344
FXUS61 KBOX 020423
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1223 AM EDT Wed Apr 2 2025

.SYNOPSIS...
Continued dry weather for most of Wednesday with below normal
temperatures, then an approaching warm front will bring a period
of showers Wednesday night into Thursday morning, with pockets
of mixed wintry precipitation possible across the interior at
the onset Wednesday night. Milder conditions arrive Thursday
into Friday, then trend cooler next weekend with unsettled
conditions returning.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Key Messages:

* Colder tonight with below normal temperatures

High pressure over eastern Canada builds into New England
tonight. Gusty NW winds will diminish, and establish rather good
radiational cooling conditions to go along with modest cold air
advection for the first part of the night.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
Key Messages:

* Dry for most Wed with below normal temperatures
* Low risk for some spotty freezing rain or light snow Wed night

Strong high pressure moves off to the east Wednesday. A low
pressure over the upper Midwest should approach the Great Lakes
by Wednesday evening. The warm front associated with this low
pressure should then approach southern New England late in the
day. Increasing clouds for sure during this time, but not as
confident in the timing or type of precipitation.

Forecast soundings are supportive of a mostly rain scenario.
However, there are windows for some light snow or icing across
the higher terrain of central and western MA. This time of year,
the pavement tends to be a little warmer, so not quite as
concerned about impacts. However, will continue to monitor this
possibility.

Below normal temperatures expected to continue Wednesday, then
should trend closer to normal Wednesday night.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...

Long Term

Key Messages

* Pleasant early spring day on Friday

* Cooler on Saturday followed by increasing warmth and shower
  chances Saturday night into Sunday

* Trending cooler again early next week

Thursday night and Friday

A dry cold front pushes through the region Thursday night into
Friday brining abnormally high 925 hPa temps near 15C down to values
closer to normal for early April in the 5 to 10 Celsius range. This
front will be accompanied by a dry northwest flow that will support
efficient mixing on Friday afternoon. As a result we can expect a
pleasant/sunny early spring afternoon with high temperatures in the
60s across southern New England. Expect the warmest temperatures in
east/southeast MA where downsloping on northwest flow may support
temperatures in the mid to upper 60s. A 70 degree observation can`t
be ruled out with ensemble probabilities suggesting a 10 to 20
percent chance of temperatures greater than 69 degrees on Friday
afternoon. The warmth will be accompanied by a northwest breeze with
some gusts of 20 mph possible across the region.

Saturday through Sunday night.

The warmth from Friday quickly cools down on Saturday as high
pressure is forecast to build north and east of southern New
England. This will allow a backdoor cold front to advect cooler air
back into the region with 925 hPa temps dipping near the freezing
mark by Saturday morning. This will support a cool/raw day with
highs peaking in the mid to upper 40s for much of southern New
England. Saturday will as mark the beginning of a wet/unsettled
period. As the aforementioned area of high pressure continues to
shift east, return flow from the south will support WAA driven
showers over southern New England likely beginning Saturday
afternoon. Expect precipitation to persist through Sunday as the
associated low-pressure system traverses over The Northeast Saturday
night through Sunday evening.

As warm sector air lifts over the region on Sunday, 925 hPa temps
rise dramatically to the 15 to 20C range. So while Sunday is
expected to be wet/rainy, it will also be on the warm/humid side
with temperatures in the low to mid 60s and dewpoints in the 50s.
Ensemble mean precipitation forecasts for Saturday afternoon through
Sunday night are ranging from 0.75 to 1 inch across southern New
England. Some of this precip may come in the form of convective
showers Sunday night as the associated cold front drives the warm
sector air out of the region. Model derived CAPE values are
unimpressive at this time, but with ensemble mean SBCAPE values
around 250 J/kg, a few showers could have a rumble of thunder,
particularly along the south coast.

Monday and Tuesday

Trending drier and more seasonable on Monday as a cold front ushers
a drier air mass over the southern New England. Ensemble mean high
temperatures on Monday afternoon currently ranging from the mid to
upper 50s across southern New England which is close to normal for
this time of year. Model spread increases on Tuesday with the
ECMWF/CMC models supporting a somewhat strong CAA pattern that would
feature high temperatures in the upper 30s/low 40s on Tuesday. The
GFS is less aggressive with cooler air and keeps high temps in the
mid to upper 40s next Tuesday. Stay tuned for further details...

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Through Tonight...High confidence.

VFR, dry weather and diminishing winds.

Wednesday...High Confidence

VFR. NE wind 5-10 kt becoming SE-S in the afternoon.

Wednesday Night...Moderate Confidence.

VFR trending to MVFR overnight. Local IFR across the higher
terrain late. Mostly -SHRA, but some risk for -SHSN or -FZRA
across the interior.

Thursday...Moderate Confidence

Mainly IFR/MVFR with -SHRA. Steady south/southwest winds from 10
to 15 knots and gusts up to 25 knots.

BOS TAF...High confidence.

BDL TAF...High confidence.

Outlook /Thursday Night through Sunday/...

Thursday: MVFR/IFR conditions possible. Windy with local gusts
up to 30 kt. Chance SHRA.

Thursday Night: Mainly VFR, with local IFR possible. Breezy.
Chance SHRA.

Friday: VFR. Breezy. Slight chance SHRA.

Friday Night: VFR.

Saturday: Mainly VFR, with local IFR possible. Chance SHRA.

Saturday Night: MVFR/IFR conditions possible. SHRA.

Sunday: MVFR/IFR conditions possible. Breezy. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Wednesday Night...High confidence.

High pressure builds across the waters late tonight into
Wednesday. While winds diminish, seas will take longer to
subside. Small Craft Advisories continue. Increasing southeast
winds behind a warm front Wednesday night should result in
building seas once more.

Outlook /Thursday Night through Sunday/...

Thursday: Strong winds with local gusts up to 30 kt. Rough seas
up to 8 ft. Chance of rain showers.

Thursday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas. Chance of rain showers.

Friday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Chance of rain showers.

Friday Night: Winds less than 25 kt. Seas locally approaching
5 ft.

Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.
Rain showers likely.

Saturday Night: Winds less than 25 kt. Seas up to 5 ft. Rain
showers likely.

Sunday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain
showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 2 AM EDT early this morning for
     ANZ231-235-237-251.
     Small Craft Advisory until 1 PM EDT this afternoon for ANZ250.
     Small Craft Advisory until 7 PM EDT this evening for ANZ254-
     255.
     Small Craft Advisory until 10 AM EDT this morning for ANZ256.

&&

$$

SYNOPSIS...KJC/RM
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...RM
AVIATION...KJC/RM
MARINE...Belk/KJC/RM