Marine Weather and Tide Forecast for Shelter Island, NY

KEY MESSAGES
1) Upper low departs to the east today with isolated to widely scattered showers.

2) Summer-like warmth builds this weekend into the first half of of next week.

3) Cold water safety concerns for this weekend with good boating weather, and water temps still in the lower 50s.

DISCUSSION

KEY MESSAGE 1
An upper low over the area this morning will pass to the east today with isolated to scattered showers. Highest coverage will be this afternoon across southern CT and eastern LI. Steep low- level lapse rates, cyclonic flow, and low-level moisture should also result in partly to mostly cloudy skies this afternoon.
W-NW winds may gust 15 to 20 mph.

Highs today are forecast to get up into the 60s, slightly below normal for most locations.


KEY MESSAGE 2
Upper level ridging builds in tonight through early Saturday, then flattens some for the rest of the weekend before significant height rises work into the easter third of the country early next week. The latter of which will result in a significant warmup, with highs 15 to 20 degrees above normal for Tuesday and Wednesday. At this time, forecast highs fall well short of record highs, with many well into the 90s.

Before then though, temperatures will steadily increase through the weekend, with highs in the 70s to lower 80s Saturday, then into the 80s for most locations on Sunday. Highs could get close to 90 across metro NE NJ. BDR and ISP are forecast to be a few degrees short of record highs Sunday, which is 85 set back in 1974.

The high temperature forecast remains a bit tricky as the NBM5.0 continues to look too warm, especially near the coast. Have generally adjusted it downward for high temps a couple of degrees Saturday and Sunday. Much of the guidance is still a bit cooler than these values as well. What is interesting, is the NBM box and whisker plots show very small differences over the weekend between the 25th and 75th percentiles. The median and NBM deterministic are nearly on top of each other. So this tells us there is not much spread in the guidance, however, the bias algorithms may be still adjusting heading into the warm season.
Time will tell.

Global model guidance for midweek continues to show a break down of the upper-level ridge in response to a closed upper-low traversing Canada. Rain chances increase with a cool down for the end of the week.


KEY MESSAGE 3
There are cold water safety concerns this weekend as water temperatures remain in the lower 50s. The cold water temperatures can quickly cause hypothermia and physical incapacitation to anyone suddenly immersed in the water. Anyone going out on small boats, canoes or kayaks should plan accordingly and use extreme caution to avoid this threat. A Marine Weather Statement will likely be issued later today.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
An upper level low departs to the NE while high pressure builds in from the west.

VFR conditions are expected through the TAF period. Some brief MVFR cigs are still possible for KGON, but with the upper low departing, chances are decreasing.

Winds will be from the northwest today, 10-15 kt with some gusts to 20 kt or so. Sea breeze is trying to make its way through KBDR, but may push back south later this afternoon as the NW flow strengthens a bit, so have TEMPO group for S winds there through 20Z. Otherwise, peak gusts of 25 to 30 kt are possible, especially for KEWR. Gusts may be occasional at times.
Winds this evening diminish and become light and variable overnight. Winds Saturday morning will become south or southwesterly at 5 to 10 kt, increasing to 10 to 15 kt by mid morning with gusts 20 to 25 kt.

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

Gusts may be occasional today. A few gusts may be slightly higher than forecast.

OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY

Saturday: VFR. S-SW wind gusts 15-20 kt with gusts 20 to 25 kt in the afternoon and early evening.

Sunday: VFR. SW winds 5-10kt.

Monday: VFR. SE winds 5-10kt.

Tuesday: VFR. S-SW wind gusts 15-20 kt afternoon and early evening.

Wednesday: VFR becoming MVFR or lower in any showers and isolated thunderstorms in the afternoon. S to SW winds 10 to 15 kt, becoming WSW by late afternoon. Gusts 15 to 20 kt.

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

MARINE
A building SE swell from low pressure heading up into the Canadian Maritime will produce SCA seas across the ocean waters today into the fist half of tonight. Any respite after this will be short-lived, as high pressure quickly builds across the waters late tonight into Saturday morning, then to the east. A strengthening southerly flow is likely to bring a return to SCA conditions on the ocean late Saturday afternoon/early evening.
Some of the south shore bays could eve see a period of 25 kt gusts. Winds and seas will then begin to gradually subside the second half of Saturday night into Sunday. However, seas could linger around 5 ft on the ocean waters for much of Sunday.

Sub-SCA conditions are anticipated Sunday night through Monday night as flow temporarily back to the as flow weaken under high pressure. SCA conditions likely redevelop on the ocean water Tue into Tue night with strengthening SW flow, potentially for all waters by Wednesday.

There are cold water safety concerns this weekend as water temperatures remain in the lower 50s. The cold water temperatures can quickly cause hypothermia and physical incapacitation to anyone suddenly immersed in the water. Anyone going out on small boats, canoes or kayaks should plan accordingly and use extreme caution to avoid this threat. A Marine Weather Statement will likely be issued later today.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ350-353- 355.