Marine Weather and Tide Forecast for Norwalk, CT

KEY MESSAGES
1) A warm front will approach today. Low pressure developing along the front will pass south of Long Island late tonight into early Monday, with overall minor impacts.

2) Possible isolated minor coastal flooding for NY Harbor, western Long Island Sound, and the western south shore bays of Long Island during the Monday morning and Tuesday morning high tide cycles. Possible high surf for ocean beaches, especially for Long Island ocean beaches.

3) Chance of showers and possible thunderstorms Tuesday night into early Wednesday with a quick moving system.

DISCUSSION

KEY MESSAGE 1
Sped up PoP slightly this morning into early this afternoon per current radar trend. Modeled rainfall has fallen slightly, but the chance remains for locally heavier bands mainly across Long Island with higher amounts with PW around 2 inches. REFS probabilistic amounts look overdone. The 06Z HRRR probabilities of an inch in 3 hours of 30% or more have trended down from the 00Z cycle, confined to eastern Long Island and SE CT early this evening, while the 12Z HRRR suggests amts of 1/2 to 1 inch in 3 hours could still occur as far west as the NYC metro area. With this in mind think this will be no more than a minor urban and poor drainage event. Timing of any heavier rain looks to be this evening.

For winds, the modeled track keeps the llvl jet over the ocean, with E flow across the CWA Peak gusts around 35 mph appear on track. There could be some locally higher gusts along the western portion of the Sound due to funneling effects.

With deep lift an elevated instability, there remains the chance for some embedded elevated tstms particularly tonight as the jet and upper trof approach.

The rain tapers off early Monday, with mostly sunny skies likely to develop in the afternoon per NBM.

KEY MESSAGE 2
Recent new moon with high astronomical levels and increased storm surge ahead of low pressure late today into early Monday will make for some water levels to potentially reach minor flood benchmarks, especially for Monday morning and Tuesday morning high tide cycles. This is mainly for the NY Harbor, western Long Island Sound and western South Shore Bays of Long Island. Additionally, this evening's high tide cycle may come close to minor for southern Fairfield.

While the low moves far enough away later Monday into Monday night, the weak high pressure moving in will present a lack of sufficient offshore flow. The northerly winds will not be that gusty and the circulation pattern changes by Tuesday with another low approaching from the north and west to give more onshore flow early Tuesday. So, water levels will be around the same as the previous day and another round of minor coastal flooding will be possible.

Along the oceanfront, building seas are progged to produce breaking waves in the 4-7 ft range. The highest surf right now is slated for tonight. Some minor beach erosion can be expected.

KEY MESSAGE 3
Less amplified and longer wavelength trough in mid levels approaches Tuesday and moves across early Wednesday. At the surface, low pressure approaches from the north and west but the center of this low remains north of the region through early Wednesday. This will bring a cold front across early Wednesday.

There will be a brief chance of showers along with a possible thunderstorm with some forecast elevated instability, mainly Tuesday night. Not expecting much rainfall with this considering the lack of atmospheric moisture within the system.

AVIATION /13Z SUNDAY THROUGH THURSDAY/
Low pressure and an associated warm front will impact the terminals through tonight.

VFR through mid morning. Rain moves in this morning, with moderate to briefly heavy rain possible during the afternoon.
Isolated thunder can not be ruled out. Conditions lower to MVFR later this morning, then IFR by the afternoon and evening hours. LIFR is possible tonight.

Winds increase this morning, with gusts 15-20 kt arriving shortly. Winds continue to increase into the afternoon, especially closer to the coast and become more easterly. Peak sustained winds of around 15 kt are expected, with gusts 25 to 30 kt later this afternoon into the evening. Winds lower a few kt overnight but remain gusty out of the north.

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

Amendments possible through tonight due to uncertainty in timing of heavier precipitation and change in flight categories.

OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY

Monday: Mainly dry, becoming VFR mid to late morning.

Tuesday: MVFR cigs possible in the morning at KGON/KBDR, otherwise mainly VFR. Chance of showers at night.

Wednesday: VFR. W-NW winds 10-15G20kt in the afternoon.

Thursday: VFR.

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

MARINE
SCA remains in effect for all waters. Increasing winds today along with building seas will produce SCA conditions by the end of the day, lasting thru tonight.

On the ocean, the SCA was extended thru Mon night as seas slowly subside. Elsewhere, winds are expected to remain blw 25 kt Mon.

Another possible SCA event late Tue night into Wed for parts of the ocean with the next frontal system, then winds and seas are expected to remain blw SCA lvls for Thu.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Monday for ANZ331-335-338- 345.
Small Craft Advisory from 2 PM this afternoon to 6 AM EDT Monday for ANZ332-340.
Small Craft Advisory until 4 AM EDT Tuesday for ANZ350-353-355.