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Area forecast discussion 
National Weather Service Taunton Massachusetts
426 PM EDT Monday Sep 22 2014

Synopsis...

High pressure will bring dry weather along with mild days and
cool nights through Wednesday. Distant coastal low pressure may
graze southeast New England with the low risk for few showers Wednesday
night into Thursday. High pressure returns Friday into early next
week with dry weather and unseasonably warm afternoon/S. Its
possible a few record high temperatures are challenged this weekend.

&&

Near term /until 6 am Tuesday morning/...
high pressure will gradually build in from the west bringing moclear
skies and a dry airmass. Gusty winds will gradually diminish
tonight but there appears to be enough gradient to limit
radiational cooling so temperatures will likely stay above frost
thresholds. Still a chilly night with mins in the middle/upper 30s in
the interior...with 40s elsewhere. Isolated frost possible in the northwest
Massachusetts and SW New Hampshire but not widespread enough to support frost headlines.

&&

Short term /6 am Tuesday morning through Tuesday night/...
Tuesday...
high pressure crests across the region which will bring mosunny skies
and light winds. Subsidence inversion will limit mixing height
below 850 mb. 925 mb temperatures 10-11c which supports temperatures 65-70
degrees...cooler higher terrain which is line with 2m temperatures. Some
of the hires guidance is hinting a seabreeze developing along the
coast in the afternoon.

Tuesday night...
high pressure builds to the north with a continuation of clear skies
and a light NE wind developing overnight. We used a blend of the
guidance which yields mins mostly in the 40s.

&&

Long term /Wednesday through Monday/...

Highlights...

* cool nights/mild days Wednesday and Thursday
* unseasonably warm afternoon/S this weekend perhaps into Monday
* dry with no appreciable rainfall in site

Details...

Wednesday...

Large high pressure centered over northern New England will result
in dry/pleasant weather for late September. Given the positioning
of the high pressure system...expect easterly winds at the surface
so coolest temperatures will be found near the eastern Massachusetts coast. Highs
should range from mainly the 60s...to perhaps near 70 in the lower
CT River Valley.

Wednesday night through Thursday night...

We will have to keep an eye on a low pressure system that will be
emerging off the middle Atlantic coast. However...weak upper level
flow and a surface high nearby are not favorable for allowing the
low pressure system to track up the coast. In addition...weak
baroclinicity will also limit northwest axis of quantitative precipitation forecast shield.
Nonetheless...the GFS and its ensembles indicate at least a low risk
for a few brief showers across our southern zones. Whether or not
this comes to fruition remains to be seen...but certainly do not
expect any appreciable rainfall.

As for high temperatures on Thursday...onshore flow will result in highs in
the 60s to near 70. Again...mildest readings will be found across
the distant interior. Low temperatures Wednesday night and Thursday night shield be
in the 40s...to the lower 50s.

Friday through Monday...

Anomalous upper level ridging takes hold of the northeast U.S. From
Friday into early next week. This will result in dry weather with
unseasonably warm afternoon/S with near record high temperatures possible
this weekend. Another factor that may help in this process is the
very dry ground...which may allow high temperatures to get a degree or so
higher than they normally would in this set up.

Guidance numbers have likely trended too much towards climatology.
High temperatures Friday...should be well up into the 70s. Sat/sun looks like
the warmest days...where highs will probably reach 80+ across the
lower elevations and areas away from the coast. Low confidence on
high temperatures for Monday...will depend whether or not a backdoor cold
front cools US off a bit like the 12z European model (ecmwf) depicts. GFS is still
quite warm...but obviously were a week out so that is uncertain. As
last shift pointed out...dry airmass will keep humidity in check so
afternoon/S will be nice for outdoor activities.

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 /21z Monday through Saturday/...
forecaster confidence levels...

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

Short term /through Tuesday night/...

High confidence. VFR. North/northwest wind gusts to 25 knots this afternoon...
diminishing tonight. Light winds Tuesday and Tuesday night with low probability
of a seabreeze Tuesday afternoon.

Kbos terminal...high confidence. Low probability of a seabreeze Tuesday
afternoon.

Kbdl terminal...high confidence.

Outlook...Wednesday through Saturday...

High confidence in VFR conditions through the period...other than
brief late night/early morning patchy ground fog in the typically
prone locales. There is a low risk for a brief period of MVFR
conditions near the South Coast/cape and islands Wednesday night into Thursday
night. This will depend upon whether a few showers can make it that
far north with an offshore low pressure system.

&&

Marine...
forecaster confidence levels...

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

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

Tonight...gusty winds will gradually diminish tonight with gusts
dropping below Small Craft Advisory thresholds this evening. However...southerly
swell will keep seas above 5 feet over the open waters through the
night so small craft advisories will continue here.

Tuesday and Tuesday night...light winds below 15 knots with seas subsiding
below 5 feet during Tuesday over the open waters. Light winds and seas
Tuesday night.

Outlook...Wednesday through Saturday...

Moderate to high confidence...

The main concern will be a low pressure system that will track near
the benchmark Wednesday night into Thursday. It will likely result in enough
swell for Small Craft Advisory seas to developing across the southern open waters Wednesday
night. Small Craft Advisory swell may persist across the outer waters right into Friday
afternoon before diminishing.

Winds should generally remain below Small Craft Advisory thresholds through the
period. However...a period of northeast wind gusts of 20 to 25
knots are possible across the southern waters if coastal low
pressure tracks close enough to our region. Visibilities should be
good through most if not all of the period.



&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...high surf advisory until 6 PM EDT this evening for maz020>024.
New Hampshire...none.
Rhode Island...high surf advisory until 6 PM EDT this evening for riz006>008.
Marine...Small Craft Advisory until 10 PM EDT this evening for
anz231>234.
Small Craft Advisory until 8 PM EDT this evening for anz230-
236-251.
Small Craft Advisory until 6 am EDT Tuesday for anz235-237.
Small Craft Advisory until 11 am EDT Tuesday for anz250-
254>256.

&&

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

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