Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 300109
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
909 PM EDT TUE JUL 29 2014

.SYNOPSIS...
MAINLY DRY AND LESS HUMID WEATHER IS EXPECTED TONIGHT INTO
WEDNESDAY. A FEW SHOWERS AND PERHAPS A THUNDERSTORM ARE POSSIBLE
THU AND FRI...BUT MOST OF THE TIME WILL FEATURE DRY WEATHER. A
PERIOD OF STEADY RAIN IS POSSIBLE SOMETIME THIS WEEKEND IF LOW
PRESSURE TRACKS CLOSE ENOUGH TO THE COAST...BUT CONFIDENCE IS LOW.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

905 PM UPDATE...

STILL A DECK OF SCATTERED TO BROKEN MID LEVEL CLOUDINESS ACROSS
PORTIONS THE REGION THIS EVENING.  THESE CLOUDS SHOULD GRADUALLY
DIMINISH IN AREAL COVERAGE OVERNIGHT...BUT IT MAY BE A SLOW PROCESS
FOR SOME LOCATIONS.  REGARDLESS...LIGHT WINDS AND A VERY DRY AIR IN
PLACE FOR LATE JULY WILL ALLOW FOR AN EXCELLENT NIGHT OF RADIATIONAL
COOLING.

LOWS BY DAYBREAK WEDNESDAY WILL BE WELL DOWN INTO THE 50S
ACROSS MUCH OF THE REGION AND PERHAPS SOME UPPER 40S ACROSS THE
NORMALLY COOLEST OUTLYING LOCATIONS OF WESTERN MA/SOUTHWEST NH.  THE
MILD SPOTS WILL BE THE URBAN HEAT ISLANDS OF DOWNTOWN
BOSTON/PROVIDENCE...WITH LOW TEMPS BOTTOMING OUT IN THE LOWER 60S.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
ANOMALOUS MID LEVEL TROUGH REMAINS ANCHORED ACROSS EASTERN
CANADA...JUST NORTH OF THE GREAT LAKES. THIS WILL RESULT IN
ANOTHER DAY WITH BELOW NORMAL TEMPERATURES. A MIXTURE OF CLOUDS
AND SUNSHINE ANTICIPATED AS A MOISTURE-STARVED SHORTWAVE MOVES
ACROSS SOUTHERN NEW ENGLAND. MAINLY DRY WEATHER EXPECTED...BUT
THE SHORTWAVE COULD RESULT IN A PASSING SPRINKLE OR TWO. WE WILL
HAVE TO WATCH A WEAK WAVE OF LOW PRESSURE PASSING EAST OF THE
40N/70W BENCHMARK...BUT AT THIS TIME APPEARS IT SHOULD BE FAR
ENOUGH AWAY TO SPARE EVEN THE CAPE/ISLANDS ANY MEASURABLE
RAINFALL.

THIS ANOMALOUS MID LEVEL LONGWAVE TROUGH NUDGES SLIGHTLY CLOSER
TO OUR REGION WEDNESDAY NIGHT. A MODEST SHORTWAVE MOVING THROUGH
THIS LONGWAVE TROUGH COULD ARRIVE SOON ENOUGH TO GIVE US A PASSING
SHOWER LATE WEDNESDAY NIGHT...ESPECIALLY ALONG AND WEST OF THE CT
RIVER VALLEY.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...

* A FEW SHOWERS POSSIBLE ON THURSDAY AND FRIDAY
* LOW PRES COULD BRING RAIN SATURDAY AND SUNDAY

THE HIGH AMPLITUDE UPPER LEVEL TROUGH ACROSS THE EASTERN U.S.
CONTINUES TO BE THE DOMINANT FEATURE THROUGH THE FIRST PART OF THE
LONG TERM. AT THE SURFACE...DURING THURSDAY AND FRIDAY SOUTHERN NEW
ENGLAND IS IN BETWEEN A HIGH PRESSURE CENTERED WELL OFFSHORE...AND A
LOW PRESSURE SYSTEM CENTERED NORTH OF THE GREAT LAKES REGION.
RETURN FLOW ON THE WEST SIDE OF THE HIGH WILL BRING SOME INCREASE IN
MOISTURE TO OUR AREA FOR THURSDAY AND FRIDAY...SUFFICIENT TO WARRANT
A CHANCE FOR MAINLY DIURNAL SHOWERS. ON THURSDAY THERE WILL ALSO BE
A SHORTWAVE ROTATING AROUND THE TROUGH WHICH WOULD ALSO CONTRIBUTE
TO THE CHANCE FOR SHOWERS. FORECAST MODEL SOUNDINGS FOR THURSDAY
INDICATE MINIMAL CAPE...SO THUNDER NOT ANTICIPATED AT THIS TIME.
FRIDAY CAPE OVER THE INTERIOR MAY INCREASE TO A FEW HUNDRED
J/KG...SOME ISOLATED THUNDER MAY OCCUR. DAYTIME HIGHS MAINLY IN THE
UPPER 70S TO LOW 80S ARE EXPECTED...BUT OVER THE COURSE OF THU AND
FRI SURFACE DEWPOINTS WILL CLIMB INTO THE 60S...BRINGING A
SLIGHTLY MORE MUGGY FEEL.

