Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Taunton Massachusetts
210 PM EDT Friday may 29 2015

high pressure will bring dry and beautiful weather this afternoon...
except along portions of the very immediate eastern Massachusetts coast where
some low clouds may affect the region. Another cold front
will slowly move across the region this weekend...bringing
a greater chance for showers and some scattered
thunderstorms. This front may linger near our area into the
beginning of the next week...with high pressure returning by midweek.


Near term /until 6 PM this evening/...

205 PM update...

Plenty of diurnal cumulus clouds have developed across southern New
England at middle afternoon...especially across central Massachusetts/Rhode Island but
there was still some partial sunshine. We are also watching
an area of low clouds trying to work onto the Plymouth
coast at middle afternoon off the ocean. They are being offset
some by diurnal heating...but will have to watch closely because they
may affect other portions of the eastern Massachusetts coast toward evening.
Low confidence in that so will continue to monitor.

Otherwise...afternoon temperatures should peak between 80 and 85 inland
from the coast. Along the coast...sea breezes and some low clouds
will hold afternoon temperatures between 65 and 75. Coolest readings along
the the Plymouth County Massachusetts coast...given lower clouds.


Short term /6 PM this evening through 6 PM Saturday/...

High pressure will begin to shift offshore as southwesterly flow
returns to the region. This will allow for another mild and muggy
night for southern New England. Warm air advection will be on the increase which
will increase cloud cover...especially for the south coastal regions.
Cannot rule out another round of marine fog/stratus. Otherwise temperatures
will remain in the upper 50s to low 60s with dewpoints also in the
middle to upper 50s.


Cold front will move across the Great Lakes region on Saturday allow
for showers and thunderstorms to develop. Best dynamics and forcing
will be well to the west of the region...however because we are in a
very warm and moist airmass cannot rule out a few pop-up showers and
thunderstorms out ahead of this front late Saturday
afternoon/evening. Otherwise bulk of the day will be dry with temperatures
warming into the low to middle 80s...cooler along the South Coast.


Long term /Saturday night through Thursday/...
overview and model preferences...

Overall model trends have not deviated much from prior runs.
Confidence growing in the timing of a slow-moving cold front as it
crosses southern New England later this weekend. Middle-level
Atlantic ridge shifts farther offshore this weekend. This will
permit a brief middle-level trough to move by during the middle of
next week. As typical with these that time range in
the forecast...there are plenty of timing differences yet to be

Leaned toward the consensus solution to smooth over the timing
differences during this portion of the forecast.


Sunday...this continues to look like the most likely period for a
more widespread rainfall. Precipitable water during this time
remains 1.7 to 1.8 could also see some heavy
downpours. At this point...thinking a cold front will push near
or south of the Mass Pike sometime Sunday night...but will tend to
slow down as it moves farther south. This will lower the risk for
thunderstorms as more stable air moves into northern Massachusetts Sunday
night...but still could see spotty convection across north CT/RI/se
Massachusetts. Showers look to taper off across the Route 2 area by around
sunrise Monday...but timing is still in question.

Monday...a lot of uncertainty continues as moving this front
across the region...with timing differences amongst the model
suite. Looks like a chance for showers lingers into Monday
night...mainly across northern CT/RI/southeastern Massachusetts. Winds do
start to shift around to north-NE across central and northern
this will cut back on thunderstorm activity as cooler air moves
in. For now...continued to taper off rainfall by Monday night
across most areas...but do linger it along the S coast through at
least midnight Monday night. It will be much cooler than what it has
been recently...with highs only in the 60s. Some locations along
the East Coast may not even break 60 with onshore winds.

Tuesday-Wednesday...showers should finally push off the South Coast
by around midday Tuesday at the latest. Northeast winds increase
as a high pressure crosses northern New England during this
timeframe. Have continued a dry and seasonable forecast for


Aviation /18z Friday through Wednesday/...
forecaster confidence levels...

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

Rest of this afternoon...high confidence except low confidence on
eastern Massachusetts coast. Mainly VFR...but we are watching an area of low
clouds just east of Boston Harbor and onto the Plymouth County
coast. Low confidence...but a period of IFR ceilings may develop toward
evening on the North Shore and into Boston Harbor.

Tonight...low confidence. Winds along eastern Massachusetts coast turn
southwest so that should limit low clouds coming in from the east.
In fact...if they do get in for a time this evening they may scour
out. Bigger concern then turns to low clouds/fog patches that may develop
along the South Coast and especially cape/islands.
Again...confidence is low so will have to monitor closely.

Saturday...moderate confidence. Any low clouds/fog patches south of
Pike probably scour out by late morning/early afternoon...except
cape/islands where they may linger into the afternoon. Dry weather
expected...although there is a low risk of a spot shower/thunderstorm
across northwest Massachusetts late in the afternoon/early evening.

Saturday night...moderate confidence. Mainly VFR to marginal MVFR
ceilings except far southeast New England coast where IFR ceilings/visibilities are
possible. Scattered showers and perhaps a thunderstorm or two will
be possible mainly across the interior with the higher risk during
the overnight hours.

Kbos terminal...low confidence in taf. IFR ceilings sitting just off
Boston Harbor at middle afternoon. They may work into Boston Harbor
for a time late this afternoon/evening...but low confidence. If
they do...probably scour out later in the evening as winds turn

Kbdl terminal...low to moderate confidence in taf.

Outlook...Sunday through Tuesday...moderate confidence.

Sunday...numerous showers with scattered thunderstorms possible during
the day with local MVFR conditions. Light winds shift to north-NE
during the day...then become NE Sunday night...which may gust up
to around 20 knots along the South Coast. Showers linger Sunday

Monday...scattered showers lingering with local MVFR conditions early.
Conditions will improve from north-S during the day...except along
the S coast...where some showers will likely linger. May see
brief MVFR in any showers. NE winds gusting to 20-25 across Outer
Cape cod and the islands.

Tuesday...mainly VFR conditions. May see isolated showers early Tuesday
along S coast but those should move offshore. NE wind gusts to 25
knots still possible across the Outer Cape and islands.


forecaster confidence levels...

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

Short term /tonight through Friday night/...

Today and tonight...high confidence. High pressure builds over the
waters. Mainly quiet boating weather expected although some
stratus/fog is possible mainly on the southern waters tonight.

Saturday...high confidence. High pressure will push east of the
waters as cold front approaches New England. SW winds may gust
near 25-30 kts. May need near shore Small Craft Advisory. Otherwise seas will be
close to 5ft as southerly swell increases.

Outlook...Sunday through Tuesday...moderate confidence.

Sunday...cold front slowly approaches the waters. May see brief
gusts to 25 knots as front slowly moves south Sunday. This front will
likely stall near or just S of the S coast Sunday night. Winds
shift to east-NE as this front passes. Areas of showers with scattered
thunderstorms. Local visibility restrictions.

Monday-Tuesday...expecting mainly NE winds. Gusts to 25 knots across
the southern open waters as this front slowly moves offshore. Seas
build up to 6-8 feet on the southern outer waters to east of Cape
Cod...and up to 5 feet on the eastern outer waters. May see
lingering showers during Monday across the southern waters.


Box watches/warnings/advisories...
Rhode Island...none.


near term...Frank
short term...dunten
long term...Belk

National Weather Service Glossary of Abbreviations