Marine Weather and Tide Forecast for Irondequoit, NY

KEY MESSAGES
1) Below normal temperatures and mainly dry weather will continue through the upcoming week, with a few showers possible across the Southern Tier at times.

DISCUSSION
KEY MESSAGE 1...Below normal temperatures and mainly dry weather will continue through the upcoming week, with a few showers possible across the Southern Tier at times.

An upper level trough and closed low will slowly move east across the Midwest to Ohio Valley through mid-week. High pressure will remain across eastern Canada, bringing continued northeast flow across the eastern Great Lakes region though a majority of the work week.

A shortwave trough will move across the Ohio Valley this evening.
Subsidence and dry air will maintain mostly dry weather across the region, however isentropic lift and deep moisture will approach the NY/PA line. Widely scattered showers are possible across the western Southern Tier through this evening. Mid-high level cloud cover will spread across the forecast area tonight. Partial clearing is expected to occur from the northwest late tonight. Low temperatures will fall to the 40s with locations across the North Country possibly seeing the upper 30s. Confidence in temperatures reaching the upper 30s is low, as the position of the high well to the north and uncertainty in cloud cover does not offer the best set-up for radiational cooling. With that being said, there is a non-zero chance of patchy frost in known cold spots across Jefferson and Lewis counties tonight.

Low-level easterly flow will increase to our south ahead of the approaching closed low Tuesday. A few showers along the NY/PA border can't be ruled out. An upper level ridge is expected to move south from eastern Canada for the end of the work week, and widespread dry weather is anticipated across the forecast area. Temperatures will gradually increase each day but stay below normal for late September.

AVIATION /18Z MONDAY THROUGH SATURDAY/
A combination of drier air and diurnal mixing continue to slowly work on the persistent moist northeasterly flow with the slow erosion of widespread MVFR CIGS across western and northcentral NY as seen visible satellite imagery. Thus, low level OVC CIGS that have been observed for much of the day so far are starting to thin and lift a bit with the latest METARs showing many locations now reporting BKN MVFR decks. Expect continued improvement this afternoon, with high pressure and associated drier air finally winning out with all terminals expected to improve to at least low VFR through the mid and late afternoon hours. Northeasterly gusts of 15-20 knots will also be possible through late afternoon.

A mainly light northeasterly flow will continue tonight, however drier air will be in place in the low levels, so expecting mainly VFR level decks overnight. The exception will be toward the western Southern Tier closer to surface troughing and deeper moisture across the Ohio Valley, which will bring the chance for a few isolated showers near or possibly just north of the NY/PA line this evening into the overnight, possibly accompanied by some MVFR CIGS.

MVFR CIGS and the chance for an isolated shower will hang on across the Southern Tier through the end of the TAF period, with VFR flight conditions expected across the remainder of the area. Northeasterly winds will again strengthen later Tuesday morning into the afternoon with widespread gusts of 15-25 knots, highest southwest of the lakes.

Outlook...

Tuesday night through Saturday...Mainly dry weather with predominantly VFR flight conditions expected through the period. The exception will be river/lake valley fog potential on any given night where winds become light, and skies become clear to partly cloudy late night into the hours surrounding daybreak.

MARINE
Expansive surface high pressure over Ontario Province will build across Quebec and strengthen through midweek...while weak surface troughing slides eastward across the Ohio Valley and mid-Atlantic states. The resulting pressure gradient will maintain a moderate to fairly brisk flow across the Lower Great Lakes through midweek that will also gradually veer from northeasterly to easterly over time.

This will allow for SCA-level conditions across the nearshore waters of both lakes with the exception of Sodus Bay to the Saint Lawrence River. SCAs will become more confined to areas from Hamlin Beach to the Niagara River Tuesday night/ Wednesday as the flow veers more easterly. Any lingering SCA-level conditions should then subside Wednesday night as the surface ridge builds further southward and results in a weakening of the pressure gradient across our region...along with a commensurate lowering of winds and wave action.

BUF WATCHES/WARNINGS/ADVISORIES
NY...Beach Hazards Statement through Wednesday evening for NYZ001- 002.
Beach Hazards Statement through Wednesday morning for NYZ003- 004.
MARINE...Small Craft Advisory until 11 PM EDT Tuesday for LEZ040-041.
Small Craft Advisory until 8 PM EDT this evening for LOZ030.
Small Craft Advisory until 8 PM EDT Wednesday for LOZ042.
Small Craft Advisory until 8 AM EDT Wednesday for LOZ043.