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Area forecast discussion 
National Weather Service Taunton Massachusetts
240 am EDT Tuesday Sep 23 2014

Synopsis...
high pressure will bring dry weather along with mild days and
cool nights through Wednesday. A distant coastal low pressure may
graze southeast New England with the low risk for few showers Wednesday
night into Thursday. High pressure returns Friday into early next
week with dry weather and unseasonably warm afternoon/S. Its
possible a few record high temperatures are challenged this weekend.

&&

Near term /through today/...
still have some rather large dew point depressions across southern
New Hampshire. Will need to monitor temperatures within the frost advisory
closely. If dew points remain in the upper 30s...that should
preclude a widespread frost. Will make a final decision at the
last minute based on temperature trends at the time.

Today...
high pressure crests across southern New England. This means
mostly sunny skies and a predominantly light west wind. Some of
the high resolution guidance is hinting at a seabreeze developing
along the coast this afternoon. The latest runs of the rap...along
with both cores of the hi-res NAM do decrease winds where a
seabreeze would be possible...but keep the boundary just off the
East Coast. The only model/guidance source which has consistently
developed a seabreeze is the hrrr.

Like the previous forecaster...am wary about the possibility of a
seabreeze developing. With the high pressure arriving later in the
day...am thinking the offshore pressure gradient should remain
just strong enough to hold it offshore...but it will be something
which will need to be watched.

&&

Short term /tonight through 6 PM Wednesday/...

Tuesday night...
high pressure builds to the north with a continuation of clear
skies and a light NE wind developing overnight. We used a blend of
the guidance which yields min temperatures mostly in the 40s. Went
higher along the East Coast of Massachusetts as well as the larger urban
centers.

Wednesday...
large high pressure centered over northern New England will
result in dry/pleasant weather for late September. Given the
positioning of this high pressure...still expecting easterly
winds at the surface. So lowest temperatures will be found near
the eastern Massachusetts coast. Highs should range from mainly the 60s...to
perhaps near 70 in the lower CT River Valley.

&&

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

* cool nights/mild days Thursday
* low risk of a few showers near the South Coast Wednesday night into Thursday
* unseasonably warm afternoon/S this weekend perhaps into Monday
* dry with no appreciable rainfall in site

Details...

Wednesday night through Thursday night...

We will have to keep an eye on a low pressure system that will be
emerging off the middle Atlantic coast. However...weak upper level
flow and a surface high nearby are not favorable for allowing the
low pressure system to track up the coast. In addition...weak
baroclinicity will also limit northwest axis of quantitative precipitation forecast shield.
Nonetheless...the GFS and its ensembles indicate at least a low risk
for a few brief showers across our southern zones. Whether or not
this comes to fruition remains to be seen...but certainly do not
expect any appreciable rainfall.

As for high temperatures on Thursday...onshore flow will result in highs in
the 60s to near 70. Again...mildest readings will be found across
the distant interior. Low temperatures Wednesday night and Thursday night shield be
in the 40s...to the lower 50s.

Friday through Monday...

Anomalous upper level ridging takes hold of the northeast U.S. From
Friday into early next week. This will result in dry weather with
unseasonably warm afternoon/S. Near record high temperatures possible this
weekend. Another factor that may help in this process is the very
dry ground...which may allow high temperatures to get a degree or so higher
than they normally would in this set up.

Guidance numbers have likely trended too much towards climatology.
High temperatures Friday...should be well up into the 70s. Sat/sun looks like
the warmest days...where highs will probably reach 80+ across the
lower elevations and areas away from the coast. Low confidence on
high temperatures for Monday...will depend whether or not a backdoor cold
front cools US off a bit like the 12z European model (ecmwf) depicts. GFS is still
quite warm...but obviously were a week out so that is uncertain. As
last shift pointed out...dry airmass will keep humidity in check so
afternoon/S will be nice for outdoor activities.

Record high temperatures this weekend into next monday:

Sat 9/27...sun 9/28...Monday 9/29...

Bos...86...1998 bos...90...1881 bos...88...1952
bdl...88...1998 bdl...83...1959 bdl...86...1945
pvd...86...1998 pvd...84...1943 pvd...87...1945
orh...85...1933 orh...84...1916 orh...84...1952

&&

Aviation /06z Tuesday through Saturday/...
forecaster confidence levels...

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

Short term /through Wednesday/...

High confidence VFR. Low probability of a seabreeze this
afternoon.

Kbos terminal...high confidence. Low probability of a seabreeze
this afternoon.

Kbdl terminal...high confidence.

Outlook...Wednesday night through Saturday...

High confidence in VFR conditions through the period...other than
brief late night/early morning patchy ground fog in the typically
prone locales. There is a low risk for a brief period of MVFR
conditions near the South Coast/cape and islands Wednesday night into Thursday
night. This will depend upon whether a few showers can make it that
far north with an offshore low pressure system.

&&

Marine...
forecaster confidence levels...

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

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

Winds and seas continue to diminish across all coastal waters
today as high pressure moves in. Rather tranquil boating
conditions expected through Wednesday. Seas may build above 5 feet
across the southern outer coastal waters late Wednesday...but the
timing is not certain.

Outlook...Wednesday night through Saturday...

Moderate to high confidence...

The main concern will be a low pressure system that will track near
or southeast of the benchmark Wednesday night into Thursday. It will likely
result in enough swell for Small Craft Advisory seas to develop across the southern
open waters Wednesday night. Small Craft Advisory swell may persist across the outer
waters right into Friday afternoon before diminishing.

Winds should generally remain below Small Craft Advisory thresholds through the
period. However...a period of northeast wind gusts of 20 to 25
knots are possible across the southern waters Wednesday night/Thursday if
coastal low pressure tracks close enough to our region.
Visibilities should be good through most if not all of the period.

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...frost advisory until 7 am EDT this morning for maz003.
New Hampshire...frost advisory until 7 am EDT this morning for nhz011.
Rhode Island...none.
Marine...Small Craft Advisory until 6 am EDT early this morning for
anz235-237.
Small Craft Advisory until 11 am EDT this morning for anz250-
254>256.

&&

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

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