Marine Weather and Tide Forecast for Cape Vincent, NY

KEY MESSAGES
1) Areas of frost tonight and Friday morning.

2) Unsettled weather expected from late in the week through the beginning of next week.

3) Cool weather will support the potential for additional frost or freeze headlines Friday night through Sunday morning.

DISCUSSION
KEY MESSAGE 1...Areas of frost tonight and Friday morning.

Cooler temperatures today and Friday as an upper low drops through the Great Lakes. Temperatures through Friday will average 10 to 15 degrees below normal with confidence fairly high in these temperatures as very little spread in the 25th-75th percentiles, on the order of 5 degrees or less. Partial clearing tonight along with lightening winds will allow temperatures tonight to fall into the 30s, which will allow frost to develop in most areas, especially inland from the lakeshores. A Frost Advisory has been issued for most of western New York where the growing season begins on May 1.

KEY MESSAGE 2...Unsettled weather expected from late in the week through the beginning of next week.

An upper low will remain across the Great Lakes from late in the week into at least through the early part of the weekend, sending a few shortwave troughs through the region within the northwest flow.

Cold pool aloft and daytime heating will support isolated to scattered showers Friday and Saturday. The better coverage of showers expected Friday afternoon a cold front approaches the region. Colder air behind the front Friday night through Saturday may support graupel/snow mixing with rain showers Saturday afternoon with any lingering showers briefing changing over to all snow showers across the higher terrain Saturday night. Little to no snow accumulation is expected.

KEY MESSAGE 3...Cool weather will support the potential for additional frost or freeze headlines Friday night through Sunday morning.

An upper level low will bring an anomalously cold airmass for this time of year across the eastern Great Lakes region from late in the week through the weekend. Daily maximum and minimum temperatures will average 10 to 15 degrees below normal Friday night through Saturday night. Low temperatures are expected to fall into the 30s and even the 20s across the higher terrain both Friday night and again Saturday night. Additional frost or freeze headlines may been needed during this time for areas where the growing season begins on May 1. This applies to all areas with the exception of Cattaraugus, Allegany, Jefferson, and Lewis counties.

AVIATION /12Z THURSDAY THROUGH MONDAY/
To start the day we'll have some scattered showers across the western Southern Tier and to a lesser extent across the North Country...with largely dry conditions prevailing elsewhere. Otherwise flight conditions will range from lower-end VFR in the vicinity of KIAG/KBUF to MVFR across the remainder of the lower elevations...and to IFR/LIFR across the higher terrain.

From mid-morning onward through the rest of the day...ceilings will gradually improve to VFR across the lower elevations and MVFR across the higher terrain with daytime heating/gradual drying of the lower levels
At the same time
this heating of our new cooler airmass will give rise to some weak diurnally-driven instability...with this and developing weak low-level convergence zones leading to the potential for some additional scattered showers across far WNY and portions of the North Country during the late afternoon/early evening hours.

Any such showers will then die out after sunset with the loss of heating...leaving behind a dry and uneventful rest of the night with flight conditions improving to mainly VFR.

Outlook...

Friday through Sunday...VFR/MVFR with scattered rain showers at times. Some wet snowflakes may mix in across the higher terrain late Friday night/early Saturday.

Monday...Areas of MVFR with showers likely.

MARINE
A wave of low pressure will move across Quebec today. Westerly winds will gradually increase on Lake Ontario and Lake Erie through today, producing choppy conditions on both lakes. The best chance of marginal Small Craft Advisory conditions will be on the eastern half of Lake Ontario this afternoon through this evening.

A continued unseasonably cool airmass and moderate pressure gradient may support additional periods of SCA conditions at times, particularly across Lake Ontario.

BUF WATCHES/WARNINGS/ADVISORIES
NY...Frost Advisory from midnight tonight to 9 AM EDT Friday for NYZ001>004-010>014-019-085.
MARINE...Small Craft Advisory from noon today to 2 AM EDT Friday for LOZ043-044.
Small Craft Advisory from 2 PM this afternoon to 2 AM EDT Friday for LOZ045.