Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 251055
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
655 AM EDT SAT APR 25 2015

.SYNOPSIS...
UNSEASONABLY COOL WEATHER CONTINUES THROUGH THIS WEEKEND WITH
SPOTTY SHOWERS OR SPRINKLES. PERIODS OF UNSETTLED WEATHER AND
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH MOST OF NEXT
WEEK AS WELL.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

700 AM UPDATE...

OVERALL TREND IN THE FORECAST REMAINS ON TRACK. WATCHING SCT
ECHOES MOVING DOWN FROM MAINE TO ESSEX COUNTY. NOT EXPECTING MUCH
IN PRECIP BUT DID ADD FLURRIES/SPRINKLES TO THE FORECAST. GUSTY
WINDS ALONG THE COAST WILL BEGIN TO SUBSIDE OVER THE NEXT FEW
HOUR. EXPECT A QUIET DAY...HOWEVER MAY SEE A SPOT SHOWER IN THE
AFTERNOON. SHORTWAVE MOVING AROUND THE FLOW COULD TRIGGER A FEW
ISO DIURNAL SHOWERS THIS AFTERNOON. OTHERWISE JUST MADE SOME MINOR
TWEAKS TO THE ONGOING FORECAST.

FREEZE WARNING WILL CONTINUE UNTIL 12Z AS MANY SITES ACROSS CT AND
RI HAVE DROPPED BELOW 32F THIS MORNING.

PREVIOUS DISCUSSION...

LATEST SATELLITE DATA INDICATES SKIES ARE NOW MOSTLY CLEAR OVER
SOUTHERN NEW ENGLAND. MESONET TEMPERATURES ARE STARTING TO REFLECT
THIS AS WELL...WITH MORE THAN A FEW READINGS AROUND FREEZING...OR
LOWER. CURRENT FREEZE WARNINGS WILL CONTINUE THIS MORNING.

THE UPPER LEVEL COLD POOL SHIFTS SLIGHTLY FURTHER AWAY FROM OUR
REGION TODAY....BUT STILL CLOSE ENOUGH TO HAVE SOME INFLUENCE ON
OUR WEATHER. THE MAIN CHANGES WILL BE SLIGHTLY LESS CLOUDS...
PARTICULARLY TOWARD SOUTHWEST NEW ENGLAND. THE SURFACE LAYER WILL
BE DRIER...SO MOST ATTEMPTS AT PRECIPITATION SHOULD EVAPORATE ON
THE WAY DOWN. DECENT MIXING...SO WE SHOULD SEE ANOTHER GUSTY DAY
WITH PEAK GUSTS AROUND 20 KT/25 MPH. MORE SUNSHINE SHOULD MEAN
SLIGHTLY HIGHER MAX TEMPERATURES THAN FRIDAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
WEAK RIDGE BUILDS OVER SOUTHERN NEW ENGLAND TONIGHT...PROVIDING
CLEARING SKIES AND LIGHT WINDS. RADIATIONAL COOLING WITH DEW
POINTS IN THE 30S...SO MINIMUM TEMPERATURES SHOULD BE IN THE 30S
ONCE MORE.

FOR SUNDAY...THE UPPER LOW IS EXPECTED TO MOVE SLIGHTLY CLOSER TO
OUR REGION. THUS WE WILL BE IN A MORE FAVORABLE POSITION FOR
DIURNAL CLOUDS AND SHOWERS. SO...AS HAS BEEN THE CASE OVER THE
LAST SEVERAL DAYS...SKIES SHOULD START OFF PARTLY TO MOSTLY SUNNY.
THEN CLOUDS DEVELOP ALONG WITH A FEW SPOTTY SHOWERS...ESPECIALLY
NEAR AND NORTH OF THE MASS PIKE. EXPECTING MAX TEMPERATURES TO BE
MAINLY IN THE 50S. IF A LITTLE MORE SUNSHINE WORKS THROUGH THE
CLOUDS ACROSS THE LOWER CT VALLEY...READINGS MAY TOUCH 60 IN A FEW
SPOTS THERE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* BELOW NORMAL TEMPERATURES THROUGH NEXT WEEK
* SCATTERED DIURNAL SHOWERS MONDAY AND TUESDAY
* HIGH PRESSURE ON WEDNESDAY
* LOW CONFIDENCE ON COASTAL SYSTEM THURS/FRIDAY

OVERVIEW...

