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Area forecast discussion 
National Weather Service Taunton Massachusetts
352 am EST Thursday Dec 25 2014

Synopsis...
a cold front will move offshore this morning followed by dry and
windy conditions this afternoon. Dry weather and above normal
temperatures will continue into Saturday. A cold front may bring
a few rain showers Sunday followed by colder but mainly dry
conditions early next week.

&&

Near term /until 6 PM this evening/...
330 am update...
two areas of rain approaching southern New England early this morning. Rain associated
with the cold front will be moving into western new eng through
12z while a second area of heavier showers and a developing fine
line aligned with the low level jet lifting NE from the ocean.
Storm Prediction Center mesoanalysis showing MUCAPES arund 500 j/kg across southeast Massachusetts and
Cape Cod but instability axis is moving east and will be offshore
so expect the fine line to remain mostly S and east of southern New England...possibly
clipping ack. However...we do expect convective showers with
locally heavy downpours developing in the coastal plain this
morning along the low level jet and so we will keep the Flood
Watch for Rhode Island and east Massachusetts...but will drop it elsewhere. Also...we kept
the Wind Advisory for mainly the upper cape where temperatures in the
lower 60s may allow for enough mixing with axis of low level jet
moving across the region through 12z.

Low level cool air really hanging tough in the CT valley and NE
Massachusetts. Warming into the 50s still likely...but not expected until
the cold front passes 10-12z with mixing of warmer air aloft to
the surface.

Today...rain this morning will exit from west to east 13-17z with
cape/islands the last to dry out. Expect pt-mosunny skies
developing in the afternoon as cold advection dries out the
column...with most clouds expected in the interior where
sufficient low level moisture will support broken strato-cu. The
main concern this afternoon is strong westerly winds as
steepening low level lapse rates allowing mixing of stronger
winds aloft. Soundings suggest potential for gusts to 30-35
knots...with low probability for near Wind Advisory threshold of 35-40 knots
across higher terrain in northern and western Massachusetts.

Maximum temperatures will occur around 12z...with readings mostly in the
50s...then falling into the 40s during the afternoon.

&&

Short term /6 PM this evening through 6 PM Friday/...
tonight...
high pressure builds across the middle Atlantic region with ridging
extending north into southern New England. Expect mostly clear skies with a few
clouds across central and west Massachusetts. Gusty west winds during the
evening...diminishing overnight but remaining gusty along the
coast. Min temperatures ranging from upper 20s to middle 30s.

Friday...
high pressure shifts to the middle Atlantic coast with mild westerly flow
into new eng. Expect mosunny skies and lighter winds with high
temperatures well into the 40s and near 50 degrees in the coastal plain.

&&

Long term /Friday night through Wednesday/...
* clearing...windy and mild Christmas day.
* Remaining dry with above normal temperatures Friday and Sat.
* Potential for some rain or snow early next week.

Friday and Saturday...high confidence.

High pressure builds to the middle Atlantic coast. Dry weather will
prevail with lighter winds. Temperatures will remain above average
with highs in 40s both days and lows mainly in 30s.

Sunday through Wednesday...low confidence.

Models drop a weak cold front through southern New England Sunday.
Moisture appears to be limited and convergence rather weak...so
only expecting widely scattered rain showers as it moves through.
Temperature profiles may be cold enough for some wet snow to mix
in across higher terrain in western Massachusetts.

24/12z models continue to struggle with the details of the
synoptic pattern next week. There are some signs the solutions are
starting to converge...with the 12z European model (ecmwf) coming into line with
the 12z GFS. That said...ensembles still showing 100-140 dam spread
in the 500 mb heights...which does not inspire much confidence in
the forecast details.

Latest deterministic and ensemble mean guidance establish a fairly
zonal flow into southern New England Monday into Wednesday. This
would steer any storms either to our north...or too our south...
depending on where it originated.

