National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 070233
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
933 PM EST Mon Feb 6 2023

.SYNOPSIS...
High pressure builds in from the west late tonight and Tuesday
with colder conditions. Scattered rain/snow showers Tuesday
night with a frontal system, then turning milder again through
the end of the week with temperatures well above normal,
especially Friday. Another frontal system will bring rain
Thursday into Thursday night followed by drier and unseasonably
mild weather Friday. Temperatures trend cooler along with
unsettled conditions into the weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...

-- Changed Discussion --
9:30 PM Update:

Both sky cover and winds have diminished more quickly than
forecast as low pressure pulls to our north and east. Some lower
clouds hang on across the Cape and Islands given their proximity
to the low compared to the rest of the region. Minor adjustments
were made to the timing of the forecast, but overall, the
forecast remains in good shape.

Given that winds have diminished rather quickly this evening,
many of our Gale Warnings were converted to Small Craft
advisories. The remaining Gales will be converted as they
expire.

Update 650 PM:

Clouds continue to shift east and away from southern New England
as a powerful surface low moves NE towards Nova Scotia. Gusts
continue to come in from the N/NE generally around 30 to 40 mph
along the coast. As the low shifts away, winds will begin to
ease. No significant changes were made as the forecast
continues to remain on track. Only made small changes to bring
the forecast in line with the latest observations.

Previous discussion below.

Tonight

A deep low pressure system off the southeast coast of southern New
England continues east over The Atlantic maritimes overnight.
As this system pulls away the pressure gradient driving gusty
north/northeast wind gusts this evening will weaken
substantially. This will eventually lead to the gusty
north/northeast winds diminishing overnight. A drier air mass
filters in from the west and results in skies clearing across
most of interior southern New England. Clouds may linger over
the coastal areas. As the atmosphere decouples after midnight we
should see fairly efficient radiational cooling that will
support chilly overnight lows in the upper teens to low 20s
across the north and western areas. Along the coastal plain,
some cloud cover and boundary layer mixing will support more
mild overnight low temperatures ranging from the mid 20s to the
low 30s over The Cape and Islands.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Tomorrow

Northeast winds continue for the first half of the day tomorrow.
This will support cooler temperatures during the afternoon with
highs struggling to escape the 30s. As high pressure shifts east of
the region during the mid-afternoon hours, southerly flow will take
over and support increasing cloud cover ahead of an approaching cold
front.

Tomorrow Night

An upper-level short-wave trough propagates over southern New
England tomorrow night. This will drag a surface cold front through
the region with a period of scattered showers. The PType associated
with these showers remains a forecast challenge, but as of now model
soundings suggest a period of snow will be likely for most of the
locations that experience precipitation after 7 pm. The high terrain
of The Berkshires/Worcester hills will be the areas where wintry
precipitation will be most likely, while the lower
elevations/coastal plain are more likely to see rain. Also can`t
rule the possibility of periods of freezing rain/sleet as model
soundings reveal a shallow melting layer as this front rolls through
the region. Any snow/ice accumulations will be limited to
dusting/trace amounts, therefore impacts from any wintry precip will
be little to none. Expect these showers to be clear of the region by
day break on Wednesday.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Highlights...

* Warming trend Wednesday into Friday, near record high temperatures
  possible on Friday, then trending cooler for the weekend.

* Unsettled pattern Thursday into Friday and then possibly into this
  upcoming weekend.

Temperatures:

Ready or not, another mild stretch of weather is around the corner
starting Wednesday. Looking at the mid-level, heights are increasing
Wednesday, transitioning towards an amplified mid-level ridge
Thursday and Friday. Much of the deterministic and ensemble guidance
continues to support well above normal temperatures Wednesday,
Thursday, and Friday... especially Friday. Mid to upper 40s would be
pretty common Wednesday and Thursday, with lower 40s in the higher
terrain. As for Friday, 850mb temperatures over southern New England
range from +7C to +10C! May not sound impressive, but that is a +12C
to +16C departure from normal. Friday appears to be the warmest day
of this week with highs potentially in the middle and upper 50s.
These temperatures could be under done by a few degrees if we
breakout into more sunshine.

That said, afternoon high temperatures will be close to the daily
record high for Friday. Record high for Boston is 60F set in 1990,
Worcester is 55F set in 1909, Providence is 58F set in 1909, and
Hartford is 55F set in 1909. As a reminder, normal highs for early
February are mid to upper 30s and lows upper teens and low 20s.

