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Area Forecast Discussion
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000
FXUS61 KBOX 291347
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
947 AM EDT FRI AUG 29 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL BUILD OVER NEW
ENGLAND WITH DRY WEATHER AND LOW HUMIDITY TODAY AND SATURDAY.
ROUGH SURF AND RIP CURRENTS WILL DIMINISH BY TONIGHT. A FRONT WILL
SLOWLY PUSH ACROSS NEW ENGLAND LATE SUNDAY AND MONDAY BRINGING A
PERIOD OF SHOWERS AND SCATTERED THUNDERSTORMS. SOME SHOWERS AND A
FEW THUNDERSTORMS MAY LINGER INTO TUESDAY. WARM...DRY CONDITIONS
LOOK TO SET UP BY LATE NEXT WEEK.

&&

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

10 AM UPDATE...

NO MAJOR CHANGES TO PREVIOUS FORECAST. 12Z OBSERVED SOUNDINGS AT
CHATHAM AND UPSTREAM AT ALBANY NY REVEAL STRONG MID LEVEL
SUBSIDENCE INVERSION...COURTSEY OF 1023 MB HIGH OVER SOUTHERN
QUEBEC. GIVEN THE CANADIAN ORIGINS OF THIS AIRMASS IT WILL BE
COOLER THAN NORMAL TODAY WITH HIGHS MAINLY IN THE 70S. HOWEVER
PLENTY OF LATE AUG SUNSHINE WILL PROVIDE PLEASANT CONDITIONS.
EARLIER DISCUSSION BELOW.

=================================================================

PREVIOUS DISCUSSION...
HIGH PRESSURE BUILDS OVER NEW ENGLAND AT THE SURFACE AND ALOFT WHILE
YESTERDAY/S UPPER TROUGH MOVES OFF THROUGH THE MARITIMES. WHILE
THERE WILL BE SOME LINGERING PRESSURE GRADIENT THIS MORNING...THIS
SHOULD BECOME LIGHT AS THE HIGH MOVES OVERHEAD. THE LIGHT GRADIENT
WILL ALLOW FOR SEA BREEZES DEVELOPING LATER THIS MORNING AND THIS
AFTERNOON ALONG ALL COASTLINES.

CROSS SECTIONS OF RELATIVE HUMIDITY SHOW A LAYER OF HIGH MOISTURE
ALSO LINGERING BETWEEN 800 AND 850 MB. MIXING WILL REACH TO AT
LEAST THE BASE OF THAT LAYER. EXPECT ANOTHER ROUND OF DIURNAL
CUMULUS...BUT WITH INCREASING SUBSIDENCE THE SKY COVER SHOULD BE
LESS THAN YESTERDAY.

TEMPS AT 850 MB WILL BE 8-10C WHICH SUPPORTS MAX SFC TEMPS IN THE
70S...POSSIBLY NEAR 80 IN A FEW WARM SPOTS SUCH AS THE LOWER CT
VALLEY. SEA BREEZES WILL BUFFER COASTAL TEMPS...WATER TEMPS ARE IN
THE 60S EAST OF MASS AND AROUND 70 ALONG THE SOUTH COAST. SO
COASTAL TEMPS SHOULD BE IN THE 60S AND LOWER 70S.

A 5 FOOT SOUTH SWELL LINGERS ON THE SOUTHERN WATERS THIS
MORNING...BUT SHOULD BE TRENDING LOWER THROUGH THE DAY. WE WILL
CONTINUE THE HIGH SURF ADVISORY THROUGH THE MORNING BUT BRING THE
ENDING TIME FORWARD TO 2 PM.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
HIGH PRESSURE MOVES OFFSHORE TONIGHT AND REMAINS IN PLACE TO OUR
EAST ON SATURDAY. THIS WILL BRING INCREASING FLOW FROM THE
SOUTH...EXCEPT SOUTHEAST NEAR THE EAST MASS COAST. DEW POINTS WILL
START TO RISE...BUT THIS TREND MAY HOLD OFF UNTIL THE FLOW PICKS
UP ON SATURDAY. AT THAT POINT...DEW POINT VALUES WILL CLIMB
THROUGH THE 50S TO NEAR 60 BY SATURDAY EVENING.

