Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 191357
AFDBOX

Area Forecast Discussion
National Weather Service Taunton MA
957 AM EDT SUN JUN 19 2016

.SYNOPSIS...

High pressure remains in control through Monday, resulting in
cool nights and warm afternoons along with low humidity. More
humid conditions are expected Tuesday, with a risk of showers and
thunderstorms late Tuesday into Tuesday night. Cooler and drier
weather will follow mid to late next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

10 am update...

Marine stratus over the CT / RI border has disintegrated with
diurnal heating and boundary layer mixing. Expecting a return as
we go into the overnight period.

Otherwise a fantastic Father`s Day. Abundant sunshine with perhaps
some scattered mid to high level clouds. Buckled beneath a mid to
upper level ridge with an abundance of dry air per the 12z Chatham
sounding. Should be a warm day with highs close to if not exceeding
90 degrees over the low lying interior of the CT and Merrimack
River Valleys. But closer to the coast and more S and E with onshore
flow it`ll be slightly cooler with highs around the upper 70s to low
80s. With the S/SE onshore flow could see some gusts up to 20 mph
especially over the E waters, so small-boat mariners should be aware.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...

Tonight...Quiet weather continues. Increasing dew points from
persistent south winds, especially late tonight, could lead to
patchy fog. Low temperatures will remain seasonable.

Monday...Expecting a coastal low pressure to stay far enough
offshore to not be a major player in our weather. Dry weather
should prevail. High temperatures similar to today.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...

Highlights...

* More humid weather expected Tuesday
* Showers and thunderstorms likely sometime Tue into Tue night
* Cooler and drier weather returns by Thursday

Overview and model preferences...
Broad synoptic ridge-trof pattern defines most of the long term
period. High pres and ridging holding fast across the S and SW
CONUS while downstream across the northeast trof resides blocked
further downstream by blocking ridge south of Greenland. This trof
will relieve the region of the heat-humid connection early in the
week and allow for a tendency back toward seasonal normal
temperatures and dwpts toward the latter half of the week. The
largest discrepancies begin late in the week with the development
of yet another offshore low pres along a stalled frontal boundary
to the S. Deterministic guidance continues to be on the northern
side of the envelope with more of a potential for impact on Srn
New England. However, ensembles are quite spread and if anything,
actually tend toward the south in the face of high pres building
across Nrn New England. Will begin using a blend of the available
deterministic guidance, bet then taper toward a blend of
ECENS/GEFS ensemble means later in the week.

Details...

Mon night into Tue night...
Cold front approaches and crosses the region as previously
advertised connected to low pres moving through QC. At odds is the
timing, while previous runs were much slower, allowing for full
destabilization to occur, latest runs are faster, pushing the
front through during the AM hours. This limits potential
destabilization and even ensemble probabilities are lower now for
+1000j/kg of CAPE. Will maintain some mention of TS as afternoon
SLIs and Showalters remain below 0 through the afternoon as the
front slows offshore and the upper trof lags. However, the earlier
passage will limit the risk for strong-severe storms. Something to
continue to watch as we approach as shear values remain elevated.

Otherwise, humid as dwpts increase to the mid 60s. With enough
sun, temps should still make a run into the low-mid 80s.

Wed through Thu...
Trof settles across the region with cyclonic flow and cooling H5
temps to near or below -15C. This should be enough for diurnally
driven clouds each day, along with a risk for shra or even an
isolated TS, however far from a washout as moisture will be
limited with stacked NW flow. Temps back down to seasonal normals,
mainly mid-upper 70s thanks to H85 temps dropping back closer to
+8C.

 Fri and Fri night...
Stalled frontal boundary remains to the S and will allow for
enhanced cyclogenesis. The resultant low pres will pass somewhere
S of New England, but how close is the question. Should it pass
near or even just S of the 40/70 benchmark it could lead to a
period of wet wx as it carries with it a subtropical moisture
source. However, ensembles are well spread and even tend S, so at
this time, will lean closer on this solution until there is better
agreement. The initiating shortwave is currently locked within the
vortex across the PACNW.

Next weekend...
Dependent on the speed with which the offshore low pres passes,
but high pres looks to regain control as the base of the longwave
trof begins a shift to the E.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...

Forecaster Confidence Levels.

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

Short Term /through Monday/...

Today...High confidence.
VFR. Winds mainly S with the potential for gusts up to 20 kts
over the E terminals.

Tonight...Moderate confidence.
Mainly VFR but low risk for another round of stratus developing
mainly across CT/RI late. Timing/extent a low confidence forecast.

Tomorrow...High confidence.
Mainly VFR after any fog/stratus burns off.

KBOS TAF...High confidence in TAF.

KBDL TAF...High confidence in TAF.

Outlook /Monday Night through Thursday/...

Mon night into Tuesday...Moderate confidence.

Mainly VFR conditions. Scattered showers and thunderstorms
Tuesday afternoon and night may result in brief periods of MVFR
conditions.

Wednesday and Thursday...High confidence.
VFR conditions.

&&

.MARINE...

Forecaster Confidence Levels.

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

Short Term /through Monday/...High confidence.

Good boating weather. Winds turning out of the S/SE today, with
the potential for 20 kt gusts during the day. Small-boat mariners
should be especially aware. Seas could get a bit choppy with
waves up to near 5 feet over portions of the E Massachusetts
coastal waters. Not enough confidence to issue a small craft
advisory, at this time.

Outlook /Monday Night through Thursday/...

Monday night into Tuesday night...Moderate confidence.

Winds and seas increase as a cold front approaches and then
crosses over the coastal waters Tuesday and Tuesday night. Winds
look to remain below SCA criteria, but seas will increase to 5 to
6 feet on the outer waters.

Wednesday and Thursday...High confidence.

Mainly quiet boating weather is expected.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

SYNOPSIS...Belk/Doody
NEAR TERM...Belk/Doody/Sipprell
SHORT TERM...Belk
LONG TERM...Doody
AVIATION...Belk/Doody/Sipprell
MARINE...Belk/Doody/Sipprell



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