textproduct: Binghamton

SYNOPSIS

Quiet weather this evening, with gradually increasing clouds. The next winter weather system will bring a period of moderate snow to all of Central NY and Northeast PA starting late tonight through the day on Tuesday. A general 3 to 7 inches of snow is expected across most of the area. Lingering lake effect snow showers and flurries are in the forecast for Tuesday night, followed by dry and seasonable weather on Wednesday. A sharp cold front will bring snow showers on Thursday, with much colder temperatures in the forecast for Thursday night and Friday.

NEAR TERM /THROUGH TODAY/

**Winter Weather Advisory in effect for much of the forecast area late tonight through early Tuesday evening. Winter Storm Warning for Sullivan County**

Main concern will be the incoming winter storm for this time period. Starting off with increasing clouds, but quiet weather this evening into the first part of the overnight period. Then a developing low pressure system and associated moisture plume moves into our area during the predawn hours Tuesday morning. Overall trends have been generally a bit weaker and further southeast with the surface low track...but the range of precipitation amounts over our forecast area has decreased. Confidence has increased that QPF amounts from this system will be between about 0.30" and 0.50" over most of Central NY and NE PA; but amounts could be slightly higher over the southeastern portion of the CWA along a stripe from Pike to Sullivan counties. The snow ratios late tonight and Tuesday morning will be between 12-15:1 for CNY and the northern Tier of PA...but a little lower between 8-12:1 over the Wyoming Valley and Pocono region. SLRs come down slightly heading into Tuesday afternoon areawide.

Therefore, overall trends are for a general moderate snowfall over most, if not all of the area with 3 to 7 inches being the most likely range for totals by late Tuesday afternoon and evening. As mentioned above there could be a stripe of slightly higher totals, especially across Sullivan County where 5 to 9 inches is most likely. Some of the higher elevations of Pike, Wayne, eastern Delaware and Otsego counties could also see localized higher amounts in the 6-8 range. Putting it all together, it seemed most prudent to issue a winter weather advisory for the entire area (except winter storm warning in Sullivan county)...especially considering the likely impact in the morning commute. Through the event temperatures will start in the low to mid-20s and slowly rise into the upper 20s to mid-30s by Tuesday afternoon. There is a chance for a little rain to mix in with the snow in the Wyoming Valley and near the Delaware river in far eastern PA Tuesday afternoon. Otherwise, precipitation type should be all snow for the Twin Tiers, Catskills and the rest of Central NY. Top snowfall rates based in the latest HREF and CAMs suggests a few hours of around 1"/hr...with perhaps 1.5 to 2 inches per hour for a short time in Sullivan county early Tuesday afternoon.

East-southeast winds will be light through the event, under 10 mph. As the coastal low pulls away Tuesday afternoon and evening the wind will turn northwesterly and increase between 10-20 mph overnight. Colder air aloft moving in will also initiate some lake effect snow showers or flurries across the Finger Lakes region heading into the overnight period, with minor accumulations under a half inch anticipated. Colder with lows in the 10s to mid-20s areawide.

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/

The main story for this period will be an incoming arctic front with snow showers, squalls and cold wind chills Thursday and Thursday night.

Brief surface ridging builds into the area for Wednesday bringing dry, partly cloudy and seasonable weather conditions. The next potent cold front approaches from the northwest Wednesday night. This will increase snow shower chances, especially across north- central NY late at night. As the front continues to swing through the area on Thursday more snow showers and even a few snow squalls are likely. The snow squall parameter is starting to light up a bit, considering the steep low level lapse rates, modest instability and much colder low level air surging into the region. 850mb temperatures are forecast to plummet to near -20C by Thursday evening, with some lingering lake effect snow showers around. Initially it will be blustery Thursday afternoon and evening, with NW winds of 15-25 mph and gusts around 30 mph. These colder temperatures and winds will produce wind chills of 5 below to 10 above zero Thursday evening and overnight. Eventually the winds diminish as a cold center of high pressure builds overhead toward daybreak Friday. Overnight lows are forecast to drop down into the single digits, and even below zero across Oneida county and perhaps the other normally colder locations.

LONG TERM /FRIDAY THROUGH MONDAY/

Generally cold and dry weather expected on Friday now as our area remains between two weather systems; one to our north and another across the Southeast US. SLight chances to low end chances for snow showers return to the forecast Friday night and Saturday as some moisture tries to spread north and a low moves up off the East Coast. Overall, this is looking like a minor system for our area at this time, with trends being for less precipitation from this one. Overall, upper level troughing remains in place through the coming weekend with scattered snow showers and flurries around, mainly due to lake effect or weak disturbances moving through. Temperatures remain seasonably cold over the weekend. Turning colder with more scattered snow showers around for next Monday. Official forecast follows the NBM guidance at this time, due to uncertainty and minor differences in the deterministic guidance. With upper level ridging remaining in place along the West Coast and SW Canada, upper level troughs should continue to build southward into the Northeast US, keeping temperatures mainly below average with occasional snow chances through next week. Upper level ridging over Greenland will help to reinforce this colder than average, negative NAO pattern for our area in this timeframe.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

VFR conditions are expected to hold on for another 2 to 3 hours across the area before ceilings start to lower and the first widespread snowfall begins to move into the area. As previously mentioned, there remains some very dry air in place that the snow needs to initially overcome, but onset still looks to be on track between 08-10Z for most terminals, with AVP being slightly later closer to 11Z. After a short period of MVFR restrictions, IFR and lower conditions are expected, with the heaviest snow and lowest visibility expected between 12Z and 18Z. As the snow departs between 18Z and 22Z, IFR restrictions are expected to end, but MVFR/fuel alt ceilings remain through the rest of the TAF. There is a low chance of spotty lake effect snow showers or flurries toward the end of the TAF, but no IFR restrictions are expected.

Outlook...

Tuesday night and Wednesday...Mainly VFR; spotty lake effect snow showers are possible with brief restrictions.

Thursday...Occasional restrictions possible in scattered snow showers, especially at the Central NY terminals.

Friday...Mainly VFR.

Saturday...Occasional restrictions possible in scattered snow showers, especially at the Central NY terminals.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Winter Weather Advisory until 6 PM EST this evening for PAZ038>040-043-044-047-048-072. NY...Winter Weather Advisory until 6 PM EST this evening for NYZ009- 015>018-022>025-036-037-044>046-055>057. Winter Storm Warning from 5 AM early this morning to 6 PM EST this evening for NYZ062.