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Area forecast discussion 
National Weather Service Taunton Massachusetts
1055 PM EDT Wednesday Jul 1 2015

Synopsis...
a cold front will move into the region tonight stalling near the
South Coast Thursday...before moving offshore Thursday night.
Aside from a few showers late Thursday and Thursday night over the
cape and islands...mainly dry and seasonable weather is expected
into early next week.

&&

Near term /until 6 am Thursday morning/...
1050 PM update...
convection diminishing in intensity this evening. A cold front was
just about to reach the North Shore. From there...it extended
through south central Massachusetts into eastern CT. Main concern for the
rest of tonight will be development of fog and stratus, just about
all areas saw some rainfall today...making fog development more
likely.

Tweaked the ongoing forecast to reflect the latest observed
trends. Forecast remains generally on track.

Previous discussion...

Tonight...any lingering showers or a thunderstorm will quickly end this
evening...otherwise mainly dry conditions expected tonight. A weak
cold front will be slowly moving into southern New England tonight but large scale
subsidence behind departing shortwave will result in dry weather.
Patchy fog possible.

&&

Short term /6 am Thursday morning through Thursday night/...
Thursday...
weak cold front stalls near the coast but the column is fairly dry
with limited to no instability. This will result in pt-mosunny
skies. Exception will be across ack where clouds will increase
and there is a low risk for a shower late in the day as area of
moisture moves up from the S ahead of weak frontal wave. Maximum
temperatures will reach into the lower 80s away from the coast...but
seabreezes will hold temperatures in the 70s along the immediate coast.

Thursday night...
weak boundary slides to the south as wave of low pressure tracks near
the benchmark. Bulk of rainfall should remain to the south...but
there is multi-model consensus that some rain will affect the
islands and possibly portions of Cape Cod. Have chance probability of precipitation for now.
Rest of the area will be dry. Low temperatures mostly in the 50s...except
lower 60s near the coast.

&&

Long term /Friday through Wednesday/...
highlights...

* seasonable to slightly above seasonable temperatures expected.
* Low chance of a shower mainly on the 4th.

Overview and model preferences...models continue to indicate a shift
in the overall pattern from a highly amplified regime to one that is
more progressive and zonal. This is in spite of the fairly robust
ridges in place across the east Pacific and the Bermuda high north of the
Antilles. Although this more zonal flow pattern does take on a
longwave trough feature between the two ridges...it is not overly
deep/sharp. This allows the ridging associated with the Bermuda
high to become the dominant player for our sensible weather into early
next week. At this point a much deeper northern stream vortex will be
in play...and will transition the drier and more stable regime
across the NE Continental U.S. To a more unsettled pattern. The only fly in
the ointment is on the 4th unfortunately...but more on that below.

Friday and Saturday...with nearly zonal flow in place...it/S not
just ridging...but weak shortwaves to concern ourselves with. Models
continue to indicate a weak shortwave passing through the region
during the early weekend. The overall column is relatively
dry...with precipitable waters near normal for early July. However...with the
front stalled to the south...the development of a weak wave of low
pressure could bring about modest lift along the South Coast of southern
New England during the day Saturday. Confidence is not high on
precipitation chances...but it is likely to not be a washout given how weak
the wave is and the lack of moisture. Just a few passing showers to
contend with.

Otherwise...temperatures run just below to near normal for Friday
and Saturday with pleasant...dry weather for much of the Holiday
weekend.

Sun into Monday...as deep er wave forms across the Canadian prairie
lands...a secondary ridge will amplify in response to warm advection
from the Bermuda high to the southeast. This will yield another period of
drier and warmer conditions across southern New England. Better chances
for temperatures inching above normal during this stretch...thanks to more
influence from the southeast.

Toward middle week...the aforementioned wave will begin a slide to
the east. This particular feature is more robust than previous
waves...so it/S likely a period of wetter and unsettled weather will
return by the middle portion of next week. Uncertainty in exact
timing.

&&

Aviation /03z Thursday through Monday/...
forecaster confidence levels...

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

Tonight...moderate confidence. Lingering isolated showers may
result in brief MVFR conditions. Otherwise...mainly VFR. But
patchy MVFR/IFR stratus and fog developing.

Thursday...high confidence. VFR. But MVFR ceilings/visibilities may develop over
ack late in the day along with the threat of a few showers.

Thursday night...moderate confidence. VFR...but areas of MVFR/IFR
possible cape/islands. Showers likely for ack possibly reaching
the S coast and Cape Cod.

Kbos terminal...high confidence.

Kbdl terminal...high confidence.

Outlook...Friday through Monday...

High confidence. Mainly VFR. A few showers possible on Sat...but
mainly dry otherwise. Sea breezes likely most days.

&&

Marine...
forecaster confidence levels...

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

Through tonight...high confidence. 5 to 6 feet seas expected over
open south coastal waters...so small craft advisories will
persist over these waters for a while longer.

Thursday...high confidence. Mainly light SW winds becoming locally
onshore over nearshore waters as seabreezes develop. Seas
gradually subsiding below Small Craft Advisory thresholds over southern waters.
Showers possible S and east of ack late in the day.

Thursday night...high confidence. Light southerly winds becoming
north. Seas below Small Craft Advisory. Visibilities reduced in showers and patchy fog S
of Cape Cod and especially S and east of ack.

Outlook...Friday through Monday...

Friday and Saturday...quiet boating weather expected for much of
this period. There is a low probability of scattered showers and
gusty winds across the southern waters on Saturday afternoon.

Sunday and Monday...quiet boating weather is expected as high
pressure builds back over the waters.

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...none.
Rhode Island...none.
Marine...Small Craft Advisory until 6 PM EDT Thursday for anz255-256.
Small Craft Advisory until 8 am EDT Thursday for anz254.
Small Craft Advisory until 2 PM EDT Thursday for anz235-237.

&&

$$
Synopsis...kjc/rlg
near term...Belk/kjc/rlg
short term...kjc
long term...doody/rlg
aviation...Belk/kjc/doody/rlg
marine...Belk/kjc/doody/rlg

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