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Area forecast discussion 
National Weather Service Taunton Massachusetts
1012 am EST Fri Dec 2 2016

Synopsis...
cooler temperatures are expected as we head into the weekend.
Other than scattered light snow showers or flurries over the
northern and western higher terrain areas, it should remain
mainly dry through most of the weekend. A few brief snow or rain
showers are possible Sunday night into early Monday. Otherwise,
high pressure will provide dry weather Monday afternoon through
midday Tuesday. Low pressure moving out of the Ohio Valley to the
mid Atlantic states may bring some mixed precipitation as far
north as southern New England late Tuesday night through
Wednesday, but timing and track remain uncertain.

&&

Near term /until 6 PM this evening/...
1012 am update...

No major changes to the ongoing forecast. Clouds were more
prevalent across the western half of MA, as well as portions of
northern CT. Expecting more diurnal clouds, again, this afternoon.
Should be mainly dry across southern New England, too.

Brought the forecast back in line with observed trends.

645 am update...

Noting clear skies across central and eastern areas
per latest observation and infrared satellite imagery as of 10z. Bands of low
and mid level clouds moving east out of New York state across west Massachusetts into north
CT, which will tend to thin out somewhat as it works eastward this
morning. Another band of high clouds starting to slide east across
central CT into west RI, which will push across remainder of Rhode Island and
southeast mass through midday or so. The lower clouds should tend to
dissipate as they slide east with downsloping winds off the
Berkshires in place.

Westerly winds will pick up by mid morning, gusting up to around
20-25 kt along coastal areas as well as across the higher inland
terrain.

Early morning forecast pretty much on track, but have updated to
bring conditions current. Made adjustments to cloud cover based
on current conditions. Remainder of forecast in pretty good shape.

Previous discussion...

Downsloping westerly winds should help keep southern New England
dry today. Temperatures will be a little cooler than yesterday
thanks to some modest cold advection. High temperatures are
expected to range from the mid 40s across the higher terrain to
near 50 across the southeast coastal plain. A fair amount of
cloudiness will probably persist today near the crest of the
Berkshires but considerable sunshine everywhere to the east.

&&

Short term /6 PM this evening through 6 PM Saturday/...
tonight...all models depict a short wave trough and some pooling
of deeper moisture passing across our area tonight. Looks to be
enough there to support scattered snow showers over the Berkshires
spilling onto the east slopes, especially in Franklin County. Can
not rule out a very minor accumulation of say a half inch or so in
the higher elevations of northwest Franklin County tonight. May
also see a few flurries tonight over the northern Worcester Hills.
We may also experience a period of gusty winds as well tonight as
the short wave trough aloft and leading edge of a pulse of cold
air advection moves through. Temperatures will drop with the cold
advection, but mixing from the wind and at least partial cloud
cover will tend to brake the temperature drop.

Saturday...looks to be dry with mostly sunny skies across most of
the area. As the surface wind becomes more northerly later in the
day, ocean effect clouds may impact the Outer Cape with a slight
chance of showers grazing the very Outer Cape. 850 mb temperatures
dropping a few degrees celsius will translate to surface high
temperatures 4 or 5 degrees cooler Saturday afternoon than Friday
afternoon. Nonetheless, highs in the lower to mid 40s are not too
far off our climatological normals, perhaps just a degree or two
below average. Winds will again be fairly gusty, reaching 20 to 25
mph during much of the day.

&&

Long term /Saturday night through Thursday/...
highlights...

* temperatures running a bit below seasonal normals through at
least Tuesday
* low pressure developing across the mid Atlantic states may push
some mixed precipitation into the region Tuesday night and
Wednesday, but confidence remains low

Saturday night and Sunday...high confidence.

Lower clouds and spotty ocean effect rain showers may continue
Saturday night into Sunday morning across Outer Cape cod as colder
air moves across the milder waters on strong north-northwest winds. Not
expecting much in the way of qpf, however. Otherwise, expect
mainly dry conditions elsewhere across the region.

Winds will be gusty, up to 25-30 kt across the higher inland
terrain as well as along the coast Saturday night, then will
diminish during Sunday.

After overnight lows mainly in the 20s inland ranging to the
lower-mid 30s along the shore Sat night, temps on Sunday only
rebound to the mid and upper 30s across the higher inland terrain
up to around 40 across the coastal plain as colder air continues
to filter in.

Sunday night through Monday night...moderate confidence.

Will see a band of clouds approach with a weak 500 mb short wave that
works toward the region Sun night into Monday. Not great model
agreement with this feature, with the 00z European model (ecmwf) being the most
robust in keeping an area of precipitation overspreading the
region by 12z Monday. Both the 00z GFS and ggem tend to dry out
the moisture with this feature, which appears most reasonable
considering the northwest flow in place aloft and not a lot of low level
moisture inflow off the ocean.

Still can not rule out a few rain and/or snow showers overnight
into Monday morning as the short wave passes. Clouds should start
to move out by midday Monday, though may linger through the day
along the coast.

Tuesday...high confidence.

