textproduct: Binghamton

WHAT HAS CHANGED

An Extreme Cold Warning has been issued for all of Central NY and Northeast PA, replacing the Extreme Cold Watch that was in effect.

KEY MESSAGES

1) A clipper system will bring widespread light snow today, especially this afternoon and evening.

2) An arctic airmass will move in early Saturday morning, which will bring frigid conditions to the area through the weekend.

3) Temperatures begin to trend warmer next week with near-normal temperatures expected by mid-week.

DISCUSSION

KEY MESSAGE 1...

A clipper system will drop into the Great Lakes Region this morning and quickly move southeastward through the day. This will bring a round of mainly light snow to the region this afternoon and evening. Snow accumulations will generally be in the 1-3 inch range, but there could be some isolated 4 inch amounts around the Finger Lakes Region as some lake moisture could enhance the snow totals in that area.

As the clipper system departs the area to the east on Saturday and 850mb temperatures fall to around -27C, lake effect snow showers are expected to develop in Central NY. Additional snow accumulations will likely be on the light side with most areas seeing an inch or less of additional snow.

KEY MESSAGE 2...

While this is the second key message listed (chronological order), this is by far the more impactful one. An arctic front will accompany the above mentioned clipper system, pushing into the area just after midnight. Temperatures will quickly fall from the upper teens to lower 20s around midnight tonight to near zero by dawn. Those temperatures will remain around or just above zero through the entire day on Saturday. Then lows between -15 degrees and 0 degrees are expected Saturday night/Sunday morning. Sunday's highs will be a few degrees "warmer," but still only in the single digits to lower teens.

The above mentioned temperatures itself are frigid enough, but gusty winds will result in wind chills that will be dangerously cold (-25 to -30 degrees). Confidence continues to grow in having the large majority of the area in that wind chill range and as a result, all Extreme Cold Watches have been converted to Extreme Cold Warnings and will be in effect from 4AM Saturday (7AM Saturday for the Poconos-Catskills) to 1PM Sunday.

In addition, winds on Saturday will occasionally gust between 30-40 mph, with some gusts locally up to 45 mph (especially the hilltops/higher elevations of Northeast PA). Winds will be near Wind Advisory criteria for those areas, so this potential will have to be monitored with upcoming forecast updates. For now, confidence in seeing Wind Advisory criteria is on the lower side, so we held off with this forecast package. Either way, the winds combined with a fresh coating of fluffy snow on the ground will also result in areas of blowing snow, which may cause significantly reduced visibilities at times.

KEY MESSAGE 3...

Uncertainty remains as to how the overall pattern will play out next week. There have been signals for a slight warmup by mid week, but guidance is mixed in how the pattern evolves, specifically how amplified an approaching ridge gets. Either way, even if the ridge ends up less amplified, temperatures would be much warmer than what we have been experiencing, which will be a welcome change. Whether "warmer" means temperatures around the freezing mark, or several degrees above freezing remains to be seen this far out.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

VFR conditions are expected until at least 15Z. Then ceilings and visibilities will begin to fall into MVFR as snow showers move into the region as early as 16Z at KELM and KAVP. Snow showers will spread eastward throughout the day with visibilities dropping to IFR and LIFR. Timing of restrictions is uncertain as snow showers may initially be scattered and lead to restrictions bouncing before settling in. Some gradual improvement is possible late in the period (after 06Z Saturday), but blowing snow may keep IFR visbys around.

South to southwesterly winds will be calm for the majority of this TAF period. An arctic front approaches the region around 03z Saturday and as it moves into the region, winds will become more west to northwesterly and stronger (gusting up to 30kts late tonight/early Saturday morning).

Outlook...

Saturday through Sunday morning...Strong winds and blowing snow possible at all terminals. Occasional ceiling restrictions and lake effect snow at Central NY terminals.

Sunday night through Tuesday...Mainly VFR.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Extreme Cold Warning from 4 AM Saturday to 1 PM EST Sunday for PAZ038-039-043-044-047. Extreme Cold Warning from 7 AM Saturday to 1 PM EST Sunday for PAZ040-048-072. NY...Extreme Cold Warning from 4 AM Saturday to 1 PM EST Sunday for NYZ009-015>018-022>025-036-037-044-045-055-056. Extreme Cold Warning from 7 AM Saturday to 1 PM EST Sunday for NYZ046-057-062.