Marine Weather and Tide Forecast for Darien, CT

KEY MESSAGES
1) Today is the last day in this stretch of early season warmth.

2) Scattered showers and a few thunderstorms are possible this afternoon, mainly for eastern areas.

3) Minor flood benchmarks may be reached along some coastlines with high tide cycles tonight and Saturday night.

4) A cold front on Sunday brings additional showers and thunderstorms, before ushering in a much colder air mass early next week.

DISCUSSION

KEY MESSAGE 1

The region sees one last day featuring well above normal temperatures this week.

While not nearly as hot as previous days with NW flow developing and an incoming trough moving over into the afternoon, temperatures should still achieve the 70s across most of the region away from the immediate coast, and perhaps into the lower 80s across NE NJ and parts of the NYC metro. Cloud cover with the cooler air mass moving in aloft could also be a limiting factor. The national blend seemed reasonable and in line with MOS and short range hi-res guidance.

These temperatures still remain about 15 degrees above normal for mid April. Though a couple sites could tie or break daily max low temperatures, daily record highs are not in jeopardy, going up against the hottest April day on record for the region back in 2002. See Climate section further down for additional detail.


KEY MESSAGE 2

A few showers around early this morning with a pre frontal trough; activity exits east and offshore by mid morning.

Thereafter, slow moving frontal boundary sags south through the area into early afternoon, with an upper trough moving in right behind it. While far from a washout, the incoming cold pool aloft and subsequent steep lapse rates should help instigate scattered showers this afternoon, with greatest focus across SE CT and the Twin Forks where instability and forcing may be highest. Can't rule out a few isolated thunderstorms with the activity, though weak parameters mitigate any severe threat.
Locally heavy downpours however will be possible, with soundings indicating a long skinny CAPE profile. Minor, nuisance flooding possible with any stronger cells.

Conditions dry out this evening with loss of any diurnal heating, and weak high pressure builds in from the north through the first half of the weekend.


KEY MESSAGE 3

Astronomically high water levels with a new moon today could allow minor flood benchmarks to be reached with tonight's high tide cycle for the most vulnerable areas along the western LI Sound, as well as some of the back bays on the south shore.

A weak onshore flow develops by Saturday, and this additional component may enhance the potential and extent of impacted coastline. A Coastal Flood Advisory could eventually be needed for the Saturday night cycle.


KEY MESSAGE 4

A sharp cold front approaches the region on Sunday, bringing another round of showers and embedded thunderstorms, as well as a much cooler air mass behind it.

Strong cold air advection kicks in with a NW flow behind the front and temperatures quickly fall by late in the evening and overnight. Any lingering areas of rain could even taper as a few wet flakes across the far interior.

Lows Sunday night drop into the 30s for most, or around 40 in the NYC metro. Afternoon highs Monday in some areas are progged nearly 40 degrees colder than what we experienced this week, with locales outside the urban metro struggling to get out of the 40s. Steep lapse rates with the cold pool aloft could allow for some shower development, possibly mixed with ice pellets, though NBM PoPs have yet to catch on to this potential. The coldest in the period looks to be Monday night, with a widespread freeze across the interior, and perhaps even toward the coast.

The cooler regime appears short-lived, with gradual moderation returning conditions to above normal by midweek.

AVIATION /09Z FRIDAY THROUGH TUESDAY/
A weak cold front moves east of the region by early this morning. Weak low pressure remains along the front with a weak trough moving through the area this afternoon into early this evening.

VFR. A chance of showers remains overnight into early this morning with VFR conditions. Additional showers are possible mid to late afternoon with a trough of low pressure, and continued with the PROB30 group. An isolated thunderstorm cannot be ruled out this afternoon, however, coverage will be isolated and chances remain low, with the better chances across southern Connecticut.

Winds likely remain below 10 kt through the forecast, NW to variable, veering NNW and then N and NE during the day.

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

Amendments are possible for timing of showers, and if convection chances increase this afternoon.


OUTLOOK FOR 06Z SATURDAY THROUGH TUESDAY

Late Friday night: VFR with MVFR to IFR possible toward Saturday morning.

Saturday: Chance of MVFR ceilings.

Sunday: MVFR or lower conditions possible. Showers likely. W winds gusts 20 kt in the afternoon and evening.

Monday-Tuesday: VFR.

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

MARINE
Conditions are expected to remain below Small Craft Advisory (SCA)
thresholds with a weak pressure gradient through Saturday.

Next potential SCA conditions will be associated with a cold frontal passage as it moves through late Sunday into Sunday night. Marginal winds and seas are possible behind the front, primarily on the ocean. Largely tranquil conditions then expected early next week, with high pressure in place through Tuesday.

CLIMATE
Daily record high minimum temperatures that could be reached:

Fri, April 17: KEWR: 68/2002 KBDR: 57/2002 KNYC: 74/2002 KLGA: 73/2002 KJFK: 60/2002 KISP: 61/2002

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...None.