Marine Weather and Tide Forecast for Irondequoit, NY

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

2) Unsettled weather expected through the start of the weekend.

3) Cool weather will support the potential for additional frost or freeze headlines each night this weekend.

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

A general troughing pattern across the eastern Great Lakes tonight, will support cold air to advect into western and north central New York under northwest flow. Temperatures at 850mb will tumble to around -3C tonight. Additionally, partial clearing tonight, combined with weakening surface winds will support temperatures to fall into the 30s, and therefore support frost development in most areas, especially inland from the lakeshores.

A Frost Advisory is in effect for most of western New York and into the Finger Lakes, where the growing season begins on May 1.

KEY MESSAGE 2...Unsettled weather expected through the start of the weekend.

An upper level low will remain parked across southeastern Canada, will support a general troughing pattern remaining across the Great Lakes through the end of the week and into the start of the weekend.
With the troughing pattern overhead, a few shortwave troughs will ripple through, maintaining northwest flow across the region.

A pool of cold air aloft, combined with diurnal heating will support isolated to scattered showers to persist during the daytime hours on Friday and Saturday. The best coverage of showers will be Friday afternoon as a decaying cold front approaches the area. Colder air in the wake of the front Friday night through Saturday, may support graupel/snow to mix in with rain showers Saturday afternoon. Any lingering showers across the higher terrain Saturday night will briefly change over to snow, though little to no accumulation is expected.

KEY MESSAGE 3...Cool weather will support the potential for additional frost or freeze headlines each night this weekend.

Upper level low parked over southeastern Canada, will support a general troughing pattern across the eastern Great Lakes through the weekend. Within the troughing pattern, shortwave troughs will ripple through, supporting colder air to filter in across the region with each passage.

Temperatures at 850mb will tumble to -5C by Saturday night, which will support temperatures to average 10-15 degrees below normal. This being said, low temperatures are expected to fall well into the 30s and even into the 20s across the higher terrain Friday night and Saturday night. Additional frost or freeze headlines will likely be needed across much of western New York and into the Finger Lakes since the growing season starts on May 1st.

AVIATION /00Z FRIDAY THROUGH TUESDAY/
For the 00Z TAFS, mainly VFR flight conditions are found, with diurnally driven showers becoming fewer in number. Through the overnight hours, generally VFR flight conditions are expected.

A shortwave trough rotating through a closed upper level low will bring back shower chances to the TAF region tomorrow after sunrise. Primarily the Southern Tier, including KJHW, will have several clusters of showers passing through, with ceiling heights lowering to MVFR if not IFR within this activity.

Showers and lower ceiling heights to MVFR will brush by the northern TAF sites of WNY, including KBUF, KIAG and KROC through the afternoon hours. East of Lake Ontario, including KART, will likely remain dry the final 12 hours of this TAF cycle.

Outlook...

Friday evening 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 and Tuesday...Areas of MVFR with showers likely.

MARINE
In the wake of surface low pressure moving across Quebec this afternoon, westerly winds will continue to gradually increase on Lakes Ontario and Erie, producing choppy conditions on both lakes.
Small Craft Advisory conditions will be met on the eastern half of Lake Ontario through this evening.

An unseasonably cool airmass and moderate pressure gradient will remain persistent to support additional periods of small craft advisory criteria at times on Lake Ontario.

BUF WATCHES/WARNINGS/ADVISORIES
NY...Frost Advisory from midnight tonight to 9 AM EDT Friday for NYZ001>006-010>014-019-085.
MARINE...Small Craft Advisory until 2 AM EDT Friday for LOZ043>045.