STRETCHED CLOSED LOW OVER THE REGION WILL BRING SEVERAL SHORTWAVES
THROUGH THE FLOW MONDAY AND INTO EARLY TUESDAY. NORTHERN STREAM
SHORTWAVE APPEARS TO PUSH CENTRAL CONUS RIDGE TOWARDS THE NORTHEAST
KICKING THIS LOW OUT TO SEA BY WEDNESDAY.

BEYOND THIS PORTION OF THE FORECAST IS UNCERTAIN AS GUIDANCE
CONTINUES TO SPLIT. OVERALL APPEARS UNSETTLED WEATHER AND BELOW
NORMAL TEMPS CONTINUE AS BLOCKING PATTERN PERSIST...SUPPORTED BY
-NAO/-AO/+PNA. BOTH MODELS AGREE IN BREAKING THE RIDGE DOWN FAIRLY
QUICKLY ON WEDNESDAY. AMONG THE OPERATIONAL MODELS THE PAST COUPLE
ECMWF RUNS AND NEW 00Z UKMET SEEM TO FORM ONE CLUSTER THAT IS QUITE
AGGRESSIVE WITH THE DEPTH/CLOSURE OF ENERGY FROM THE GREAT LAKES
INTO MID ATLC...AND STILL WITH VERY DIFFERENT SFC SOLNS...WHILE SOME
RECENT GFS RUNS AND THE 00Z/24 ECMWF WERE MOST PRONOUNCED IN
BRINGING TRAILING NERN PAC AND/OR CANADIAN ENERGY ACROSS THE
NORTHEAST AS A CONCENTRATED UPR LOW LATE IN THE PERIOD.  THE LATTER
FEATURE WOULD BRING DEEP SFC LOW PRES CLOSE TO NEW ENGLAND OR AT
LEAST THE CANADIAN MARITIMES AS IN THE THE NEW 00Z GFS. REGARDLESS
BOTH CAMPS CONTINUE TO PUT THE EASTERN CONUS IN A DEEP TROUGH AT THE
END OF THE WEEK INTO EARLY NEXT WEEKEND. THEREFORE FELT ENSEMBLE
GUIDANCE WAS BEST FOR THE WORK WEEK FORECAST.

DETAILS...

* MONDAY INTO TUESDAY...MODERATE CONFIDENCE.

THE UPPER LEVEL LOW WILL CONTINUE TO SPIN BRINGING ITS COOL POOL
OVER EASTERN NEW ENGLAND. CHANCES OF PRECIP HAS INCREASED...ESP ON
MONDAY AS A POTENT SHORTWAVE MOVES THROUGH THE FLOW FROM THE NORTH.
EXPECT SCT DIURNAL SHOWERS AS COLD POOL ALOFT WILL BE SITTING OVER
THE REGION. PRECIP CHANCES ARE SLIGHTLY LOWER ON TUESDAY AS COLD
POOL AND UPPER LEVEL LOW BEGIN TO MOVE OFFSHORE...ESP LATE IN THE
DAY. TEMPERATURES APPEAR TO BE AROUND 10 DEGREES BELOW NORMAL ON
MONDAY AND ABOUT 5 DEGREES BELOW NORMAL ON TUESDAY.

* WEDNESDAY...MODERATE CONFIDENCE.

DIGGING TROUGH ACROSS THE CENTRAL CONUS WILL PUSH RIDGE OVER THE
REGION. THIS WILL GIVE SOUTHERN NEW ENGLAND A BREAK IN PRECIP AND
TEMPS NEAR NORMAL. STILL CANNOT RULE OUT A DIURNALLY DRIVEN SHOWER
THANKS TO PERSISTENT NORTHERLY FLOW.