TONIGHT...
THE LIGHT WIND/FAIR SKIES WILL ALLOW ANOTHER COOL NIGHT TONIGHT
WITH SURFACE TEMPS IN THE UPPER 40S AND 50S. THIS WILL BE CLOSE
ENOUGH TO SATURATION FOR PATCHY FOG. BEST CHANCES WOULD BE IN THE
CT VALLEY AND IN THE LOW SPOTS OF EASTERN MASS.

SATURDAY...
SUNSHINE THROUGH CIRRUS ON SATURDAY WILL MEAN A PLEASANT DAY. THE
SUNSHINE WILL BE FILTERED A LITTLE...BUT TEMPS IN THE MIXED LAYER
WILL BE A LITTLE MILDER THAN TODAY. SO SFC TEMPS SHOULD BE AT
LEAST THE SAME AS TODAY AND PROBABLY A LITTLE MILDER. BASED ON A
MIXED LAYER TO 900 MB OR A LITTLE ABOVE...WE WENT WITH MAX TEMPS
75 TO 80.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
OVERVIEW AND MODEL PREFERENCES... 
NOTING OVERALL CHANGES ON THE MEDIUM RANGE MODELS TOWARD A BROAD
RIDGING PATTERN DEVELOPING ACROSS THE EASTERN SEABOARD...MORE OF A
TYPICAL SUMMER PATTERN THOUGH LATE IN THE SEASON...AS OPPOSED TO
THE LONG WAVE TROUGHING THAT HAS BEEN ACROSS THE EAST OVER THE
LAST SEVERAL MONTHS.

WILL CONTINUE WITH TREND OF BROAD TROUGHING TO START OFF THIS 
PORTION OF THE FORECAST...THEN TRANSITION TOWARD NEARLY ZONAL 
NORTHERN TIER UPPER FLOW WHICH THE MODELS/ENSEMBLES HAVE BEEN 
ADVERTISING OVER THE LAST FEW NIGHTS. MODEL SOLUTION DIFFERENCES IN 
THE STEERING CURRENTS WORK IN BEGINNING EARLY NEXT WEEK...SO SOME 
QUESTION AS TO TIMING OF SURFACE SYSTEMS TO THE EASTERN SEABOARD. 

LEANED TOWARD A BLEND OF AVAILABLE GUIDANCE THROUGH LATE MONDAY... 
WHICH SHOWED GOOD RUN TO RUN CONSISTENCY OVER THE LAST SEVERAL DAYS. 
FOR TUESDAY AND BEYOND...WENT CLOSER A BLEND OF THE EC/GEFS ENSEMBLE 
MEANS. WITH SOLUTION TIMING ISSUES...HAVE LOWER CONFIDENCE DURING 
THIS TIMEFRAME. 

DETAILS...

SATURDAY NIGHT THROUGH SUNDAY NIGHT...
LARGE SURFACE HIGH SLOWLY PUSHES E OF NEW ENGLAND DURING THIS
TIMEFRAME. LOOKS LIKE THIS WILL BE SLOW TO CLEAR THE COAST...SO
HAVE CARRIED DRY CONDITIONS. PERSISTENT SW WINDS WILL BRING IN
MORE HUMIDITY TOWARD THE REGION ESPECIALLY ON SUNDAY AHEAD OF AN
APPROACHING FRONT. DEWPTS FORECASTED TO INCREASE TO THE MID 60S TO
AROUND 70 DEGS DURING SUNDAY. WILL SEE PATCHY FOG DEVELOP SAT
NIGHT MAINLY AFTER MIDNIGHT WITH LOWS IN THE LOWER-MID 60S.

