Area Forecast Discussion Issued by NWS Boston, MA
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000
FXUS61 KBOX 141923
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
323 PM EDT FRI JUN 14 2013
.SYNOPSIS...
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A SECONDARY TROUGH OF LOW PRESSURE WILL SWING ACROSS SOUTHERN NEW
ENGLAND THIS EVENING AND MAY BE ACCOMPANIED BY A BRIEF SHOWER OR
THUNDERSTORM BEFORE SUNSET...ESPECIALLY OVER WESTERN NEW ENGLAND.
OTHERWISE HIGH PRESSURE AND A DRIER AIRMASS OVERSPREADS THE REGION
TONIGHT INTO SATURDAY NIGHT PROVIDE SEASONABLE AND DRY WEATHER. BY
LATE SUNDAY ANOTHER TROUGH OF LOW PRESSURE APPROACHES THE AREA
BRINGING A RISK OF SHOWERS FROM LATE SUNDAY INTO EARLY MONDAY.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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330 PM UPDATE...
THROUGH 8 PM...
SHOWERS WITH EMBEDDED TSTMS HAVE DEVELOPED OVER EASTERN NY ON THE
LEADING EDGE OF INSTABILITY GRADIENT AND SECONDARY TROUGH. MESO
ANALYSIS INDICATES SB CAPES ON THE ORDER OF 500-1000 J/KG. THIS
CONVECTION ALSO ON THE LEADING EDGE OF COOLER H5 TEMPS WHICH IS
YIELDING MID LEVEL LAPSE RATES OF AROUND 6C/KM. LATEST VISIBLE
SATELLITE IMAGERY INDICATES A HEALTHY CU FIELD OVER THE HIGHER
TERRAIN OF WESTERN VT-MA-CT. AS COLDER TEMPS ALOFT APPROACH WESTERN
NEW ENGLAND COMBINED WITH A FEW MORE HOURS OF SOLAR
HEATING...EXPECTING SHOWERS WITH EMBEDDED THUNDER TO FIRE ACROSS THE
BERKS AND LITCHFIELD HILLS. NOT ENOUGH INSTABILITY FOR STRONG STORMS
ESPECIALLY WITH DEEP LAYER SHEAR LESS THAN 30 KT. BUT CAN/T RULE OUT
AN ISOLATED STRONGER STORM WITH SMALL HAIL/GUSTY WINDS AND BRIEF
HEAVY DOWNPOURS.
ANY SHOWERS/TSTMS WILL COLLAPSE WITH SUNSET/LOSS OF DAYTIME
HEATING.
WINDS BEGINNING TO RELAX ACROSS CAPE COD AND THE ISLANDS AS
GEORGES BANK LOW CONTINUES TO MOVE SEAWARD. WINDS WILL ALSO SHIFT
FROM NE TO NW AS THE AFTERNOON PROGRESSES.
A HIGH SURF ADVISORY CONTINUES FOR THE EAST COAST OF CAPE COD AND
NANTUCKET...AND A RIP CURRENT RISK FOR EAST FACING BEACHES OF
MASSACHUSETTS. NE WIND WAVES WILL YIELD ROUGH SURF AND STRONG RIPS
ACROSS EASTERN MA BEACHES ESPECIALLY WITH OCEAN EXPOSURE AND EAST
FACING.
AFTER 8 PM...
ANY LINGERING SHOWERS/TSTMS ERODE WITH SUNSET/LOSS OF DAYTIME
HEATING. BEHIND SECONDARY TROUGH DRIER AIRMASS OVERSPREADS THE
REGION. SLIGHTLY COOLER THAN NORMAL WITH MIN TEMPS ABOUT 3-5 DEGS
COOLER THAN CLIMO. MODEST NW PGRADIENT WILL PERSIST SO NOT
EXPECTING WINDS TO DECOUPLE ALONG THE COAST/ISLANDS AND THE URBAN
AREAS.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
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SATURDAY...
MEAN MID LEVEL TROUGH AXIS EAST OF NEW ENGLAND AND MEAN RIDGE AXIS
ACROSS THE GREAT LAKES. THIS WILL PROVIDE ANTICYCLONE FLOW OVER NEW
ENGLAND WITH DEEP LAYER SUBSIDENCE DRYING THE COLUMN. THUS EXPECTING
ABUNDANCE SUNSHINE WITH TEMPS WARMING TO 75-80! WHILE THESE TEMPS
ARE SEASONABLE FOR JUNE 15TH...IT WILL FEEL MUCH WARMER GIVEN THE
RECENT DAMP/COOL WEATHER. REAL NICE DAY...ENJOY!
