the TAFs category were raised to mostly VFR with BGM potentially seeing MVFR cigs with showers being at elevation.

More widespread rain showers and rain move into NY in the morning with SYR, ITH, and RME seeing more steady rain while ELM and BGM see more intermittent showers on the south side of the warm front. AVP will escape most of the morning showers but given that it will get warmer, there is potential for thunderstorms after 18Z. ELM and BGM also have thunder chances but they are too low to include this far out in the TAFs.

Outlook:

Sunday...Restrictions possible as another front pushes through the area from the NW with scattered showers.

Monday through Tuesday...High pressure building in across the Northeast with mainly VFR conditions; Low chance for off-and-on snow showers in Central NY and possible restrictions with morning fog.

Wednesday...Cold front begins to move in from the west with rain and snow showers as well as potential restrictions.

Thursday... Warm front pushes up from the southwest with restrictions possible.

BGM WATCHES/WARNINGS/ADVISORIES

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