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Area forecast discussion 
National Weather Service Taunton Massachusetts
450 am EST Thursday Dec 25 2014

a cold front will move offshore this morning followed by dry and
windy conditions this afternoon. Dry weather and above normal
temperatures will continue into Saturday. A cold front may bring
a few rain showers Sunday followed by colder conditions early next
week. There is a low probability that low pressure passing to our
south on Tuesday could be close enough to cause some snow but that
is far away at this point.


Near term /until 6 PM this evening/...
450 am update...
we have dropped the Flood Watch at this time. A band of heavy
rain showers will exit Outer Cape cod and Nantucket by 6 am.
Otherwise...a band of showers will be moving across the region
from west to east this morning but the risk of any flooding has

Previous discussion...
we kept the Wind Advisory for mainly the upper cape where temperatures
in the lower 60s may allow for enough mixing with axis of low
level jet moving across the region through 12z.

Low level cool air really hanging tough in the CT valley and NE
Massachusetts. Warming into the 50s still likely...but not expected until
the cold front passes 10-12z with mixing of warmer air aloft to
the surface.

Today...rain this morning will exit from west to east 13-17z with
cape/islands the last to dry out. Expect pt-mosunny skies
developing in the afternoon as cold advection dries out the
column...with most clouds expected in the interior where
sufficient low level moisture will support broken strato-cu. The
main concern this afternoon is strong westerly winds as
steepening low level lapse rates allowing mixing of stronger
winds aloft. Soundings suggest potential for gusts to 30-35
knots...with low probability for near Wind Advisory threshold of 35-40 knots
across higher terrain in northern and western Massachusetts.

Maximum temperatures will occur around 12z...with readings mostly in the
50s...then falling into the 40s during the afternoon.


Short term /6 PM this evening through 6 PM Friday/...
high pressure builds across the middle Atlantic region with ridging
extending north into southern New England. Expect mostly clear skies with a few
clouds across central and west Massachusetts. Gusty west winds during the
evening...diminishing overnight but remaining gusty along the
coast. Min temperatures ranging from upper 20s to middle 30s.

high pressure shifts to the middle Atlantic coast with mild westerly flow
into new eng. Expect mosunny skies and lighter winds with high
temperatures well into the 40s and near 50 degrees in the coastal plain.


Long term /Friday night through Wednesday/...
* remaining dry with above normal temperatures Saturday
* chance of showers Sunday
* turning colder for next week. Still a chance of some snow
around Tuesday but highly uncertain.

Friday night and Saturday...high confidence.

High pressure builds over the middle Atlantic coast Friday night and
settles off the coast of North Carolina Sat. Some discrepancy
in model forecast temperatures for Sat afternoon with European model (ecmwf)
cooler than GFS...with 3c vs. 6c at 925 mb. With mostly sunny
skies...light winds...and SW flow opting for warmer
temperatures. Have gone 5+ degrees warmer than guidance...with
highs reaching 50 to 55 Sat afternoon.

Sunday...high confidence.

Strong low pressure will move across Quebec and far northern
Maine. A cold front trailing from the low will move across southern
New England. Skies will be cloudy but moisture will be limited and
there is only a chance of some light rain showers with this front
mainly in the morning and early afternoon. Expecting skies to
become mostly sunny again by late in the day...from northwest to southeast.
Cooler but still above normal temperatures with highs in the 40s.

Monday and Tuesday... low confidence on precipitation but moderate
to high confidence on temperature.

What we are confident of is that colder air returns to the
region. After will be the end of December. Looking for
highs in the 30s and lows in the 20s...could even see some upper
teens in northwest Massachusetts late Monday night.

However...there remains a great deal of uncertainty in the
evolution of the weather pattern by Tuesday. Monday looks to be
partly cloudy but with clouds increasing by nightfall. For several
runs now...the European model (ecmwf) has come into agreement with the operational
GFS runs which suppress a low pressure system to our south and
leave US dry. The Canadian model also agrees that the low will be
well south of the region but has a much broader area of precipitation
to the north...such that we could see some snow from the northern
fringes. Closer inspection of the GFS ensembles leads one not to
dismiss this system quite yet. A few of the gefs members have low
pressure much farther to the the New Jersey coast or south of
the islands. Yet other members have strong high pressure building
in and no low at all. Hence...a high level of uncertainty exists.

