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Area forecast discussion 
National Weather Service Taunton Massachusetts
650 PM EDT Tuesday Sep 23 2014

Synopsis...

High pressure will bring another dry and mild day Wednesday. Low
pressure moving up the East Coast will likely bring rain and cool
temperatures to portions of southern new eng south of the Massachusetts
Turnpike Thursday into Thursday night. A few showers could linger
into early Friday...then high pressure returns for the weekend with
warm and dry conditions. Cooler weather will arrive sometime next
Monday or Tuesday.

&&

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

650 PM update...

Mainly clear skies early this evening...other than a touch of strato-
cumulus affecting a portion of our extreme northwest zones. May
also see a touch of very thin high cloudiness near the South Coast
tonight...but generally mostly clear skies.

High pressure builds to the north tonight and light winds suggest
good radiational cooling conditions. However...higher dewpoints
will limit cooling potential somewhat compared to last night. Expect
min temperatures mostly in the 40s with lower 50s bos/pvd urban
centers...but some upper 30s possible in normally cold spots in the
upper CT valley and interior east Massachusetts.

&&

Short term /6 am Wednesday morning through Wednesday night/...
Wednesday...
high pressure builds east of new eng with easterly flow developing.
The column is still dry so expect mosunny skies although high
clouds will be increasing from the south. Temperatures should be similar
to today...except a bit cooler along the east Massachusetts coast.

Wednesday night...
coastal low lifts north from the NC coast but high pressure in the
Gulf of Maine will be slow to budge. Dry air in the low and middle
levels hangs on through most of the night which will likely keep
rain to the south through Wednesday night. Just a low probability for some
light rain reaching the S coast by daybreak...but it is more
likely that rain holds off until Thursday.

&&

Long term /Thursday through Tuesday/...

Highlights...

* confidence increasing for soaking rain Thursday/Thursday night south of I-90
* lingering showers possible early Friday across eastern New England
* unseasonably warm afternoon/S this weekend
* backdoor cold front cools US down some by next Monday or Tuesday

Details...

Thursday and Thursday night...

Pretty much all of our models except for the UKMET have trended
significantly further north with ocean storm Thursday/Thursday night over the
past 24 hours. Confidence is now increasing in appreciable rainfall
for areas south of the Massachusetts Turnpike Thursday into Thursday night...but plenty
of uncertainty remains.

The main story will be a cutoff low pressure system off the Middle
Atlantic States that will lift northeast. We certainly need to
react to the significant model trends at this point. The potential
for a soaking rain looks much better south of the Massachusetts Turnpike.
However...still some red flags in this situation. The models
notoriously struggle with cutoff low pressure systems...especially
with limited baroclinicity this time of year. So while appreciable
and perhaps even a period of heavy rain appears more likely south of
the Massachusetts Turnpike...amounts and where a sharp cutoff in quantitative precipitation forecast amounts
takes place is uncertain. Its possible that areas north of Route 2
and into southern New Hampshire...see little if any rainfall if models trend a
bit back to the south. Still 48+ hours out so a trend further north
or south is certainly possible.

So all in all...confidence is much higher in appreciable rainfall
south of the Massachusetts Turnpike Thursday/Thursday night. Across our northern areas
confidence in rainfall is lower...but still a possibility.

High surf...since its still September we will likely need to issue a
high surf advisory for ocean exposed beaches of the South Coast/cape
and islands.

Friday...

There could be some lingering showers into at least part of Friday
along the New England coast. Onshore flow and lingering clouds may
keep highs in the 60s on the coast...but the interior will probably
reach 70 to 75 as sun is expected to emerge.

Saturday and Sunday...

Anomalous upper level ridge will build over the northeast states
providing dry weather and unseasonably warm afternoon/S. The models
do not look quite as warm as they have the last couple of days.
This is a result of the ocean system having much more of an impact
than earlier thought. Still think there is a decent shot for lower
elevations away from the immediate coast to see highs top out near
80. Definitely great weather for outdoor activities with low
humidity.

Monday and Tuesday...

A backdoor cold front will likely swing through the region Monday.
Not much more than a spot shower or two expected with the
front...but northeast winds will bring cooler weather. May still be
able to reach into the 70s on Monday..."if" the backdoor cold front
moves through later in the day. Obviously timing is uncertain at
this point. Highs probably will be held in the 60s by Tuesday but
looks mainly dry.

Record high temperatures this weekend into next Monday...

Sat 9/27... sun 9/28... Monday 9/29...

Bos...86...1998 bos...90...1881 bos...88...1952
bdl...88...1998 bdl...83...1959 bdl...86...1945
pvd...86...1998 pvd...84...1943 pvd...87...1945
orh...85...1933 orh...84...1916 orh...84...1952

&&

Aviation /00z Wednesday through Sunday/...
forecaster confidence levels...

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

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

VFR...but isolated fog possible late tonight and Wednesday night in the
interior valleys. Any rain should remain S of New England through
Wednesday night.

Kbos terminal...high confidence.

Kbdl terminal...high confidence.

Outlook...Thursday through Sunday...

Thursday and Thursday night...moderate confidence. MVFR-IFR
conditions expected to develop Thursday and continue Thursday night in rain
south of Massachusetts Turnpike. Its more uncertain if rain and lower
ceilings/visibilities reach into northern Massachusetts and southern New Hampshire.

Friday...moderate confidence. Lower ceilings may linger into Friday along
the coast for at least a part of the day. Otherwise...rest of the
region should be mainly VFR by late morning.

Saturday and Sunday...high confidence in VFR conditions.

&&

Marine...
forecaster confidence levels...

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

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

Light winds and seas tonight. Easterly winds begin to increase
over the southern waters during Wednesday in response to increasing
pressure gradient. Gusts up to 20 knots expected Wednesday afternoon and night
over the southern waters...with gusts to 25kt possible late Wednesday
night. Seas will build to 5-6 feet over the Rhode Island coastal waters Wednesday
night.

Outlook...Thursday through Sunday...

Thursday into Friday...moderate to high confidence. Cutoff low
pressure moving south of the waters will generate a good northeast
gradient with a high pressure system to the north. Northeast wind
gusts of 25 to 30 knots expected with perhaps a period of near gale
force wind gusts across the southern waters. Seas will build to 10
feet across the southern waters. In addition...rain will reduce
visibilities for mariners at times.

Friday night...moderate to high confidence. Small Craft Advisory seas will likely
linger across the outer-waters as a result of left over swell.
However...winds will diminish as Friday night wears on.

Saturday and Sunday...moderate to high confidence. Upper level
riding will keep winds/seas below Small Craft Advisory thresholds.

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...none.
New Hampshire...none.
Rhode Island...none.
Marine...none.

&&

$$
Synopsis...kjc/Frank
near term...Frank/kjc
short term...kjc
long term...Frank
aviation...kjc/Frank
marine...kjc/Frank

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