Marine Weather and Tide Forecast for Sandy Creek, NY

KEY MESSAGES
1) Summer-like heat today through Tuesday.

2) Marginal Risk for isolated severe thunderstorms this evening, supporting a threat for damaging winds.

3) Widespread showers and thunderstorms arrive Tuesday evening and last into Wednesday morning, where a few thunderstorms may become severe (Slight Risk for Severe Weather Tuesday/Tuesday Night).

4) Drier and cooler conditions arrive in the wake of the cold front Wednesday afternoon and last through Friday, before the potential for unsettled weather returns for the holiday weekend.

DISCUSSION
KEY MESSAGE 1...Summer-like heat today through Tuesday.

Mid and upper level ridging will continue to amplify across the eastern United States today while gradually shifting its ridge axis eastward tonight and Tuesday. As such, deep southwesterly flow will advect warm Gulf air into the region helping to surge temperatures well into the 80s and a few climatologically warmer locations toward 90. Today will be the warmer of the two days, as the ridge axis lies overhead. However, for locations closer to the lakeshores, expect temperatures in the mid 60s to low 70s due to the air coming off of the cold lake waters. NBM high temperatures continue to trend too warm, but it is not as overdone as it has been in previous runs.
This being said, continued to lower high temperatures a couple to a few degrees for locations. While temperatures are warm, dewpoint temperatures will range in the 60s supporting lower humidity values, which will keep the potential for heat headline criteria low.

KEY MESSAGE 2...Marginal Risk for isolated severe thunderstorms this evening supporting a threat for damaging winds.

A weak shortwave trough will ride along the western edge of the ridge this afternoon and evening, introducing a forcing mechanism along with a 40-50 knot low-level jet to graze the western edges of the the forecast area, which will help support a few isolated showers and thunderstorms. Due to the warm, moist, unstable air mass already overhead, and the introduction of the low-level jet later this evening, any storm that does develop could become severe. This being said, a Marginal Risk for Severe Thunderstorms (Threat Level 1 of 5) is in place across the region, with the main hazard being damaging wind gusts.

KEY MESSAGE 3...Widespread showers and thunderstorms arrive Tuesday evening and last into Wednesday morning, where a few thunderstorms may become severe (Slight Risk for Severe Weather Tuesday/Tuesday Night).

As the mid-level ridge axis departs east Tuesday, the next mid-level trough will jut northwestward out of the longwave trough overhead of the western half of the CONUS. Its associated surface low will continue to track northeastward across Ontario and Quebec, Canada dragging an attendant cold front across the region Tuesday night.
Despite the unfavorable timing of the front's arrival being past peak diurnal heating hours, there continue to be high confidence in a few strong to severe thunderstorms Tuesday evening and Tuesday night ahead of the strong cold front's arrival. CAPE values of 1500 to 2000 J/kg along with 30 to 40 knots of 0-6km shear will nurture the potential for damaging wind gusts, which will be the primary hazard threat. However, large hail can't be ruled out as forecast soundings continue to highlight "fat" CAPE profiles. Additionally, an isolated tornado can't be ruled out either with Storm Relative Helicity values of 200 to 300 m^2/s^2.

This all being said, the Storm Prediction Center continues to place the entire region under a Slight Risk (Level 2 of 5) for Severe Thunderstorms. With a 2% risk for tornadoes, 15% risk for damaging winds, and 5% risk for large hail.

KEY MESSAGE 4...Drier and cooler conditions arrive in the wake of the cold front Wednesday afternoon and last through Friday, before the potential for unsettle weather returns for the holiday weekend.

In the wake of the passing cold front Wednesday morning, cold air and surface high pressure will side across the region for the later half of the week, supporting mainly cool and dry weather. The coolest day will be Thursday with many locations remaining in the 50s for highs. There will then be a slow rebound in temperatures heading into the holiday weekend, with highs ranging in the 60s and a few locations reaching the low 70s.

An area of low pressure will then approach the region from the southwest, supporting the return of unsettled weather for the holiday weekend.

AVIATION /18Z MONDAY THROUGH SATURDAY/
VFR conditions are present this afternoon across the region with warm and breezy conditions. VFR conditions are expected to continue tonight and through tomorrow morning, however increasing low level wind shear could bring hazardous aviation conditions this evening into the overnight hours.

Diurnal cumulus field at around 4000-5000 ft will persist until later this evening, and then expect the lower levels to be clear tonight as high based clouds increase. The remnants of an impressive squall line over the central Great Lakes may reach WNY, but most forecast guidance dissipates this activity before it reaches the eastern Great Lakes. Still, can't rule out a shower or thunderstorm overnight on the periphery of this activity. Fair amount of clouds expected tomorrow, with lower level ceilings developing (4000-6000 ft) with surface heating by late morning.

Wind concerns continue through the TAF period with SW wind gusts 20- 25 kts this afternoon, and then LLWS developing this evening and into the early morning hours. After daybreak tomorrow, SW winds will increase again with 25-30 kt winds gusts likely.

Outlook...

Tuesday afternoon through Wednesday...Areas of MVFR/local IFR with showers and thunderstorms of which a few storms may contain gusty winds, with this activity ending from west to east and improving to VFR Wednesday morning.

Thursday through Friday...VFR.

Saturday...Potential for sub-VFR with as a low pressure system brings rain to the region.

MARINE
Pressure gradient between exiting high pressure and an approaching cold front will continue to gradually tighten through Tuesday, which is currently supporting the moderate southwesterlies and very choppy conditions on the western end of Lake Ontario this afternoon.

Winds will increase further Tuesday ahead of the aforementioned cold front, supporting winds and waves worthy of Small Craft Advisory criteria on the western end of Lake Ontario by Tuesday afternoon, before spreading toward the eastern end of Lake Ontario late Tuesday night through Wednesday with the passage of the cold front. Winds on Lake Erie will be somewhat lighter, but still strong enough to produce a moderate chop Tuesday through Wednesday.

Additionally, just ahead of the cold frontal passage Tuesday evening into Tuesday night, expect showers and embedded thunderstorms to pass across the lakes producing damaging winds with a possibility of large hail.

Winds will then relax as high pressure returns Wednesday night and Thursday.

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