Area Forecast Discussion Issued by NWS Boston, MA
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000
FXUS61 KBOX 151855
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
255 PM EDT Fri Mar 15 2024
.SYNOPSIS...
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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.-- End Changed Discussion --
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.NEAR TERM /THROUGH TONIGHT/...
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Drying trend is already underway across southern New England,
with vast majority of the lingering showers offshore. Clouds
have been stubborn, with what little sunshine we had across CT,
RI and southeast MA late this morning quickly filling in early
this afternoon. Winds have turned north already, and will
continue to flip around to the northwest, and eventually the W
overnight. This could bring some clearing to portions of the CT
River valley after midnight.
With rather light winds and plenty of clouds, not expecting strong
radiational cooling or cold air advection tonight. Thus, low
temperatures should come in as above normal.-- End Changed Discussion --
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.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
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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.-- End Changed Discussion --
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.LONG TERM /SUNDAY 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 --
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.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Tonight...High Confidence in trends. Moderate confidence in
timing.
Mainly MVFR ceilings will linger this evening across eastern
New England, but VFR conditions overspread this region from the
west as the night progresses. Light and variable winds.
Saturday...High Confidence.
VFR, except for some lingering IFR across the Cape and Nantucket
early. SW winds 5-10 kt, but localized sea breezes developing
during the afternoon along portions of the immediate coast.
Saturday Night...High Confidence.
Mainly VFR, with increasing areas MVFR after 17/midnight EDT.
Local IFR across the higher terrain towards daybreak Sunday.
KBOS TAF...High confidence in trends. Moderate confidence in
timing.
KBDL TAF...High confidence in trends. Moderate confidence in
timing.
Outlook /Sunday through Wednesday/...
Sunday: Mainly VFR, with local IFR possible. Breezy. Chance RA.
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 --
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.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 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 --
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.BOX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 PM EDT this evening for ANZ231-
250-251.
Small Craft Advisory until 10 PM EDT this evening for ANZ232.
Small Craft Advisory until 4 AM EDT Saturday for ANZ254-256.
Small Craft Advisory until 7 AM EDT Saturday for ANZ255.-- End Changed Discussion --
&&
$$
SYNOPSIS...Belk/KP
NEAR TERM...Belk
SHORT TERM...Belk
LONG TERM...KP
AVIATION...Belk/KP
MARINE...Belk/KP