Marine Weather and Tide Forecast for Grandyle Village, NY

NEAR TERM /THROUGH TONIGHT/
A warm front will lift across WNY today leaving a humid airmass in place across Western New York. This moisture, coupled with daytime heating and the passing of a convective shortwave trough will bring blossoming showers and thunderstorms this afternoon and evening.

There is not a lot of wind shear, so storms should not build to great heights...with just garden variety storms for the region this afternoon and into the evening hours. Heavier downpours will be possible for the southern two tier of counties of WNY where the better lift ahead of the shortwave trough intersects the axis of deeper moisture.

Convection will taper down through the evening with the loss of daytime instability, weakening lake breeze circulations and also the exit of the shortwave trough. However a lingering frontal boundary within ample supply of low level moisture will allow for a few spot showers through the night, especially from the Southern Tier northeastward across the Finger Lakes and eastern Lake Ontario region.

Some patches of fog are likely to form tonight, especially in areas that received a shower today...increasing the near ground moisture content.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
Mid level shortwave trough will push east into the Great Lakes Wednesday as a deepening surface low pushes into the Ohio Valley along with associated cold front. This will place the entire area within the warm sector ahead of the low and front with surface dewpoints increasing into the upper 60s and lower 70s. As diurnal instability increase, showers and thunderstorms will increase in coverage, peaking during the afternoon and early evening. Severe threat look limited with unfavorable shear profiles, but with ample moisture in place pockets of heavy rainfall certainly looks possible.

Prefrontal trough and cold front push through the area Wednesday night into Thursday morning, with an additional round of showers and thunderstorms. Unfavorable timing should limit severe threat, but precipitable water value over 1.5" suggests the potential for locally heavy rainfall.

Convection will gradually diminish late Thursday into Thursday night as the cold front exits.

LONG TERM /FRIDAY THROUGH MONDAY/
The next stout upper level ridge will slide across the Gulf States Saturday before amplifying northeastward Sunday and into the start of the next work week. This upper level feature will bring steady increasing heat and humidity into the region for the weekend and into the start of new work week. However, an ill-timed shortwave ridge-runner will support the possibility for a few rounds of showers and thunderstorms Saturday through Sunday before surface high pressure then dominates overhead for Monday. As alluded to previously, the combination of 500 mb heights building to near 600dm over the Ohio Valley and lower Great Lakes would support very hot and humid conditions with heat index values climbing well into the 90s by Monday.

AVIATION /07Z TUESDAY THROUGH SATURDAY/
For the 06Z TAFS a warm front lifting northward into our region will bring an increase in low level moisture, maintaining IFR ceiling heights for the Southern Tier (KJHW) and lowering ceiling heights for KBUF/KIAG and KROC to MVFR in the 12 to 18Z timeframe. MVFR ceiling heights east of Lake Ontario (KART) should prevail through the morning hours.

Chances for showers and a few thunderstorms will increase this afternoon as a convective shortwave trough passes through. The best chances for thunderstorms will occur across the Southern Tier and Upper Genesee Valley. Ceiling heights may improve briefly to VFR this afternoon and early evening, especially for the lake plain, before settling back to lower terrain MVFR and higher terrain IFR for tonight. Some patches of fog are likely to form tonight, especially in areas that received a shower today...increasing the near ground moisture content.

Outlook...

Wednesday and Thursday...VFR/MVFR with showers and thunderstorms likely.

Friday...Mainly VFR. A chance of showers and thunderstorms, mainly east of KROC.

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

MARINE
Light southeast to southerly flow today as a stable regime of cool lakes and warm inland temperatures sets up. This flow will become slightly stronger and more defined tonight as the airmass cools and lake breeze circulations weaken. The wind flow will become more southwesterly tomorrow, but wind speeds will likely remain below small craft advisory criteria.

By Thursday, a cold front will be drawing upon our region and a tightening pressure gradient ahead of the front will allow for southwest winds to increase to possible SCA criteria on both lakes.
This flow will also increase the waves on the lakes especially the eastern half of Lake Ontario by Thursday evening where waves may breach the 4-foot mark.

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