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Area forecast discussion 
National Weather Service Taunton Massachusetts
1000 am EDT Tuesday Oct 13 2015

low pressure will cross southeastern New England this morning. A
cold front across western New York state will sweep across the region
tonight. Expect mainly dry and cooler conditions Wednesday into
Thursday. Low pressure and a cold front will cross northern New
England Friday into Friday night. Increasing winds and the
arrival of colder air may lead to localized wind hazards. The
coldest air so far this season follows for Sunday into
Monday...with the possibility of an area wide freeze. A return to
more seasonable conditions is expected beginning Tuesday.


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

1000 am update...

Cluster of thunderstorms have weakened and moved offshore.
However...scattered showers were still affecting areas east of the
CT river and particularly the eastern Massachusetts coast at late morning.
Should see this activity come to an end from west to east through
noon or so. Areas of fog will continue to burn off as well.

Otherwise...expect dry weather for much of the afternoon and should
see at least peeks of sun develop. Given mild 850t...should see middle
to late afternoon high temperatures recover in the lower 70s but cooler
along the South Coast/cape and islands with marine influence. Expect
southwest winds to start to gust between 20 and 30 miles per hour by middle
afternoon with the help of peeks of sun and decent low level jet.

While dry weather will dominate for several hours this
afternoon...potent upper level shortwave will approach by late
afternoon. This should result in scattered showers re-developing
across western Massachusetts/CT by late afternoon. Low risk for isolated
thunder given cold pool aloft...will continue to monitor but will
leave out of the forecast for now. Through early evening...the
second batch of scattered showers should generally remain west of
the coastal plain.


Short term /6 PM this evening through 6 PM Wednesday/...
tonight...cold front will steadily move east early tonight. Winds
will shift to west as drier air works in...and may be briefly gusty
along the S coast as the front moves through. Some clouds will
linger across the east slopes of the Berkshires along with a few
light showers as colder air works in. Expect temperatures to fall back to
the upper 40s to middle 50s...except the middle to upper 50s along the
immediate coast.

as broad trough aloft sets up west of the region...will remain west
winds will continue to bring cooler air into the region though the
core of it looks to remain across northern New England. Will be
enough instability to cause some diurnal clouds to develop across
most of the region. May still see some widely scattered showers across
the east slopes of the Berkshires as well. Highs will be in the
60s...mildest across east Massachusetts into Rhode Island as well as the middle and lower CT


Long term /Wednesday night through Monday/...
highlights ...

- thursday: a potential lull in the weather and seasonable
- Friday-saturday: cool and wet with potential wind-hazards
- Sunday-monday: coldest air so far...potential freeze

Discussion ...

13/00z guidance is in rather good agreement on the overall
synoptic pattern. Still some differences in the details...which is
not that uncommon for this time range. The most significant
difference is the evolution of a low pressure moving through
southeast Canada and northern New England. 13/00z European model (ecmwf) retains a
single low pressure...while the 13/00z GFS and Canadian split off
some energy and develop a secondary low pressure over southern
Ontario. This will have implications on how long precipitation may
stick around Saturday.

Eastern USA middle level trough gets reinvigorated this weekend as
the coldest air so far this season puts in an appearance. More
seasonable conditions expected to develop next week.

Given the good overall agreement...and the typical predictability
for the details this weekend into early next week...will continue
to follow a consensus approach for now.

Wednesday night into Thursday...

Modest middle level shortwave during this portion of the forecast...
but not a lot of moisture to work with. Thinking we will remain
mainly dry. The greatest risk for a shower would be Thursday
afternoon. Will need to continue to monitor the see if
more moisture can interact with this shortwave.

Friday into Saturday...

As mentioned above...the details are not so clear for this portion
of the forecast. In general...expecting a low pressure to be
nearby to our north...with a strong cold front poised to cross
Friday into Friday night. This front should result in gusty winds
as it moves on by...particularly across Rhode Island and southeast Massachusetts. Not
expecting a washout...but this will probably be the wettest period
in this portion of the forecast. Still need to resolve the
evolution of a secondary low pressure...if it develops at
all..Saturday. For now...will maintain a slight chance of showers
due to uncertainty in available moisture.