A FRONTAL SYSTEM WILL SHIFT SLOWLY E DURING SUNDAY...SO WILL SEE 
CLOUDS INCREASING AS WELL AS THE HUMIDITY. WILL START TO SEE SHOWERS 
AND SOME SCT THUNDERSTORMS PUSH INTO WESTERN AREAS DURING THE 
AFTERNOON...WITH THE BEST SHOT FOR PRECIP DURING SUN NIGHT. MODELS 
SIGNALING A SHARP INCREASE IN PWATS AS WELL...ON THE ORDER OF 2.1 TO 
2.3 INCHES...WHICH RUNS CLOSE TO 3 SD ABOVE NORMAL FOR EARLY 
SEPTEMBER BY SUN NIGHT. SO...WILL PROBABLY SEE SOME HEAVY DOWNPOURS 
WITH SOME OF THESE SHOWERS AND STORMS. PRETTY GOOD INSTABILITY ALSO 
MOVING ACROSS WITH K INDICES IN THE LOWER-MID 30S...ALONG WITH A 
BAND OF BELOW ZERO SHOWALTER INDICES CROSSING THE REGION SUN NIGHT. 

HIGHS ON SUNDAY WILL BE STEAMY...IN THE LOWER-MID 80S...WITH LOWS 
SUN NIGHT BETWEEN 65 AND 70 DEGREES. 

MONDAY...
FRONT CROSSES THE REGION AS IT WASHES OUT...BUT MOISTURE LINGERS
ACROSS THE REGION ALONG WITH THE HIGH HUMIDITIES. KEPT CHANCE POPS
GOING DURING THE DAY INTO EVENING HOURS MAINLY DUE TO DIURNAL
HEATING. ALSO HAVE MENTIONED CHANCE FOR THUNDER ACROSS CENTRAL AND
SOUTHERN AREAS. EXPECT PRECIP TO WEAKEN MON NIGHT. WILL REMAIN
WARM AND HUMID.

TUESDAY... 
ANOTHER COLD FRONT APPROACHES...SO WILL SEE ANOTHER ROUND OF SCT
SHOWERS/TSTMS. WARM AND HUMID CONDITIONS WILL CONTINUE WITH HIGHS
AGAIN IN THE LOWER-MID 80S. THE FRONT SHOULD CLEAR THE COAST TUE
NIGHT...BUT WIND FLOW REMAINS FROM THE W WITH THE DRIER AIR
REMAINING N OF THE REGION.

WEDNESDAY AND THURSDAY... 
SOMEWHAT DRIER AIR WILL WORK INTO THE REGION DURING THIS
TIMEFRAME...BUT TEMPS LOOK TO REMAIN ON THE WARM SIDE AS A RIDGE
BUILDS ACROSS THE EASTERN U.S. STILL SOME QUESTIONS WITH THE
EVOLVING UPPER LEVEL PATTERN ACROSS THE CONUS...SO LOWER
CONFIDENCE ON THIS PORTION OF THE FORECAST.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

10 AM UPDATE...

NO MAJOR CHANGES TO 12Z TAFS. 

SHORT TERM /TODAY THROUGH SATURDAY/...HIGH CONFIDENCE.

VFR. PATCHY IFR FOG LATER TONIGHT/EARLY SATURDAY IN THE CT VALLEY
AND IN THE LOW SPOTS OF E MASS. AS NE WINDS DIMINISH THIS
MORNING...WINDS BECOME ONSHORE ALONG IMMEDIATE E COAST DURING THE
AFTERNOON. ON SAT...SEA BREEZES WILL DEVELOP ON ALL COASTS. THIS
WILL DIMINISH TOWARD EVENING.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA BREEZES DEVELOP
INITIALLY TURNING NORTHEAST LATE MORNING...THEN SOUTHEAST BY MID
AFTERNOON AND SOUTH AT SUNSET.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF. 

