Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 180145

Area Forecast Discussion
National Weather Service Taunton MA
945 PM EDT Mon Oct 17 2016

A stalled front over Southern New England this evening moves north
as a warm front Tuesday morning. This will bring unseasonably
warm conditions with the potential for near record high
temperatures Tuesday and Wednesday. Unsettled weather likely at
times Thu and Fri. Not as warm late week but still mild for mid
Oct. A drying and cooling trend likely next weekend.


945 PM update...
Isolated showers which moved through N MA late afternoon and
evening have shifted to Essex county and will be moving offshore.
Meanwhile watching a weakening MCS moving east from northern NY.
Weakening will continue as the complex outruns low level jet
energy and what is left of the instability, but sct showers may
clip northern MA overnight per the HRRR and RAP. Will increase
PoPs north of the Mass Pike. A mild night by October standards
with mins mostly 55-60 and even a tad humid.

The other forecast consideration which may have a big impact on
temps tomorrow is a backdoor front which is pushing south across
southern ME and may get into NE MA by daybreak. Some of the hi-res
guidance holds temps in the 60s across NE MA into the afternoon
before pushing the front to the north, while other guidance keeps
the front just north of SNE. Will have to examine this in more
detail with 00Z guidance suite.


Unseasonably warm weather is in store for the region. Southwest
flow and increasing sunshine Tuesday will mix the column to at
least 900 mb. Temps at 900 mb fully mixed would support max sfc
temps around 80. If the mixing reaches 850 mb it would support mid

Meanwhile winds in the mixed layer will be around 25 knots. Expect
gusty southwest winds near 25 knots.

Dew points will remain 55 to 60 Tuesday night. This will mean
another mild night with readings in the upper 50s and low 60s. If
winds diminish sufficiently overnight, this would allow patches of
fog to form.



* Unseasonably warm Wednesday, with near record high temperatures
* Widespread showers possible Friday
* Drying and cooling trend likely next weekend


Southeast to west winds continue, providing a little downslope
component across eastern MA. Plenty of sunshine will mean another
summer-like day. High temperatures expected to approach the
records, which are in the 81-84 degree range. See the climate
section below for more information.

A weak cold front should cross our region Wednesday night. This
front could produce some showers.


A weak front along the the south coast of New England is
anticipated to move back north as a warm front during the day.
While this front is nearby, cannot rule out the possibility for
some showers during the day. More clouds and easterly winds should
mean seasonable high temperatures.

Thursday night and Friday...

Showers look to be most widespread during this period. The timing
of various weather features will be crucial to the actual outcome.
Latest run of the GFS has much more amplified mid level trough
than the ECMWF. Thus, the GFS brings a potentially subtropical or
tropical low much closer to our region than the ECMWF. In
addition, a low pressure is forecast to move through the Great
Lakes into Quebec. Just about all of the models try to establish
some form of energy transfer, and develop a secondary low pressure
somewhere of the Mid Atlantic coast.

Were this to occur, our region would be more likely to get a
soaking rain, if this secondary low pressure gets close enough.
This is where the timing of all the major weather features will
come into play. If the mid level trough is more like the ECMWF
solution, then most of the moisture plume stays off to our east. A
solution more like the GFS gets us some much-needed rain.

At this time, only have moderate confidence in this portion of the
forecast. We`re still a day or two away from getting better
sampling of the shortwave energy which will ultimately amplify the
mid level longwave trough over the eastern USA. Will just have to
wait a bit more until this happens to have a better idea on the
likely outcome.

Saturday into Monday...

Risk for showers may linger into a portion of Saturday. However,
upper air pattern is progressive, so trend will be for drier and
cooler weather later this weekend. Cooler weather persists into
Monday, with below normal temperatures.


Forecaster Confidence Levels.

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

Short Term /through Tuesday Night/...

Tonight...Moderate confidence. Mainly VFR. Patchy MVFR cigs and
sct showers possible across northern MA overnight. Patchy MVFR/IFR
vsbys and cigs possible toward the south coast. Low confidence in

Tuesday...Moderate to high confidence. VFR. Increasing SW winds
with gusts 25 knots in the afternoon.

Tuesday night...Moderate to high confidence. VFR. Diminishing
wind. Areas of IFR cigs/vsbys in developing fog overnight.

Outlook /Wednesday through Saturday/...

Wednesday...Any lingering MVFR conditions in patchy fog lifts to
a SCT-BKN VFR deck. Dry weather prevails.

Thursday and Friday...VFR likely to start but then lowering to
MVFR or IFR with a risk of rain. High confidence in trends, but
low confidence in details.

Saturday...Becoming drier. Mainly MVFR to IFR during the day, with
slow improvement to VFR Saturday night. Low confidence in timing.


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.


A cold front will likely stall across the waters and southern New
England this evening. This front will slowly return north as a
warm front late tonight. Winds will remain light much of the
night. A 3-4 foot east swell will continue on the eastern waters.
A Small Craft Advisory continues on these eastern waters for the
combined seas.


As the front moves to the north Tuesday, winds will pick up out
of the southwest, with gusts 25 to 30 knots by Tuesday afternoon.
These will slowly diminish in the evening. A 3-foot east swell
will linger on the eastern waters through the day.

A Small Craft Advisory will be in effect on most waters for both
winds and seas.

Tuesday night...

Diminishing winds, but seas linger at 5-6 feet. Small Craft
advisory may be needed for some of the waters.

Outlook /Wednesday through Saturday/...

Wed...winds diminish as a weakening cold front sags into the
region during the night. Thus, seas will subside as well. Dry
weather and good vsby, although risk of patchy fog toward Thu

Thu...onshore winds as a low pres enters PA and NY state. Low
risk for showers and areas of fog.

Friday into Saturday...This is a complicated period, which will
be dominated by the exact track and strength of a potentially
subtropical or tropical low off the East Coast of the USA.
Expecting increasing E to SE winds Friday, which will start to
build seas. Eventually, these winds turn N to NW Friday night into
Saturday. Low confidence in the timing, but moderate confidence in
the trend.

While expecting rough seas to develop, mainly due to large
southeast swell, we may be underforecasting them at this point.
Should the aforementioned low off the East Coast get closer to our
region than currently forecast, wind waves would also be
increased, resulting in higher significant wave heights.

Mariners should pay close attention to the forecast during the
course of this week, and adjust their plans, as needed.


Record High Temperatures:

Tuesday October 18th                Wednesday October 19th

Boston 82 in 1947                   Boston 84 in 1945
Worcester 85 in 1908                Worcester 81 in 1963
Providence 85 in 1908               Providence 81 in 1945
Hartford 80 in 1968                 Hartford 82 in 1963


MARINE...Small Craft Advisory from noon to 8 PM EDT Tuesday for
     Small Craft Advisory until 8 PM EDT Tuesday for ANZ250-254.


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