Marine Weather and Tide Forecast for Corfu, NY

KEY MESSAGES
1) Showers and thunderstorms return Sunday with a severe weather and heavy rainfall risk.

DISCUSSION
KEY MESSAGE 1...Showers and thunderstorms return Sunday with a severe weather and heavy rainfall risk.

Quiet, seasonable weather through tonight will break down on Sunday.
A longwave trough centered on a closed low over northern Ontario Province will become increasingly negatively tilted as a shortwave pivots through its base and across the Great Lakes. At the surface, an area of low pressure will force a cold front into the region from the northwest, with a secondary wave ahead of the boundary hindering its progression. This will cause multiple waves of showers and thunderstorms to spread into the forecast area through the day.

Severe Weather Potential...

Sunday looks to be a messy low CAPE/high shear type of setup. Brisk 35-40kt southwesterly mid-level winds ahead of the cold front will drive deep layer shear values near or above 40kts tomorrow. The initial wave of showers/storms will likely arrive in WNY in the morning however. Combined with potential lake shadowing, this should limit MUCAPE values to just a few hundred J/kg northeast of the lakes. The biggest question is how convection evolves through the day as the secondary wave rides northeast along the front, as this may cause it to slow enough such that greater instability (500-1000J/kg)
can build across southeastern portions of the region, heightening the overall severe weather threat. This lines up fairly well with SPC's assessment and subsequent Day 2 Marginal/Slight Risk areas.
Damaging wind gusts look to be the primary concern, with the limited instability precluding a greater hail threat and low 0-1km SRH minimizing the potential for a brief tornado.

Excessive Rainfall...

PWATs climbing to around 1.5-1.75" along and ahead of the cold front Sunday will provide ample fuel for showers and storms to produce a few drenching downpours. Primary concern here continues to be with the secondary low pressure wave, which will slow the overall progression of storms through the first half of the day. Basin- averaged amounts should be between a half inch and an inch, though REFS LPMM QPF indicates a couple of swaths of 2-3" over a couple of hours across portions of the Southern Tier and upper Genesee Valley.
Confidence is low in any one particular area seeing this much rainfall.

AVIATION /00Z SUNDAY THROUGH THURSDAY/
VFR weather will prevail through at least 12z Sunday as a ridge of surface high pressure shifts off the Northeast coast. Modest southwesterly breeze coming off Lake Erie will result in gusts 20- 25kts at KBUF/KIAG/KROC for the next few hours. Otherwise, expect VFR conditions and winds to weaken this evening.

A strong cold front will cross the eastern Great Lakes region from the northwest Sunday afternoon into Sunday evening. Showers and thunderstorms will spread into the region ahead and behind this front, arriving at KIAG as early as 13z. These may contain localized MVFR/IFR conditions, though the unfavorable timing at most of the terminals lends lower confidence in TSRA potential. Continue to cover this with PROB30s with the 00z TAFs.

More widespread lowering of cigs to MVFR/IFR is expected behind the front itself Sunday afternoon, likely beginning at KBUF/KJHW/KIAG around 18z.

Outlook...

Sunday night...Mainly MVFR/IFR with showers early. Conditions improve from west to east across the lower terrain overnight.

Monday...Mainly VFR. Slight chance for a few showers across the North Country.

Tuesday...Mainly VFR. Slight chance for a shower or storm south and east of KBUF/KROC.

Wednesday and Thursday...Restrictions possible with periodic showers/storms crossing the region.

MARINE
Light to moderate southwesterlies will continue into tonight with speeds of 10-15 knots, creating choppy conditions at times on Lake Erie and Lake Ontario. Southwest winds will eventually turn westerly later Sunday/Sunday night following the passage of a cold front.
Speeds near 20 knots on Lake Ontario may bring a period of small craft headlines, especially on the eastern end.

The frontal passage on Sunday will also help to generate widespread showers and scattered thunderstorms, with some of the storms possibly producing locally higher winds and waves.

BUF WATCHES/WARNINGS/ADVISORIES
NY...None.
MARINE...None.