textproduct: Binghamton

WHAT HAS CHANGED

Not many big changes from the previous forecast. Temps tonight lowered from guidance as radiational cooling will take hold. A messy wintry mix on Tuesday was edited to show p-types closer to model soundings.

KEY MESSAGES

1) A return of very cold temperatures tonight as high pressure moves overhead.

2) A wintry mix is expected Tuesday and Tuesday night with a variety of light accumulations.

3) Temperatures trend warmer the rest of the week but the pattern will remain active with multiple chances for rain. The potential for ice jams and flooding increases toward the end of the week.

DISCUSSION

KEY MESSAGE 1...

A high pressure system will move into the area this afternoon and into the overnight hours, keeping weather conditions calm. Skies have scattered this afternoon, allowing more sun to reach the ground but CAA from WNW winds will keep temperatures across much of NY below freezing. The Wyoming valley will be the hot spot, with temps pushing into the mid 30s.

With the center of the high moving overhead tonight, winds will become very light and variable and skies will become mostly clear. With the cold Canadian airmass overhead, temps in NY will easily fall into the single digits by late evening, with most in the low single digits overnight. Northern Oneida county will be the cold spot, with -5F to -12F expected. PA will be warmer with the cold air mass not reaching as far south, but overnight lows will still be in the upper single digits to low 10s. Temps on Monday will recover into the mid 20s to mid 30s.

KEY MESSAGE 2...

A messy Tuesday is in store as a wintry mix of snow, sleet, freezing rain and rain is expected.

A shortwave will propagate eastward across the Ohio Valley Monday night into the Mid-Atlantic before butting up against the previously mentioned high pressure system and turning to the north. General low to mid level flow will become SSWerly, pushing warm air into the region. This will help erode the cold air already present, but that cold air will stubbornly stick around as it gets trapped at the surface with the warmer air riding over the top of it. Initial precipitation is expected to start after sunrise as light snow across NEPA and the Southern Tier. Precip and a warm nose at 850mb will continue to push NNE as the morning progresses, with a wintry mix of snow, sleet and patchy freezing rain and rain spreading over the southern Finger Lakes, S Tier and into the Catskills and NEPA. Along and east of I-81, cold air remains in place with snow showers expected into the early afternoon. This warm nose pushes east in the afternoon, bringing the wintry mix to the east and north. Rain will fill in across the Finger Lakes and western Southern Tier as surface temps climb above freezing. Much of the area will see all rain by late afternoon, outside of areas in the Catskills where cold air damming remains and Oneida county, where the warm air will struggle to reach. Here, a mix of snow and freezing rain and rain will be possible during the late afternoon and evening hours. Precipitation clears out overnight, with some light lingering showers remaining.

With all the messy wintry mix expected, freezing accumulations at this time look to be light. 0.5-2in of snow is forecast east of I-81, with a few hundreths of an inch of ice possible across the area. Guidance remains uncertain as to where the highest QPF falls. Some models build in a surface high from the Great Lakes that keeps the higher QPF to the east and south of the region, while others have a weaker high that allows the QPF to move farther north into CNY. The good news is that most of this heavier QPF occurs during the overnight hours, when much of the precip across the region will be rain. Headlines were not issued on this forecast package as there still remains high uncertainty as to how quick or slow the cold air will erode as the warm front pushes into the area.

KEY MESSAGE 3...

After Tuesday's weather system exits the area, a very nice and much welcomed warm up will occur. A cutoff low will develop over the SW US, which will allow a large troughing pattern to develop across the US, pushing warm Gulf air into the region. Unfortunately, the weather will remain active through the rest of the week and into the weekend as shortwaves develop within the broad longwave trough pattern, pushing a parade of rain filled low pressure systems through the region. Temps will climb into the mid 40s to low 50s on Wed, jumping to the mid to upper 60s by Saturday. Oneida county and the Catskills will be the cool spots during this time, but temps will still feel like spring!

With this warm up and expected rain fall and snow melt, ice jams and minor flooding will be possible along rivers and streams going into the end of the week and weekend.

AVIATION /00Z MONDAY THROUGH FRIDAY/

There will be some lake enhanced clouds and snow flurries around ITH, ELM and BGM that may bring MVFR ceilings at times this evening. Otherwise, high pressure builds overhead and all VFR conditions are expected from after midnight tonight through tomorrow evening.

Outlook:

Monday Night...VFR early with flight restrictions lowering late tomorrow night into early Tuesday morning. Chance for IFR visibilities in snow by morning.

Tuesday...Snow mixing with sleet and freezing rain likely. A good chance for IFR and Alternate Minimums. Mixed precipitation turns to mainly rain Tuesday afternoon and evening.

Wednesday through Friday...Rainy periods likely with a chance for low ceilings, fog, and associated flight restrictions.

BGM WATCHES/WARNINGS/ADVISORIES

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