695 
FXUS61 KBOX 271421
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1021 AM EDT THU JUN 27 2013

.SYNOPSIS...
WARM AND MUGGY CONDITIONS WILL CONTINUE WITH HIT AND MISS SHOWERS 
AND THUNDERSTORMS INTO EARLY NEXT WEEK. RAINFALL LOOKS TO BE THE
MOST WIDESPREAD THIS AFTERNOON INTO FRI...WITH THE THREAT FOR
HEAVY RAIN AND FLOODING.

&&

.NEAR TERM /THROUGH TONIGHT/...
*** FLASH FLOOD WATCH IS IN EFFECT STARTING THIS AFTERNOON. ***

1030 AM UPDATE...MADE MINOR UPDATES TO THE TEMPERATURES AND
DEWPOINTS TO ACCOUNT FOR THE CURRENT TRENDS. SCATTERED SHOWERS ARE
MOVING ACROSS PORTIONS OF SOUTHERN NEW ENGLAND...ALL SOUTH OF THE
MASS PIKE. EXPECT THESE TO CONTINUE TO MAKE THEIR WAY EAST ACROSS
THE AREA. THE BACK DOOR COLD FRONT HAS WASHED OUT IN EASTERN
MASSACHUSETTS. THE WARM FRONT SOUTH OF NEW ENGLAND WILL BE THE BIG
FEATURE TO WATCH OVER THE NEXT FEW HOURS. ON REGIONAL RADAR CAN
SEE THE NEXT BATCH OF PRECIPITATION MOVING INTO WESTERN NEW YORK
STATE AND PENNSYLVANIA. EASTERLY FLOW HAS KEPT MUCH OF THE AREA IN
FOG AND LOW CLOUDS THIS MORNING. EXCEPTIONS ARE THE CONNECTICUT
RIVER VALLEY AS WELL AS A FEW OTHER LOCATIONS FARTHER WEST IN
SOUTHERN NEW ENGLAND WHERE THE FOG HAS LIFTED AND TEMPERATURES
HAVE WARMED INTO THE 70S.

TODAY...

ELONGATED TROUGH ACROSS THE GREAT LAKES AND NEW ENGLAND WILL
BRING A SERIES OF SHORTWAVES KEEPING THE WEATHER ACTIVE FOR
SOUTHERN NEW ENGLAND. FIRST ROUND WILL BE THIS MORNING INTO THE
AFTERNOON...AS A SHORTWAVE PUSHES THROUGH NEW YORK. THIS WILL AID
IN THE DEVELOPMENT OF A LOW PRESSURE SYSTEM WHICH WILL APPROACH
THE AREA BY THIS EVENING. HOWEVER A STALLED BOUNDARY WILL BE
DRAPED ACROSS THE REGION TODAY WHICH IS THE MAIN FOCUS FOR SHOWERS
AND THUNDER.

BELIEVE THE THREAT FOR SEVERE WEATHER IS LOW TODAY AS CLOUD DEBRIS 
WILL LIMIT DAYTIME HEATING...KEEPING INSTABILITY ELEMENTS LOW. SHEAR 
AND MID LEVEL LAPSE RATES ARE ALSO ON THE LOW SIDE. HOWEVER PWAT 
VALUES ARE STILL HIGH...NEARING 2.0 INCHES. SO IF ANY THUNDERSTORM 
DOES DEVELOP...HEAVY DOWNPOURS WILL BE THE MAIN THREAT. THE BEST 
AREA TO SEE ANY STRONG STORMS WILL BE ACROSS THE BERKSHIRES WHERE 
INSTABILITY AND LI VALUES ARE HIGHER. EXPECT SHOWERS AND 
THUNDERSTORMS TO BE FOCUSED ALONG THE DRAPED BOUNDARY AND EVENTUALLY 
BECOME MORE WIDESPREAD LATE THIS AFTERNOON INTO THE EVENING HOURS 
WHICH WILL IMPACT THE EVENING COMMUTE. 

TEMPERATURES TODAY WILL BE COOLER THANKS TO CLOUD DEBRIS LIMITING 
DAYTIME HEATING. ALSO EASTERLY FLOW OFF THE COOLER WATERS WILL MAKE 
THE MAX TEMPS TRICKY. CLOSER TO THE OCEAN WILL BE COOLER THAN THE 
INTERIOR. HOWEVER IF THE WINDS SWITCH TO THE SOUTH AS FRONTAL 
BOUNDARY LIFT NORTHWARD THEN TEMPS WILL INCREASE. FOR NOW BELIEVE 
TEMPS WILL BE IN THE MID TO UPPER 70S.

&&

.SHORT TERM /FRIDAY/...
TONIGHT...

BOUNDARY THAT IS DRAPED ACROSS THE REGION WILL EVENTUALLY BEGIN ITS 
NORTHWARD MOVEMENT AS LOW PRESSURE MOVES ACROSS THE NORTHEAST. THIS 
BOUNDARY WILL ACT MORE AS A WARM FRONT ALLOWING FOR DEWPOINTS IN THE 
70S AND PWAT VALUES OF 2+ INCHES. THIS AIRMASS WILL FEEL A LITTLE 
TROPICAL IN NATURE THUS ALLOWING FOR A GREATER POTENTIAL FOR HEAVY 
DOWNPOURS AND LOCALIZED FLOODING. 

