Marine Weather and Tide Forecast for Three Mile Bay, NY

KEY MESSAGES
1) The chance for showers and thunderstorms will increase late Monday night through Tuesday.

2) Dangerous heat and humidity expected for a majority of the week.

DISCUSSION
KEY MESSAGE 1...The chance for showers and thunderstorms will increase late Monday night through Tuesday.

A warm front is expected to move across the forecast area Monday night through Tuesday and bring the arrival of a very warm and moist airmass. Increasing mid-level lapse rates and high PWATS will support increasing chances for showers and thunderstorms across western NY. Some guidance suggests upstream convection or a convectively induced shortwave trough may ride along the ridge into western NY by Tuesday morning. Due to the uncertainty in the evolution of the upstream convection and time of day, the threat for any strong storms remains low. If this activity materializes, it would likely move across the Finger Lakes to eastern Lake Ontario region through Tuesday afternoon.

KEY MESSAGE 2...Dangerous heat and humidity expected for a majority of the week.

An upper level ridge will build across the eastern Great Lakes region through the week. Ensemble systems show the core of the 500mb ridge reaching it's peak of 596dm over the Ohio Valley to Mid- Atlantic region Wednesday through Friday. This is around the 99th percentile of a 3-week climatology based on the latest NAEFS. A warm front is expected to move across the forecast area Monday night through Tuesday. This will bring 850mb temperatures +20C and dewpoints rising into the upper 60s to low 70s. Forecast high temperatures are in the upper 80s to low 90s, with heat indices in the 90s Tuesday. There is a chance of showers and thunderstorms across western NY Tuesday morning, and across north-central NY Tuesday afternoon. The combination of rain and cloud cover may limit the full potential for heat across the region.

As the ridge builds across the region Wednesday through Thursday, precipitation chances will decrease, and mostly sunny skies are expected. Very warm and humid conditions will develop during the day, with muggy conditions persisting overnight. Confidence is increasing that widespread heat indices will surpass 95F. Some locations along the lake plains south of Lake Ontario are expected to reach 100F. A southwest wind is expected to increase Wednesday, which may give some relief during the day. Overnight low temperatures in the 70s and high dewpoints will result in little relief overnight. Confidence is high that heat headlines will be in effect.

The ridge will begin to slowly flatten across the region Friday into the weekend. Warm and humid conditions are expected to continue across the region, however an increasing chance of showers and thunderstorms may limit the full potential for heating.

AVIATION /00Z MONDAY THROUGH FRIDAY/
Mainly VFR flight conditions continuing tonight. The only exception will again be across the Southern Tier where conditions will be favorable for some valley fog formation later tonight through an hour or two after sunrise. This may also bring a period of MVFR/IFR to KJHW, especially between 08Z-11Z.

Any fog across the Southern Tier burns off early Monday, with widespread VFR flight conditions expected through the day. VFR diurnal cu will blossom again Monday afternoon along and inland of any lake breeze boundaries.

Outlook...

Later Monday night and Tuesday...Mainly VFR. Showers and thunderstorms likely with localized flight reductions possible in heavier showers/storms.

Wednesday and Thursday...Mainly VFR.

Friday...Mainly VFR. Chance of showers and thunderstorms.

MARINE
Surface high pressure will persist across the eastern Great Lakes region through Monday. Light to modest winds and minimal wave action will continue on the Lakes. A warm front will move across the region early Tuesday, and southwest winds will increase each day during the week.

The warm frontal passage may also bring the potential for at least a few showers and thunderstorms Monday night and Tuesday...some of which could produce locally higher winds and waves.

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