textproduct: Binghamton

WHAT HAS CHANGED

Minor adjustments to the ongoing winter storm based on the latest model guidance and observations. Increased chances for lake effect snow off of Lake Ontario Monday night into Tuesday morning and again Tuesday night into Wednesday. Temperatures and wind chill trending colder most nights and morning, with the coldest readings likely to be Thursday night into Friday morning.

KEY MESSAGES

1) High impact winter storm in progress, tapers off to snow showers and blowing snow by Monday.

2) Lingering lake effect snow showers, windy and very cold Monday night. Weak clipper systems and additional chances for lake effect snow showers through much of next week. Temperatures remain well below average right into next weekend, with only a slight moderating trend possible toward Sunday. Wind Chills will be between 0 below and 20 below zero each night and morning, with the coldest readings likely to be Thursday night into Friday morning.

DISCUSSION

KEY MESSAGE 1...

Snow continues to move northward through the region this afternoon as low pressure develops in the Delmarva region by evening. Somewhat warmer and moister air will continued to be advected into the region through the early evening. FEGN forcing from 600-800 mb continues to support the potential for snowfall rates from banding around 2 inches per hour for most of CNY and NEPA from early this afternoon into the early evening hours. This signal is still showing up on most of the hires model guidance. Lighter snow showers should last through the overnight and Monday. Overall, timing continues to trend slightly faster. modeled soundings and observations seem to indicate ratios of 15-20:1 too. These still may lower some in the Wyoming Valley as warmer air aloft moves in. A changeover to sleet is looking to be less of a potential now though. Overall, totals have come up a bit for NEPA (10-15in) and are about the same in CNY (15-20in). Temperatures look to remain in the single digits today, perhaps rising into the teens tonight. With a little bit of wind, single digit to below zero wind chills are possible as well.

Cold weather continues Monday with temperatures still mainly in the teens for highs, maybe a few low 20's. Our main concern will be from blowing snow as winds increase during the afternoon hours. Some additional snow showers should occur as well. With a west to northwest flow some lake response is likely to occur off of Lake Ontario bringing a higher coverage of snow showers toward the NY Thruway corridor. Ratios should continue to high, so another inch or two of fluff is quite possible by Monday night.

KEY MESSAGE 2...

As the upper trough mentioned above departs to the east and weak ridging builds in aloft, winds become more west then southwesterly early Tuesday morning which will lift the lake effect snow to the north of the I-90 corridor toward daybreak. Wind gusts of 20-30 mph are still likely Monday night, with areas of blowing snow expected, especially before 4 AM EST. Lows Monday night will be in the single digits to a few degrees below zero. Wind chills be very cold Monday night into Tuesday morning, between 0 to 15 below for most locations. Cold Weather Advisories may be needed if confidence increases in these very cold wind chill values.

A weakening clipper approaching from the north and west Tuesday can lead to some scattered light snow showers across the area, especially over CNY. This system will bring with it a reinforcing shot of cold air and as the upper level shortwave with this disturbance swings through, west to northwesterly winds are expected to lead to lake effect snow showers dropping back south into CNY Tuesday night into Wednesday morning. This lake effect snow band could be rather well organized along or just north of I-90 for a time overnight into Wednesday morning, with several inches of snow possible here.

Highs Tuesday range from the upper single digits to mid-teens. Lows Tuesday night range from about 5 degrees above to 5 degrees below zero around the area.

The next deeper 500mb trough drops into the region Wednesday night and Thursday, along with a potential clipper system. This will keep chances for snow showers in the forecast, especially across CNY. At this time, model guidance keeps a rather stagnant pattern over the area right into next weekend, with the a 500mb trough in place across the Great Lakes and Northeast brining occasional clipper systems and lake effect snow showers off of Lake Ontario. With the NBM being underdone with this lake effect setup, the Canadian was blended into the forecast through the end of the week to increase PoPs, QPF and snow amounts in the favored locations. Temperatures remain steady, with lows 5 below to 5 above zero, and highs in the upper single digits to teens through at least Friday. Temperatures moderate some, closer to, but still below average by next weekend. Highs will be in the upper 10s to 20s by Sunday under partly sunny skies.

AVIATION /06Z MONDAY THROUGH FRIDAY/

Most of the snow has moved east of the area with conditions improving to widespread MVFR and even some VFR. Additional light snow develops over the next few hours mainly affecting CNY terminals with some IFR vis and potentially cigs as well. It also looks a bit drier in lower elevations so increased cigs later tonight and into tomorrow morning.

Lake effect snow develops late morning and persist into the evening, with SYR and RME likely seeing IFR or worse vis as the snow bands move through. There is uncertainty if the bands make it to ITH and BGM so did not lower restrictions much but there is potential for MVFR to IFR cigs and vis if the bands can make it far enough inland.

Outlook...

Monday night...Lingering snow showers and/or lake effect possible at SYR and RME with associated restrictions. Blowing snow may be present with NW winds gusting 15-25 kt at times.

Tuesday thru Friday...Isolated snow showers with associated restrictions, otherwise mainly VFR.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Winter Storm Warning until 7 PM EST this evening for PAZ038>040. Winter Storm Warning until 1 PM EST this afternoon for PAZ043- 044-047-048-072. NY...Winter Storm Warning until 7 PM EST this evening for NYZ009- 015>018-022>025-036-037-044>046-055>057-062.