West Hartford, Connecticut 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

964
FXUS61 KBOX 130547
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
147 AM EDT Wed Aug 13 2025

.SYNOPSIS...
Patchy fog overnight gives way to another hot and humid day on
Wednesday. An approaching cold front will bring a chance for showers
and thunderstorms later Wednesday afternoon and evening.
Additional showers and thunderstorms are possible into Thursday,
but considerable cloud cover will limit instability. Seasonable
temperatures and lower humidity levels are expected for Friday
and Saturday, although temperatures briefly warm up again for
Sunday. After midweek, our next chance for rain is with a cold
front which looks to move in on Monday.

&&

.NEAR TERM /UNTIL 1 PM THIS AFTERNOON/...

Near Term

Wednesday

Key Messages:

* Increasing Heat and Humidity Today

* Thunderstorm chances increase early to mid afternoon, mainly west
  of I-95

Heat and humidity peaks this afternoon as southwest flow ahead of an
approaching cold front will support dewpoints increasing into the
upper 60s to low 70s across southern New England today. The air mass
in place remains unsually warm for mid-August with 925 hPa temps in
the low 20s Celsius. This will support another day with afternoon
high temperatures in the upper 80s to low 90s. Since we anticipate
higher dewpoints today, we can expect higher head indices as well in
the mid to upper 90s.

As the aforementioned cold front approaches from the west, southern
New England will see increasing chances for showers and
thunderstorms during the early to mid afternoon hours. Latest HREF
model run (00Z) and its associated members support thunderstorm
activity as far east as Boston. Confidence in showers and storms is
highest west of Worcester, where forcing for ascent should arrive in
time to take advantage of diurnal instability. The last several runs
of the HREF model dating back to 00Z Tuesday, have trended toward a
faster arrival of the cold front which has resulted in thunderstorm
chances gradually increasing further east. With southwest flow
supporting a surge in PWATs to 2+ inches, any storms that do develop
will have the potential to support heavy downpours. Severe
thunderstorm potential is very low since both mid-level lapse rates
and deep layer windshear will be very weak. Nonetheless, we can`t
rule out an isolated strong storm as precip loading, steep low-level
lapse rates, and high surface based instability could result in
isolated instances of strong dowburst winds.


&&

.SHORT TERM /1 PM THIS AFTERNOON THROUGH 6 PM THURSDAY/...
Key Messages

* Increasing heat and humidity on Wednesday

* Isolated to scattered thunderstorms possible Wednesday
  afternoon and evening

Wednesday

Increasing heat and humidity on Wednesday with dewpoints in the
upper 60s to possibly low 70s in the CT and Merrimack River Valleys.
Another hot day in store with high temperatures in the mid 90s. With
the increased humidity we can expect heat indices in the mid to
perhaps upper 90s.

A weak cold front will be the trigger for scattered showers and
thunderstorms later Wednesday afternoon. Not expecting much in the
way of severe weather with rather weak mid-level flow, poor lapse
rates, and effective shear <25kts. CAMs show CAPE values approaching
2000 J/kg so there could be a few instances of isolated stronger
downbursts and marginally severe wind. Bigger story will be the
chance for some heavier rain. HREF PMM precipitation forecast shows
swatches of 1"+ rainfall across portions of western and central
Massachusetts. The timing of the front will be well after peak
heating so activity will wane in coverage and intensity as it makes
its way east.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Key Messages:

* Still on the humid side Thurs, but considerable cloudiness with
  showers and t-storms as cold front moves offshore.

* Cooler with lower humidity levels Fri/Sat with drier weather.

* Warming trend with rising humidity levels Sun precedes a cold
  front on Mon.

Details:

Still on the humid side for Thurs as cold front will be slowly
lurching eastward and eventually offshore. Considerable cloudiness
limiting diurnal heating will cut into how much we can destabilize,
but we should still be able to muster another period of scattered
showers and thunderstorms. Not expecting severe weather with this
activity but could be capable of heavier downpours given the humid
airmass. Highs mid to upper 80s, with falling dewpoints/humidity
levels into the evening and overnight hours as ridging builds in
from the north.

High pressure then allows for dry weather and a cooler and lower-
humidity airmass to filter in for Fri into Sat. We get a brief
warmup into Sunday with rising humidity levels, which precedes a
cold frontal passage around Mon which will offer our next best
chance for rain.

&&

.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

06Z TAF Update:

Through 12Z...High Confidence

Mainly VFR with light winds. Some low-stratus fog may support
periods of IFR/LIFR at Cape/Islands terminals through sunrise.

Today...High Confidence

VFR. Any IFR/LIFR near the south coast should lift by 13-14Z.
Chance for thunderstorms after 18Z, mainly over the western
terminals, though there is also at chance at both BED and BOS.

Tonight...Moderate Confidence

Any thunderstorm activity will wind down after sunset. A few
showers may linger. Ceilings fall to IFR/MVFR mainly south of
I-90.

Tomorrow...Moderate Confidence

Mainly VFR. Some MVFR over the south coast, Cape, and Islands.
Periods of scattered showers with embedded thunderstorms during
the afternoon.

KBOS terminal...High confidence in TAF. Lower confidence in TSRA
chances, but would likely be in the 20-00Z time frame at
BED/BOS.

KBDL terminal...High confidence in TAF. Moderate confidence in
TSRA at BDL after 18Z.

Outlook /Thursday Night through Sunday/...

Thursday: VFR. Chance SHRA, chance TSRA.

Thursday Night: VFR. Slight chance SHRA.

Friday through Saturday Night: VFR.

Sunday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

High confidence through the period.

South/southwest winds remain modest, generally below 10 knots.
This will keep seas on the lower side with significant wave
heights in the 2 to 3 foot range. Some fog/stratus may develop
over the south coast on Wednesday morning.

Winds increase out of the southwest to 10 to 15 knots on
Wednesday afternoon with a slight chance for an
afternoon/evening thunderstorm. SCY headlines may be needed east
of Boston where some gusts to 25 knots could be possible, though
confidence is low at this time.

Outlook /Thursday Night through Sunday/...

Thursday through Thursday Night: Winds less than 25 kt. Chance
of rain showers, slight chance of thunderstorms.

Friday through Sunday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Air Quality Alert from 11 AM this morning to 11 PM EDT this
     evening for CTZ002.
MA...None.
RI...None.
MARINE...None.

&&

$$

SYNOPSIS...RM
NEAR TERM...RM
SHORT TERM...RM
LONG TERM...RM
AVIATION...RM
MARINE...RM