textproduct: Binghamton

WHAT HAS CHANGED

Increased PoPs, QPF and snow amounts down wind of the Finger Lakes into the Twin Tiers as multi-bands of lake effect snow continue tonight. Snow amounts will still be light, but could see localized 2-3 inches through the overnight hours SSE of the Finger Lakes.

KEY MESSAGES

1) Light lake effect snow across the Finger Lakes expected thru the morning hours.

2) Cold clipper system with accumulating snow moves through the Northeast late Tuesday night through the day Wednesday.

3) Another potential winter system is possible late Thursday into Friday, but trends are pushing it south.

4) Widely varying temperatures this weekend with warm conditions Saturday, followed by a cold blast Sunday.

DISCUSSION

KEY MESSAGE 1...

Lake effect snow continues across CNY into NEPA tonight. 850mb temperatures around -16C are moving across unfrozen Great Lake waters with temps around 0-4C. NW flow through the boundary layer with a connection to the Georgian Bay has produced steadier, more widespread snow than guidance suggested earlier today. Soundings show saturation through the DGZ tonight into the morning hours for much of the area. PoPs, QPF and Snow fall amounts had to be manually adjusted based on radar trends and observations as most guidance was too low on QPF amounts and ended the snow chances before midnight. 1-3 inches will be possible into the morning hours, with the highest amounts SE of the Finger Lakes from S Cayuga into Broome county. Winds will slowly shift westerly as the morning progresses, pushing the snow showers to the NE. Snow should end by the early afternoon as weak ridging builds in and the boundary layer winds become unfavorable for lake effect development.

Winds will remain active tonight, with gusts up to 35mph possible in the more moderate snow showers. With the light and fluffy nature of the snow, blowing snow will be easily achieved, causing reduced visibilities and snow covered roads across areas where this is usually an issue. Winds are expected to decrease by the early afternoon hours.

KEY MESSAGE 2...

A trough will dig into the Great Lakes region Tuesday night with an associated surface low developing over the northern Great Lakes and tracking to the east, north of the CWA. This puts us in the "warm sector" of the low with a warm front that will push through the area Tuesday night, kicking off snow showers across the region. Temps will start in the low to mid teens, climbing to the mid 20s by daybreak. The warm front will provide the lift to kick off snow showers, but it is expected to push through pretty quickly, with much of this frontal driven snow ended by day break. 1-3 inches of snow is currently forecast to fall across the area, with higher amounts along upslope areas along and east of I-81.

Temperatures will continue to climb through the day, reaching the mid to upper 30s for most, with some low 40s in the valleys of the Southern Tier and NEPA. This warmup will set the stage for some convectively driven snow showers to develop in the afternoon ahead of a cold front that will push through the area in the late afternoon to early evening hours. Soundings show sufficient CAPE, especially in the DGZ, to get some moderate to heavy convective showers to develop across the area. Synoptic winds luckily look to be light, but they could be gusty within the heavier showers. Given the warm temps at the surface and late Feb sun angle, accumulations for most areas will be very light and more than likely stick to elevated surface vs roadways. Northern Oneida county will have the best chance for snow to stick as temps will be hovering around freezing in the afternoon. These showers should dissipate after sundown. Up to an inch of snow could fall over N Oneida county, with higher elevations south of the Mohawk Valley seeing a few tenths of an inch.

Behind the cold front, lake effect snow showers are expected to develop Wed night into Thursday morning across the Mohawk Valley and north into the Tug Hill region as westerly winds will prevail. An additional inch of snow will be possible across this area.

Having said all of this, N Oneida county looks to see mostly persistent snow showers from Tues night into Thursday morning with 3-5 inches of snow expected to fall during this period. Because of this, a Winter Weather Advisory has been issued from 1am Wed to 7am Thurs.

KEY MESSAGE 3...

All of the major models are advertising another low pressure system tracking into the east coast Thursday into Friday. Deterministic model trends have pushed the low south of our area as the trough driving it has dug a little farther south but is not getting very amplified which is allowing the low to move eastward and not get any kick to push it to the NNE. Ensemble guidance is a little more uncertain with the GFS suite keeping snow chances across our area while the Euro suite advertises the low staying to the south. Because of the uncertainty in the development of this system, NBM guidance was used and not altered much. This produces light snow across the area with amounts in the 1-3 inch range for this time period.

KEY MESSAGE 4...

This weekend could see a drastic temperature swing.

Rising heights on Saturday with SW flow advecting warm air from the southern US will push the warmest air of 2026 into the region, with most of the CWA seeing temperatures in the mid to upper 40s and valleys pushing 50 degrees. Ensemble guidance is advertising these warm temps as well.

Unfortunately, this brief glimpse of spring will not last long as a strong cold front will push into the area overnight, dropping overnight temps into the low to mid 20s. Temps on Sunday are not expected to recover much as NW flow will persist in pushing the cold airmass into the region. Highs top out in the mid to upper 20s for CNY with some low 30s in NEPA. Sunday night into Monday will see a return of single digit lows across much of the area, with N Oneida possibly falling below 0.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

Lake effect snow showers off of Lake Ontario and the Finger Lakes are expected to maintain a pretty wide coverage across the area through about 12-13Z bringing primarily MVFR/fuel-alt restrictions to most of the terminals. Some of the steadier and heavier narrow bands off the Finger Lakes can lead to IFR or worse restrictions for both ITH and BGM over the next several hours.

The lake effect activity is expected to retreat to the north and east and diminish during the early afternoon, generally between 17-19Z as winds become more westerly and the flow eventually turns southwesterly by the evening as high pressure builds in briefly. As the west to southwesterly flow develops, ceiling restrictions are expected to retreat and give way to VFR conditions and lighter winds. PROB30 groups were added to ELM and ITH at the end of the TAF as snow is expected to approach with the next quick-moving clipper.

Outlook...

Late Tuesday night through Wednesday: Restrictions likely with a period of widepsread light to moderate snow overnight, becoming mixed snow and rain showers Wednesday. Confidence moderate to high. Scattered snow showers and possible restrictions linger into Wednesday evening.

Late Wednesday Night - Thursday morning...Mainly VFR; there can be some scattered lake effect snow showers around SYR/RME. Confidence moderate.

Thursday afternoon and night...Restrictions possible with another round of snow and/or rain-snow mix. Confidence low at this time.

Friday and Saturday...Mainly VFR. Confidence moderate to high.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...Winter Weather Advisory from 1 AM Wednesday to 7 AM EST Thursday for NYZ009.