JUST AS WARM AT THE BEACHES GIVEN WNW WINDS. BEWARE OF SOME LEFTOVER
ROUGH SURF AND STRONG RIP CURRENTS AT OCEAN BEACHES...BOTH SOUTH AND
EAST COAST GIVEN SE SWELLS. WIND WAVES AND SWELLS APPEAR TO
ERODE/DECAY FAIRLY QUICK GIVEN SOURCE REGION OF SWELLS WAS OVER AND
NEAR NEW ENGLAND /CLOSE TO SHORE VERSUS WELL OFFSHORE/. IF SWELLS
WERE FROM DISTANT OCEAN STORM WAVE ENERGY WOULD BE MORE LONG LIVED.
THUS WHILE SURF MAY BE SOMEWHAT ROUGH TOMORROW ALONG WITH MODEST RIP
CURRENTS...THINK WE WILL FALL SHORT OF HIGH SURF AND/OR HIGH RISK
CRITERIA. LATER SHIFTS WILL HAVE TO MONITOR HOW WAVE ENERGY
DISSIPATES.
SAT NIGHT...
ANTICYCLONIC FLOW LINGERS SO DRY WEATHER PREVAILS. NOT AS COOL AS
AIRMSS MODIFIES ALONG WITH WINDS BECOMING WSW.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
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HIGHLIGHTS...
* SEASONABLE TEMPS THIS WEEKEND WITH A CHANCE OF SHOWERS SUNDAY
* UNSETTLED AT TIMES EARLY NEXT WEEK WITH BEST CHANCE OF SHOWERS TUE
* MAINLY DRY AND SEASONABLE WED AND THU
OVERVIEW...
WEATHER PATTERN WILL REMAIN SOMEWHAT ACTIVE THROUGH EARLY NEXT WEEK
AS A SERIES OF WEAK DISTURBANCES MOVE THROUGH THE REGION. TIMING
THE SHOWERS WILL BE DIFFICULT ALTHOUGH GFS AND ECMWF AGREE ON TWO
PERIODS OF SHOWERS...SOMETIME LATE SUNDAY AND/OR SUN NIGHT WITH THE
BEST CHANCE COMING LATER MON NIGHT INTO TUE ASSOCD WITH A COLD
FRONT. THEREAFTER...MAINLY DRY CONDITIONS EXPECTED.
SUNDAY INTO SUNDAY NIGHT...
FAST MOVING LOW AMPLITUDE SHORTWAVE SWINGS THROUGH THE REGION SUN
AFTERNOON/EVENING AS A WARM FRONT APPROACHES FROM THE SW. GFS IS
ABOUT 6 HRS FASTER THAN THE ECMWF BRINGING A PERIOD OF SHOWERS INTO
THE REGION SUN AFTERNOON...WITH ECMWF FOCUSING THE RAIN MORE DURING
SUN NIGHT. TIMING IS UNCERTAIN AND WE OPTED FOR CHC POPS SUN
AFTERNOON INTO SUN NIGHT. DID NOT INCLUDE THUNDER AS INSTABILITY
PARAMETERS ARE UNFAVORABLE. EXPECT SUNSHINE TO START THE DAY BEFORE
CLOUDS INCREASE IN THE AFTERNOON FROM WEST TO EAST. SEASONABLE
TEMPS.
MONDAY...
IT APPEARS MOST OF THE DAY MAY SEE DRY CONDITIONS AS SNE WILL BE IN
BETWEEN SYSTEMS AS NEXT AMPLIFYING SHORTWAVE MOVES INTO THE GT LAKES
WITH WEAK SHORTWAVE RIDGING INTO NEW ENG. HOWEVER...GFS AND ECMWF
SHOW INDICATE MARGINAL INSTABILITY DEVELOPING SO CANT RULE OUT AN
ISOLD AFTERNOON SHOWER/TSTM. MONDAY WILL LIKELY BE THE WARMEST DAY
OF THE EXTENDED PERIOD AS 850 MB TEMPS INCREASE TO 12-14C WHICH
SUPPORTS MAXES 80-85 DEGREES AWAY FROM THE COAST.
MON NIGHT INTO TUESDAY...
BEST CHANCE OF SHOWERS/TSTMS AS COLD FRONT MOVES INTO THE REGION ON
TUESDAY. ECMWF IS MORE AMPLIFIED THAN GFS WITH MID LEVEL SHORTWAVE
AND INDICATES A STRONGER FROPA.
WEDNESDAY AND THURSDAY... MAINLY DRY AND SEASONABLE CONDITIONS AS
HIGH PRES BUILDS INTO THE REGION.-- End Changed Discussion --
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
2 PM UPDATE...
OVERVIEW...MODERATE TO HIGH CONFIDENCE THROUGH SAT NIGHT.
VFR CIGS CONTINUE THROUGH 00Z. NEW AREA OF SHOWERS OVER EASTERN NY
STATE WILL SPREAD INTO WESTERN NEW ENGLAND THROUGH 00Z...
