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000
FXUS61 KBOX 210117
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
917 PM EDT Sat Apr 20 2024

.SYNOPSIS...
A ridge of high pressure will result in dry weather Sunday
through Tuesday with mild days and cool nights, along with
elevated fire weather potential. Unsettled, wet and cool on
Wednesday. Turning drier late in the week.

&&

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

915 PM Update...

* Clearing overnight with lows in the 30s to lower 40s
* Areas of frost toward daybreak in normally coolest locales

The last of the showers were now confined to the Cape/Islands
along the advancing cold front. There was even a few rumbles of
thunder/graupel with this activity earlier near the south coast.
But this activity will exit the Cape/Islands in the next hour
or so. As the wind shifts behind the front...the remaining low
clouds/fog across the Cape/Islands will scour out over the next
few hours.

Otherwise...a much drier west to northwest flow of air follows
behind the cold front overnight. A brief surge of WNW 20-25 mph
immediately behind the front will not last too long. The drier
airmass followed by diminishing wind overnight will allow for
overnight low temps near 30 across the normally coolest
locations of western MA. The rest of the region should see
overnight lows mainly between 35 and 40 with lower 40s in the
Urban Heat Island of Boston and Nantucket. Patches of frost may
also develop toward daybreak in some of the normally coolest
low-lying locations.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
High pressure starts to build across southern New England
through Sunday night, providing dry weather. Expecting a period
of clouds Sunday afternoon and evening as a weak trough passes
by. This weak trough will also help generate gusty afternoon
west winds. Near to slightly below normal temperatures.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Highlights

* Very seasonable weather next week with daily high/low temps
  close to the climatological normal

* Rainy on Wednesday


Monday through Saturday

No anomalous or impactful weather is expected in the extended
forecast for southern New England next week. The week begins
with the region largely dominated by high pressure building in
from the west. This should support a sunny/dry start to the week
with highs in the upper 50s/low 60s and lows in the upper
30s/low 40s. The only active period of weather this week will be
on Wednesday when a modest short-wave disturbance aloft
traverses over the region. Southerly flow ahead of this feature
will increase the moisture over southern New England allowing
for widespread stratiform precipitation during the day
Wednesday. With neither forcing nor moisture forecast to reach
impressive levels, the total rainfall accumulation with this
system is expected to be modest with amounts likely between 0.1
and 0.25 inches. As the associated surface cold front pushes
through the region behind this system Wednesday night, we`ll be
left with a dry but cooler air mass on Thursday which should
feature temperatures only slightly below normal. High pressure
then builds over The Northeast to end the week with more dry,
quiet, and seasonable conditions.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Forecast Confidence Levels:

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


Tonight through Sunday Night...High confidence.

Any lingering MVFR-IFR conditions across the Cape/Islands
clear to VFR this evening. VFR conditions expected into Sunday
Night. WNW generally 5-10 knots, shifting to the WSW Sunday at
10 to 15 knots with some afternoon gusts of 20 to 25 kt. Winds
turn WNW Sunday night and become less gusty.

KBOS TAF...High Confidence in TAF. A brief period of gusty winds
is possible between now (23Z) and 01Z along the leading edge of
a surface front moving through southern New England. KBDL
registered a 34 knot gust as the front past over the terminal a
short while ago. Not expecting gusts quite that strong at BOS,
but 20 to 25 knots may be in the cards for a brief time. Any
strong gusts should diminish shortly after 01-02Z.

KBDL TAF...High Confidence in TAF.

Outlook /Monday through Thursday/...

Monday: VFR. Breezy.

Monday Night: VFR.

Tuesday: VFR. Windy with local gusts up to 30 kt.

Tuesday Night: VFR. Windy with gusts up to 35 kt. Slight chance
SHRA.

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

Wednesday Night: VFR. Breezy. Chance SHRA.

Thursday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Sunday Night...High Confidence.

A relatively weak pressure gradient should keep winds and seas
generally below Small Craft Advisory thresholds through Sunday
night. However, good mixing on westerly flow Sunday may yield a
few afternoon nearshore wind gusts of 20-25 knots creating some
chop.

Outlook /Monday through Thursday/...

Monday through Monday Night: Winds less than 25 kt.

Tuesday: Low risk for Small Craft Advisory winds with areas of
gusts up to 30 kt.

Tuesday Night: Low risk for Small Craft Advisory winds with
local gusts up to 30 kt. Seas locally approaching 5 ft.

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

Wednesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain
showers.

Thursday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft.

&&

.FIRE WEATHER...
Sunday...

Dry westerly flow in pre-greenup should allow for elevated fire
weather concerns on Sunday. The airmass will mix deeply and
allow for a large temp/dewpoint spread. Highs should reach the
upper 50s to near 60 with dewpoints dropping into the lower to
middle 20s. This should result in minimum afternoon relative
humidities between 20 and 30 percent. The deep mixing should
also produce some 20 to 25 mph wind gusts with perhaps a few
locales approaching 30 mph briefly. However, the rainfall today
was wetting for most locations. Will continue to monitor this
potential overnight.

&&

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

&&

$$

SYNOPSIS...Belk/RM
NEAR TERM...Frank
SHORT TERM...Belk
LONG TERM...RM
AVIATION...Belk/RM
MARINE...Belk/RM
FIRE WEATHER...Belk