Marine Weather and Tide Forecast for Oswego, NY

NEAR TERM /THROUGH FRIDAY/
Latest satellite and radar imagery shows showers and thunderstorms associated with a cold front extending down from southeast Ontario. The strongest of these storms is now entering Lewis Co and should be east of the CWA by 9 PM. Enough instability ahead of the front remains in place to keep these storms sustained, but the overall environment is no longer conducive of severe storm development. With the deeper moisture, these storms east of Lake Ontario may yield heavy downpours with any backbuilding or training producing a localized flood risk. Additionally, a few lingering showers remain with low- level moisture behind the front that will continue this evening.

Winds will ramp down tonight. Otherwise, expect a period of wraparound upslope showers east of Lake Ontario late this evening through the overnight, with just some scattered light upslope showers possible east of Lake Erie. Otherwise, most of the area will dry out with cooler and more comfortable conditions expected.

Much cooler and more comfortable day Friday. Surface high pressure building in from the southwest will provide mainly dry weather, however we will remain under cool cyclonic flow aloft, which may lead to a few showers or an isolated storm by afternoon.

SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/
Northwest flow ridge-runner type events will be possible from Friday evening through Sunday morning as a strong ridge builds into the eastern half of the CONUS. Guidance is still having issues on timing, track and strength of the different shortwave troughs crossing the region. The shortwaves and thunderstorm complexes will track from northwest to southeast along a earlier stalled frontal boundary that will then push northeast as a warm front. As the warm front pushes north and a surge of warm moist air pushes into the region, instability will increase significantly Saturday into Sunday. Along with increased shear, thunderstorms that do develop and/or move across the region will have the potential for strong winds and heavy downpours. WPC currently has a 'Marginal Risk' for excessive rainfall for most of the forecast area for Saturday and Saturday night. SPC also has all of the forecast area in a 'Marginal Risk' for severe thunderstorms on Saturday/Saturday night. Would not be surprised if that goes to at least a 'Slight Risk'.

Temperatures will start to warm Saturday and even warmer on Sunday.
Saturday values will be in the low to upper 80s and Sunday will warm to the mid 80s to low 90s.

LONG TERM /SUNDAY THROUGH THURSDAY/

Dangerous Heat Through Tuesday

As alluded to previously in the short term section, a stout mid- level ridge at 500 mb will build towards 600dm through Tuesday, while slowly advancing east towards the East Coast. This being said, expect a period of hot, humid and dry weather for the end of the weekend and into the start of the new work week. Temperatures climbing up into the mid 80s to mid 90s from Sunday through Tuesday, along with dewpoint temperatures well into the 60s and low 70s will support dangerous heat indices. Heat index values will climb up into the mid 90s and towards 100 degrees in a few locations. The warmest day of the heat wave will be Monday.

The next system will approach the region from the northwest as the next frontal boundary sags southeastward from Canada, late Tuesday through Thursday, introducing the potential for showers and thunderstorms for mid-week. With the introduction of the frontal boundary, temperatures will begin to cool, however continue to remain above normal for late June. How far south the boundary sags south will greatly impact how much relief from the heat the region will experience.

AVIATION /23Z THURSDAY THROUGH TUESDAY/
Rain showers continue to move through western and north-central NY this evening as the cold front moves through our area. Lingering showers, gusty winds, and low clouds remain behind the front and will continue to bring MVFR ceilings to most terminals through 06z.
KJHW and additional terminals across the Southern Tier are currently under lower conditions at IFR levels that look to persist through the night with moist low levels and cooling temperature behind the front. Additional low-level moisture will support MVFR ceilings once again for most area terminals closer to daybreak continuing through the morning. While coverage should remain fairly isolated, showers and thunderstorms will return across western NY late Friday afternoon.

Outlook...

Friday...Mainly VFR. A chance of showers and thunderstorms.

Saturday...Mainly VFR. Increasing chances for showers and thunderstorms.

Sunday, Monday, and Tuesday...Mainly VFR.

MARINE
A deepening area of low pressure will track north of Lake Ontario, reaching the Ottawa Valley by this evening with Small Craft Advisories remaining in effect for most zones, as well as the Upper Niagara River.

Winds will then veer to westerly and then northwesterly this evening and tonight behind the cold front. While winds will peak late this afternoon, waves will remain rough on the waters through tonight.

High pressure building towards the eastern Great Lake region Friday will lower wind speeds below small craft criteria range, though a light chop will be found on the waters through the day.

BUF WATCHES/WARNINGS/ADVISORIES
NY...Wind Advisory until 8 PM EDT this evening for NYZ001>003-010- 011-019-085.
Beach Hazards Statement until 5 AM EDT Friday for NYZ001-002.
Beach Hazards Statement through Friday afternoon for NYZ003>007.
Beach Hazards Statement until 11 PM EDT this evening for NYZ010-019-085.
MARINE...Small Craft Advisory until 10 PM EDT this evening for LEZ020- 040-041.
Small Craft Advisory until 4 AM EDT Friday for LOZ042.
Small Craft Advisory until 2 PM EDT Friday for LOZ043>045.