Marine Weather and Tide Forecast for Mexico, NY

NEAR TERM /THROUGH SUNDAY/
Regional radar shows weak reflectivity across most of western and north central NY this evening. Light snow will continue to move from the Genesee Valley to the North Country, while drier air moves into far western NY this evening. Gusty, southwest winds will become stronger through the night hours. Wind gusts of 40-50mph will be possible along the Lake Erie shoreline to the Niagara Frontier tonight.

A surface low will pass by just north of the Great Lakes late today through early Sunday, with an associated warm frontal boundary moving east across the eastern Great Lakes tonight. A wing of warm advection and isentropic upglide in advance of the warm front will produce a shield of snow across Western NY this afternoon and evening. Accumulations will be minor in the west, with a coating to an inch in most areas.

The warm frontal snow east of Lake Ontario will last longer and will be a little heavier, with comparatively deeper moisture and stronger isentropic ascent. Expect another 3-6" east of Lake Ontario from late this afternoon through early Sunday, with the greatest amounts across the Tug Hill Plateau, and lowest amounts across low elevations.

It will become quite windy late this afternoon and tonight, especially across far Western NY. A 55+ knot low level jet will move into the eastern Great Lakes overnight. The warm advection pattern will keep low level lapse rates weak, but nonetheless, there may be enough mixing close to Lake Erie to support surface wind gusts in the 45-50 mph range from the Chautauqua County shoreline northward across the Niagara Frontier. The same low level jet will cross areas farther east, but even less favorable thermal profiles in the boundary layer will likely prevent stronger gusts from mixing down.
Expect gusts of 25-35 mph for the rest of the area. The low level jet will exit Sunday, and winds will quickly diminish as the eastern Great Lakes becomes situated in a col between systems by late afternoon.

Sunday, there may still be some light snow east of Lake Ontario early, but this will exit by late morning. If the precipitation lasts long enough into the day, it may mix with a little rain as temperatures warm. Otherwise, the rest of the day will be mainly dry with plenty of clouds lingering. It will turn notably warmer, with highs in the lower 40s on the lake plains and mid to upper 30s for higher terrain.

SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/
Any remaining lake induced precipitation will end Sunday night as warm advection processes take over across the region. Lows Sunday night will be found in the 20s to low 30s.

Winter will hit the pause button Monday as a warmer air mass advects into the region. It will also bring with it some rain which will help to begin to melt some of the snow pack on the ground.

A compact mid-level wave tracking through the Ohio Valley Monday will bring the first wave of precipitation through the area. Given continuing strong deep layer warm advection ahead of the approaching attendant surface low, this event should be all be in the form of rain for most locales. There may be enough colder air at the onset to allow for some wet snow flakes east of Lake Ontario. This should be short-lived for lower elevations, but may remain mixed with wet snow on the top of the Tug Hill region
Overall
rainfall amounts with this first wave will range from a 0.25 to 0.50 of an inch over area basins. Given that these amounts are manageable, no hydro issues will likely occur but it will serve to start the process of ripening up the snowpack a bit.

Otherwise...given the milder airmass working into the region temperatures will rise into low to mid 40s across the forecast area.

This first wave moves off to our northeast Monday evening. There may still be some lingering showers ahead of the next system but most locales will see a reprieve. Have kept just low end PoPs for Monday night.

Another round of 'rain' arrives Tuesday and then last into Tuesday night. A deep mid-level trough and a couple surface waves will bring what looks like to be a rather damp raw day Tuesday. With this update...latest guidance shows another 0.25 to 0.50 of an inch, with slightly higher amounts across our far eastern locales. That said...there is still some variability in model QPF amounts. Taking a look at NAEFS/GEFS/HEFS most all Ensemble River Forecasts keep area creeks and rivers below action stage but there will be some rises. Its worth noting that SWE values are in the 4 to 6 inch range
At this point
there is a low threat of creek and river flooding, but certainly poor drainage ponding of water is likely with the snowmelt and rain.

LONG TERM /WEDNESDAY THROUGH SATURDAY/
For the lake snows, synoptic moisture and lake parameters will be favorable for again heavy lake snows east of the Lakes.
Wednesday night through Thursday are the most favorable period with EQL levels back up over 10K feet on a westerly flow. There is some hint in the models that the band of snow will lift northward towards Buffalo/Watertown for Friday, but at the same time dry air advection with an incoming surface high will lower favorable lake effect snow parameters.

A warm air front may bring some precipitation to our region to start next weekend, with deep southerly flow allowing for temperatures to be above normal.

AVIATION /00Z SUNDAY THROUGH THURSDAY/
Light snow will continue to spread across western and north central NY tonight. Flight restrictions have improved to MVFR/VFR this evening, however local IFR/LIFR remains possible at KROC through 2z and KART through 8z. Light snow will move out of western NY this evening which will improve conditions to VFR. Stratus will then re- develop late tonight and continue through much of Sunday, with MVFR lower elevations and IFR higher terrain.

East of Lake Ontario, the warm frontal snow will last longer and be somewhat heavier, with IFR/LIFR this evening through much of tonight. The snow will end later Sunday morning, and may mix with some rain by late morning or midday before ending. Following the warm frontal snow areas of low stratus will continue for the rest of Sunday, with MVFR lower elevations and IFR higher terrain.

Finally, a strong 55+ knot low level jet will cross the eastern Great Lakes tonight. The stronger winds aloft will partially mix down to the surface, especially across Western NY where gusts of 35- 40+ knots are expected, including KBUF and KIAG. Elsewhere, gusts of 25-35 knots will be common overnight through early Sunday. Low level wind shear will occur where surface winds are not gusty, mainly across the higher terrain east of Lake Erie.

Outlook...

Monday.. MVFR/IFR with periods of rain.
Tuesday...Areas of MVFR, with rain developing late.
Tuesday night and Wednesday.. MVFR/IFR with rain changing to wet snow from west to east.
Wednesday night and Thursday...VFR/MVFR with a chance of snow showers. Heavier lake effect snow east of the lakes with LIFR.

MARINE
Low pressure will pass by just north of the Great Lakes tonight through early Sunday, with a warm front moving east across the eastern Great Lakes tonight. The pressure gradient will tighten as the low passes by, and a 55+ knot low level jet will move across the eastern Great Lakes. This will bring a period of gale force winds to Lake Erie and Lake Ontario tonight through early Sunday. Winds will quickly diminish Sunday afternoon as the system moves off into the Canadian Maritimes.

BUF WATCHES/WARNINGS/ADVISORIES
NY...Wind Advisory until 7 AM EST Sunday for NYZ001-002-010>012-019- 085.
Winter Storm Warning until 10 AM EST Sunday for NYZ006>008.
MARINE...Small Craft Advisory until 10 AM EST Sunday for LEZ020.
Gale Warning until 7 AM EST Sunday for LEZ040-041.
Small Craft Advisory until 10 AM EST Sunday for LOZ030.
Small Craft Advisory until 7 PM EST Sunday for LOZ042.
Small Craft Advisory until 10 PM EST Sunday for LOZ043>045.
Gale Warning until 10 AM EST Sunday for LOZ062.
Gale Warning from 2 AM to 10 AM EST Sunday for LOZ063>065.