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Area forecast discussion 
National Weather Service Taunton Massachusetts
309 PM EDT sun Jul 5 2015

Synopsis...

Dry and above-seasonable conditions prevail beneath high pressure
into Tuesday morning. A series of fronts will bring scattered
showers and thunderstorms Tuesday and Wednesday. Dry weather
should prevail into next weekend...although a stalled front south
of New England may trigger a few showers from time to time.

&&

Near term /until 6 am Monday morning/...

Into this evening...

Quiet weather with light winds. Sea-breezes pushing onshore will
begin to wash out. Highs around the low- to middle-80s will drop back
into the upper-70s. Cooler along the shores with the onshore flow.

Tonight...

Nice. Pleasant. Beneath the ridge surface high pressure prevails.
Mostly clear overall under light SW-winds. Anticipating some
level of radiational cooling and thus will drop lows several
degrees below MOS-guidance. Lows around the upper-50s with the
coolest spots in northwest Massachusetts...warm along the coasts. Patchy dense fog
likely especially where onshore flow keeps dewpoints above the
60-degree mark. Focus across the CT-River Valley / Rhode Island / SW Massachusetts. Can
not rule out some low-lying areas in central / east Massachusetts as well.

&&

Short term /6 am Monday morning through Monday night/...

Monday...

Continued ridging influence of high pressure. Will see the push of
warm-moist air north along its west-periphery into S/W-portions of New
England...along with some thin-high clouds late. With effective
boundary-layer mixing above h9 expect highs into the into the middle-
to upper-80s over all interior locales immediately away from the
shoreline. Can not rule out a location or two reaching 90-degrees.
With forecast light winds expect sea-breezes to push inland.

Monday night...

With the ridge slipping further east allowing return S-flow across much
of New England undergoing gradual isentropic ascent...expect the
encroachment of thicker clouds into S/W-portions of New England.
Though an increasing presence of Theta-E from the wobbling low
pressure center across the mid-Atlantic...feel the presence of dry
air per the influential ridge will keep light showery weather at a
minimum. Prevailing light S-winds will keep lows slightly milder
around the low-60s. Continuing rising dewpoints. Another night of
patchy dense fog not out of the question.

&&

Long term /Tuesday through Sunday/...

Highlights...

* showers/storms Tuesday and Wednesday
* high uncertainty later in week but mainly dry

Details...

Uncertainty increases as we head through week due to transition in
larger scale pattern. Initially high amplitude pattern with ridging
over eastern states gives way to more zonal flow across northern
tier of states as ridge becomes suppressed and we feel more of
effects of closed low over central Canada. How quickly ridge shifts
to our S and how much we become influenced by northern stream
remains to be seen...but makes difference between dry and seasonable
weather later this week or more in way of cooler/showery conditions.
Forecast is largely weighted on blend of available guidance and
ensembles to help Iron out uncertainty...especially beyond day 3.

Tuesday and Wednesday...moderate confidence.

Warm front lifts through region Tuesday. After possibility of few
morning showers primarily across interior...airmass should be able
to destabilize with sb convective available potential energy approaching 1500 j/kg in afternoon in
western New England. However 0-6km shear and middle level lapse rates
are rather weak...in addition to lack of large scale forcing so
overall severe threat is low. Nonetheless we should see scattered
showers/storms focused near Berkshires Tuesday afternoon. Potential for
localized flooding given precipitable water values around +2 South Dakota.

Another round of showers/storms expected Wednesday as cold front crosses
southern New England. Conditions look a little more favorable for
strong or isolated severe storms in afternoon and evening but as is
typically case there are mixed signals. Sb convective available potential energy should be near 1500
j/kg but 0-6km shear 20-25kt and weak middle level lapse rates argue
against a more widespread severe threat. One area to keep an eye on
is actually across east Massachusetts later in day which should be on edge of
an area of higher 0-6km shear located offshore.

Thursday through sun...low confidence.

Depending on how larger scale pattern evolves...to either more of
zonal flow or weak ridging ahead of Canadian closed low...we could
end up with stretch of dry weather or periods of showers/storms. For
now we are leaning toward drier solution and will keep probability of precipitation low.
Does look like temperatures will be at or perhaps slightly below
average for middle July.

&&

Aviation /19z Sunday through Friday/...

Forecaster confidence levels...

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

Short-term /through Monday night/...high confidence.

Mainly VFR. Patchy IFR fog possible overnight. Focus CT-River
Valley / low-lying locales of Massachusetts / Rhode Island. Light winds turning S into
Monday at or below 10 kts. Sea-breezes along the shores around
16z.

Kbos terminal...high confidence in taf. Sea-breeze presently will
continue to waffle over the terminal as we go into evening. Winds
should remain at or below 6 kts. Another sea-breeze expected
around 16z Monday.

Kbdl terminal...high confidence in taf. Patchy fog possible around
8-11z.

Outlook /Tuesday through Friday/...

Tuesday and Wednesday...moderate confidence. MVFR/IFR in scattered showers/tstms.
Patchy fog at night.

Thursday and Friday...low confidence. VFR.

&&

Marine...

Forecaster confidence levels...

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

Short-term /through Monday night/...high confidence.

Quiet boating weather. Seas continue to diminish beneath high
pressure. Winds turn S through Monday into Monday night with any
gusts remaining below 20 kts. Patchy dense fog possible during
the overnight periods.

Outlook /Tuesday through Friday/...

Moderate confidence. Mainly light winds and flat seas as a series of
weak fronts cross waters...but could see 4-5 feet seas on southern
waters S of islands by Wednesday or Thursday due to building swell.

Main concern is for scattered showers/storms Tuesday and Wednesday...as well
as patchy late night/early morning fog.

&&

Box watches/warnings/advisories...

CT...none.
Massachusetts...none.
Rhode Island...none.
Marine...none.

&&

$$

Synopsis...sipprell/jwd
near term...sipprell
short term...sipprell
long term...jwd
aviation...sipprell/jwd
marine...sipprell/jwd

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