Sunday into Monday...

Still looking like the coldest air so far this season arrives
ahead of a strong high pressure. With the clear skies and light
winds...still expecting many locations away from the coast to
likely be dealing with freeze...or frost. Will likely need to
consider frost/freeze headlines as we get closer in time...much
of this driven by cold air advection.

With such cold air aloft...any sunshine could lead to diurnal
clouds and showers. However...the amount of moisture remains in


Aviation /14z Tuesday through Saturday/...
forecaster confidence levels...

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

Near term /through Wednesday/...

Today...moderate confidence. Thunderstorms have exited the
cape...but still some showers persisted as of late morning. Should
see showers exit the region by noon or so. Conditions were
improving...but lingering MVFR/IFR conditions were affecting
portions of the region....especially northeast Massachusetts. Should see much
of the region improve to VFR over the next few hours...but process
will be slowest along the coast. Southwest wind gusts of 25 knots
possible on the coastal plain by middle to late afternoon. Scattered
showers should re-develop by late afternoon across the interior.

Tonight...high confidence.
Cold front will push across the region. Leftover MVFR ceilings/local
MVFR visibilities in any showers will move east through 03z-05z. Some -shra
will linger overnight across east slopes of the Berkshires...may see
brief MVFR conditions. Otherwise...VFR. Winds shift to west.

Wednesday...high confidence. Will see diurnal clouds develop at
around 4kft. Expect scattered-broken cloud deck through the day. May also
see brief local sprinkles with cold air chance for
-shra across east slopes of the Berkshires. Expect west-SW winds to gust
to around 20 knots along S coast...Cape Cod and the islands.

Kbos terminal...moderate confidence in taf. Improvement to VFR by
noon or perhaps as late as early afternoon.

Kbdl terminal...high confidence in taf. Improvement to mainly VFR by

Outlook /Wednesday night through Saturday/...moderate confidence.

Breezy west winds with scattered rain showers activity Wednesday night
into Thursday. Scattered-broken low-end VFR ceilings. Strong southwest winds
Friday ahead of a cold front with gusts in excess of 30 kts
possible. Greater chance for MVFR-LIFR conditions. Improving
Saturday to MVFR to low-end VFR with sct-bkn. Strong northwest
winds with gusts in excess of 30 kts possible.


forecaster confidence levels...

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

Short term /through tonight/...

Today...moderate to high confidence. Showers/isolated storms will exit
waters by early afternoon. Otherwise...decent low level jet should
result in some 25 knot southwest wind gusts for a few hours during
the middle to late afternoon. Have expanded Small Craft Advisory for all waters for
several hours this afternoon and early evening.

Tonight and Wednesday...high confidence. Cold front from the
Great Lakes sweeps offshore early tonight as winds shift to west.
Will see gusts up to 20 knots late tonight and Wednesday.

Outlook /Wednesday night through Saturday/...moderate overall

May see west winds and waves diminish some into Thursday beneath
a weak area of high pressure.

Friday S/SW gales are possible...but will hold at 30 kts for now.
Seas expected to be quickly building over all waters Friday...but
especially the outer coastal waters. Winds turn northwest behind a cold
front and remain blustery with gale force gusts possible. Gusty
winds and rough seas should linger into Saturday.


Box watches/warnings/advisories...
Rhode Island...none.
Marine...Small Craft Advisory from 2 PM this afternoon to 7 PM EDT this
evening for anz230>234-236-251.
Small Craft Advisory from 2 PM this afternoon to 6 PM EDT
Wednesday for anz235-237-254>256.
Small Craft Advisory from 2 PM this afternoon to noon EDT
Wednesday for anz250.


near term...Frank
short term...evt
long term...Belk

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