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Area forecast discussion 
National Weather Service Taunton Massachusetts
959 PM EDT Monday may 25 2015

Synopsis...
warm and muggy conditions start to build in along with an increasing
chance of showers and thunderstorms through the end of the week. The
threat for scattered showers and thunderstorms will increase from
late Wednesday through Thursday and again over the upcoming weekend.

&&

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

1000 PM update...

Warm front has pushed through much of the area...however a few
echoes are developing along the front as it is still lingeringnear
the region. Temperature/dewpoint spread is still pretty high so expect
just clouds/or virga. Could see a sprinkle or two across Essex and
Middlesex counties.

Otherwise increasing cloud cover will limit temperatures dropping
overnight. So have raised temperatures a degree or two.

Previous discussion...
expect clouds to linger as dewpoints increase behind the warm front.
Expect the front to move north of the area after midnight
tonight.

The front will keep dewpoints in the 50s overnight which in turn
will keep overnight temperatures in the upper 50s to lower 60s.

There is a low probability of showers and sprinkles along the Massachusetts/New Hampshire
border late tonight as the warm front moves through. However...most
of the energy available to produce showers remains farther north.

&&

Short term /6 am Tuesday morning through Tuesday night/...
Tuesday...a real Summer-like day is expected with the warm front
through the area. Expect warm...muggy conditions with temperatures
climbing into the middle to upper 80s across much of southern New
England. Southwesterly winds will keep the South Coast of Rhode Island and Massachusetts
as well as the southern side of Cape Ann significantly cooler with
highs in the upper 60s to lower 70s. Models are indicating some
instability in the afternoon. This may be enough to pop a few
scattered thunderstorms in northwest CT and western Massachusetts. So kept the
slight chance to chance probability of precipitation there. Not expecting anything in the
way of precipitation across eastern MA/RI.

Tuesday night...the upper ridge that has been in place along the
eastern Seaboard starts to break down...shifting to the east. This
will allow better instability to slowly filter into southern New
England. Showers and thunderstorms that develop over New York state could move
into the western portions of southern New England overnight. Have
slight chance to chance probability of precipitation in place for these areas during the
overnight period.

Continued southwesterly flow will keep things warm and muggy. It/ll
be another night with lows in the 60s.

&&

Long term /Wednesday through Monday/...
overview and model preferences...
overall surface and upper level pattern looking more and more like
Summer with 500 mb ridge building across eastern Seaboard through
late this week. Will see warm and humid conditions into this
weekend at least. Models and ensembles then diverge on how quickly
this ridge will break down...allowing frontal systems to try and
push S out of Quebec and northern New England. With these fronts
moving into a nearly parallel upper flow...will tend to slow down
and weaken as they shift toward the region. Will see some relief
to the extended dry conditions especially during the Wednesday-Friday
timeframe when best shot for deep moisture plume moving NE out of
the central u... the record flooding rains have been
occurring over the last few weeks. Timing issues come into play
this weekend as another front tries to approach and whether it
will move offshore or slow down across the region.

Leaned toward available guidance through the remainder of the work
week...then transitioned over to the 00z European model (ecmwf) and ecens means
which were slower in bringing the weekend front into the region as
one would expect with how models handle long wave pattern
transitions.

Details...

Wednesday...500 mb ridging shifts east during Wednesday with SW wind flow at
surface and aloft in place. Will see first in series of cold
fronts will slowly push southeast toward the region. Good instability out
ahead of this front. Model convective available potential energy rising to around 1000 j/kg /NAM
is higher/...k indices rising to the Lower-Middle 30s and Li/S
falling below zero. Lowest parameters look to move into central
and western areas during the afternoon and continue through Wednesday
night. Also noting increasing precipitable waters ...up to 1.8 to 1.9
inches...so could see some downpours with any convection.

Have chance probability of precipitation going...with highest from NE...central and
western mass into north central CT where best shot for any strong or
even possibly severe storms could occur. Storm Prediction Center has marginal shot for
severe storms in these areas. Expect highs in the 80s...with a
couple of spots approaching 90 well inland.

May see areas of fog...which could be locally dense along the
immediate S and southeast coasts...develop during Wednesday night as dewpoints
continue to slowly rise.

Thursday...frontal boundary washes out but still some instability
lingering with soupy airmass across the region. Instability
parameters not quite as strong as on Wednesday but still decent so could
see a few strong storms as middle layer starts to cool a bit lending
to elevated instability. Somewhat lower precipitable waters ...around 1.5 inches
but still enough with the high dewpoints for heavy rainfall from any
convection. Expect areas of fog to redevelop along S coastal areas
Thursday night into Friday morning.