Precipitation:

Those yearning for winter conditions will not appreciate the
forecast for the second-half of the week. A few showers do linger
Wednesday morning in the wake of a passing cold front. But, high
pressure settles in for the rest of Wednesday and first-half of
Thursday. Forecast soundings point to a fairly dry atmosphere along
with deterministic and ensemble forecasts. PWATs are generally less
than two tenths of an inch through Wednesday night, not expecting
any real weather during this period. Sky cover remains mainly clear
Wednesday through Wednesday night, increasing clouds by Thursday
morning.

Weather becomes unsettled Thursday into Friday as a vertically
stacked low pressure system travels through the Great Lakes and
moves northeast into southern Canada. Given how far inland the
system is, once again to be a mainly rain event. Isolated snow or
wintry mix are possible Thursday afternoon as a frontal boundary
lifts north. Areal coverage at this time would be limited to the
higher elevation of northern and western Massachusetts. For what it
is worth, forecast sounding at KORE [Orange, MA] does have an hour
or two of -SN before changing over. Lower confidence in coverage of
showers on Friday, deterministic guidance would support the
precipitation ending in the morning... But the ensembles would
continue it. Given lower confidence during the day Friday, left POPs
at chance.

Looking ahead at the upcoming weekend, guidance would like to place
a surface low off the coast of southern New England. GFS running a
bit on the warmer side, versus a colder Euro solution. Pounds of
time, so stay tuned!

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
Forecaster Confidence Levels:

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

00Z update...

Tonight... High confidence.

Mainly VFR, but areas of MVFR cigs may develop over
Cape/Islands. N wind gusts 25 kt near the coast but up to 35 kt
Cape/Islands. Winds diminishing overnight.

Tuesday... High confidence.

VFR, but may see some MVFR cigs Cape/Islands in the morning. N
wind gusts to 25 kt Cape/Islands diminishing by mid morning.
Winds turn southerly in the afternoon, increasing late in the
day.

Tuesday Night...Moderate Confidence.

Rain/snow showers move through the region with a cold front
tomorrow night.This may bring periods of MVFR ceilings over the
western areas during the frontal passage, but otherwise VFR
conditions should prevail. South winds from 10 to 20 knots
becoming westerly by Wednesday morning.

KBOS Terminal...High Confidence in TAF.

KBDL Terminal...High Confidence in TAF.

Outlook /Wednesday through Saturday/...

Thursday: Mainly VFR, with local IFR possible. Breezy. RA
likely.

Thursday Night: Mainly VFR, with areas IFR possible. Windy with
gusts up to 30 kt. RA likely, patchy BR.

Friday: VFR. Breezy. Chance RA.

Friday Night: Mainly VFR, with local MVFR possible. Breezy.
Chance RA.

Saturday: Mainly VFR, with local IFR possible. Windy with local
gusts up to 30 kt. Chance RA.

Saturday Night: VFR. Windy with gusts up to 30 kt.

Sunday: Windy with gusts up to 30 kt.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
Forecaster Confidence Levels:

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

Marine

Tonight through Tuesday night

Gale force wind gusts gradually diminish during the hours following
midnight. Northeast winds continue to weaken throughout the day
tomorrow as high pressure builds over the region. A cold front will
push through the region late tomorrow night with scattered showers
and 20 to 30 knot wind gusts out of the west.

Outlook /Wednesday through Saturday/...

Thursday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain.

Thursday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Local rough seas. Rain, patchy fog.

Friday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Local rough seas. Chance of rain.

Friday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. Chance of rain, patchy
fog.

Saturday: Moderate risk for Small Craft Advisory winds with
areas of gusts up to 30 kt. Areas of rough seas. Chance of
rain.

Saturday Night: Moderate risk for gale force winds with gusts
up to 35 kt. Rough seas up to 9 ft. Slight chance of rain.

Sunday: Low risk for gale force winds with gusts up to 35 kt.
Areas of rough seas.
-- End Changed Discussion --

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 1 PM EST Tuesday for ANZ230-233>237.
     Small Craft Advisory until 7 PM EST Tuesday for ANZ231-232-251.
     Gale Warning until 5 AM EST Tuesday for ANZ250-254-255.
     Gale Warning until 3 AM EST Tuesday for ANZ256.
-- End Changed Discussion --

&&

$$
SYNOPSIS...Gaucher/RM
NEAR TERM...Gaucher/RM/KS
SHORT TERM...RM
LONG TERM...Gaucher
AVIATION...Gaucher/RM
MARINE...Gaucher/RM