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Area forecast discussion 
National Weather Service Taunton Massachusetts
349 PM EDT Tuesday Jun 2 2015

Synopsis...
low pressure along a frontal boundary south of New England will move
farther offshore resulting in drier but cool weather tonight. High
pressure along with light winds...sunshine and milder temperatures
return Wednesday. High pressure and dry weather lingers into much of Thursday
with showers possible Thursday night into Friday...as another cold
front moves into the region. Then high pressure and dry weather
return for the weekend. Weather pattern may become unsettled
early next week with a chance of showers most days...but a washout
not expected. Temperatures warm through the period...finally
reaching seasonal norms by early next week.

&&

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

345 PM update...

This evening...

Rain shield continuing to make good progress southeast with back
edge at 330 PM into northern portions of CT-Rhode Island to just south of
Boston...as northern stream short wave over Quebec continues to move
steadily eastward as well. Watching second batch of rain over
northeast PA into northern New Jersey...NYC area...Long Island and lower
Hudson Valley. However on the backside of the Quebec short wave middle
level dry air in the 850-700 layer is advecting southeast into much
of Massachusetts/northern CT-RI...which is eroding the northern edge of the
rain shield and precluding much if any rain from reaching the ground
across this area. Thus this band of rain is likely to be confined
to the southern Rhode Island and southeast Massachusetts especially the South Coast. At
18z the 12z NAM appears to be verifying best when compared to
surface observations...with the 12z GFS the worst. Thus this
evening/S forecast will be based on a non-GFS solution. As the rain
ends temperatures are climbing from the u40s into the low and middle 50s.
Still well below normal for early June!

Overnight...

K indices from all model guidance show sharp middle level drying across
the entire region behind departing short wave. However low level
flow does not become northwest instead north-NE which may preclude complete
drying at the surface. Thus patchy stratus-S/cumulus may linger along
with some patchy fog overnight. Although neither should be
widespread. Another chilly night as 1027 mb anticyclone advects
southward from Quebec into northern New England...with low level
northerly flow draining cool air southward. Thus all locations fall
into the 40s tonight with a few interior spots briefly dipping to at
or just under 40.
&&

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

Wednesday...

Weak short wave ridging builds into the area along with surface
settling over the area. Cross sections reveal some low level
moisture may remain trapped beneath subsidence inversion so scattered to
perhaps broken scu/cumulus may develop during the afternoon. Nevertheless
partial June sunshine will combine with light winds for very
pleasant weather. Afternoon seabreezes will cool off the coastline.
Strong June sunshine will warm maritime airmass with highs in the
mu60s for most locales...70-75 CT River Valley and 55-60 along the
immediate coast given light onshore winds.

Wednesday night...

1026 mb high over the area will combine with light winds and
relatively dry airmass for temperatures to fall fairly quickly with sunset
especially inland removed from the maritime layer. Dry weather
prevails with middle and high clouds arriving toward morning on the
south-southwest horizon.

&&

Long term /Thursday through Tuesday/...

Highlights...

* mainly dry with below normal temperatures Thursday
* a few showers possible Thursday night into Friday and again Friday night into
Sat as a cold front approaches
* dry and seasonable sun then threat of showers returns Monday and Tuesday

Operational models are not in great agreement with this model run.
They are offset timing wise at the very least with the GFS being
slower than the European model (ecmwf). Seems the European model (ecmwf) ensemble mean has been more
consistent...if not the operational run as well over the last few
days so will guide the forecast towards that. Overall...we/ll start
the forecast off with zonal flow and high pressure Thursday.
Following that will be a cold frontal passage Friday night with a
few showers. Saturday and Sunday will see mostly dry weather as
high pressure builds in and then moves offshore. And finally some
more seasonable temperatures early next week ahead of another cold
front.

Thursday into Friday...high pressure moves offshore Thursday
allowing for a few showers to develop Thursday night into Friday
with a weak shortwave. Temperatures will be warming slowly but will
still be below normal.

Friday night into Saturday...a better chance for showers ahead of a
cold front that will move through the area early Saturday morning.
Again...not a washout but another chance for much needed rain.
Temperatures warm to near normal levels Saturday.

Sunday through Tuesday...temperatures continue to warm reaching
seasonal levels and possibly a few degrees above normal by Tuesday.
Sunday and Monday should be mostly dry with showers and possibly
thunderstorms on Tuesday with a cold frontal passage.

&&

Aviation /20z Tuesday through Sunday/...
forecaster confidence levels...

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

Through 00z...

Rain shield continues to advanced eastward. Rain over northeast
PA...northern New Jersey into southeast New York state will track east-southeast and be
confined to the South Coast of CT/Rhode Island and southeast Massachusetts. Mainly MVFR
conditions will dominate with a trend toward VFR. Moderate to high
forecast confidence.

After 00z...

Gradual improvement expected with rain exiting the South Coast
around 00z. However not expecting a clean Post frontal airmass
with some patchy MVFR ceilings possible. Low confidence on exact areal
coverage.

Wednesday...

Low probability of patchy lingering MVFR ceilings in the morning but all
terminals VFR by 15z. North winds trend northeast by afternoon
especially along the coast. High forecast confidence.

Wednesday night...

VFR with a low probability of MVFR in patchy fog across western Massachusetts late.

Kbos terminal...high confidence in overall taf trends but lower
in exact timing.

Kbdl terminal...high confidence in overall taf trends but lower in
exact timing.

Outlook...Thursday through Saturday...

Thursday through Friday...moderate confidence. Mainly VFR. Very
low probability of brief MVFR conditions in isolated -shra.

Friday night through Saturday morning...moderate confidence. Mainly
VFR. Low probability of brief MVFR conditions in scattered -shra.

Saturday afternoon through Sunday...high confidence. VFR.

&&

Marine...
forecaster confidence levels...

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

Short term /through Wednesday night/...moderate to high
confidence.

Tonight...

Modest north-northeast winds as weak wave of low pressure tracks NE from Georges
Bank to southeast of Nova Scotia toward morning. Combination of modest north-northeast
wind and long fetch will keep seas up much of the night. Rain this
evening moves offshore from northwest to southeast with visibility improving.

Wednesday...

High pressure builds over New England from Quebec. Light winds but NE
swells will continue. Visibility good along with dry weather.

Wednesday night...

More of the same...light winds with high pressure overhead. NE swells
continue to subside. Dry weather and good visibility prevail.

Outlook...Thursday through Sunday...

Quiet boating weather expected through the period with occasional
isolated rain showers possible.

&&

Climate...

Record low maximum temperatures for today...

Bos...50...1946
bdl...50...1907 (record for the month)
pvd...47...1907 (record for the month)
orh...47...1946 (record for the month)

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...none.
Rhode Island...none.
Marine...Small Craft Advisory until midnight EDT tonight for anz231>235-
237-250-251-255-256.
Small Craft Advisory until 8 PM EDT this evening for anz230.
Small Craft Advisory until 10 am EDT Wednesday for anz254.

&&

$$
Synopsis...nocera/rlg
near term...nocera
short term...nocera
long term...rlg
aviation...nocera/rlg
marine...nocera/rlg
climate...kb

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