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Area forecast discussion 
National Weather Service Taunton Massachusetts
205 PM EDT Monday Jul 25 2016

Synopsis...
Summer heat will continue into much of the upcoming week. A weak
front will bring an increased risk of showers and thunderstorms...
some possibly severe...this afternoon and evening. Showers and
thunderstorms are possible again late next week.

&&

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

Heat indices are in the 95-100 degree range in the regions where a
heat advisory is in effect...generally from the Connecticut valley
northeastward to the Merrimack valley as well as interior
southeast Massachusetts. Actual temperatures were in the mid 90s
with dewpoints from 65 to 70.

Convective update... thunderstorms were approaching the Berkshires
and western CT. Downdraft cape has increased to 1100-1200 in
western sections. Any thunderstorms have the potential to produce
strong to damaging wind gusts this afternoon and evening.

A second line of strong to severe thunderstorms was moving through
southern New York near the PA border. These were moving to the east and
mesoscale models bring them across our region late this afternoon
into the evening hours. Again, a few could be severe with damaging
wind gusts. Locally heavy rain and dangerous cloud to ground
lightning strikes will also accompany any of the storms.

Winds have become rather gusty...to 20-25 mph at some interior
locations. Easterly sea breezes at Boston and the North Shore are
expected to shift to the south/southwest late this afternoon.
Temperatures could then rapidly shoot up from the lower 80s to
above 90 in the Boston area.

&&

Short term /6 PM this evening through 6 PM Tuesday/...
tonight...
with increasing mid lvl lapse as the core of the upper shortwave
moves across the region, it may lead to lingering convection into
the earlier overnight hours. This correlates to ml CAPES near
1000j/kg lingering along with an increase in shear, closer to 35
kt. Timing of shortwave will be key, but eastern areas could see
the remnant of this convection linger through 02-04z (10-midnight
local).

Otherwise, dwpts will be slow to decrease even as winds shift
toward the W-NW. Expect some localized ground fog especially where
rainfall is observed. Indications suggest cape/islands see a mix
of marine fog/stratus. Min temps mainly in the 60s.

Tomorrow...
even with nose of high pres, northwest flow and some cooling aloft. Temps
will still approach the low to mid 90s thanks to some downsloping
and 850 mb temps starting near +18c. Clearing skies after any stratus
and or remnant high clouds dissipate.

&&

Long term /Tuesday night through Sunday/...
highlights...

* hot temperatures continue through the middle of this week, away
from the coast
* should be a little less humid Tuesday and Wednesday
* showers and thunderstorms are possible again late this week

Overview...

25/00z guidance is in decent overall agreement through mid week,
then more significant differences in the details start to emerge.
This is a bit of change from previous runs. Will favor a consensus
approach for this forecast. That should smooth over the more minor
differences through mid week, as well as account for the greater
uncertainty late this week into next weekend.

Details...

Tuesday night and Wednesday...drier weather with high pressure in
control. Still hot, especially away from the coasts. Sea breezes
are more likely

Thursday and Friday...uncertainty increases with this portion of the
forecast. Temperatures will cool a few degrees Thursday as clouds
increase and a cold front starts to move through southern New
England. This front is expected to stall somewhere near our region
on Friday. The presence of this front, and likely increase in
clouds, should lower Max temperatures Friday.

Scattered showers and thunderstorms will be possible with this
frontal passage, particularly on Thursday when more instability is
expected. They may linger into Friday, but as mentioned above, that
will largely depend on how far off the South Coast the front pushes.
Regardless, Friday is likely to be cloudy and cooler, though more
humid than previous days.

Saturday and Sunday...lots of uncertainty remains with this portion
of the forecast, leading to a low confidence forecast. Latest runs
of the models now keep a frontal boundary nearby. Will mention a
chance of showers, for now.

&&

Aviation /18z Monday through Saturday/...
forecaster confidence levels.

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

Short term /through Tuesday/...

Through today...moderate confidence.
Mainly VFR through the afternoon. Between 19z and 03z, there could
be two rounds of thunderstorms. The first between 19z and 22z
moving across southern Massachusetts and northern CT...and then eastward
across Rhode Island and southeast Massachusetts. The next may move through from west to
east between 22z and 03z. Damaging wind gusts are possible in any
thunderstorms, along with locally heavy rain. IFR possible in
thunderstorms.

Later tonight...moderate confidence.
Most thunderstorms/showers end between 02z and 04z with VFR
developing initially then late night fog especially at typically
prone airports. Stratus also possible along the cape/islands
especially. Mix of IFR/MVFR conditions.

Tomorrow...high confidence.
Mainly VFR after early morning fog/stratus dissipates. Winds
mainly northwest with gusts 15-20 kt.

Kbos taf...moderate confidence in taf. Sea breeze in place.
VFR but chances of strong thunderstorms late this afternoon and
evening.

Kbdl taf...moderate confidence in taf. Chance of strong
thunderstorms this afternoon.

Outlook /Tuesday night through Friday/...moderate to high confidence.

Quiet boating weather is expected through this time. The exception
will be Thursday into Friday. While winds and seas will remain below
Small Craft Advisory criteria, low clouds, fog, and periodic showers
and thunderstorms should limit visibilities.

&&

Marine...
forecaster confidence levels.

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

Short term /through Tuesday/...high confidence.

Seas remain below Small Craft Advisory. Winds from the west-SW, then shift to the northwest
tomorrow with some gusts 15-20 kt. Onshore sea breezes in Boston
Harbor and off of Cape Ann should shift back to the southwest
toward evening. There is a risk for strong thunderstorms late
this afternoon and evening.

Outlook /Tuesday night through Friday/...moderate to high confidence.

Quiet boating weather is expected through this time. The
exception will be Thursday and Friday when winds and seas will
remain below Small Craft Advisory criteria, but low clouds, fog, and periodic
showers and thunderstorms will limit visibilities.

&&

Climate...
here are the record high Max and min temperatures for July 25:

Boston - 96 (1882)/78 (2001)
Hartford - 98 (2001)/75 (2001)
Providence - 96 (2001)/75 (2001)
Worcester - 93 (1941)/73 (2001)

&&

Box watches/warnings/advisories...
CT...heat advisory until 6 PM EDT this evening for ctz002>004.
Air quality alert until 10 PM EDT this evening for ctz002-003.
Massachusetts...air quality alert until 11 PM EDT this evening for maz004>016-
026.
Heat advisory until 6 PM EDT this evening for maz005-010>013-
017.
Rhode Island...heat advisory until 6 PM EDT this evening for riz001.
Marine...none.

&&

$$
Synopsis...Belk/doody/field
near term...field
short term...doody
long term...Belk
aviation...Belk/doody/field
marine...Belk/doody/field
climate...staff

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