textproduct: Binghamton

WHAT HAS CHANGED

Cold weather advisories have been allowed to expire, flurries were added through the rest of the afternoon for CNY.

KEY MESSAGES

1) The cold and dry pattern continues through Friday.

2) A Clipper system will bring a chance for snow showers and possible squalls on Friday into Friday night. Following the Clipper, a strong arctic front will move in over the weekend, resulting in very cold temperatures and gusty winds.

DISCUSSION

KEY MESSAGE 1...

The pattern this week does not change much, with a strong ridge out over the Western US and a long wave trough persisting in the Eastern US. The long wave trough axis is just off the east coast so that puts us predominantly under NW flow. Shortwaves rotating around the back side of the trough will continue to bring cold air into our region. 850 mb temperatures do not look to rise above -10C and stay closer to -15C through this week keeping temperatures below to well below average for this time of the year. Snow chances remain low through Friday morning as there is not much moisture for any of the shortwaves to acquire as they move into the Northeast. With the Great Lakes total ice cover over 50%, and with Lake Erie >95% as well as Lake Huron nearing 75%, lake effect snow is going to be limited. The NY thruway and north will still likely see some lake effect snow as Ontario is still mostly open water but the lack of upstream open waters in other lakes keeps most accumulating snow closer to the coast rather than extending inland.

KEY MESSAGE 2...

A potent 500 mb shortwave drops into the Great Lakes region Friday into Friday night, with cold arctic air mass moving in behind it. Chances of snow are higher with this shortwave due to better lift but overall there is still not going to be much moisture in place to get much widespread accumulating snow. Forecast soundings do look better for snow squalls with steepening low level lapse rates ahead of a strong surface front. Winds also look to become gusty behind the front with 850 mb winds up near 50 knots Friday night through Saturday. Using NBM to look at the probability of temperatures below 0 and winds over 20 mph (near extreme cold warning criteria of apparent temperatures <-25F), there were areas in the Finger Lakes, Tug Hill, and into the Catskills where the probabilities were near 25%. Trends in the deterministic models this morning have been towards the coldest core of the arctic air mass to move into New England rather than through the Great Lakes so we may miss out on getting those -25F or colder wind chills. This will continue to have to be monitored as if the cold air trends back south, the ice on the Great Lakes would prevent most of the usual temperature moderation we see from these cold air masses so it will be easier to achieve very cold temperatures for this area.

AVIATION /18Z MONDAY THROUGH SATURDAY/

Clouds and very light snow showers off of Lake Ontario will keep MVFR/Fuel Alt conditions for a few NY terminals. These should shut off going into the late afternoon/early evening (21-23Z), and conditions improve to VFR for the majority of terminals after 00Z.

Outlook...

Tuesday: Stratus clouds redevelop and expand, with widespread MVFR CIGs likely areawide.

Tuesday Night Into Wednesday Morning: Lingering MVFR stratus clouds around the region. A few snow showers possible across Central NY.

Wednesday Afternoon: Period of VFR possible at ELM, BGM and AVP...better chance for BKN MVFR CIGs to remain at ITH, SYR and RME in the cold NW flow.

Wednesday Night and Thursday..Mainly VFR; low chance (25% or less) for snow showers and restrictions at times due to occasional lake effect snow showers at SYR and RME.

Friday...Restrictions likely with a system bringing periods of snow, transitioning to snow showers and blowing snow Friday night. Squalls possible.

Saturday...Restrictions possible at SYR and RME with possible development of lake effect snow showers

BGM WATCHES/WARNINGS/ADVISORIES

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