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Area forecast discussion 
National Weather Service Taunton Massachusetts
350 am EDT Tuesday may 5 2015

Synopsis...

A weak cold front may bring a few brief showers today...but dry
weather and mild temperatures will dominate. Little change is
expected through the weekend...with mild to warm afternoon/S and
mainly dry weather persist.

&&

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

A weak cold front will slowly work across the region today.
Instability and low level moisture is fairly limited...so the vast
majority of the day will be dry. However...a few showers will
likely develop with the front but areal coverage should be limited
and activity should not last long at a given location. Rainfall
amounts should generally be just a trace to just a few hundredths of
an inch in most locales. Did not include the mention of thunder as
instability looks too marginal.

Plenty of middle level cloudiness will be around during the
morning...but still expect peeks of sun. As the afternoon wears on
expect sunshine to become more prevalent as drier air works in
behind the cold front.

Given very mild start...high temperatures in most locales should climb well
up into the 70s. Its not out of the question that a spot location
or two hits 80. However...across the immediate coast weakening
pressure gradient behind the cold front will allow cooling sea
breezes to develop. In these locations...mild late morning temperatures
will probably fall back into the upper 50s and lower 60s...including
Boston. Just inland from the coast though it will remain quite mild
even behind the front.

&&

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

Tonight and Wednesday...

Dry and pleasant weather expected for most of tonight as high
pressure builds in behind the cold front. Low temperatures will mainly be
in the 40s...to lower 50s.

A moisture starved shortwave will drop down in west to northwest
flow aloft Wednesday morning. Not sure if it will track far enough
northwest to result in a brief period of scattered showers across
any portion of our region. Best shot is northern CT...and perhaps
even into part of Rhode Island and southeast Massachusetts for a short time.
Regardless...even if a few showers occur they will be short-lived
and not amount to much. More in the way of sunshine should develop
from north to south through Wednesday afternoon. Highs should generally
reach well into the 70s in most locations...with the warmest
readings north of the Pike where the most sunshine is expected. Its
also possible that areas near the South Coast do not reach 70 on
Wednesday...if clouds hang on longer then expected.

&&

Long term /Wednesday night through Monday/...

348 PM update...

Highlights...

* Spring to Summer-like temperatures much of the period
* mainly dry weather Wednesday through Sat with increasing risk of showers
sun/Monday

Synoptic overview and model/guidance evaluation...

00z ecens/eps and 12z gefs ensembles in good agreement on the large
scale flow this period which features an anomalous closed low
evolving over the northwest Atlantic of about -3 Standard deviations from
climatology...along with a ridge centered over the Great Lakes and Ohio
Valley. This places New England in a dry northwest flow regime Wednesday
through Friday. By the weekend the upper air pattern becomes somewhat
progressive with the closed low moving into the central Atlantic
allowing Great Lakes ridge/height anomaly to advect eastward into
New England...continuing the dry weather into at least the first
half of the weekend. Then by late in the weekend and especially
early next week the question becomes how quickly does the ridge
erode as upstream trough approaches. In addition...ridge becomes
somewhat of a dirty ridge with moisture from remnant closed low over
the southeast states advecting northward up the eastern Seaboard. As
expected at this time range the deterministic runs of the 12z European model (ecmwf)
and 12z GFS handle this differently along with ensembles. Thus
forecast confidence becomes low on shower potential later this
weekend into early next week.

Temperatures...

As surface high slips south of New England Thursday...surface
winds become west-southwest and this will support temperatures warming to 75 to 80 and
potentially climbing into u70s and l80s by Friday. Warm weather
continues Sat with highs in the l80s away from the South Coast. In
addition with south-southwest surface winds dew points will climb into the 50s.
Still comfortable but this will result in nightly temperatures not as cool
along with patchy fog. Sunday...tricky as potential backdoor front
impacts eastern Massachusetts and possibly Rhode Island. Not as warm early next week
given likely cloud cover...southerly flow and risk of showers.
However temperatures will still average warmer than normal.

Precipitation...

As mentioned above dry pattern prevails Wednesday through Friday and probably
into Sat. Risk of showers increases Sunday as upstream trough
approaches along with remnant moisture offshore from closed low over
the southeast states later this week. However greatest risk of
showers appears to be early next week as upstream trough gets closer
to the region and begins to interact with deeper moisture along and
off the eastern Seaboard.

&&

Aviation /08z Tuesday through Saturday/...
forecaster confidence levels...

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

Short term /today through Wednesday/...

Today...high confidence. Low level wind shear around 2 thousand feet of 40 to 50
knots will weaken after 12z. Otherwise...VFR conditions expected the
vast majority of the day. Very brief localized MVFR conditions are
possible in a few brief showers later this morning and afternoon
with a cold front.

Tonight and Wednesday...high confidence. Mainly VFR conditions. A
brief period of isolated to scattered showers may affect northern CT
and possibly a part of Rhode Island/southeast Massachusetts for a time Wednesday am. This may
result in very brief localized MVFR conditions if any occur.

Kbos taf...high confidence in taf. Sea breezes expected to develop
this afternoon as a result of a weakening pressure gradient behind a
cold front.

Kbdl taf...high confidence in taf.

Outlook...Wednesday night through Saturday...

High confidence for VFR and dry weather. Low risk for patchy fog
each night between midnight and sunrise with local IFR cigs/vsbys.

&&

Marine...
forecaster confidence levels...

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

Short term /today through Wednesday/...

Today through Wednesday...high confidence. Marginal small craft
seas will continue into middle to late this morning across the outer-
waters before dropping below criteria. Otherwise...winds/seas will
remain below Small Craft Advisory thresholds through Wednesday under
a weak ridge of high pressure.

Outlook...Wednesday night through Saturday...

Thursday...high slips south of New England with winds becoming south-southwest.
Tranquil/dry weather with good visibility continues.

Friday...high pressure moves east of New England. Dry/tranquil weather
continues.

&&

Fire weather...

Mainly dry weather with little appreciable rainfall will continue
through at least Saturday if not into sun/Mon. While winds for the
rest of the work week will probably not be strong enough for fire
weather headlines...we may have to be more concerned by Saturday.
There will be at least a bit more potential for some marginal fire
weather headline wind gusts.

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...none.
Rhode Island...none.
Marine...Small Craft Advisory until 10 am EDT this morning for anz250-
254>256.

&&

$$
Synopsis...Frank
near term...Frank
short term...Frank
long term...nocera
aviation...Frank/nocera
marine...Frank/nocera
fire weather...Frank

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