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Area forecast discussion 
National Weather Service Taunton Massachusetts
413 am EDT sun Apr 26 2015

Synopsis...

Unsettled weather and below normal temperatures will continue into the
first half of the week. A little relief on Wednesday with temperatures
warming near to above normal. Below normal temperatures and unsettled
weather return Thursday into Friday...with improvements for the
weekend.

&&

Near term /until 6 PM this evening/...
254 am update...

As has been the case the past few nights...clouds were playing a
significant role in the forecast for this time of night. Latest
satellite imagery continues to show abundant middle level clouds
along and north of I-90. This has kept temperatures from dropping
of as much as they might have with the light winds and low level
dry air in place. Farther south...a frost advisory continues
across northern CT...and portions of Rhode Island and southeast Massachusetts. These
areas recently cleared...but it is only a matter of time before
more clouds arrive from the north and east.

06z mesonet temperatures showed many areas within the frost
advisory area just a little higher than the normal range where
frost would develop. The expectation is with a brief period of
clearing...temperatures will fall quickly and frost will remain a
possibility.

The upper low which has been over the Maritimes the past day or so is
expected to move slightly closer to our region today. Thus we
will be in a more favorable position for diurnal clouds and
showers. Skies should start off partly to mostly sunny then clouds
develop along with a few spotty showers. These showers are more
likely to occur north of the Mass Pike. High temperatures should
be in the 50s once again...though if enough sunshine peeks through
the clouds...could see temperatures near 60 through the Connecticut
valley and in parts of Rhode Island and southeastern Massachusetts.

&&

Short term /6 PM this evening through 6 PM Monday/...
tonight...isolated to scattered showers will continue to affect
southern New England with the upper low just east of the area.
With cloudy skies and rain showers...expecting temperatures to be
a bit warmer than either of the previous two nights with lows in
the upper 30s to the lower 40s.

Monday...upper low retrogrades even further west...and induces
some low level moisture convergence...besides the cold pool
aloft...to support showers. Increased probability of precipitation to likely across
portions of eastern Massachusetts...especially northeast Massachusetts...which will be
closer to the better dynamics. That said...still not expecting a
washout Monday with the greatest risk for showers in the
afternoon.

&&

Long term /Monday night through Saturday/...

Highlights...

* unsettled and below average temperatures for Monday and Tuesday
* relief on Wednesday with above average temperatures
* digging trough returns on Thursday/Friday yielding below normal temperatures
* improvements for the weekend

Overview...

Closed low which has plagued the region for several days now will
begin to to eject offshore by tues/Wed. This will allow for the
region to rebound back to normal temperatures. However watching two systems
which will put the northeast back into a deep trough by
Thursday/Friday. Still a lot of uncertainty on how the northern
stream phases with the southern stream...but the 00z GFS appears to
be in better agreement with the 00z ec/UKMET this time around. Once
the systems develop the East Coast trough...surface low pressure
will develop over the Carolinas and move up the eastern Seaboard.
Appears that this coastal low will stay far enough south and east of
the region...which is supported by the 12z ec ensembles. Beginning
of the weekend should be improvements as central Continental U.S. Ridge will
move eastward. Pna is forecasted to go more negative with a +nao
during this time period so perhaps Spring will stay into early next
week.

Details...

Tuesday...moderate confidence.

The upper level low will continue to spin but start pulling offshore
during this time period. Cold pool is still lingering especially across the
mass East Coast. As surface temperatures warm and lapse rates steepen could
see some isolated diurnal showers. Otherwise near or below average temperatures
will continue.

* Wednesday...high confidence.

Digging trough across the central Continental U.S. Will push ridge over the
region. This will give southern New England a break in precipitation and
temperatures near to above normal....a few models are even spitting out 70s
for highs out west. Still cannot rule out a diurnally driven shower
thanks to cyclonic flow and steepening lapse rates but with building
heights believe precipitation chances are low.

* Thursday and beyond...low confidence.

Still some uncertainty in this portion of the forecast. Everything
is dependent on how the low currently in the Desert Southwest and
the digging northern stream waves behaves. Regardless appears deep
trough will develop putting southern New England back below normal
for temperatures. This trough will develop a coastal low off the Carolinas
and push northwards. The GFS bring the coastal low closest to the
region while the ec still keeps it south and east of the benchmark.
Trended closer to the ec which has been persistent over the past
several runs. Believe Thursday and Friday will be more hit of miss showers
and continue to keep chance probability of precipitation along the cape and islands for coastal
system.

* The weekend...moderate confidence.

Upper level trough will begin to move offshore by Saturday as weak
ridge builds over New England. May need to watch quick moving
northern stream energy which could give showers to the area on
Sunday...but overall hoping for a nice weekend with temperatures near
normal.

&&

Aviation /08z Sunday through Thursday/...
forecaster confidence levels...

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

Today...high confidence. VFR with light winds. Sea breezes
expected...especially along the East Coast of Massachusetts. Possible brief
MVFR in spotty showers.

Tonight...high confidence. VFR with light winds. Possible brief
MVFR in spotty showers.

Monday...VFR most of the time. Areas of MVFR ceilings/visibilities in
scattered showers...especially in the afternoon.

Kbos taf...high confidence in overall taf. Sea breeze expected...
but onset timing may be off by an hour or so.

Kbdl taf...high confidence in overall taf.

Outlook...Tuesday through Thursday...

Tuesday...moderate confidence. VFR with MVFR conditions in isolated
showers. Sea breeze development is possible along the East Coast.

Wednesday...moderate confidence. VFR conditions.

Thursday...moderate confidence. VFR conditions with MVFR possible in
scattered showers.



&&

Marine...
forecaster confidence levels...

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

High confidence. Relatively tranquil winds and seas expected
through Monday. Light and variable winds become more northwest
tonight...then more northerly Monday.

Outlook...Tuesday through Thursday...moderate confidence

Enough northerly gradient anticipated Monday night into Tuesday morning
that Small Craft Advisory conditions might be met...especially
coastal waters to the east. May take until Tuesday evening before seas
subside back below 5 feet.

Offshore low may bring increasing winds and seas...to the outer
south coastal waters late Thursday or Thursday night. Confidence is low and
even undercut wna wave guidance by 40 percent.

&&

Box watches/warnings/advisories...
CT...frost advisory until 8 am EDT this morning for ctz002>004.
Massachusetts...frost advisory until 8 am EDT this morning for maz017-018.
Rhode Island...frost advisory until 8 am EDT this morning for riz001-003.
Marine...none.

&&

$$
Synopsis...Belk/dunten
near term...Belk/Thompson
short term...Belk
long term...dunten
aviation...Belk/dunten
marine...Belk/dunten

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