textproduct: Binghamton

SYNOPSIS

Cold Canadian air continues to filter into the region with lake effect snow showers expected through this morning. A weak wave of low pressure drops out of Canada this afternoon, with with more widespread light snow showers. Warmer conditions develop by midweek with chances for rain increasing on Thursday with an approaching cold front.

NEAR TERM /THROUGH TONIGHT/

650 AM Update

Winter weather advisory for Southern Cayuga county will be allowed to expire at 7 AM EST this morning. Some occasional light snow may continue through the mid to perhaps late morning hours before completely lifting northeast and exiting. However, additional accumulations will be light, under 1 inch for souther Cayuga county.

Also updated PoPs, QPF and snow amounts based on latest radar trends, with the Finger Lakes effect narrow snow bands continuing until mid to late morning, then also shifting north and east. Accumulations in this area generally 1 inch or less. Special Weather Statement issued to acknowledge the potential for snow covered and slippery conditions on untreated surfaces this morning.

Previous Discussion Below

Cold air mass is in place this morning with 850 mb temperatures near -18 degrees C. North northwest flow is directing this frigid air mass over the finger lakes allowing lake effect snow showers to continue into the early morning over the Twin Tiers regions of NY/PA. Although QPF is light, with this air mass in place, snow ratios are high, so we will see some light accumulations. A lake effect band is expected to reorganize over S. Cayuga and Onondaga counties this morning bringing a additional 1 to 2 inches over the far northwestern portion of the county through late morning. As a result, the winter weather advisory for Onondaga has been extended through 1 PM today.

Ridging will build in from the southwest later this morning and the lake effect snow showers will start to diminish and gradually lift back north. However, another shortwave moves into the area this afternoon and evening, bringing a period of light warm air advection snow to most of Central NY and perhaps parts of NE PA. Minor snow accumulations up to about 1 inch are expected from this weak weather system. Otherwise temperatures improve slightly with highs making it back into the low to mid 20s, but still much below average for this time of year. Drier conditions are expected overnight with exceptions over northern Oneida where a lake effect shower may clip the county. Lows will be chilly with temperatures in the single digits to low teens.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/

Westerly flow shifts southwest on Tuesday with zonal flow aloft and weak high pressure at the surface. Conditions are expected to remain quiet and dry with mostly sunny skies in the morning. This will be short lived as another weak system approaches the region, thus increasing cloud cover out ahead of it. Warm air gets advected into the region as the day progresses and we start to see temperatures trending slightly warmer. Although highs will still remain in the mid to upper 20s for one more day. A weak system in Canada will drift eastward Tuesday night and eventually clip the region Wednesday afternoon with precipitation for north-central NY. Temperatures Wednesday will climb in the mid 30s to low 40s allowing initial precip to fall as rain, but higher elevations could see a mix of rain and snow. Conditions dry out overnight with high pressure building into the region along with a ridge. Temperatures overnight will fall into the upper teens to mid 20s.

LONG TERM /THURSDAY THROUGH SUNDAY/

High pressure briefly builds in Wednesday night into Thursday, while a developing low over the upper midwest strengthens southwesterly flow and brings milder air into the region. With above normal temperatures, precipitation on Thursday will fall as rain and continue into Thursday night as the low tracks north. A cold front moves through early Friday, allowing rain to transition to a rain and snow mix or snow. Precipitation tapers off by Friday evening, though some lingering snow showers are still possible. Behind the system, brief lake effect snow may develop east of Lake Ontario, ending by Saturday morning as high pressure returns. Another weak system passing north over the weekend on Sunday could bring a chance for light rain or snow to parts of central NY and possibly northeastern PA.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Narrow bands of lake effect snow are coming off the Finger Lakes early this morning in the cold northwest flow regime. ITH and BGM should stay predominately IFR through sunrise, but the snow may occasionally lighten up, with MVFR visibilities at times (in between the more pronounced snow bands). ELM is on the western edge of these lake effect snow bands, but could see occasional MVFR visibilities in as a few steadier snow showers drift down from the north through 13z. RME is expected to stay mainly VFR through mid to late morning.

Beyond 12Z, a band of snow showers is expected to move across SYR through the early afternoon hours, before lifting north and exiting this terminal by around 18-19z. There is the potential for IFR visby with this band during the 12-18z timeframe, with visibility potentially at 1SM or even lower at times. The lake effect snow band lifts north toward RME in the 18-22z time period, as a weak frontal system also arrives. This will bring the potential for tempo IFR visibility here.

A weak wave moving through is expected to keep ceiling restrictions (and occasional light snow/MVFR visibility) in place much of the afternoon, except for AVP. Then, as winds start to turn southwesterly at the end of the TAF period, ceilings should start to gradually lift, with widespread VFR conditions expected after 23z; except later, after about 04z Tuesday at RME.

Outlook...

Tuesday through early Wednesday.. Mainly VFR.

Wednesday...MVFR Ceilings possible across portions of Central NY.

Wednesday Night and Thursday...Mainly VFR expected over the area.

Thursday Night into Friday...Strong frontal passage with rain showers, possibly mixing with or ending as snow showers along with associated restrictions. LLWS possible.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...Winter Weather Advisory until 1 PM EST this afternoon for NYZ018.