textproduct: Binghamton

WHAT HAS CHANGED

Updated Onondaga and Madison County in NY to Lake Effect Snow Warning due to stronger banding and reports approaching 7 inches.

KEY MESSAGES

1) Lake effect snow showers continue over Central NY today and into Thursday.

2) A shortwave brings some additional snow showers Friday night into Saturday. Continuing to monitor another system Sunday into Monday.

DISCUSSION

KEY MESSAGE 1... Quick update to Lake Effect Snow Warning for Onondaga and Madison County has lake effect snow banding intensified and snow reports rapidly approaching 7 inches. Expecting locally up to 10 inches, especially southern hills on Onondaga and Madison Counties.

Lake effect snow continues downwind of Lake Ontario this evening. This really is a lake enhanced event with synoptic moisture that is wrapping all the way around an upper level low over norther Maine. The synoptic moisture combined with cold air low- level air (-12C or so at 850 mb) moving across Lake Ontario and riding upslope into the highlands of central NY continues to cause fairly widespread light to occasionally moderate snowfall. Decided to add Chenango and Otsego into the winter weather advisory as per radar signatures and the flow pattern. The snow is enhancing in the higher terrain as expected. Colder and drier air is expected to work south later tonight and shut down the snows east of I-81 as per some of the CAM models but the persistent northwest low-level flow across Lake Ontario looks to prolong the lake effect snow east of I-81 and north of BGM. We may have to continue the advisory longer or up amounts and potentially go to a lake effect snow warning in these areas. We will be looking into this as new guidance comes in. In the mean time, a widespread 3 to 7 inches snowfall expected mainly north and east of a BGM to ITH line.

Previous Discussion below... Lake effect snow showers will continue across Central NY, with the most numerous snow showers downstream of Lake Ontario this afternoon. These snow showers will be aided by a weak mid- level disturbance and some instability, which could help produce a gusty snow shower or a few smaller snow squalls for northern Central NY this evening. As flow becomes more prominently northwest tonight, lake effect snow showers will likely develop off of the Finger Lakes, as well as Lake Ontario, continuing snowfall for areas south and east of the Finger Lakes. Some of these showers could possibly extend into portions of the Southern Tier as well. These showers are expected to last until at least Thursday early afternoon, and the Winter Weather Advisories for Onondaga- Southern Cayuga- Tompkins- Cortland have been extended in time to 1pm Thursday to account for these showers off of the Finger Lakes and Lake Ontario. Snow showers should diminish going into Thursday late afternoon with high pressure beginning to build in.

KEY MESSAGE 2...

Model guidance is starting to key in another shortwave moving through Friday night into Saturday with another round of snow showers and some light accumulations. This feature has trended stronger so we will continue to monitor.

Looking into the late weekend, another system looks to track through the Southern United States Sunday into Monday. The latest run of the ECWMF is the latest update that has our area under any impact, which would bring some mixed rain/snow into the area. Even though very few scenarios exist with impacts from this system, we've maintained some rain and snow showers in the forecast.

Confidence is increasing temperatures will get into the 40s for highs early next week. This would suggest a slower instead of sudden thaw process which would be helpful in terms of lowering the risk of any potential ice jams.

AVIATION /01Z THURSDAY THROUGH MONDAY/

Snow showers in the area continue to bring mainly a mix of MVFR to IFR conditions across most of the CNY terminals this evening. Drier air is expected to push in as winds become a bit more northerly tonight, but soundings suggest that northwest winds and moisture off of Lake Ontario may keep snow showers around longer than what the high resolution guidance shows, especially around RME and SYR, so confidence is on the lower side in the near term for the northern terminals. However, snow showers are expected to remain around ITH and BGM much of the night through tomorrow morning with a mix of MVFR and IFR restrictions. ELM is another tricky terminal with lower confidence in the near term as they will be close to the edge of the ceiling and visby restrictions and can see snow showers occasionally push in this evening.

As snow showers diminish tomorrow afternoon, some ceiling restrictions are expected to linger around CNY before starting to see some improvement late in the period.

While AVP is not expected to see snow showers, high end MVFR ceilings are expected to dip down over the terminal for a time overnight.

Outlook...

Friday and Saturday... High pressure returns with VFR conditions expected at this time.

Sunday...Restrictions possible with the potential for a system to move into the area.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...Winter Weather Advisory until 8 AM EST Thursday for NYZ009-037- 045-046. Winter Weather Advisory until 1 PM EST Thursday for NYZ017-025- 044. Lake Effect Snow Warning until 1 PM EST Thursday for NYZ018- 036.