Marine Weather Net

Lake Ontario - Open Waters from Sodus Bay to Mexico Bay Marine Forecast


REST OF TODAY

SW
WINDS
5 - 15
KNOTS

TONIGHT

S
WINDS
10
KNOTS

MONDAY

W
WINDS
10
KNOTS

MONDAY NIGHT

SW
WINDS
10
KNOTS

The Marine Weather Forecast In Detail:
LOZ064 Forecast Issued: 1002 AM EDT Sun Jul 13 2025

Rest Of Today...Southwest Winds 5 To 15 Knots Becoming South. A Chance Of Showers And Thunderstorms Late This Morning, Then Showers With Thunderstorms Likely This Afternoon. Waves 1 To 3 Feet.
Tonight...South Winds 10 Knots Or Less Becoming Southwest. Showers Likely With A Chance Of Thunderstorms Early, Then A Chance Of Showers And Thunderstorms. Waves 2 Feet Or Less.
Monday...West Winds 10 Knots Or Less Becoming Southwest. Waves 1 Foot Or Less.
Monday Night...Southwest Winds 10 Knots Or Less. Waves 1 Foot Or Less.
Tuesday...Southwest Winds 10 Knots Or Less Becoming South. Waves 1 Foot Or Less.
Wednesday...South Winds 5 To 10 Knots. A Chance Of Showers During The Day, Then A Chance Of Showers And Thunderstorms Wednesday Night. Waves 2 Feet Or Less.
Thursday...Southwest Winds 5 To 15 Knots Becoming Northwest. Showers Likely With A Chance Of Thunderstorms. Waves 1 To 2 Feet. Winds And Waves Higher In And Near Thunderstorms.
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Area Forecast Discussion
National Weather Service Buffalo NY
1047am EDT Sunday July 13 2025

Synopsis
A cold front will approach the area today...and in the process will generate widespread showers and thunderstorms, some of which could produce strong gusty winds and locally heavy rainfall. In the wake of the front drier weather will return on Monday night, along with less humidity.

Near Term - Through Monday
A very warm and humid airmass resides across the eastern Great Lakes region today. An upper level trough over northern Ontario will move east-northeast while an upper level ridge persists off the east coast. Water vapor satellite products show a shortwave trough over Ohio, and Gulf and Atlantic moisture converging across the region late this morning. A cold front will slowly approach the forecast area through this evening. Daytime heating and deep moisture with dewpoints in the lower 70s will result in 1500-2000 J/kg of CAPE across the region this afternoon. Showers and thunderstorms will develop ahead of the front, with a focused area of convection along a pre-frontal trough east of the Genesee River. Forecast PWATs (Precipitable Waters) of 2"+ and mean RH% of 80%+ will support heavy rain in any convection. Upwind propagation vectors are forecast to remain weak across the region and training storms are possible. 1-hr FFG of 1.5-2.5" and 3-hr FFG of 2-2.5" extends from Allegany county to the northern Finger Lakes region which could result in localized flash flooding if training storms develop. FFG is slightly higher across Oswego and Lewis county, however ingredients are there for training storms. A Flood Watch remains in effect for the areas mentioned from 11am today through 5am Monday. Shear is rather modest with 20- 25kts of 0-6km bulk shear, but coupled with a very moist environment may result in an isolated severe storm across the area today, mainly especially east of the Genesee Valley. Temperatures will again reach the mid to upper 80s across the lake plains and Genesee Valley today. The combination of humidity and warm temperatures may result in heat indices in the mid 90s.

Instability will wane into the evening hours and so will the severe threat. Training showers and storms may be ongoing and the flash flood threat will continue through the evening hours. Elsewhere, deep moisture will be present as the cold front trudges through the region and showers are possible overnight.

The upper level trough axis will move through the region with the cold front finally exiting the eastern edge of the forecast area Monday. There remains a corridor of deep moisture from the Ohio Valley into New England, which keeps the chance for showers and thunderstorms across interior portions of the forecast area. A convergence zone may develop along the lake plains south of Lake Ontario and there is a low chance of showers developing by afternoon. Warm weather will continue however dewpoints will be lower.

Short Term - Monday Night Through Wednesday Night
Building heigheights and surface high pressure will bring drier weather Monday night through Tuesday night.

A fast moving shortwave trough will move from the northern Rockies to the Upper Great Lakes Wednesday into Thursday. Moisture and warmth will stream northward while a surface low moves across the Great Lakes region. Wednesday will be a transition day with increasing chances for showers and thunderstorms. Hot and humid conditions may warrant heat headlines beginning Wednesday.

.LONG TERM /THURSDAY THROUGH SATURDAY/... A humid (Mean PWATs (Precipitable Waters) 1.75") and a very warm airmass (surface temperatures in the 80s) Thursday will be accompanied with showers and thunderstorms upon a warm front...with additional lift for storm development supported by the passage of a mid level shortwave trough.

Chances for showers and thunderstorms continue Thursday night through Friday with the approach and passage of a cold front.

Surface high pressure and mostly zonal flow is possible across the region this weekend. There has been some flip-flopping with guidance for the weekend so confidence is low that it will be quiet and dry. That being said, post-frontal conditions should result in temperatures approaching normal (low 80s.)

Marine
A slow moving cold front will then bring increasing chances of showers and thunderstorms through tonight. Special Marine Warnings may be needed for locally strong winds. Winds will pick up a bit ahead and with the front, but will still remain well below any headline criteria.

Behind the front...winds will be fairly light tonight through Tuesday as high pressure builds in across the lakes.

NOAA Buffalo NY Office: Watches - Warnings - Advisories
NY...Flood Watch through late tonight for NYZ003>006-008-013-014- 021.

Marine
None.

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