Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 241345
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
945 AM EDT SUN AUG 24 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING DRY WEATHER AND A WARMING TREND THROUGH
THE MIDDLE OF THE WEEK. A FRONT MAY APPROACH FROM QUEBEC LATE
THIS WEEK WITH A LOW CHANCE OF UNSETTLED WEATHER.

&&

.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...
PATCHY VALLEY FOG IN THE CT VALLEY HAS BURNED OFF LEAVING MOSUNNY
SKIES. SOUNDINGS SHOW ENOUGH LOW LEVEL MOISTURE TO SUPPORT SCT TO
OCNLY BKN CU TODAY...BUT OVERALL MOSUNNY SKIES EXPECTED. MOISTURE
IS A BIT GREATER ACROSS N NEW ENG TODAY WHERE BEST CHANCE FOR A
ISOLD SPOT SHOWER. VERY LOW PROB FOR A BRIEF SHOWER/SPRINKLE IN
THE MONADNOCKS AND BERKSHIRES...BUT OTHERWISE A DRY DAY AS THE
COLUMN IS RATHER DRY. 850 MB TEMPS NEAR 10C AT 18Z WITH SLIGHT
WARMING TOWARD EVENING. EXPECT MAX TEMPS 75 TO 80 DEGREES...A BIT
COOLER ALONG THE IMMEDIATE COAST WHERE SEABREEZES WILL DEVELOP.

&&

.SHORT TERM /MONDAY/...
TONIGHT...
SHOULD BE ANOTHER GOOD NIGHT FOR RADIATIONAL COOLING THANKS TO
CORE OF HIGH PRES MOVING JUST TO THE W AND LOSS OF DIURNAL CU WITH
SUNSET. SLIGHTLY WARMER EVENING TEMPS MEANS THAT EVEN WITH FULL
RADIATIONAL PROCESSES...MINS ARE LIKELY TO BE A BIT WARMER
ALTHOUGH SEVERAL LOW MID 50S ARE POSSIBLE. PATCHY LATE NIGHT FOG
LIKELY IN THE TYPICALLY PRONE VALLEYS AND GRASSY AREAS.

MON...
HIGH PRES SLIDES SLIGHTLY TO THE SW WITH A RIDGE AXIS ORIENTED
NEAR AND ALONG THE S COAST. THIS WILL ALLOW FOR A SLIGHT S TURN IN
THE FLOW AND INCREASE THE LOW-MID LVL WARM ADVECTION THROUGH THE
DAY. THEREFORE...SINCE MOSTLY SUNNY CONDITIONS ARE ONCE AGAIN
EXPECTED...HIGHS SHOULD MODERATE INTO THE MID 80S ALTHOUGH A FEW
UPPER 80S CAN/T BE RULED OUT. SEA BREEZES ARE LIKELY AGAIN ON
COASTS THOUGH THANKS TO WEAK FLOW...SO EXPECT HIGHS TO BE LOWER
THERE. RH VALUES REMAIN RELATIVELY LOW THANKFULLY...AS DWPTS
SHOULD STAY IN THE 50S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* DRY WEATHER EXPECTED FOR MOST OF THIS WEEK
* INCREASING HEAT AND HUMIDITY THROUGH THE MIDDLE OF THIS WEEK
* LOW FORECAST CONFIDENCE LATE THIS WEEK

OVERVIEW...

24/00Z GUIDANCE REMAINS IN VERY GOOD AGREEMENT HEADING INTO TUESDAY.
THE GUIDANCE AGREES ON THE OVERALL PATTERN WEDNESDAY...BUT
DIFFERENCES IN SOME IMPORTANT DETAILS BEGIN TO CREEP IN. BY
THURSDAY...THE TIMING AND LOCATION DIFFERENCES MAKE HAVING
CONFIDENCE IN THE DETAILS OF THE FORECAST RATHER DIFFICULT. USED A
CONSENSUS BLEND TO SMOOTH OVER THE MINOR DIFFERENCES EARLY THIS
WEEK...AND ALSO TO MITIGATE THE LARGER DIFFERENCES LATE THIS WEEK.

A LARGE MID-LEVEL RIDGE OVER THE SOUTHERN USA IS PROJECTED TO NUDGE
EVER SO SLIGHTLY EAST TOWARD THE MIDDLE OF THIS WEEK. THEN THE
24/00Z GUIDANCE BREAKS THIS RIDGE DOWN LATE THIS WEEK.  THE SPEED
WITH WHICH THIS HAPPENS WILL BE CRUCIAL TO THE OUTCOME OF WHAT IS
CURRENTLY TROPICAL DEPRESSION NUMBER 4. THE QUICKER THIS RIDGE
BREAKS DOWN...THE CLOSER THIS SYSTEM COULD GET TO THE EAST COAST.

THE PRESENCE OF A BLOCKING STATIONARY TROUGH OVER THE WESTERN
ATLANTIC...ALSO HINTED AT BY THE POSITIVE PNA AND NEGATIVE NAO...
INDICATES THIS SETUP SHOULD EVOLVE SLOWLY THIS WEEK.

