Marine Weather and Tide Forecast for Southport, CT

KEY MESSAGES
1) Dangerous heat is expected mid-late week. Extreme Heat Watches have been issued.

DISCUSSION

KEY MESSAGE 1
H5 ridging is already in the process of building across the Gulf region as of Sunday afternoon, with guidance projecting the ridge to build north-northeast thanks to deepening Pacific cutoff through the coming week. As previous forecaster noted, heights reach 2-2.5 standard deviations above normal by Wednesday, just as it crests near the Great Lakes. With this ridge in place, and a modified subtropical airmass, will be looking at the potential for a prolonged period of dangerous heat mid to late week.

There is a bit of uncertainty with the dominant factors being the placement/amplification of the ridge axis and as such the moisture profile. GFS and its ensembles remain the slightly more amplified/eastern outlier (22-24C at H8) while other extended deterministic/ensemble guidance is not as warm along the immediate coast. Dewpoint spreads still remain on the order of 3-6F mainly with their typical medium range uncertainty.
However, even on the lower 25th-10th percentile, dewpoints are still in the upper 60s to near 70F over a nearly 72 hour period.

Even with this uncertainty recent run to run consistency support a potentially dangerous heat situation with only a few degrees difference between potential Advisory and Warning level heat indices Wednesday through at least Friday. The rising surface dewpoints will also limit overnight relief. Given these factors, have hoisted an Extreme Heat Watch for all areas Wednesday through Friday. This could be a dangerous situation especially for sensitive groups.

AVIATION /20Z SUNDAY THROUGH FRIDAY/
High pressure slowly builds in through the TAF period.

VFR through this evening with dry conds, however included PROB30 for -SHRA/MVFR at KSWF this aftn. IFR probable for KGON/KISP/KJFK/KBDR late tonight through mid-morning Monday.
There is a chance of IFR for KLGA/KEWR/KHPN/KTEB for roughly the same time period, but confidence not high enough at this time to include in TAFs.

SE-S winds at around 10kt or less this afternoon and Monday, but light and variable tonight.

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

IFR possible from approx 08z-12z Monday for KLGA/KEWR/KTEB.
Chance that IFR does not occur at KJFK tonight, or that start/end timing of IFR is off by 1-2 hours.

OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY

.Monday PM: VFR.

.Tuesday: VFR in the morning. Chance of sub-VFR with shower/TSTM PM.
S-SW wind gusts 15-20 kt.

.Wednesday: VFR. S-SW wind gusts 15-20 kt.

.Thursday: VFR.

.Friday: VFR in the morning. Chance of sub-VFR with shower/TSTM PM.

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

MARINE
Conditions forecast to remain below SCA thresholds on the non ocean waters through Thu. Wind gusts reach around 20 kt on the ocean waters late day Tue and Wed, but should remain below SCA criteria. Seas approach 5 ft on the ocean in a S flow late Wed into Wed night.

Rip Currents: The rip current risk remains low through Monday with 1-2 ft swell sets with period varying between 5-10 s and onshore winds at or below 10 kt.

CLIMATE
Record High Temperatures:

July 1: KEWR: 100/1963 KBDR: 95/1963 KNYC: 100/1901 KLGA: 97/2018 KJFK: 102/1963 KISP: 96/1964

July 2: KEWR: 102/1966 KBDR: 100/1966 KNYC: 100/1966 KLGA: 101/1966 KJFK: 101/1966 KISP: 99/1966

July 3: KEWR: 105/1966 KBDR: 99/1966 KNYC: 103/1966 KLGA: 107/1966 KJFK: 104/1966 KISP: 104/1966

Record High Minimum Temperatures:

July 1: KEWR: 77/2018 KBDR: 73/2013 KNYC: 79/2018 KLGA: 79/2018 KJFK: 75/1968 KISP: 73/2025

July 2: KEWR: 79/2022 KBDR: 73/2022 KNYC: 82/1901 KLGA: 78/2002 KJFK: 74/2018 KISP: 74/2014

July 3: KEWR: 82/2002 KBDR: 75/2002 KNYC: 82/2002 KLGA: 81/1966 KJFK: 78/2002 KISP: 76/2018

OKX WATCHES/WARNINGS/ADVISORIES
CT...Extreme Heat Watch from Wednesday afternoon through Friday evening for CTZ005>012.
NY...Extreme Heat Watch from Wednesday afternoon through Friday evening for NYZ067>075-078>081-176>179.
NJ...Extreme Heat Watch from Wednesday afternoon through Friday evening for NJZ002-004-006-103>108.
MARINE...None.