THREATENING KBDL. AREAL COVERAGE WILL BE SCATTERED WITH ISOLATED
TSTM. LOW TOP STORMS. RI AND EASTERN MA SHOULD REMAIN DRY. WINDS
SHIFT FROM NE TO NW AS THE DAY PROGRESSES. TONIGHT...VFR AND ANY
EARLY EVENING SHOWERS/TSTMS ACROSS WESTERN NEW ENGLAND WILL
DIMINISH WITH SUNSET. DISREGARDED LOWER VSBYS FROM MET AND MAV
OVERNIGHT AS DRY NW WINDS SHOULD PROVIDE VFR VSBYS. SAT...VFR AND
DRY WEATHER. WEST WINDS SHOULD PRECLUDE SEABREEZE DEVELOPMENT...
ALTHOUGH WINDS MAY GO SW ALONG THE SOUTH COAST OF MA AND RI.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. WEST WINDS SHOULD PRECLUDE
SEABREEZE SAT.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. LOW RISK OF SCT SHOWERS
WITH EMBEDDED TSTM THROUGH 00Z.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT...HIGH CONFIDENCE. VFR.
SUNDAY INTO MONDAY...MODERATE CONFIDENCE. MOSTLY VFR...BUT LOW PROB
OF BRIEF MVFR IN SHOWERS SUN AFTERNOON/NIGHT. PATCHY IFR COASTAL FOG
SUN NIGHT.
TUESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS LIKELY AT TIMES
IN -SHRA/FG.
&&
.MARINE...
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FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH SATURDAY NIGHT...HIGH CONFIDENCE.
TONIGHT...
GALES HAVE DIMINISHED AND WINDS WILL CONTINUE TO RELAX THIS EVENING
AND SHIFT TO WNW BEHIND PASSAGE OF SECONDARY FRONT. ISOLATE SHOWER
POSSIBLE WESTERN/SOUTHERN WATERS. EAST WIND WAVES TRANSITION TO
SWELLS. VSBY REMAINS GOOD.
SAT...
HIGH PRES OVER THE MID ATLC REGION PROVIDES DRY WEATHER AND GOOD
VSBY ACROSS THE SOUTHERN NEW ENGLAND WATERS. WNW WINDS 10-15KT WITH
G20 NEAR SHORE. E SWELLS LINGER ACROSS THE OCEAN WATERS.
SAT NIGHT...
DRY WEATHER AND GOOD VSBY PREVAILS. WINDS SHIFT TO SW AS HIGH PRES
SLIDES OFF MID ATLC REGION.
OUTLOOK...SUNDAY THROUGH TUESDAY...
MODERATE CONFIDENCE THROUGH THE PERIOD.
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA THRESHOLDS THROUGH
MONDAY. A PERIOD OF PREFRONTAL SW WIND GUSTS MAY APPROACH 25 KT ON
TUE WITH SEAS BUILDING TO 5-6 FT OVER THE SOUTHERN OUTER WATERS.
SHOWERS AND FOG MAY LIMIT VISIBILITIES AT TIMES SUNDAY NIGHT THROUGH
TUESDAY.-- End Changed Discussion --
&&
.HYDROLOGY...
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DESPITE RAIN DEPARTING SOUTHERN NEW ENGLAND FLOOD WATCH REMAINS IN
EFFECT UNTIL MIDNIGHT ACROSS NORTHEAST CT/RI AND EASTERN MA AS
RIVERS AND STREAMS ACROSS THIS AREA REMAIN IN FLOOD AND CONTINUE
TO RISE RAPIDLY. THEREFORE FLOOD WATCH IN EFFECT UNTIL MIDNIGHT.
ELSEWHERE FLOOD WATCH HAS BEEN CANCELLED.
MINOR FLOODING WILL BE MAIN CONCERN FOR NEXT FEW DAYS ON LARGER
RIVERS. THIS INCLUDES PORTIONS OF LOWER CONNECTICUT...
FARMINGTON...CHARLES AND PAWTUXET RIVERS. SMALLER STREAMS IN
HARTFORD COUNTY ARE EXPECTED TO FALL BELOW FLOOD STAGE THIS
MORNING...WHILE PAWCATUCK IN SOUTHERN RI WILL TAKE A FEW DAYS.
REFER TO THE LATEST FLOOD STATEMENTS FOR SPECIFIC FORECASTS.-- End Changed Discussion --
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
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CT...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR CTZ004.
MA...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR MAZ005>007-012>021.
HIGH SURF ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ022-024.
NH...NONE.
RI...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR RIZ001>007.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ231>235-237-250.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT SATURDAY FOR ANZ254>256.-- End Changed Discussion --
&&
$$
SYNOPSIS...NOCERA
NEAR TERM...NOCERA
SHORT TERM...NOCERA
LONG TERM...KJC
AVIATION...KJC/NOCERA
MARINE...KJC/NOCERA
HYDROLOGY...