textproduct: Binghamton

WHAT HAS CHANGED

reduced inland extent of the chances of precipitation later this afternoon into the early evening.

KEY MESSAGES

1) Lake effect snow winding down today with light snow moving in with a clipper system tonight into Sunday morning.

2) Several clipper systems to start the week; one on Monday into Monday night and another Tuesday night into Wednesday.

3) Gradual warm up through the week with well above average temperatures expected by the end of the week.

DISCUSSION

KEY MESSAGE 1...

Cold westerly flow continues across Lake Ontario with a lake effect band persisting for western Oneida county early this morning. Forecast soundings and mean 925 to 850 mb flow shows that this band will persist but as the mean winds in the low levels weaken to 10 to 20 knots, the inland extent will lessen through the day. Still snow rates on the NYSM site Camden is over an inch per hour at times. The lake effect band becomes much less organized through the day with the lack of vertical shear but it is likely that there will be some lake effect snow continuing for portions of Oneida into northern Onondaga for most of the day. Snow rates with the disorganization will be much lighter so little to no additional snow accumulation is expected after 7 am.

Light snow redevelops tonight as a 500 mb shortwave swings through. This is looking similar to last night where most of the area saw a trace to a half inch of snow. There is very little moisture for this shortwave to work with. It does look like the lake effect regions may perform a bit better with some moisture off of the lake helping enhance snowfall tonight into tomorrow morning. Lake effect snow likely redevelops Sunday morning but boundary layer flow is Northwest to almost northerly so that will favor the southern shoreline of Lake Ontario with not much inland extent without much fetch.

KEY MESSAGE 2...

As a ridge slowly builds in through the week, we remain under NW flow with a few fast moving clippers, each a little warmer than the last. The first shortwave Monday still has plenty of cold air in place for all snow and there is better moisture return ahead of it. Given that it is a clipper, most of the precipitation will fall on the front of the wave with the warm air advection. Trends have been moving the warm front ahead of the weak low farther north so the better chances of accumulating snow will be north of the NY/PA border. The second system can't quite be classified as a clipper as it develops in the lee of the Rockies Monday night and becomes a weak closed low in the Great Lakes region. With the low west of the region, a stronger warm front lifts in late Tuesday into Tuesday night. Depending on timing, there could be a freezing rain threat if the precipitation with the warm front does not move in until later Tuesday night into Wednesday morning. An earlier arrival late Tuesday may help keep temperatures above freezing at the surface while the later arrival will allow for some radiational cooling ahead of the clouds and a shallow inversion to form.

KEY MESSAGE 3...

As the long wave trough departs to the east and a western trough slowly takes hold through the week, the 500 mb heights rise gradually from around 530 dm today to 570 dm Friday. With the NW flow under the departing trough and building ridge, cool low level flow keeps temperatures cooler through mid week. By lake week, temperatures begin to rise to 10 to 20 degrees above average. There is a good probability that even overnight lows late week may remain above freezing. With the warm up being gradual and there is not too much wind or any significant rain expected, snow melt should remain slow keeping streams and tributaries high but likely remaining in their banks.

AVIATION /07Z SATURDAY THROUGH WEDNESDAY/

Lake effect snow showers will continue through the night, with RME being the only terminal that should see restrictions. IFR with tempo LIFR visby should occur through the night. IFR should ease by midday as the snow band finally weakens, with MVFR ceilings remaining.

A weak clipper system will quickly transit the area this evening and overnight, bringing snow and associated restrictions. Currently, BGM/SYR/RME were showing strong enough signals for IFR conditions to include them at these terminals in this TAF set. ITH/ELM/AVP could also see IFR conditions from the snow, but the signal was weaker so MVFR conditions were introduced in this TAF set.

Outlook...

Saturday Night into Sunday...Another potential clipper can bring additional snow showers overnight with lake effect snow showers during the day on Sunday. Restrictions likely.

Monday...Another clipper system may bring snow showers and associated restrictions.

Tuesday through Wednesday...A low chance of rain/snow showers and possible restrictions.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...Lake Effect Snow Warning until 7 AM EST this morning for NYZ009-018-036-037.