Dry conditions will continue on Tuesday as high pressure ridge
remains across the northeast into Quebec. Mostly sunny skies to
start, then will start to see mid and high clouds work in from the
SW during the afternoon. Expect temps to top off in the 35-40
degree range across the higher inland terrain, and in the lower
40s across the coastal plain and lower CT valley.

Tuesday night and Wednesday...low confidence.

Elongated precip shield lies to the S and west of the region as high
pressure shifts east of the region Tuesday night. Big question will
be the timing as the high exits, if it does. Also, as mid level
ridge builds north into Hudson Bay, 500 mb short wave will ride NE in the
developing SW flow. Timing issues also exist amongst the model
suite with the movement of this short wave.

Noting two surface low pressure centers develop, one associated
with the short wave near the eastern Great Lakes while a second
forms off the mid Atlantic coast by 12z Wednesday. Again, model
and ensemble solution spread lending to lower than average
confidence, with the 00z GFS appearing to be the most robust and
furthest NE with the precip shield while the ggem keeps what is
left of the 500 mb system further S and weaker. Also noting a pretty
good easterly low level jet in place helping to feed moisture into
the system on the GFS. Both the 00z ggem and 12z European model (ecmwf) tend to dry
the system out as the high pressure remains stronger as it extends
S out of Quebec across eastern New England through Wed.

Will continue to lean toward a model blend at this point due to
the remaining uncertainty. Will keep chance pops going for now
during this timeframe.

Thursday...low confidence.

Timing and track issues continue with the passing system across
the region, mainly due to how the mid level development takes
place. The GFS does not develop the mid level long wave trough
nearly as much as the ECMWF, which allows the 500 mb cutoff low to
shift NE faster than the European model (ecmwf). This produces wide surface
solution spread, along with issues with how the sensible weather
evolves. Also, with ec keeping the strong system further W, will
see ptype issues. Overall, low confidence continues.

Will keep chance pops going, but go no higher than 40 percent for
now.

&&

Aviation /15z Friday through Tuesday/...
forecaster confidence levels...

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

Short term /through Saturday/...

High confidence. Broken-overcast clouds at 2500-3000 ft at times near the
crests of the Berkshires today through Saturday. There could also
be a band of clouds near or a little under 3000 feet across the
Outer Cape during mid to late Saturday afternoon. Otherwise, VFR
conditions should prevail. West winds today and northwest winds Saturday
at the surface may gust to 20 knots at times. Scattered snow
showers tonight over the Berkshires could locally lower the
visibility to 5 or 6 miles.

Kbos taf...high confidence in overall taf. VFR. West wind may gust
between 20 and 25 knots this afternoon into this evening.

Kbdl taf...high confidence in overall taf.

Outlook /Saturday night through Tuesday/...

Saturday night and Sunday...high confidence. Mainly VFR. May see
some spotty light -shra Saturday night into Sunday morning across
Outer Cape cod. Northwest wind gusts up to 25-30 kt, especially in the
higher terrain and along the south and east coasts then should
diminish Sunday afternoon.

Sunday night and Monday...low confidence. May see patchy MVFR
conditions in spotty -shra/-shsn Sunday night into Monday
morning, then should be mainly VFR by Monday afternoon.

Monday night...moderate confidence. VFR.

Tuesday...moderate confidence for overall trends, lower on exact
timing. Mainly VFR. May see MVFR ceilings/visibilities move into central and
western areas Tuesday afternoon in mainly -ra, but may see mixed
precipitation toward Tuesday evening.

&&

Marine...
forecaster confidence levels.

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

Short term /through Saturday/...

Moderate confidence for this period. Gusty winds will persist
from the west today and northwest Saturday. Will keep small craft
advisories up for most waters through at least daybreak Saturday.
Our mixing height tool suggests increasing gusts over Boston
Harbor and Narragansett Bay as well toward evening and have small
craft advisories going into effect again at 3 PM today. That may
be a few hours early but believe it wise to have a small buffer in
the event the timing is off some. Anticipate west wind gusts
between 25 and 30 knots across most of the coastal waters this
evening.

Outlook /Saturday night through Tuesday/...moderate confidence.

Saturday night...northwest winds gusting up to 25-30 kt, highest over
the outer waters. Seas will range up to 5-7 ft over the outer
waters. Winds should diminish over Boston Harbor and Narragansett
Bay after midnight Saturday night.

Sunday and Monday...expect winds and seas to diminish below small
craft criteria during Sunday, then should remain below small craft
Sunday night and Monday.

Monday night and Tuesday...winds and seas remain below small
craft criteria. North-NE winds gusting up to 20 kt during Tuesday on
the outer waters south of Block Island.

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...none.
Rhode Island...none.
Marine...Small Craft Advisory until 7 am EST Saturday for anz231>235-
237-250-251-254>256.
Small Craft Advisory from 3 PM this afternoon to 7 am EST
Saturday for anz230-236.

&&

$$
Synopsis...evt/Thompson
near term...Belk/evt/Thompson
short term...Thompson
long term...evt
aviation...evt/Thompson
marine...evt/Thompson

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