Friday...while another boundary tends to weaken over the region...
not a whole lot of forcing in between systems during this
timeframe. Also noting somewhat drier air aloft which does not
help in developing convection. However...still can not rule out
chance for diurnal showers/thunderstorms to develop mainly from NE mass
across central and western areas into north central CT with dewpoints in
the 60s. One more round of fog looks to develop along the coast
mainly from coastal Plymouth County southward.

Saturday...models begin to diverge on their solutions as another
front tries to slip southeast out of southern Quebec. Looks like more
diurnal showers/thunderstorms during the afternoon/evening across inland
areas.

Sunday-Monday...timing differences with the approaching front lend
to low confidence during this timeframe. Went with the slower
European model (ecmwf) guidance...which tends to be the case with upper level
blocking patterns trying to break down. In any event...have more
chances for showers/thunderstorms for Sunday as the front looks to
slowly push across the region...then stalling near or just off the
S coast on Monday with lower chance for showers. May see drier air
work into north Massachusetts during Monday afternoon...but again low confidence on
this timing.

&&

Aviation /02z Tuesday 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.

00z update...

Tonight...VFR. May see patchy fog with MVFR visibilities late S coast/
Cape Cod/islands. SW winds will increase 40-45 knots at 1000-2000 feet
above the surface...highest along the S coast. Not quite strong
enough for low level wind shear to be inserted into
terminals...but should be aware of this.

Tuesday...VFR. Could still have some patchy MVFR visibilities in fog near
the S coast...mainly early. Chance of a thunderstorm with MVFR visibilities in
northwest CT and western Massachusetts...including bdl/baf and in the Berkshires
late in the afternoon.

Tuesday night...VFR deteriorating to MVFR/IFR in areas of fog
particularly along the South Coast...cape...and islands.

Kbos terminal...high confidence in taf.

Kbdl terminal...high confidence in taf.

Outlook...Wednesday through Saturday...moderate confidence.

Wednesday...expect SW winds to gust up to 20-25 knots at times mainly
across Rhode Island/southeast Massachusetts Wednesday afternoon/evening. Areas of fog develop Wednesday
night with MVFR-IFR visibilities. May see patchy LIFR ceilings/visibilities with
ocean clouds/dense fog along the immediate S and southeast coasts
overnight. Chance for -shra/thunderstorms and rain with local MVFR-IFR conditions
Wednesday afternoon/night.

Thursday and Friday...expect chance for -shra/thunderstorms and rain with local
MVFR-IFR conditions. Will also see areas of fog develop each late
night/early morning period with IFR-LIFR visibilities.

Saturday...patchy fog early Sat morning with MVFR-IFR conditions
will improve. Scattered rain showers/thunderstorms and rain Sat through Sat night with local
MVFR-IFR conditions.

Sunday...S-SW winds will gust up to 25 knots at times Sat afternoon/
evening...mainly along the S coast...Cape Cod and the islands.
Scattered showers/isolated thunderstorms may lingering through Sunday...but should
end Sun night. May see brief MVFR conditions.

&&

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.

Small craft advisories are up for tonight through Tuesday
night...mainly on the outer waters for increasing seas and
southwesterly winds. While the winds may only reach criteria
briefly...seas will climb to 5 feet and remain there through the
period. In addition...areas of fog are likely to develop Tuesday
night...reducing visibilities.

Outlook...Wednesday through Saturday...moderate confidence.

Wednesday...SW winds gusting up to 25 knots over the outer waters.
May need to extend small crafts into Wednesday night. Seas up to 5-6 feet.
Reduced visibilities areas of fog...locally down to one quarter of a
mile or less...mainly across the open waters during the overnight
hours into the early morning hours.

Thursday through Saturday...S-SW winds remain persistent with
gusts up to around 20 knots mainly Thursday into Thursday night. Seas lingering
at around 5 feet across the southern open waters through Thursday then
should subside. Visibilities reduced in areas of fog...locally dense
offshore both Thursday and Friday nights.

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...none.
Rhode Island...none.
Marine...Small Craft Advisory from 2 am Tuesday to 6 am EDT Wednesday
for anz250-254-255.
Small Craft Advisory until 6 am EDT Wednesday for anz235-256.

&&

$$
Synopsis...rlg/evt
near term...dunten/rlg
short term...rlg
long term...evt
aviation...rlg/evt
marine...rlg/evt

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