Marine Weather and Tide Forecast for Brockport, NY

KEY MESSAGES
1) A few spotty showers and thunderstorms today.

2) More unsettled weather will return Monday and Tuesday with increasing coverage of showers and thunderstorms.

3) Showers and storms will linger into Wednesday, with drier conditions for the end of the work week.

DISCUSSION
Key Message 1...A few spotty showers and thunderstorms today.

As the next shortwave trough moves into the eastern Great Lakes region, moisture will increase today. Diurnal heating combined with lake breeze and terrain effects will support a chance for a few scattered showers and thunderstorms across the inland portions of the area this afternoon and into the early evening. High-res guidance continues to support an area of numerous showers and thunderstorms across the metro area of Toronto to move across the Niagara Peninsula and into the Buffalo/Niagara Falls metros this evening.

Key Message 2...More unsettled weather will return Monday and Tuesday with increasing coverage of showers and thunderstorms.

A broad longwave trough will remain overhead of the region Monday and Tuesday, while a large upper level ridge to the east of the trough, will allow multiple shortwave trough to ripple through the longwave pattern. The shortwave disturbances combined with the seasonably warm air, will result in unsettled weather with rounds of showers and scattered thunderstorms.

As an initial shortwave trough passes over the area during the time of peak diurnal heating and instability, showers and scattered storms will form inland from the lakes Monday afternoon, especially across the the Finger Lakes and into the eastern Lake Ontario region where there will be more available moisture and the maxima of forcing from the passing shortwave will overlap. Given the timing of the shortwave passage being during peak heating, there is a Marginal Risk for Severe Weather Monday due to the weak low to mid level winds and weak shear across the region. Additionally given the weak flow, localized heavy downpours will be the main concern, due to PWAT values of around 1.5 inches. However, deep-layer shear of 25 to 30 knots across the western Southern Tier may support a couple to a few stronger storms.

Another stronger shortwave trough and associated surface wave will pass southeast across the Great Lakes Monday night and into Tuesday supporting more widespread showers and scattered thunderstorms, with the best coverage occuring Tuesday afternoon and evening correlating to the timing of diurnal heating/destabilization effects. Shear profiles continue to be weak, and do not support organized severe storms, however across the Southern Tier there may be enough shear to support a few stray showers across the Ohio Valley and Mid- Atlantic to become severe. Otherwise, a soupy airmass overhead (PWAT values of around 1.5 inches or slightly higher, will support a few heavy downpours.

Key Message 3...Showers and storms will linger into Wednesday, with drier conditions for the end of the work week.

In the wake of the passing system Tuesday, lingering longwave troughing will remain across the region, supporting another round of diurnally driven convention to develop inland from the lakes Wednesday. However due to the notably weaker instability Wednesday, most of the activity will be constrained to brief and numerous showers with a few widely scattered thunderstorms.

Otherwise, surface high pressure will lift northeast across eastern Canada supporting a generally dry trend for the remainder of the week.

AVIATION /12Z SUNDAY THROUGH THURSDAY/
Moisture across western New York from the passing showers the evening prior will continue to support some fog, mainly across the Southern Tier, supporting localized IFR conditions. Fog will dissipate within the next couple of hours.

Otherwise mainly VFR conditions will prevail across the remainder of the TAF sites today. A few showers and thunderstorms may develop inland from the Lakes this afternoon, with mainly VFR conditions expected.

Outlook...

Sunday night...VFR/MVFR with a low chance for showers/thunderstorms.

Monday through Wednesday...VFR/MVFR with showers and thunderstorms possible.

Thursday...Mainly VFR. Slight chance of showers and thunderstorms.

MARINE
Light and variable winds will linger through the start of the week, resulting in gentle waves.

Southwest winds will increase ahead of a cold front Tuesday, where choppy waters will develop on the northeast ends of the lakes.

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