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Area forecast discussion 
National Weather Service Taunton Massachusetts
305 PM EDT Monday Jul 28 2014

Synopsis...
a rather strong area of low pressure by July standards will move
across northern New England this evening with its attending cold
front sweeping across the region later tonight and then offshore
Tuesday. Mainly dry and less humid weather follows for the remainder
of this work week. This weekend an offshore front may build back
into New England along with a wave of low pressure. This will
result in the risk of showers and more humid weather.

&&

Near term /through tonight/...
*** few strong/severe storms this afternoon ***

Latest mesoanalysis showing in excess of 1000 j/kg mean layer cape
across all of southern New England. Surface-based cape values were
approaching 2000 j/kg. In addition to this fairly potent
instability...effective shear values of 30-45 knots were observed.
All these ingredients point to the development of showers and
scattered thunderstorms this afternoon. The main threats will be
damaging winds and locally heavy rainfall. Cannot completely rule
out the risk for large hail or an isolated tornado. A Severe
Thunderstorm Watch has been issued until 8 PM. We are monitoring.

Once storms diminish this evening...expecting a cold front to
finally push offshore after midnight. This should mean less humid
air arrives late tonight...along with drier air and clearer skies.
Depending upon the timing of the clearing...and the amount of
leftover low-level humidity...there could be some areas of fog in
the usual valleys for the morning commute.

&&

Short term /Tuesday through Tuesday night/...
ridge of high pressure builds over New England Tuesday...resulting
in plenty of sunshine. Not much of airmass change so highs once
again should top off in 70s to around 80 but with significantly
lower humidity. Weak gradient supports afternoon sea breezes
along both coasts. Dry weather continues into Tuesday night.

&&

Long term /Wednesday through Sunday/...

Highlights...

* mainly dry/quiet and seasonable weather Wednesday through Friday
* possibly unsettled and more humid this weekend

Wednesday through Friday...

Long wave trough remains over the northeast early this period
however the mean middle level trough axis is far enough east to keep
the deep plume of subtropical moisture offshore. Thus mainly dry
weather will prevail Wednesday through Friday. However given cool temperatures aloft
combined with cyclonic middle level flow can/T rule out a low risk of a
few diurnal showers/T-storms inland.

As for temperatures...given the below normal 500 heights expect late
July/early Aug sun angle to provide mild days but dew points in the 50s
will yield comfortably cool nights.

This weekend...

Northeast trough retrogrades to the MS valley this weekend. This opens
the door for tropical moisture and the offshore front to back into
New England...especially eastern Massachusetts and Rhode Island. This will increase the
risk for showers and T-storms along with more humid conditions.

&&

Aviation /19z Monday through Saturday/...
forecaster confidence levels...

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

High confidence in trends tonight and Tuesday. Moderate confidence
in timing.

Mainly VFR across southern New England this afternoon and evening.
Scattered MVFR in low clouds towards the South Coast. Expecting
more MVFR...and possibly brief IFR...in scattered rain showers/thunderstorms and rain
through 29/00z. A few storms may produce strong or damaging wind
gusts.

Improving conditions to VFR after 00z Tuesday...although patchy
MVFR/IFR possible in fog. VFR Tuesday with afternoon sea breezes.
Mainly VFR Tuesday night.

Kbos taf...moderate confidence in taf. Most thunderstorms and rain should remain west
of Airport through 29/00z.

Kbdl taf...moderate confidence in taf. Ts most likely through
28/22z.

Outlook...Wednesday through Saturday...high confidence through Friday
then lower confidence into this weekend.

VFR expect a low risk for patchy IFR in early morning fog each day.
MVFR ceilings/visibilities in widely scattered afternoon thunderstorms mainly west of
mht and orh. By Sat chance of MVFR/IFR coming onshore into eastern
Massachusetts and Rhode Island along with threat of showers. Marginal VFR-MVFR likely
elsewhere.

&&

Marine...
forecaster confidence levels...

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

Moderate confidence through Tuesday night. Main concern is for rough
seas on south coastal waters...where Small Craft Advisory continues
into Tuesday. A cold front approaches waters tonight...but
expecting another round of patchy dense fog...at least early
tonight before drier air arrives late. High pressure builds over
the waters Tuesday...with light winds and afternoon sea breezes.
Seas slowly subside offshore.

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

Fairly light winds and seas Wednesday through Friday then southeast winds possibly
increasing Sat pending strength and track of frontal wave moving NE
from the middle Atlantic. Fair visibility Wednesday through Friday then possibly lowering Sat
in showers and fog.

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...none.
New Hampshire...none.
Rhode Island...none.
Marine...Small Craft Advisory for hazardous seas until 2 PM EDT Tuesday
for anz235-237-250-254>256.

&&

$$
Synopsis...Belk/nocera
near term...Belk
short term...Belk
long term...nocera
aviation...Belk/nocera
marine...Belk/nocera

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