Area Forecast Discussion
Issued by NWS Boston, MA

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758
FXUS61 KBOX 250837
AFDBOX

Area Forecast Discussion
National Weather Service Taunton MA
437 AM EDT SAT JUN 25 2016

.SYNOPSIS...

Large high pressure ridge extending across the northeast U.S.
into the Gulf of Maine will slowly shift down the coast, with
warm and dry conditions through Monday. An approaching cold
front brings showers and possibly some thunder later Monday
night through Wednesday. High pressure then brings dry
seasonable weather for the end of next week.

&&

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

Clear skies continue across the region at 08Z. Noting patchy low
clouds and fog across some of the normally susceptible spots of E
Mass extending down to the lower Cape and Martha`s Vineyard. Temps
have dropped back to 45-50 from KBED-KEWB, with the lowest reading
of 43 on the Vineyard, and even 47 at KPVC as winds have dropped
off to calm.

W-E high pressure ridge axis sitting from W NY state to the Gulf of
Maine will slowly shift to the S coast during the day today.
Expect a generally light E-SE wind, becoming more southerly across
N CT and the CT valley this afternoon. With a light pressure
gradient, sea breezes will kick in by midday with speeds up to
around 10 kt.

With a very dry airmass in place through the layer, expect excellent
subsidence through the day even with fair lapse rates as H5 temps of
-14C to -15C. Do note some afternoon showers trying to develop, but
mainly across the Hudson Valley into the northern mountains of
NH/VT as winds become more S there.

Expect temps to rise to the 80s away from the coast, highest across
the CT valley where a 90 degree reading may be possible, while
holding in the 70s along the immediate coast.  It will feel
comfortable though as dewpts remain in the lower-mid 50s.


&&

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

Tonight...

With high pressure ridge across the region, will continue to be
dry and comfortable as dewpts fall back to the upper 40s to mid
50s. Light/variable winds in place, dropping off to calm across
some inland areas. With continued good radiational cooling, will
see temps fall back to the upper 40s to around 50 in the normally
prone areas of interior E Mass to the lower Cape and the Vineyard,
ranging to the mid 50s to around 60 in the urban centers. Once
again, may see a few hours of patchy low clouds and fog around or
after 06Z in the typically prone locations.

Sunday...

As the ridge begins to push S of the region, light winds will
become more S-SE across the region. While dry conditions continue
with dewpts in the lower-mid 50s, will start to see them creep up
during the afternoon across the CT valley. Expect another warm day
with highs in the 80s away from the coast, and in the lower-mid
70s near the shore.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Big Picture...

A shortwave originating over the Pacific Northwest moves east across
Canada and then digs over New England Tuesday and Wednesday. Above
normal heights Monday diminish to near normal the rest of the week.
This suggests above normal temps Monday trending to normal during
mid to late week.

Model forecast mass fields are similar much of the period. There are
differences between GFS and ECMWF with timing on the midweek cold
front. Confidence is limited as to exact timing, but potential for
convection should exist for both days.

Details...

Sunday night through Monday...

High pressure offshore moves farther away, and the surface flow
turns more from the south and southwest. Expect dry weather during
this time. 850 mb temps of 14-16C would support max sfc temps in the
mid 80s.

Monday night through Wednesday...

Northern shortwave approaches from the Great Lakes. At this time the
upper shortwave digs southeast toward New England and turns the
upper flow more from the southwest and parallel to the cold front.
With flow moving along the cold front rather than pushing it, we
should see the forward progress slow until the trough axis swings
overhead. Meanwhile the surface flow will bring a warm humid airmass
across New England with dew points climbing into the 60s. Stability
parameters will favor convection. The cold front will be the
eventual focusing mechanism on Wednesday, but a pre-frontal
trough may concentrate convection on Tuesday.

Thursday-Friday...

High pressure builds in behind the cold front but with upper
contours and 850 temps near seasonal normals.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels.

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

Short Term /through Sunday/...High Confidence.

Through 12Z...VFR. Patchy fog with MVFR-IFR across interior E
Mass to KMVY/KFMH.

Today...VFR. Light S-SE winds, becoming sea breezes along the
coast up to around 10 kt by midday.

Tonight and Sunday...VFR. Low risk for patchy MVFR conditions in
fog late after midnight tonight in normally prone locations.

KBOS TAF...High confidence. VFR. E-SE winds increasing to around
10 kt by midday today becoming light S tonight. Winds shift back
to E-SE around 10 kt by midday Sunday.

KBDL TAF...High confidence. VFR. Low chance for MVFR-IFR
conditions in patchy fog 07Z-11Z tonight.

Outlook /Sunday Night through Wednesday/...

Sunday night and Monday... High confidence.

VFR. Light winds. Areas of IFR/LIFR possible in late night/early
morning fog.

Monday night through Wednesday... Moderate confidence.

Mostly VFR. Areas of IFR/LIFR in late night/early morning fog.
Also brief MVFR cigs/vsbys in scattered showers/thunderstorms.

&&

.MARINE...
Forecaster Confidence Levels.

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

Short Term /through Sunday/...High confidence.

Expect winds and seas below small craft criteria through Sunday
as high pressure ridge remains across the waters.

Outlook /Sunday Night through Wednesday/... Moderate confidence.

Winds and seas remain below Small Craft Advisory thresholds
through the period. Potential for low vsbys in fog, especially
Tuesday and Wednesday early mornings. Scattered showers and
thunderstorms with brief poor vsbys Tuesday and Wednesday.

&&

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

&&

$$
SYNOPSIS...WTB/EVT
NEAR TERM...EVT
SHORT TERM...EVT
LONG TERM...WTB
AVIATION...WTB/EVT
MARINE...WTB/EVT



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