Area Forecast Discussion Issued by NWS Boston, MA
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000
FXUS61 KBOX 160524
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
124 AM EDT Sat Mar 16 2024
.SYNOPSIS...
Drying out on Saturday with unseasonably mild temperatures away
from the immediate coast. Round of showers Sunday morning with
the passage of a cold front. Temperatures trend cooler next week
along with gusty winds and near daily chances for isolated
showers.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
930 PM Update...
* Clouds will hang tough overnight...but should see some breaks
* Overnight low temps mainly in the 30s
Quiet weather this evening with rather cloudy skies with lots of
lingering stratus. Cyclonic flow will allow allow clouds to
hang tough overnight without much of a dry low level push. That
being said...a weak ridge of high pressure gradually building in
from the west will allow for some breaks to develop in the
cloud cover overnight especially across the interior. Low temps
will bottom out mainly in the 30s with light/calm winds.
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.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
A weak high pressure should be centered over the Mid Atlantic
coast Saturday, then move offshore Saturday night. This will
open the door for a low pressure to move across eastern Canada,
pushing its cold front across southern New England Sunday.
Mainly dry Saturday with some sunshine developing during the
day. While not full sunshine, there should be enough to boost
high temperatures above normal region-wide. Light pressure
gradient should also result in localized sea breezes along the
coast. There is some question as to when. Without the full
sunshine, thinking this should be more on the later side of the
sea breeze window.
Clouds increase Saturday night, with an increasing risk for some
rain showers after midnight. Much like today, the greatest risk
for these showers is expected across northern MA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
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Key Points
* Temperatures trend cooler this week
* Daily chances for showers and light graupel through Wednesday
Sunday
Cold front swings through the region Sunday morning bringing a
quick round of showers along the front. Otherwise Sunday
afternoon is trending drier as a dry slot behind the front works
in. Winds along the cold front could be quite gusty up to
20-35mph out of the WSW. Winds calm down briefly overnight
before becoming gusty again Monday. High temperatures top out in
the mid to upper 50s where sun can be realized, but if clouds
end up lingering, highs will stay in the low 50s.
Monday - Wednesday
Stuck under cyclonic flow and cold pool aloft, temperatures
begin to trend cooler with daily chances for diurnal showers.
Steep low level lapse rates each afternoon of 8-10C/km and
moderately steep mid level lapse rates of 6-8C/km, combined with
the strong March sun angle, will lead to isolated convective
showers. With 850mb temps dropping from -5C to -10C during this
time period, any graupel that these low topped convective
showers produce could reach the ground esspically across the
high terrain. Did push POP`s up each afternoon to force
isolated/slight chance showers. Winds remain gusty through this
period with a tight pressure gradient bringing NNW winds gusting
25-35 mph. It will feel much cooler this week compared to last
week as cold air advection will leave highs only in the mid 40s
by Tuesday. With the gusty winds, the wind chill factor will
only make it feel like the 20s and 30s by Tuesday and Wednesday.
Thursday and Beyond.
Weak upper level ridge brings rising heights and quick moving
high pressure Thursday before some models indicate a shortwave
exiting out of the Great Lakes. Given this is a week out, there
is large spread among the different model and ensemble systems.
Won`t speculate more then the next chance for more substantial
precipitation could be late next week or weekend.-- End Changed Discussion --
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
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Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06z TAF Update...
Today...High Confidence.
Any lingering MVFR ceilings should dissipate across eastern New
England through 12z...but may persist a few hours longer across
the Cape/Nantucket. Otherwise...VFR with winds becoming SW at
5-10 knots and localized sea breezes developing in the afternoon
along parts of the very immediate coast.
Tonight and Sunday...Moderate Confidence.
Mainly VFR conditions this evening. A period of MVFR with brief
localized IFR conditions possible overnight into Sunday
morning with a few brief showers also possible. Conditions will
tend to improve to mainly VFR by the middle of Sunday
afternoon...but this process may be delayed several hours across
parts of the Cape/Islands. S winds up to 10 knots or so tonight
shift to the west by mid afternoon Sunday with some gusts of
20-25 knots developing.
KBOS TAF...High confidence in the overall TAF...but uncertainty
if we do see an period of ESE sea breezes during the afternoon.
KBDL TAF...High confidence in TAF.
Outlook /Sunday Night through Wednesday/...
Sunday Night: VFR. Breezy.
Monday: VFR. Breezy. Slight chance SHRA.
Monday Night: VFR. Breezy.
Tuesday: VFR. Breezy. Slight chance SHRA.
Tuesday Night: VFR. Breezy.
Wednesday: VFR. Breezy. Slight chance SHRA.-- End Changed Discussion --
&&
.MARINE...
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Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Low pressure departs with diminishing winds this evening. Seas
will take a little longer to subside. Will permit Small Craft
Advisories to eventually expire tonight into Saturday.
Otherwise, good visibility with rather light winds expected into
Saturday evening. Increasing winds Saturday night should also
result in building seas across the southern coastal waters of
MA and RI.
Outlook /Sunday Night through Wednesday/...
Sunday: Low 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.
Monday: Winds less than 25 kt. Seas locally approaching 5 ft.
Monday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of seas approaching 5 ft.
Tuesday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Seas up to 5 ft. Slight chance of rain
showers.
Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Seas up to 5 ft.
Wednesday: Low risk for Small Craft Advisory winds with gusts
up to 25 kt. Areas of seas approaching 5 ft. Slight chance of
sleet.-- End Changed Discussion --
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 2 AM EDT early this morning for
ANZ231-232-250-251-256.
Small Craft Advisory until 7 AM EDT this morning for ANZ254-
255.-- End Changed Discussion --
&&
$$
SYNOPSIS...Belk/KP
NEAR TERM...Frank
SHORT TERM...Belk
LONG TERM...KP
AVIATION...Frank/KP
MARINE...Belk/KP