DURING THIS WEEKEND THE UPPER TROUGH SHIFTS SOMEWHAT TO THE
WEST...ENABLING A FRONT TO APPROACH THE REGION FROM THE
SOUTHEAST. IN ADDITION A WAVE OF LOW PRESSURE MAY MOVE ALONG THE
FRONT. THIS WILL BRING THE POTENTIAL FOR STEADY RAIN TO AT LEAST A
PORTION OF THE REGION. THERE CONTINUE TO BE SOME RUN TO RUN MODEL
DISCREPANCIES REGARDING HOW CLOSE THE FRONT COMES TO OUR
AREA...AND HOW LONG IT LINGERS NEARBY. THE CLOSER THE FRONT COMES
TO THE AREA...THE MORE WIDESPREAD THE RAIN. THE 12Z GFS AND ECMWF
HAVE SOME DIFFERENCES IN PRECIP TIMING...BUT BOTH SHOW THE
POTENTIAL FOR PERIODS OF RAIN SATURDAY AND/OR SUNDAY. WILL GO WITH
CHANCE POPS FOR MOST OF THIS TIMEFRAME. 12Z GFS SHOWS ROBUST
MOISTURE WITH A RIBBON OF UP TO 2 INCH PWATS LINGERING IN OUR
AREA. IF THIS SCENARIO DOES COME TO FRUITION THERE COULD BE SOME
LOCALLY HEAVY RAINFALL DURING THE WEEKEND. CONSIDERABLE MODEL
SPREAD ON CONDITIONS FOR MONDAY...ECMWF INDICATES FRONT MAY BE
OFFSHORE AT THIS POINT...WILL GO WITH ONLY A LOW CHANCE POP.

DRIER CONDITIONS MAY PREVAIL FOR TUESDAY...AS BY THIS TIME THE FRONT
SHOULD BE FURTHER OFFSHORE.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...

TONIGHT AND WEDNESDAY...HIGH CONFIDENCE. VFR CONDITIONS OTHER
THAN LATE NIGHT/EARLY MORNING PATCHY GROUND FOG IN THE TYPICALLY
PRONE LOCATIONS. AFTERNOON SEA BREEZES ONCE AGAIN EXPECTED ACROSS
PORTIONS OF THE IMMEDIATE COAST WEDNESDAY.

WEDNESDAY NIGHT...HIGH CONFIDENCE. MAINLY VFR. A SLIGHT CHANCE OF
A SHOWER LATE WEST OF KMHT-KORE-KBDL-KHFD.

KBOS TAF...HIGH CONFIDENCE IN TAF TRENDS. SEA BREEZE IS EXPECTED
FOR WEDNESDAY AFTERNOON.

KBDL TAF...HIGH CONFIDENCE IN TAF.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY THROUGH FRIDAY...HIGH CONFIDENCE.  MAINLY VFR. LOW
PROBABILITY OF A BRIEF PERIOD OF MVFR CONDITIONS IN -SHRA.  DURING
FRI ISOLATED THUNDER POSSIBLE IN THE AFTERNOON/EVENING...MAINLY OVER
THE INTERIOR.

SATURDAY AND SUNDAY...LOW CONFIDENCE. MAINLY VFR NW...CHANCE FOR
MVFR CIGS/VSBYS IN SCATTERED SHOWERS. MVFR CONDITIONS MORE PROBABLE
TOWARDS EASTERN MA/RI IN -SHRA.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...

HIGH CONFIDENCE. AS OF EARLY THIS EVENING LEFTOVER SWELL HAS
DIMINISHED OVER THE SOUTHERN OUTER COASTAL WATERS...AND SEAS ARE
EXPECTED TO REMAIN BELOW SCA THRESHOLDS OVERNIGHT.

OTHERWISE...WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS THROUGH WEDNESDAY. SEAS MAY BUILD TO 5 FEET ACROSS THE
OUTER COASTAL WATERS LATE WEDNESDAY NIGHT AS AN OFFSHORE LOW
PRESSURE MOVES BY.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY AND FRIDAY...HIGH CONFIDENCE.  LINGERING ROUGH SEAS ON THE
OUTER WATERS ON THURSDAY FROM AN OFFSHORE LOW SHOULD SUBSIDE DURING
THE DAY...WITH HIGH PRESSURE OVER THE WATERS. WINDS BELOW SCA
THRESHOLDS THROUGH THE PERIOD.

SATURDAY AND SUNDAY...LOW CONFIDENCE.  MORE UNSETTLED WEATHER
POSSIBLE WITH AN APPROACHING FRONT AND POSSIBLE WAVE OF LOW
PRESSURE.  THERE IS A CHANCE OF SCA SEAS/WINDS DEVELOPING DURING
THIS TIMEFRAME.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BELK
NEAR TERM...FRANK
SHORT TERM...BELK
LONG TERM...NMB
AVIATION...BELK/NMB
MARINE...BELK/NMB



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