Marine Weather and Tide Forecast for East Hampton, CT

KEY MESSAGES
1) A colder air mass has settled in. Sub-freezing temperatures expected again for much of the area outside NYC and the nearby suburbs tonight.

2) Milder weather should return mid to late week, before turning more unsettled this weekend.

DISCUSSION

KEY MESSAGE 1
Showers are possible with a secondary cold frontal passage into early this afternoon. HRRR forecast soundings are even showing some potential for thunder across eastern Long Island this afternoon via minimal SBCAPE up to 200 J/kg and forced ascent right along the front.

Behind the front will be the coldest air of the week as high pressure builds in through tonight, with clearing skies, and winds becoming near calm. Temperatures across most of the area will be sub-freezing and a Freeze Warning remains in effect. In addition with the light winds and clear skies, areas of frost will be likely. The Freeze Watch for Nassau county was cancelled as temperatures there are expected to remain just above freezing. Record daily low temperatures will be approached or may be set for a few climate stations Tuesday morning. See the Climate section for details.

Temperatures remain several degrees below normal Tuesday, and then return to near normal levels Tuesday night as high pressure moves off the coast with a return flow. In addition warm air advection sets up as a warm front approaches and moves through Wednesday morning. Lift along the front increases Tuesday night, and light rain showers will be possible. Also, a weak low will pass across the area early Wednesday keeping a chance of showers late Tuesday night into Wednesday morning.


KEY MESSAGE 2
The cooler regime is short-lived as the upper trough exits offshore and ridging attempts to build in from the Midwest.

Afternoon temperatures Wednesday jump 5 to 10 degrees from the previous day for most, with highs in the mid 50s to mid 60s, though remaining a bit cooler across SE CT. Thursday is likely the mildest day of the week, downsloping off NW flow helping temps get into the upper 60s to low 70s from NYC and points north and west, with low to mid 60s along the coast.
Temperatures then begin to gradually cool down late week, though not as cold as earlier in the week.

Still a bit early for the fine details, but pattern appears to turn more unsettled into the weekend. Decreasing forecast confidence in this period with diverging solutions in guidance.
Shortwave energy looks to drop down along the eastern side of the ridge, helping carve out an upper low near the Canadian Maritimes. This should block further advancement of the ridge and help break it down, with a nearby frontal boundary likely serving as focus for showers at times. Placement and timing of these features, as well as any frontal waves, will determine exact impacts and extent of unsettledness, but doesn't appear to be a washout. Will continue to carry chances for rain through the weekend and into early next week, with a bit cooler conditions.

AVIATION /13Z MONDAY THROUGH FRIDAY/
A cold front passes through this morning, followed by high pressure building in from the west.

Mainly VFR thru TAF period. Brief MVFR possible with isolated to scattered rain showers around into this afternoon. There is a chance the showers mix with snow NW of the NYC terminals, mainly KSWF.

Winds become NW by 15Z for most terminals, and speeds increase with gusts aoa 20 kt this afternoon and early evening. Gusts diminish and flow lightens as it gradually veers NNW late this evening and into early Tuesday AM.

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

PROB30 timing for showers may be off by 1-3 hours.

OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY

Tuesday: VFR.

Wednesday: Mainly VFR. Slight chance of showers in the morning.

Thursday and Friday: VFR.

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

MARINE
Wind gusts in NW flow after a cold frontal passage may approach 25 kt for a few hours late this afternoon or early this evening on NY Harbor and on the adjacent ocean waters right at the harbor entrance. Have not yet issued SCA as confidence in this happening is only medium at best, and so will watch trend with winds early this afternoon over land in northern NJ and the NYC metro area. Otherwise, winds and seas should remain below advisory levels through Friday night.

CLIMATE
Daily record low temperatures for Tue Apr 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 Warning from midnight tonight to 9 AM EDT Tuesday for CTZ005>012.
NY...Freeze Warning from midnight tonight to 9 AM EDT Tuesday for NYZ067>071-078>081.
NJ...Freeze Warning from midnight tonight to 9 AM EDT Tuesday for NJZ002-004-103>108.
MARINE...None.