* THURSDAY AND BEYOND...LOW CONFIDENCE.

STILL SOME UNCERTAINTY IN THIS PORTION OF THE FORECAST. EVERYTHING
IS DEPENDENT ON HOW THE CUT-OFF LOW IN THE DESERT SOUTHWEST AND
DIGGING NORTHERN STREAM WAVES BEHAVES.  REGARDLESS APPEARS DEEP
TROUGH WILL DEVELOP PUTTING SOUTHERN NEW ENGLAND BACK BELOW NORMAL
FOR TEMPS WITH AN INCREASE IN UNSETTLED WEATHER. STILL WATCHING THE
DEVELOPMENT OF A COASTAL LOW ON THURSDAY/FRIDAY. BOTH THE GFS AND EC
HAVE PUSHED THE LOW OUT TO SEA...OR FOCUSED ON THE MID-ATLANTIC
WHERE THE ENSEMBLES KEEP IT NEAR SOUTHERN NEW ENGLAND. STILL A LOT
OF UNCERTAINTY AND WILL NEED TO WAIT UNTIL MODELS CAN GET A BETTER
SAMPLE ON THE SHORTWAVES WHEN THEY COME OFF THE PACIFIC.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

.SHORT TERM /THROUGH SUNDAY/...

TODAY...HIGH CONFIDENCE. VFR. POSSIBLE BRIEF MVFR IN SPOTTY
SHOWERS. NORTHWEST WINDS GUSTING AROUND 20 KNOTS.

TONIGHT...HIGH CONFIDENCE. VFR WITH LIGHT WINDS.

SUNDAY...HIGH CONFIDENCE. VFR WITH LIGHT WINDS. SEA BREEZES
LIKELY. POSSIBLE BRIEF MVFR IN SPOTTY SHOWERS.

KBOS TAF...HIGH CONFIDENCE IN OVERALL TAF. LOW CONFIDENCE IN LATE
SEA BREEZE DEVELOPMENT.

KBDL TAF...HIGH CONFIDENCE IN OVERALL TAF.

OUTLOOK...MONDAY THOUGH WEDNESDAY...

MONDAY INTO TUESDAY...MODERATE CONFIDENCE. VFR WITH MVFR CONDITIONS
IN SCT SHOWERS. SEA BREEZE DEVELOPMENT IS POSSIBLE ALONG THE EAST
COAST.

WEDNESDAY...MODERATE CONFIDENCE. VFR CONDITIONS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...

WEST-NORTHWEST WINDS GUST TO 20 KT...WITH A FEW GUSTS TO 25 KT
OFFSHORE. SEAS LINGER NEAR 5 FEET ON THE OUTER WATERS THIS
MORNING...THEN SUBSIDE.

TONIGHT AND SUNDAY...WINDS AND SEAS BELOW SMALL CRAFT ADVISORY
CRITERIA. EXPECT NW WINDS TO SHIFT TO NE SUNDAY...BUT REMAIN
BELOW 15 KT. SEA BREEZES LIKELY SUNDAY.

OUTLOOK...MONDAY THOUGHT WEDNESDAY...

MONDAY THROUGH TUESDAY...HIGH CONFIDENCE. UPPER LEVEL LOW WILL
CONTINUE TO SPIN ACROSS THE NORTHEAST. HIT OR MISS SHOWERS POSSIBLE
DURING THE DAY. WIND AND SEAS TO REMAINS BELOW SCA ON SUNDAY. POTENT
COLD POOL WILL FILTER IN FROM THE NORTH CREATING STRONG CAA AN
INCREASE WINDS/SEAS FOR MONDAY AND TUESDAY. SCA MAY BE NEEDED.

WEDNESDAY...MODERATE CONFIDENCE. HIGH PRESSURE WILL BUILD OVER THE
REGION FROM THE NORTH KEEPING SEAS AND WINDS BELOW SCA.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR CTZ002>004.
MA...NONE.
RI...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR RIZ001-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR ANZ250-
     256.
     SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ254-255.

&&

$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK/DUNTEN/EVT
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN


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