Fire Island Inlet NY to Moriches Inlet NY out 20 NM Marine Forecast
|Tonight...Sw Winds 5 To 10 Kt. Seas Around 3 Ft. Slight Chance Of Showers This Evening. Chance Of Showers After Midnight, Then Showers Likely Late.|
|Thu...Se Winds 5 To 10 Kt, Becoming E 10 To 15 Kt With Gusts Up To 20 Kt In The Afternoon. Seas 3 To 4 Ft. Rain. Vsby 1 To 3 Nm In The Afternoon.|
|Thu Night...Ne Winds 15 To 20 Kt, Becoming Nw 20 To 25 Kt After Midnight. Gusts Up To 30 Kt. Seas 3 To 5 Ft, Building To 4 To 7 Ft After Midnight. Rain, Mainly In The Evening. Vsby 1 To 3 Nm.|
|Fri...W Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 4 To 7 Ft. Chance Of Rain.|
|Fri Night...Nw Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 4 To 6 Ft. Chance Of Rain In The Evening.|
|Sat...Nw Winds 15 To 20 Kt With Gusts Up To 25 Kt, Becoming W 5 To 10 Kt In The Afternoon. Seas 3 To 5 Ft.|
|Sat Night...Sw Winds 5 To 10 Kt. Seas 2 To 3 Ft.|
|Sun...W Winds 5 To 10 Kt. Seas Around 2 Ft.|
|Sun Night...Sw Winds 5 To 10 Kt. Seas Around 2 Ft.|
|Mon...Sw Winds 5 To 10 Kt. Seas Around 2 Ft. Chance Of Showers.|
|Mon Night...W Winds 5 To 10 Kt. Seas Around 2 Ft.|
| 657 PM EDT Wed Apr 14 2021 |
Synopsis for the Long Island Waters and New York Harbor - ANZ300
Weak low pressure will move east off the Mid Atlantic coast tonight, then intensify Thursday into Thursday night as an upper level low approaches from the Great Lakes. Low pressure will exit the area Friday through early Saturday. Weak high pressure will then build in through early next week.
| Area Forecast Discussion|
National Weather Service New York NY
832pm EDT Wednesday April 14 2021
Weak low pressure will move east off the Mid Atlantic coast tonight, then intensify Thursday into Thursday night as an upper level low approaches from the Great Lakes. Low pressure will exit the area Friday through early Saturday. Weak high pressure will then build in through early next week. A cold front will approach toward the middle of next week.
Near Term - Until 6am Thursday Morning
Forecast has been updated to capture latest trends. Have slowed down precipitation as showers continue to fall apart west of our area. The rest of the forecast remains on track.
Showers to the west of NYC are falling apart as they encounter dry low level air and should not amount to much through this evening. As the upper level low approaches from the west tonight and the surface low moves off the Mid Atlantic coast, low level convergence as an inverted trough starts to develop N of the sfc low plus difluent flow aloft should result in increasing changes for showers, with likely Probability of Precipitation across Long Island and most of southern CT and chance elsewhere. Low temps tonight on the milder side of MOS guidance, with lower 50s in NYC and NE NJ, and mid/upper 40s to the north/east.
Short Term - 6am Thursday Morning Through Thursday Night
Mode guidance has trended wetter with the system impacting the area during this time. An inverted trough extending N of the intensifying surface low, with low level warm air advection to its east, should result in at least a moderate rainfall. Rain should become heavy at times from late day Thu into Thu evening across S CT and Long Island, during peak low level WAA/destabilization. Any elevated CAPE should be shallow so do not expect thunder, but with TT nearing 50 cannot totally rule it out either.
With most of the precipitation along and E of the inverted trough, NYC and points west may not see much precipitation late Thu night, but CAA on the back side of the intensifying low as it passes between Montauk and the 40/70 benchmark should pull down enough cold air to allow precipitation to mix with or change to wet snow across interior S CT and the lower Hudson Valley, with a coating of accumulation possible on grassy surfaces especially in the higher elevations of northern Fairfield/New Haven.
Temps Thu and Thu night are a blend of MOS guidance and model 2m temps, weighted more toward the NAM, with highs in the mid 50s in NE NJ, and upper 40s/lower 50s elsewhere, then low temps ranging from the lower 40s in NYC and immediate burbs, to the mid 30s well inland.
Long Term - Friday Through Wednesday
Scattered light rain will stick around Friday as the low is slow to exit our area. It is possible that southern areas dry out for several hours and then see showers work their way back into the area as the low retrogrades. Winds will continue to be gusty and with a northwest flow expect highs well below seasonable, in the 40s to lower 50s.
Very brief ridging builds in aloft to keep the first half of the weekend dry. Slight chance Probability of Precipitation returns late Sunday as a piece of shortwave energy breaks off of an upper low that is currently over the northwest coast. This will suppress the ridging and with little moisture may produce light showers. Winds will drop off significantly Saturday evening with calm winds prevailing through the start of the week.
The pattern remains unsettled through the middle of next week. Another shortwave dips just south of our area bringing another chance of light Showers Monday afternoon. Brief ridging aloft then builds in to keep the first half of Tuesday dry. The next feature to look at is a surface low over the Great Lakes that will head northeast and drag a cold front over the area. There is still much uncertainty with this feature and where it develops a secondary low. Any precipitation with the passing front looks to be late Tuesday through Wednesday.
SCA (Small Craft Advisory) conditions are likely for the eastern Sound/ocean waters Thu afternoon via increasing E flow, then on all ocean waters Thu night in NW-N on the back side of departing low pressure. Expecting peak gusts 25-30 kt and max ocean seas 5-7 feet, though there could be a few gusts as high as 35 kt on the eastern ocean waters late Thu night.
SCA (Small Craft Advisory) conditions likely for all waters Friday through Friday evening, with the ocean waters holding on to stronger wind gusts a bit longer. Mainly below SCA (Small Craft Advisory) conditions for the weekend through early next week.
Basin average Quantitative Precipitation Forecast late tonight into Fri now over and inch north/east of NYC, with ams over 2 inches for parts of southern CT. This could cause nuisance flood impacts across southern CT and perhaps parts of Long Island from late day Thu into Thu night.
NOAA New York NY Office: Watches - Warnings - Advisories
CT...None. NY...None. NJ...None. MARINE...None.