Norwalk, Connecticut 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

311
FXUS61 KOKX 191231
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
Issued by National Weather Service Boston/Norton MA
831 AM EDT Thu Jun 19 2025

.SYNOPSIS...

A cold front approaches late today and moves across the region
Thursday night. High pressure builds Friday and into the
weekend. Bermuda high pressure will then settle just south of
the region for the first half of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...

Key Messages...

* Hot and Humid today
* scattered severe thunderstorms possible between 2 and 10 pm

Areas of dense fog was in the process of burning off this
morning. The strong late June sun angle should allow most of
this to dissipate by lunchtime.

Shortwave approach in late afternoon, encountering a moderately
unstable and deeply sheared environment, should allow for
scattered multi-cell and supercell development along/ahead of
the pre-frontal trough across central NY/PA in the early
afternoon. This activity should work east towards the region in
the late afternoon/evening, with organization into a bowing line
segment or two possible. Scattered severe storms are possible
(SPC-WFO coordinated slight risk for the area) with damaging
wind gusts the primary threat (15% probability of occurrence w/i
25 miles of a point), particularly with any bowing segment
development. There is a marginal risk of large hail (5%
probability of occurrence w/i 25 miles of a point) with any
supercell/multi cluster activity, and an isolated tornado threat
(2% probability of occurrence w/i 25 miles of a point) along
bowing segments or supercells. Farther east across LI/CT,
expectation is that storms should gradually weaken in intensity
after 8pm as storms encounter a stabilizing environment.

With the passage of the cold front tonight the showers and
thunderstorms will end. High pressure then builds toward the
region for Friday, with slightly cooler temperatures.

&&

.SHORT TERM /FRIDAY NIGHT/...

High pressure will remain in control of our weather Friday
night with lows mainly in the 60s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...

* PATTERN CHANGE TO HOT AND HUMID CONDITIONS BY EARLY NEXT WEEK *

Expect a significant long wave pattern change for the period. A
shortwave feature exits Northern New England and SE Canada
early on Friday. In its wake gradual height rises are expected
to take place for the most part beginning Friday and into the
weekend. Much of the NWP global guidance is suggestive of a
shortwave feature which attempts to ride and break through the
northern portion of the building ridge. This will be a transient
feature as questions remain as to how this feature will track
and whether its effects will be mainly north of the CWA towards
the middle of the upcoming weekend. For now have covered this
feature with slight chance to low end chance PoPs. In any event,
the turn to a hot and humid regime looks likely into early next
week as higher heights and thicknesses build across the region.
The warm up is expected to begin to build by late Sunday,
especially for western and southwestern most areas.

Hot and humid conditions thus are likely to prevail Monday
through Wednesday with primarily dry weather as any shower /
t-storm activity is likely to remain west and northwest of the
region. At this time it appears that a good portion of the
region will experience the first heat wave of the season, with
less certainty further east. Regardless, temperatures will
average well above normal into next week. Towards the tail end
of the period (say mid to late week) if the ridge break downs
enough, the chance of diurnally driven convection would increase
and could introduce some chance of late day and early evening
showers and t-storms.

&&

.AVIATION /13Z THURSDAY THROUGH MONDAY/...

12z TAF Update...

Main issue is the areas of dense fog/low clouds which will burn
off in most locations by lunch time with most locations
improving to VFR. Then the concern shifts to the scattered
thunderstorm threat after 18z. This activity will be hit or
miss...but a few of the storms may become strong to severe. This
may result in brief IFR to even LIFR conditions under any storm.
SW winds may gust to 25 knots at times this afternoon shifting
to the west later tonight.

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

Main concern revolves around areas of fog/low clouds that should
be burning off through lunchtime. Then we will be watching for
scattered thunderstorms after 18z into the evening.

.OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...

Friday through Monday: Mainly VFR.

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

&&

.MARINE...

We expanded the Marine Dense Fog Advisory until 15z...but should see
visibility to improve through lunch time. Southwest flow ahead
of a cold front will result in gusts to near 25 kt are likely
on the ocean waters and southern bays. As a result ocean seas
will likely build to around 5 feet late today into Fri AM.
Behind the cold front, NW gusts are expected to run below 25 kt.


Winds and waves are expected to fall below Small Craft Advisory
criteria Friday afternoon and continue through early next week.
Ocean seas should settle in around 2 ft, occasionally up to 3
ft during the weekend and into early next week.

&&

.HYDROLOGY...

Once again a marginal risk of flash flooding (around 5% probability)
today, with scattered locally heavy downpours and thunderstorms
late Thursday afternoon into the evening. The quicker storm
motion as compared to today, will limit the flash flood threat
to any localized areas of training.

There are no hydrologic concerns Friday through early next
week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Air Quality Alert until 11 PM EDT this evening for CTZ005>007-
     009>011.
NY...High Risk for Rip Currents from noon EDT today through this evening
     for NYZ075-178-179.
NJ...None.
MARINE...Dense Fog Advisory until 11 AM EDT this morning for ANZ331-332-
     335-340-350-353-370.

&&

$$

SYNOPSIS...Frank
NEAR TERM...Frank
SHORT TERM...Frank
LONG TERM...99
AVIATION...Frank
MARINE...Frank
HYDROLOGY...99