Marine Weather and Tide Forecast for Portland, CT

NEAR TERM /THROUGH TONIGHT/
Not much change with the surface features today. High pressure continues to nose in from the northeast and may just shift/weaken slightly. A stalled frontal boundary remains well offshore. Aloft, heights look to rise slightly as shortwave ridging builds in.

Continues to be a tough precip forecast as Sunday seemed to overperform a bit. There is plenty of moisture around in the low levels, specifically for western LI, NYC and northeast NJ which is farther away from the high pressure influence. The question just remains if there is enough lift around again today. Weak convergence in the low levels may be enough for light rain so have kept slight chances in the forecast.

Plenty of clouds around again today, with some breaks of sun possible for eastern CT once again. Given very little change in flow, cloud cover and airmass today, blended in Sunday's observed highs with NBM and 10th percentile NBM highs. This gave just a few degrees warmer than Sunday. Stuck with straight NBM for lows tonight with radiational cooling not expected.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
High pressure weakens further on Tuesday and the flow becomes more southeasterly. Additionally, some shortwave energy approaches aloft.
With plenty of moisture still around this will allow for shower activity, mainly north and west of NYC. Given clouds and potential showers went with the cooler side of NBM guidance for highs.

Some uncertainty as we head into Wednesday morning with an approaching warm front and potential wave of low pressure. Pwats surge Wednesday morning, with new 00z guidance a tad lower but still well above average for this time of year, about 2 inches.
Guidance has also come in with a less potent shortwave and less QPF than runs 24 hours ago. This is good news for any sort of heavy rainfall threat, but heavier downpours with any showers can not be ruled out. It looks like there is then potential for another shortwave to approach later in the afternoon/evening.
This could trigger more showers and thunderstorms, especially given the destabilization that is expected to take place during the day. It is worth noting that the CSU machine learning severe outlook product does have western portions of our area outlined in a 5% risk for damaging winds.

With the warm front pushing through, a deep W/SW flow and some clearing, temperatures will likely be back up in the 80s across the area. Although we may be clear Wednesday night, the moist airmass will likely keep temperatures from dropping below the upper 60s.

LONG TERM /THURSDAY THROUGH SUNDAY/
Timing of a cold frontal passage through the region remains consistent from previous forecasts, with the passage expected Thursday night. An amplifying shortwave moves out of the upper Midwest Thursday and tracks across the region Thursday night into Friday morning. And a cold front moves through the region Thursday night. With a warm and humid airmass in place for Thursday, and a vigorous vort max passing mainly to the north, showers and thunderstorms will become likely across the the lower Hudson Valley and into northeastern New Jersey Thursday afternoon. Surface CAPE increases to 1500 to around 2000 J/kg by late Thursday afternoon with shear 25 to 30kt. And atmospheric profiles show inverted V with a low level jet. Strong to locally severe thunderstorms will be possible late day into the early evening across these areas with damaging winds the main threat, and the Storm Prediction Center continues to highlight a 15% outlook for severe weather into Western Orange county, and into portions of western northeast New Jersey.
Brief periods of heavy rainfall will also be possible with the storms, however, the threat of flooding is expected to be minimal with the quick movement of the storms and no training of cells expected.

Otherwise, the remainder of the extended period will be generally quiet, except for a slight chance of thunderstorms inland Sunday afternoon as a surface trough develops and becomes the focus for lift. Temperatures will be above average Thursday into the upcoming weekend.

AVIATION /15Z MONDAY THROUGH FRIDAY/
A weak ridge of high pressure remains across the terminals and a stationary front will remain off to the south with waves of low pressure along it. The front begins to move north as a warm front during Tuesday.

There remains a few pockets of low end VFR for a few northeastern terminals into a portion of this afternoon, otherwise widespread MVFR, with pockets of IFR prevail. There will be occasional pockets light rain or drizzle throughout the day and into this evening for some terminals, mainly at the NYC metro terminals and across Long Island. Low confidence forecast continues through today and tonight with regard to the timing of specific flight categories, especially for this afternoon and early this evening. Confidence increases for widespread IFR, and LIFR for the city and coastal terminals overnight. Very little to no improvement is anticipated during Tuesday morning.

Winds will generally be E to NE 7-13kt this afternoon, with a few gusts possible across eastern most coastal terminals. The winds overall will be lighter tonight, generally closer to 5 kt or slightly less late.

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

Low confidence with exact flight categories and specific timing through this evening.

Amendments likely for flight category changes through tonight.

Periods of light rain or drizzle through this afternoon, with no specific timing.


OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY

Tuesday: IFR, with some pockets of MVFR likely. A chance of showers, mainly at night.

Wednesday: Chance of IFR in the morning, otherwise VFR. A chance of showers and thunderstorms with MVFR.

Thursday: VFR. Chance of afternoon/evening showers and thunderstorms with MVFR.

Friday: VFR.

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

MARINE
A weak pressure gradient will result in winds and waves remaining below Small Craft Advisory criteria through Wednesday night.

Ocean seas east of Moriches Inlet may briefly reach SCA levels Thursday evening as southwest winds ahead of a cold front increase.
Otherwise winds and seas will remain below advisory levels across the forecast waters Thursday through Friday night.

HYDROLOGY
At this time there are no hydrologic concerns through the Wednesday night.

Locally heavy downpours will be possible in any thunderstorms Thursday afternoon into the evening across portions of the lower Hudson Valley and into northeastern New Jersey with a moisture laden atmosphere in place and warm cloud processes dominating. However, the risk of flooding will be mitigated by the speed of any cells and lack of overall cell training.

TIDES/COASTAL FLOODING
Rip current risk remains at moderate for today and Tuesday. While winds will be mainly parallel to the coast, the resultant 4 ft 8s wave will be enough for a moderate risk. The winds become a bit more southeasterly on Tuesday and with the onshore component expecting moderate again.

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