Marine Weather and Tide Forecast for Mount Sinai, NY

KEY MESSAGES
1) Rain showers develop this morning and fall intermittently through much of the day.

2) Colder air mass settles in early this week, with subfreezing temperatures likely outside the urban NYC metro Monday night.

3) Milder weather returns mid to late week.

DISCUSSION

KEY MESSAGE 1

Broad upper trough swings into the East, pushing a cold front through the region later this morning.

Abundant low stratus and patchy fog around to start the day.
The fog may be locally dense in a few spots, but most surface obs have been coming in aoa a half mile. Pockets of drizzle and scattered showers ahead of the frontal boundary is gradually working into the local area early this morning. As the front moves through late this morning, additional rain develops behind it supported by the rapidly falling heights as the trough comes in and an incoming 120 kt upper jet. The rain tapers from west to east late this afternoon into early evening.

QPF is relatively light, on the order of a couple of tenths for most, with highest amounts up to a half inch off to the north and west into the LoHud Valley. While a brief downpour cannot be ruled out, the bulk of the activity should remain light to moderate with no hydrologic concerns.


KEY MESSAGE 2

With the fropa late this morning, temperatures will struggle to climb any higher than where they started the day, and more likely, fall several degrees into the 40s through the afternoon as colder air advects in on the NW flow behind the fropa.

CAA continues tonight with temperatures bottoming out in the 30s for most, and low to mid 40s in the NYC metro. Additional cloud cover develops early Monday AM as a secondary front approaches, and could help spur a few isolated snow showers into the LoHud Valley and rain showers along the coast after daybreak Monday as some hi-res CAMs are depicting. Cyclonic flow and steep lapse rates with the cold pool aloft should lead to plenty of stratocu Monday, as well as the continued possibility of isolated to scattered showers. Can't rule out some wet flakes across the far interior. The bulk of the day remains dry though, and much drier compared to the previous day.

The coldest temperatures early next week appear likely Monday night with clearing skies and light winds helping to efficiently cool the BL. Opted to blend in a bit cooler MAV/MET guidance given this setup, and a widespread freeze appears likely for most outside NYC. Freeze Watch hoisted for areas away from the urban metro. Lows range from the mid 20s across the interior to mid 30s in the city, or about 10 to 15 degrees below normal. Record daily lows are even in reach for a few sites, see Climate section below for detail.

Temperatures remain below normal on Tuesday with highs ranging from the upper 40s to mid 50s. High pressure overhead shifts offshore Tuesday night, setting up a weak return flow and a milder night compared to Monday night.


KEY MESSAGE 3

The high shifts offshore Tuesday night as a warm front lifts through the region. Chance for a few showers as it does into Wed AM, but coverage looks scattered at best. A weak cold front follows later Wednesday, but despite the fropa, temperatures nudge upwards into late week with downsloping NW winds.

Afternoon temperatures Wednesday jump 5 to 10 degrees from the previous day, with highs mostly in the upper 50s to mid 60s.
Thursday likely the mildest day of the week with ridging building from the west; forecast highs into the 60s and 70s.

AVIATION /09Z SUNDAY THROUGH THURSDAY/
An approaching cold front and wave of low pressure moves into the region early this morning, moving east of the area during the afternoon. Weak high pressure briefly builds this evening.

IFR to LIFR conditions have become widespread, with local VLIFR.
Showers have begun to move into KSWF with drizzle elsewhere.
Showers will continue to advance into the area, ahead of and with a cold front, this morning, and conditions may improve slightly, remaining IFR until late morning, then MVFR. An isolated thunderstorm remains possible this morning , however, with low coverage and uncertainty with where, have not included in the TAFs. Showers will be possible after a cold front passage, with improving conditions to high end MVFR this afternoon and then becoming VFR.

Winds generally light E/SE to variable, shifting to NW and becoming gusty with a cold front passage mid to late morning west, and into the mid afternoon east. Highest winds and gusts will likely be a few hours after frontal passage. with gusts and winds diminishing during the afternoon. Gusts end early in the evening.

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

High confidence in winds. Medium to low confidence in timing and extent of lower ceilings and visibilities into early this morning. Amendments likely.


OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY

Late Sunday night: VFR.

Monday: Mainly VFR. Chance of showers. NW winds G20kt.

Tuesday: VFR.

Wednesday: Mainly VFR. Slight chance of showers.

Thursday: VFR.

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

MARINE
Areas of fog around this morning, likely under 1 nm given reported surface obs along the coast. Dense Fog Advisory issued for all coastal waters until 9 am this morning. Vsbys should improve by mid morning as rain showers overspread the waters.

Cold front moves through later in the morning, with increasing NW flow behind it. This should produce SCA wind gusts (25 to 30 kt) on the near shore ocean waters, LI Sound, LI Bays, and NY Harbor for the afternoon. Nearshore ocean seas will likely build to around 4 or 5 ft. Winds and seas subside this evening, and conditions then remain below SCA levels through at least midweek.

CLIMATE
Daily record low temperatures:

Tue, April 21

KEWR: 31/1981 KBDR: 29/1956 KNYC: 26/1875 KLGA: 33/1956 KJFK: 34/1956 KISP: 30/1965

OKX WATCHES/WARNINGS/ADVISORIES
CT...Freeze Watch from late Monday night through Tuesday morning for CTZ005>012.
NY...Freeze Watch from late Monday night through Tuesday morning for NYZ067>071-078>081-177-179.
NJ...Freeze Watch from late Monday night through Tuesday morning for NJZ002-004-103>108.
MARINE...Dense Fog Advisory until 9 AM EDT this morning for ANZ331-332- 335-338-340-345-350-353-355-380-383-385.
Small Craft Advisory from 11 AM this morning to 6 PM EDT this evening for ANZ331-332-335-338-340-345.
Small Craft Advisory from 8 AM this morning to 11 PM EDT this evening for ANZ350.
Small Craft Advisory from 8 AM this morning to 6 PM EDT this evening for ANZ353-355.