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT AND SUNDAY...MODERATE CONFIDENCE. 
MAINLY VFR. S/SW WINDS GUSTING UP TO 20-25 KT DURING SUNDAY.
MVFR- IFR CIGS/VSBYS POSSIBLE ALONG THE S COAST SATURDAY NIGHT.
CHANCE FOR SHRA/TSRA ACROSS CENTRAL AND WESTERN AREAS BEGINNING
AROUND MIDDAY SUNDAY ONWARD.

SUNDAY NIGHT AND MONDAY...LOW CONFIDENCE.
MIX OF LOW END VFR TO MVFR. WIDESPREAD SHRA ACROSS THE TERMINALS.
POSSIBLE TSRA ACROSS THE INTERIOR MONDAY. CONTINUED S/SW WINDS.

TUESDAY...MODERATE CONFIDENCE.
COLD FRONT SWEEPING ACROSS THE TERMINALS LATE TUE/TUE NIGHT. LOW
END VFR. CHANCE OF SHRA/TSRA. WINDS BACKING OUT OF W BEHIND THE
FRONT TUE NIGHT.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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


10 AM UPDATE...

SE SWELLS CONTINUE TO SLOWLY DIMINISH ALONG WITH N-NE WINDS AS
HIGH PRES CREST OVER CAPE COD LATER TODAY. EARLIER DISCUSSION
BELOW.


SHORT-TERM /TONIGHT THROUGH FRIDAY NIGHT/...HIGH CONFIDENCE.

TODAY...HIGH PRESSURE BUILDS OVER THE WATERS. THIS MEANS NORTH
WINDS WILL DIMINISH AND BECOME LIGHT. LIGHT WINDS WILL ALLOW SEA
BREEZES TO DEVELOP NEAR SHORE. A 5 FOOT SOUTH SWELL FROM
CRISTOBAL LINGERS ON THE EXPOSED WATERS BUT IS SHOWING A LOWERING
TREND. WE WILL CONTINUE THE SMALL CRAFT ADVISORY FOR A FEW MORE
HOURS...ENDING IT ON THE SOUNDS BY 8 AM...AND ON ALL OUTER WATERS
BY 2 PM.

TONIGHT...SEAS WILL BE BELOW 5 FEET AND WINDS LIGHT.

SATURDAY...WINDS INCREASE FROM THE SOUTH...BUT SEA WILL REMAIN
BELOW 5 FEET.

SATURDAY NIGHT AND SUNDAY...MODERATE CONFIDENCE. 
S-SW WINDS GUSTING UP TO 20 KT MAINLY ON THE SOUTHERN OUTER
WATERS ALONG WITH SEAS BUILDING UP TO AROUND 5 FT. PATCHY FOG WITH
REDUCED VSBYS. SCT SHOWERS/TSTMS POSSIBLE ON THE NEAR SHORE WATERS
LATE SUN.

SUNDAY NIGHT AND MONDAY...MODERATE CONFIDENCE. 
S-SW WINDS GUSTING UP TO 20 KT WITH SEAS AROUND 5 FT MAINLY ON
THE SOUTHERN OUTER WATERS. MAY SEE PATCHY FOG DEVELOP LATE SUN
NIGHT INTO MON MORNING.

TUESDAY...MODERATE CONFIDENCE. 
EXPECT SW WINDS BELOW SMALL CRAFT CRITERIA ALONG WITH SEAS BELOW
5 FT.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...HIGH SURF ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MAZ022-
     024.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM EDT THIS 
     MORNING FOR ANZ250.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS 
     AFTERNOON FOR ANZ254>256.

&&

$$
SYNOPSIS...WTB/EVT
NEAR TERM...WTB/NOCERA/EVT
SHORT TERM...WTB
LONG TERM...EVT
AVIATION...WTB/NOCERA/EVT
MARINE...WTB/NOCERA/EVT



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