Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 140137
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
937 PM EDT Wed Mar 13 2024

.SYNOPSIS...
Continued dry and clear weather through tomorrow with a outside
chance for an isolated shower late tonight. Tomorrow will
feature mild temperatures away from the coasts where sea
breezes will keep temperatures cooler. A more unsettled weather
pattern develops Friday into the weekend, with rainy conditions
for Fri and again on Sunday. Temperatures trend above normal
through this weekend, with a cooling trend toward more
seasonable temperatures by early next week.

&&

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

935 PM Update...

* A brief spot light shower possible through 2-3 AM
* Decreasing clouds toward daybreak with lows mainly in the 30s

A moisture starved shortwave and mid level warm front will cross
the region over the next several hours. Low level moisture is
quite limited along with a dry boundary layer...so nothing more
than a brief spot light shower/sprinkle through about 2-3 am.
Behind the shortwave we should see decreasing cloudiness with
light/calm winds. This should result in overnight lows mainly
in the 30s.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...

Weak mid level ridge builds back in with continued high
pressure at the surface. Skies remain mostly sunny again
tomorrow setting the stage for another warm day. With 925mb
temps jumping from roughly +7C to +11C range, high temps away
from the coasts will likely reach the low to mid 60s, with a
good chance at 70F for the CT river valley. Near the coasts,
seas breezes will develop again, and with ocean temps in the low
40s, high temps will struggle to top the low 50s. Winds
tomorrow turn light NW for the interior less then 10mph.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...

Highlights

* Rain Thursday night into Friday

* Drying out on Saturday with partial sunshine and seasonable
  temperatures

* More unsettled weather Sunday into Monday will be followed by a
  period of dry but cold and blustery conditions through the middle
  of next week.

Thursday night and Friday

A modest and progressive low-pressure system will move over The
Northeast Thursday night into Friday. Overall forcing associated
with the system is modest, so not expecting any significant impacts.
Most of the region should see a decent soaking of rain with
PWATs up to an inch supporting rainfall amounts between a
quarter and half an inch. Currently expecting the
steadier/heavier precip to be focused north of the I-90 corridor
where stronger forcing and enhancements from the left jet exit
region aloft should allow for more efficient rainfall processes.
Steady southeast winds ahead of the low on Friday morning will
transition to a north/northwest flow into Friday afternoon as
the low moves overhead. With this will come drier air that will
bring precip to an end. Could be some breaks of sun mid to late
afternoon, but generally expect overcast skies for much of the
day. Temperature forecast is a bit uncertain on Friday as it
will depend on the track of the low. As it stands now, a west to
east track along I-90 is expected to support warmer south of
I-90 in the mid to upper 50s with upper 40s/low 50s more common
north of that mark. A north/southward shift in the track would
support a shift in observed temperatures as well.

Saturday and Sunday

Drier air settles in behind the departing low pressure system on
Saturday supporting some clearing over the region. This is expected
to result in some sunshine and seasonable high temperatures in the
low to mid 50s Saturday afternoon. Cloudiness returns Saturday night
into Sunday as a low-pressure system over Canada drags a cold front
through the region with another round of modest precipitation.
Timing a bit uncertain at this time range, but most recent suite
of model guidance supports showers clearing out of the region
sometime Sunday night.

Next Week

Much of the first half of next week looks to be on the cold and
blustery side as model guidance supports a persistent period of
cyclonic flow positioned to our northeast. This is expected to
support a persistent period of a dry deep northwest flow and CAA
over southern New England. With CAA supporting deep diurnal
mixing during the afternoon hours between Monday and Wednesday,
we are likely to experience gusty winds during the afternoon
and perhaps during the overnight hours as well. How strong wind
gusts will be depends on the strength of the pressure gradient
in place which remains uncertain at this time range. Ensemble
guidance doesn`t support anything eye popping at this time, but
periods of 30 to 40 mph gusts are in the realm of possibility on
Tuesday or Wednesday of next week. As previously stated,
temperatures will be cold as well with temps at 925 hPa forecast
to remain below 0 Celsius for much of the first half of next week.
This would translate to high temps in the low to mid 40s during
the afternoon and upper 20s to low 30s during the evenings.
More details to follow as we get into the weekend.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Forecast Confidence Levels:

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

00Z TAF Update

Tonight...High Confidence.

VFR with light and variable winds.

Thursday...High Confidence.

Light NW winds across the interior with sea breezes developing
along the coast around 13-15Z.

Tomorrow Night...

VFR ceilings falling to MVFR/IFR levels as steady rain
overspreads southern New England. Winds increase to modest
speeds (~10 knots) out of the southeast.

KBOS TAF...High confidence in TAF. Steady sea-breeze should die
down to light south/southeast between 00-01Z. Sea breeze
redevelops again tomorrow morning between 14 and 15z, but winds
will already be SE.

KBDL TAF...High confidence in TAF.

VFR with light and variable winds.

Outlook /Thursday Night through Monday/...

Thursday Night: VFR. Chance RA.

Friday: VFR. Breezy. Chance RA.

Friday Night: Chance RA.

Saturday:

Saturday Night: Breezy. Slight chance RA.

Sunday through Sunday Night: Breezy. Chance RA.

Monday: Breezy. Slight chance RA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Tonight through Thursday...High Confidence.

a weak pressure gradient will keep winds/seas below small craft
advisory thresholds today through Thursday with good vsbys. Low
chance for an isolated shower over the waters tonight.

Outlook /Thursday Night through Monday/...

Thursday Night: Winds less than 25 kt. Slight chance of rain.

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

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

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

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas locally approaching 5 ft.

Sunday: Moderate risk for Small Craft Advisory winds with gusts
up to 25 kt. Seas up to 5 ft. Chance of rain.

Sunday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain.

Monday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

SYNOPSIS...RM/KP
NEAR TERM...Frank
SHORT TERM...KP
LONG TERM...RM
AVIATION...RM/KP
MARINE...RM/KP


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