Marine Weather and Tide Forecast for Bay Shore, NY

NEAR TERM /UNTIL 6 AM THIS MORNING/
The forecast remains mostly on track, but will need to continue to monitor for the potential need for a dense fog advisory for at least the coastal zones tonight. Light winds with light turbulent mixing potential at the base of the inversion along with low dewpoint depressions have already resulted in patchy dense fog across Long Island and a few other coastal locations.
SPS is posted for the time being. Dry weather otherwise with lows ranging from the mid 50s to lower 60s.

SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/
A subtle mid level shortwave moves across Friday with some associated positive vorticity advection. At the surface, the frontal boundary across the area dissipates, leaving a general weak pressure gradient between low pressure well to the north and west and high pressure well to the south and east.

Light southerly flow at the surface is expected. A warmer day is expected. NBM/NBM 50th percentile combination used for daytime high temperatures, well into the 70s for most locations and some locations reaching 80. More instability will be generated at the surface as a result, making for a higher chance of showers and thunderstorms. Marginal risk for damaging winds with these thunderstorms, particularly for areas that have more instability.

The convection trends downward Friday night with the loss of diurnal heating. Winds in lower levels increase. This will keep warmer min temperatures Friday night. Again used combination of NBM and NBM 50th percentile, with lows ranging from upper 50s to lower 60s. Fog will be possible but was not put in forecast due to uncertainty with how well mixed boundary layer could be.

Upper level low approaches the region Saturday with greater height falls. At the surface, a cold front approaches from the north and west. There is a likely a pre-frontal trough that develops that will be the focus for convective initiation.
Chances for showers and thunderstorms increase during the day with highest chances mid afternoon through early evening.

The southerly flow increases Saturday and with further increase in winds in 5-10 kft, bulk shear increases. Warmer temperatures are forecast also using NBM and NBM 50th percentile. Outside of Twin Forks and SE Connecticut which have highs more in the lower 70s, rest of area is in mid 70s to near 80 with NYC Metro and parts of NE NJ getting more into the lower 80s. With more low level instability and more bulk shear, there is more of a risk for damaging winds with thunderstorms. SPC has western parts of the region with a slight risk for severe thunderstorms.

LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
Key Messages:

* A cold front cuts off precip Saturday night.

* Becoming mostly sunny on Sunday with only slight chances for showers.

* Dry & quiet Monday into Tuesday.

* Another frontal system may bring a return to rainfall Wednesday into Thursday.

A surface low in southern Canada/northern New York sends a cold front through Saturday night. Showers and/or any remaining thunderstorms diminish with the passage of the cold front with drier air getting advected in.

Mostly sunny skies take over as high pressure gradually builds in from the northwest. To our northeast, low pressure will continue to exit into New England and into the Canadian Maritimes through Monday. This will lead to breezy W/WNW winds from an increased pressure gradient through Monday.

An upper-level trough to our west on Saturday passes east SUnday night. As it moves farther away, it takes the surface low with it farther out to sea Monday night and thereafter. This allows a ridge to our west with high pressure at the surface to fully take hold, if briefly, Tuesday into Tuesday night. Dry conditions continue with winds becoming light under a weak pressure gradient.

A frontal system from the Great Plains then moves into the Ohio or Tennessee River Valleys on Tuesday, moving through or in the vicinity of our region Wednesday into Thursday. Expecting showers during this timeframe. Too soon to call chances for thunderstorms.
MOdel guidance still varies with timing, magnitude, and track of this frontal system. Have gone with chance POPs Wednesday into Thursday, as a result.

Temperatures look to cool each day in the long-term period. Highs on Sunday will be in the low/mid 70s with all highs in the mid/upper- 60s by Wednesday. Nightly lows will range from the mid-50s to the mid-40s.

AVIATION /06Z FRIDAY THROUGH TUESDAY/
Low pressure trough remains in the vicinity tonight. Another trough approaches from the west on Friday.

Expecting IFR or lower overnight. Improvement to MVFR Friday afternoon, but with potential showers. A passing thunderstorm is possible, mainly for the NYC terminals, but the chances for this are decreasing. Improvement to VFR for some terminals late in the day such as the metro terminals and KSWF. Conditions deteriorate once again for all terminals to IFR or lower Friday night.

Light and variable winds tonight becoming southerly at 10 kt or less for Friday and continue into Friday night with outlying terminals becoming light and variable again.

...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Timing of IFR onset could be off by an hour or two for KTEB and KLGA. Timing of improving categories on Friday may also be off by an hour or two.

OUTLOOK FOR 06Z SATURDAY THROUGH TUESDAY

Friday night: IFR or lower.

Saturday: IFR to start, improving to MVFR mid-morning, then becoming VFR in the afternoon with showers likely, and a chance of thunderstorms with MVFR.

Sunday: Mainly VFR. Slight chance of showers inland. W winds G20- 25kt.

Monday - Tuesday: VFR. Monday NW winds G20-25kt.

Detailed information, including hourly TAF wind component forecasts, can be found at: https:/ www.weather.gov/zny/n90

MARINE
Dense fog advisory has been issued for all waters tonight through much of Friday morning. Otherwise, generally weak pressure gradient in place in the short term through Saturday with conditions remaining below small craft advisory thresholds.

Winds and waves are currently expected to fall below SCA criteria Saturday night through Tuesday. However, wind gusts may near SCA criteria on all waters Sunday under an increased pressure gradient.

HYDROLOGY
Basin averaged amounts with showers and thunderstorms is expected to be near quarter to a half inch with locally higher amounts through Saturday. Thunderstorms could result in areas experiencing minor flooding, especially within urban, low lying and poor drainage areas. With increasing translational speed to thunderstorms, flash flooding is not expected.

There are currently no hydrologic concerns Saturday night through the middle of next week.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until 11 AM EDT this morning for ANZ331-332- 335-338-340-345-350-353-355.