Another possibility is that skies could become cloudy with
scattered snow showers as a result of the cold pool aloft coming
over southern New England Tuesday. For now...have opted to include
slight chance probabilities of snow for our region to acknowledge
the possibility but lean toward the southern solutions.

Wednesday...moderate confidence.

Wednesday looks to be a dry and seasonably cold day with highs mainly
from 30 to 35.


Aviation /10z Thursday through Monday/...
forecaster confidence levels...

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

Short term /through Friday/...

Through 12z...widespread IFR/LIFR continues improving toward 12z
in the CT valley. Areas of dense fog north and west of the warm
front in the interior will improve as the front lifts north. Renewed
area of rain redevelops across southern New England 08-12z as the cold front
approaches. SW gusts to 35-40 knots possible across portions of Rhode Island
and southeast Massachusetts.

Today...high confidence on trends. Lower confidence on timing.
IFR/MVFR conditions will improve to VFR from west to east 14-18z
as the rain moves offshore. Gusty west winds developing late
morning through the afternoon with gusts to 30-35 knots. Low probability for
g40 knots over higher elevations in northern and western Massachusetts.

Tonight...high confidence. VFR. West winds gusting to 25-30 knots
early...highest along coast...then diminishing after midnight.

Friday...high confidence. VFR.

Kbos terminal...high confidence in taf trends. Timing of warm
front may be too fast by a few hours but we do expect wind shift
to S before daybreak.

Kbdl terminal...high confidence in taf trends.

Outlook...Friday night through Monday...

Friday night and Saturday...high confidence VFR.

Sunday...moderate confidence. MVFR possible in scattered
rain showers.

Monday...moderate confidence. Mainly VFR. Conditions may lower to
MVFR Monday night.


forecaster confidence levels...

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

Short term /through Friday/...high confidence.

Today...prefrontal SW winds are below gale...but after wind shift
to west...steepening low level lapse rates will allow for gusts to
increase to 35 knots especially this afternoon. Gale warnings are in
effect for all waters except Boston Harbor and Narragansett Bay.

Tonight...near gales over the outer waters in the
evening...otherwise Small Craft Advisory wind gusts with gradual diminishing wind

Friday...diminishing wind below Small Craft Advisory with subsiding seas.

Outlook...Friday night through Monday...moderate confidence.

Friday night and Saturday...seas may still be near 5 feet over the
outer waters Friday night but should subside to below Small Craft Advisory criteria by
Sat. SW to west winds could still gust to 15-20 knots at times.

Sunday...a cold front will move across the waters. SW winds will
shift to the northwest but speeds should be below Small Craft Advisory criteria. Seas
could build to 5 feet on the outer waters. Scattered showers could
cause some brief visibility restrictions.

Monday...relatively light northwest to north winds expected. Seas below 3 feet.
There is a low probability that winds could become NE late at
night if low pressure south of New England come farther north than
expected toward Tuesday morning.


record highs for today / Christmas day

Bos...61 in 1996 / 65 in 1889
pvd...60 in 1990 / 63 in 1964
bdl...59 in 1996 / 64 in 1964
orh...57 in 1996 / 60 in 1964


Box watches/warnings/advisories...
Massachusetts...Wind Advisory until 8 am EST this morning for maz022.
Rhode Island...none.
Marine...Gale Warning from 10 am this morning to 7 PM EST this evening
for anz232>234.
Small Craft Advisory until midnight EST tonight for anz230-236.
Gale Warning from noon today to 7 PM EST this evening for
Gale Warning from 9 am this morning to 7 PM EST this evening
for anz235-237.
Gale Warning from noon today to 10 PM EST this evening for
Gale Warning until 10 PM EST this evening for anz254>256.


near term...kjc/gaf
short term...kjc
long term...gaf

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