textproduct: Binghamton

WHAT HAS CHANGED

No significant changes to the forecast at this time. Forecast remains on track, with a Winter Storm Warning for Northern Oneida County, and Wind Advisories areawide.

KEY MESSAGES

1) A potent clipper system moves through today, bringing a chance of mixed rain and snow, along with gusty southerly winds. There will be a potential evening snow squalls ahead of the cold front. Accumulating snow will mainly affect higher elevations, with the Southern Tug Hill having the best chances to see larger accumulations.

2) A very strong low pressure system will move into the region early next week, bringing another large swing in temperatures, strong winds, and potential severe thunderstorms.

3) Well below average temperatures mid next week behind the departing early week low pressure system.

DISCUSSION

KEY MESSAGE 1...

The potent clipper system is currently centered over Michigan and has pushed an initial wave of snow into the area ahead of a warm front moving into western PA and NY. This initial snow will serve to saturate the atmosphere ahead of the next wave of precipitation that will move in later this afternoon. Temps will rise above freezing for valley areas with a rain/snow mix expected. Higher elevations should remain mostly snow. Southerly winds this afternoon and evening will be strong, with gusts of 20-30kts expected across the area. The Finger Lakes and western Twin Tiers will see the strongest winds with gusts up to 40kts possible. Because of this, a Wind Advisory is in effect until Sat afternoon.

With the warm front moving in late this afternoon, temps will warm a little bit. It will not be much, but it will inject some weak CAPE across the area that will provide enough energy to kick off convective snow showers. Some of these showers could have some snow squall characteristics with gusty winds and low visibility. These showers should move in from the west around 6-7pm and exit to the east by midnight. Behind these showers, a cold front will push through, switching winds from southerly to westerly as cold air spills in. Gusts up to 45kts will be possible spreading from east to west late tonight into Saturday afternoon. A Wind Advisory was issued to cover the rest of the CWA from late tonight into Saturday afternoon.

As the center of the clipper moves to the NE, north of the CWA and drags the cold front through, lake effect snow will develop, impacting most of CNY. 2-5 inches is possible in the higher elevations south of the Mohawk Valley thanks to the convective snow showers this evening and upslope lake effect snow tonight into Saturday. The main snowfall impacts will be across N Oneida county where 6-12 inches of snow is expected from this afternoon into Saturday afternoon thanks to upslope enhanced snowfall this afternoon and evening, followed by lake effect snow into Saturday afternoon. Because of the increased confidence in the higher snowfall totals across N Oneida county, the Winter Weather Advisory was upgraded to a Winter Storm Warning.

The rest of the CWA should see a dusting to a few inches of snow.

High pressure will build into the area late Saturday afternoon, ending the lake effect snow.

KEY MESSAGE 2...

A very strong low pressure system will develop in the central US Sunday, bringing blizzard conditions from South Dakota to Michigan. A warm front will surge into the Northeast Sunday into Monday, with strong southerly flow pushing temps into the 60s. The low is currently progged to deepen to near 980mb as it moves into the Great Lakes, which is about 35mb deeper than average for this time of year. A strong low level jet will form in the warm sector of the low over NY and PA. A slight stable layer is currently keeping the strongest winds from mixing down to the surface, but a slight warmup in the boundary layer from the current guidance would bring strong, gust winds to the area. This could be especially prevalent in the Finger Lakes where downsloping from the Southern Tier could push wind gusts into the 40-50mph range Sunday afternoon into Monday.

With the warm temperatures and a strong cold front moving through the area Monday afternoon, there is a chance for a line of strong showers to potentially a few isolated severe thunderstorms to develop. Shear will be very high ahead of the front, likely 60 to 80 knots of 0-6 km shear, though overall CAPE will be low, likely less than 100 j/kg. Strong convergence along the front and strong pressure rises behind the cold front should overcome the lack of instability and allow for some strong winds to mix to the surface with the line of showers/storms along the cold front. Much of the QPF is currently behind the front, so anafrontal snow is expected to develop, with several inches possible.

KEY MESSAGE 3...

An anomalously cold air mass moves in behind the strong low pressure system. 850 mb temperatures between -15C to -20C are expected Tuesday and Wednesday over Lake Ontario. This would kick off late season lake effect snow showers through most of the region. With the increasing strength of solar radiation as we continue to progress through spring, diurnally driven convective snow showers should develop in the afternoons of Tuesday and Wednesday. Highs Tuesday will remain in the low 20s to low 30s, with a slight warm up Wednesday into the upper 20s to mid 30s. Tuesday night could be one of the last, if not last blast of cold air across the region this season. Temps will fall into the low to mid teens, with single digits in Northern Oneida county.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

The heaviest of the snow is through the region early this morning but lake effect snow showers will persist for much of the morning at CNY terminals. A batch of snow showers is headed towards AVP and should move through between 6Z and 8Z so a tempo was added but otherwise AVP is expected to be VFR and windy. Snow showers persist longer at BGM, ITH, and ELM but diminish in coverage after sunrise around 12Z. Lake effect snow last the longest at SYR and RME as is typical, and there is the best chance at IFR or worse with the snow from around 9Z to about 16Z and taper off thereafter. Winds remain strong out of the west and northwest from about 9Z through sunset around 0Z before winds diminish quickly.

Outlook:

Saturday Night and Sunday...Mainly VFR expected.

Sunday Night through Monday...Restrictions expected in rain, thunderstorms possible Monday afternoon.

Monday Night through Tuesday...Scattered snow showers with occasional restrictions possible, especially at the Central NY terminals.

Wednesday...Mainly VFR.

BGM WATCHES/WARNINGS/ADVISORIES

PA...Wind Advisory until 2 PM EDT this afternoon for PAZ038-043. Wind Advisory from 5 AM early this morning to 2 PM EDT this afternoon for PAZ039-040-044-047-048-072. NY...Winter Storm Warning until 2 PM EDT this afternoon for NYZ009. Wind Advisory until 2 PM EDT this afternoon for NYZ015>017- 022>025. Wind Advisory from 5 AM early this morning to 2 PM EDT this afternoon for NYZ018-036-037-044>046-055>057-062.