Marine Weather and Tide Forecast for Liverpool, NY

KEY MESSAGES
1) A strengthening low passes north of the region Friday into Saturday bringing rain, wind, as well as a strong cold front.

2) High pressure and southwest flow will lead to a gradual warm up through next week after a chilly weekend.

DISCUSSION
KEY MESSAGE 1

A trough digging into the front range of the Rockies today will help two shortwaves phase. A strong early season low pressure system forms and moves into the Great Lakes region Thursday night into Friday. A warm front lifts into the northeast Thursday night with rain overspreading the area. There is still some uncertainty if the warm front can lift all the way through our region into northern NY putting us completely in the warm sector or if the front may stall near the I-90 corridor. If we are in the warm sector, strong warm air advection drives 850 mb temperatures to around 15C so areas that see breaks of sun may warm into the mid 70s. Full sun may drive temperatures into the upper 70s but given the moisture in place in forecast soundings, odds are there will be plenty of clouds. Showers and drizzle may be persistent as well in the warm sector.

Given the cloud cover and fairly stable warm sector, severe thunderstorms are not anticipated as the cap will be tough to break. Shear is in place, with 0-6 km shear around 50 knots. The main trigger for any storms will be the frontal passage in the afternoon so there is a chance that a few thunderstorms along the cold front could become severe with strong wind gusts being the main concern. NEPA would have the best chance at getting breaks of sun and some better instability. SPC has a marginal risk just to the south and it could be expanded northward though todays model trends have been to a slightly weaker low.

Post frontal, the 850 mb temperatures drop nearly 25C from around 15C above to -7C to -9C. Lake effect rain showers quickly develop for much of the Southern Tier and Northward. It does look like towards Sunrise Saturday, as the 850 mb temperatures near their lowest readings, that some wet snow will mix in with the lake effect rain at elevations above 800 feet or so. With the lake effect winding down by then as subsidence takes over with high pressure building in, no accumulation is expected.
Saturday will be windy under the strong cold air advection, with winds bumped up over the NBM. BUFKIT soundings hint that gusts could approach 40 mph though that will likely be in the higher terrain though gusts over 30 are likely region wide.

KEY MESSAGE 2

Saturday night into Sunday is looking cold as surface high pressure builds in. Depending if we can completely clear from some lake effect clouds, we could radiate out well into the 20s for much of the area. Even so, it is likely we see the first widespread killing freeze. Sunday and beyond, upper level ridging builds back in and 500 mb heights rise back above 580 dm. offshore flow and slow moisture return will also keep us dry through most of next week.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/
MVFR to VFR conditions expected this afternoon as areas of thicker low level stratus move through. the Southern Tier has managed to break up but the MVFR cigs likely fill back in after sunset. A cold front passage will bring some MVFR to near IFR cigs overnight with an increase in winds as well. Tomorrow, high pressure and dry air leads to cigs scattering out and winds becoming light and variable.

Outlook...

Thursday... Increasing clouds, mainly VFR.

Thursday night Friday...Low pressure system passing by, increasing winds and rain will lead to restrictions.

Saturday...Lake effect cloud cover keeps cig restrictions likely for all terminals but AVP. Early morning snow showers possible at ITH and BGM.

Sunday into Monday...High pressure returns with mostly VFR conditions expected.

BGM WATCHES/WARNINGS/ADVISORIES
PA...None.
NY...None.