THE MAJOR PLAYER FOR THIS TIME FRAME IS THE OF COURSE THE POTENTIAL
TROPICAL SYSTEM...AS ITS WHEREABOUTS WILL PLAY A ROLE IN WHERE THE
OTHER PIECES SET UP. AS OF THIS WRITING...GUT FEELING IS THIS SYSTEM
WILL TURN OUT TO SEA BEFORE REACHING SOUTHERN NEW ENGLAND. THINKING
THE MOST LIKELY IMPACTS FROM THIS SYSTEM WILL BE A PERIOD OF ROUGH
SURF AND RIP CURRENTS. HOWEVER...LOW CONFIDENCE IN THE DETAILS...SO
MANY THINGS COULD CHANGE BETWEEN NOW AND THEN. STAY TUNED TO LATER
FORECASTS FROM THIS OFFICE AND THE NATIONAL HURRICANE CENTER FOR
MORE INFORMATION.

DAILIES...

MONDAY NIGHT AND TUESDAY...WITH THE RIDGE EXTENDING TO THE
NORTHEASTERN USA AND A CORRESPONDING SURFACE HIGH PRESSURE...WEATHER
SHOULD BE DRY WITH A FEW DIURNAL CUMULUS CLOUDS. TUESDAY HAS LESS OF
A CHANCE FOR A SEA BREEZE THAN MONDAY BECAUSE OF STRONGER WINDS
ALOFT.

WEDNESDAY...WITH HIGH PRESSURE SHIFTING SOUTH...SHOULD SEE
TEMPERATURES AND HUMIDITY INCREASE. MODELS BEGIN TO DIVERGE HERE IN
HOW TO HANDLE A POTENTIAL TROPICAL SYSTEM SO THE EXACT TRACK OF THAT
STORM WILL MAKE A DIFFERENCE IN THE FORECAST HERE. REGARDLESS...
INCREASING CLOUDS ARE EXPECTED...EITHER FROM THE TROPICAL SYSTEM OR
A COLD FRONT APPROACHING FROM THE NORTH.

THURSDAY...THIS IS A TRICKY PERIOD. CURRENTLY THINKING A WEAK COLD
FRONT WILL PUSH JUST SOUTH OF NEW ENGLAND DURING THE MORNING.
DEPENDING ON MOISTURE AVAILABILITY...COULD SEE SOME SHOWERS.  NOT
CONFIDENT ENOUGH IN THE DETAILS TO INSERT THOSE INTO THE FORECAST
JUST YET.

 FRIDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS LOW WITH THE
POTENTIAL TROPICAL SYSTEM AND ITS TRACK LARGELY DICTATING THE
FORECAST. OVERALL...LOOKING AT COOLER TEMPERATURES...AN INCREASE IN
CLOUDS...AND INCREASING POTENTIAL FOR PRECIPITATION.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM...THROUGH MONDAY...HIGH CONFIDENCE.

MAINLY VFR...WITH THE ONLY CAVEAT BEING LOCALIZED FOG AT TYPICALLY
PRONE AIRPORTS AGAIN LATE TONIGHT. A FEW MVFR CLOUDS POSSIBLE
THIS MORNING ACROSS OUTER CAPE COD AND NANTUCKET...BUT THESE WILL
LIKELY BE SHORT-LIVED.

OTHERWISE...FLOW REMAINS LIGHT THROUGH TODAY...PREVAILING N-NE.
SEA BREEZES LIKELY AT NEAR SHORE TERMINALS.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA BREEZE BEGINS LIKELY
14-15Z.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY NIGHT AND TUESDAY...HIGH CONFIDENCE VFR. LOW PROBABILITY OF
PATCHY MVFR/IFR FOG MONDAY NIGHT.

WEDNESDAY AND THURSDAY...LOW CONFIDENCE...MAINLY DUE TO TIMING
ISSUES. MAINLY VFR. BRIEF PERIODS OF MVFR/IFR CONDITIONS IN SHOWERS
AND/OR FOG POSSIBLE.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT-TERM...THROUGH MONDAY...HIGH CONFIDENCE.

THE NE FLOW WILL GRADUALLY WEAKEN THROUGH THE DAY AS HIGH PRES
MOVES OVER THE WATERS. THIS WILL ALSO ALLOW THE MODEST SWELL OFF
THE SRN COAST TO SUBSIDE AS WELL. CONDITIONS REMAIN BELOW SMALL
CRAFT ADVISORY LEVELS THROUGH MON...BUT WINDS SHIFT MAINLY TO THE
SW BY THE DAYLIGHT HOURS MON.

OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...

INCREASING SEAS ACROSS THE OUTER COASTAL WATERS FROM THE APPROACHING
TROPICAL SYSTEM WEDNESDAY NIGHT INTO THURSDAY...OTHERWISE WINDS AND
SEAS BELOW SMALL CRAFT ADVISORY CRITERIA.

&&

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

&&

$$
SYNOPSIS...BELK/DOODY
NEAR TERM...KJC
SHORT TERM...DOODY
LONG TERM...BELK
AVIATION...BELK/DOODY
MARINE...BELK/DOODY


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