Leaned toward a consensus model blend to help Iron out these
differences for now. This would bring a chance for precipitation
to southern New England during this time period. Thermal profiles
suggest the possibility for light snow across much of southern New
England...with rain more likely closer to the South Coast.

This is several days away...with low confidence in the details. Low
level temperatures look a bit warm for any significant
accumulations...especially from the Mass Pike to the South Coast.
We need to see how larger scale features will be resolved over the
next few days.

&&

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

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

Short term /through Friday/...

Through 12z...widespread IFR/LIFR continues improving toward 12z
in the CT valley. Areas of dense fog north and west of the warm
front in the interior will improve as the front lifts north. Renewed
area of rain redevelops across southern New England 08-12z as the cold front
approaches. SW gusts to 35-40 knots possible across portions of Rhode Island
and southeast Massachusetts.

Today...high confidence on trends. Lower confidence on timing.
IFR/MVFR conditions will improve to VFR from west to east 14-18z
as the rain moves offshore. Gusty west winds developing late
morning through the afternoon with gusts to 30-35 knots. Low probability for
g40 knots over higher elevations in northern and western Massachusetts.

Tonight...high confidence. VFR. West winds gusting to 25-30 knots
early...highest along coast...then diminishing after midnight.

Friday...high confidence. VFR.

Kbos terminal...high confidence in taf trends. Timing of warm
front may be too fast by a few hours but we do expect wind shift
to S before daybreak.

Kbdl terminal...high confidence in taf trends.

Outlook...Friday night through Monday...

Friday night and Saturday...high confidence VFR.

Sunday...moderate confidence. MVFR possible in isolated rain
showers.

Monday...moderate confidence. Mainly VFR. Lower conditions south
of New England. Low probability these lower conditions move
farther north into southern New England.

&&

Marine...
forecaster confidence levels...

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

Short term /through Friday/...high confidence.

Today...prefrontal SW winds are below gale...but after wind shift
to west...steepening low level lapse rates will allow for gusts to
increase to 35 knots especially this afternoon. Gale warnings are in
effect for all waters except Boston Harbor and Narragansett Bay.

Tonight...near gales over the outer waters in the
evening...otherwise Small Craft Advisory wind gusts with gradual diminishing wind
overnight.

Friday...diminishing wind below Small Craft Advisory with subsiding seas.

Outlook...Friday night through Monday...moderate confidence.

Winds gradually diminish Friday...with seas also slowly subsiding
into Saturday as a high pressure builds over the Middle Atlantic
States. A weakening cold front may bring an isolated shower or two
as it drops through New England Sunday. Winds and seas should
remain below Small Craft Advisory levels across all but the
outermost coastal waters from midday Saturday into Monday.
Moderate probability of 5 foot seas across the outermost coastal
waters...particularly south and east of Nantucket.

&&

Climate...
record highs for today / Christmas day

Bos...61 in 1996 / 65 in 1889
pvd...60 in 1990 / 63 in 1964
bdl...59 in 1996 / 64 in 1964
orh...57 in 1996 / 60 in 1964

&&

Box watches/warnings/advisories...
CT...none.
Massachusetts...Flood Watch until noon EST today for maz005>007-013>022.
Wind Advisory until 8 am EST this morning for maz022.
Rhode Island...Flood Watch until noon EST today for riz001>007.
Marine...Gale Warning from 10 am this morning to 7 PM EST this evening
for anz232>234.
Small Craft Advisory until midnight EST tonight for anz230-236.
Gale Warning from noon today to 7 PM EST this evening for
anz231-251.
Gale Warning from 9 am this morning to 7 PM EST this evening
for anz235-237.
Gale Warning from noon today to 10 PM EST this evening for
anz250.
Gale Warning from 6 am this morning to 10 PM EST this evening
for anz254>256.

&&

$$
Synopsis...kjc
near term...kjc
short term...kjc
long term...Belk
aviation...Belk/kjc
marine...Belk/kjc
climate...

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