EXPECT THE THREAT OF EMBEDDED THUNDERSTORMS TO CONTINUE AS 45KT LOW 
LEVEL JET WILL INCREASE DURING THE OVERNIGHT HOURS. ISENTROPIC LIFT 
COMBINED WITH GOOD MOISTURE TRANSPORT WILL BE ANOTHER CONTRIBUTING 
FACTOR. EXPECT A GOOD INCH TO INCH AND A HALF OF PRECIP TO FALL 
DURING THE OVERNIGHT HOURS. THIS MAY OCCUR IN A SHORT TIME 
FRAME...ESPECIALLY UNDER ANY CONVECTION. THEREFORE HAVE CONTINUED 
THE FLASH FLOOD WATCH. SMALL RIVERS AND STREAMS WILL ALSO RISE 
QUICKLY. RIGHT NOW ALL MAIN STEM RIVERS SHOULD REMAIN WITHIN THEIR 
BANKS. THIS MUCH RAIN FALLING WITHIN A SHORT TIME MAY CAUSE URBAN 
FLOODING ISSUES FOR PRONE AREAS. 

FRIDAY...

LOW PRESSURE SYSTEM WILL SLIDE NORTHWARD BY FRIDAY. THIS WILL PUSH 
THE WARM FRONT/BOUNDARY NORTHWARD INTO NH ALLOWING FOR GOOD 
SOUTHERLY FLOW ACROSS THE REGION. EXPECT NUMEROUS SHOWERS AND 
THUNDERSTORMS DURING THE MORNING COMMUTE AND SLOWLY DISSIPATING IN 
AREAL COVERAGE BY THE AFTERNOON HOURS. LOW LEVEL JET WILL STILL BE 
ANCHORED ACROSS THE CAPE/EASTERN WATERS THROUGH THE DAY. SOME MODELS 
ARE HINTING AT DRYING IN THE MID-LEVEL IN THE AFTERNOON HOURS. THIS 
MAY LIMIT PERCEPTION CHANCES. HOWEVER WITH ELONGATED TROUGH OVER 
THE REGION...BELIEVE PRECIP AND CLOUD COVER WILL HOLD OUT THROUGH
THE DAY ON FRIDAY. CONTINUED WITH THE MENTION FOR THUNDER AS LI
VALUES DROP TO -4C AND WITH SOME SHEAR COULD SEE A STRONG STORM.
HOWEVER WITH LACK OF INSTABILITY BELIEVE IT WILL BE A STRUGGLE.

TEMPERATURES WILL WARM INTO THE UPPER 70S TO LOW 80S. IF THE SUN 
DOES PEAK OUT THEN CHANCE FOR MORE THUNDERSTORMS INCREASE AS WELL AS 
TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HEADLINES...

* NUMEROUS SHOWERS AND THUNDERSTORMS INTO FRIDAY MAY LEAD TO
  FLOODING 
* HIT AND MISS SHOWERS/THUNDERSTORMS THIS WEEKEND INTO EARLY NEXT
  WEEK
* WARM AND HUMID THROUGH THE PERIOD

OVERVIEW AND MODEL PREFERENCES...

27/00Z GUIDANCE CONTINUES TO EXHIBIT OVERALL AGREEMENT WITH THEIR
SYNOPTIC PATTERNS AND EVOLUTION. THERE ARE SOME POTENTIALLY
SIGNIFICANT DETAIL DIFFERENCES HEADING INTO EARLY NEXT WEEK...MAINLY
WITH THE LOCATION AND MAGNITUDE OF AN ANOMALOUS MID LEVEL CUTOFF
LOW IN THE PLAINS. THIS WILL HAVE IMPLICATIONS FOR THE LOCATION OF
THE BERMUDA HIGH AND HOW CLOSE IT MAY GET TO SOUTHERN NEW ENGLAND.
AT THIS POINT...IT IS VERY DIFFICULT TO PICK ANY ONE MODEL OVER
ANOTHER. AS SUCH WILL FOLLOW THE CONSENSUS SOLUTION ONCE MORE AND
MAINTAIN AT LEAST A CHANCE OF SHOWERS THROUGH WEDNESDAY. TIMING
MOST FAVORS THE TYPICAL AFTERNOON AND EVENING TIMING...BUT THAT IS
NOT SET IN STONE.

THE MAIN CONCERNS WITH ANY SHOWERS AND THUNDERSTORMS CONTINUES TO
BE HEAVY RAINFALL GIVEN PRECIPITABLE WATER VALUES REMAINING
BETWEEN 1.5 AND 2 INCHES. THIS WILL RESULT IN THE THREAT FOR
LOCALIZED FLOODING AND PERHAPS A FEW INSTANCES OF FLASH FLOODING.

AS FOR SEVERE WEATHER POTENTIAL...THERE LIKELY WILL BE ENOUGH 0
TO 6 KM SHEAR AND INSTABILITY FOR THE THREAT OF SOME STRONG TO
SEVERE THUNDERSTORMS AT TIMES. TIMING WHICH DAYS END UP MORE
FAVORABLE AT THIS POINT REMAINS UNCERTAIN. IT WILL DEPEND UPON
EXACT TIMING OF SHORTWAVES AND INSOLATION THAT OCCURS EACH DAY.
THE ONE LIMITING FACTOR WILL BE POOR MID-LEVEL LAPSE RATES GIVEN
SOUTHWEST FLOW ALOFT. NOW THAT CERTAINLY DOES NOT MEAN THERE WON/T
BE SEVERE WEATHER...BUT A HIGH END WIDESPREAD SEVERE WEATHER
OUTBREAK APPEARS UNLIKELY.

&&

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

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

TODAY INTO TONIGHT...MODERATE CONFIDENCE. ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS POSSIBLE WITH SOME HEAVY RAIN AS WELL.
WIDESPREAD IFR IN EARLY MORNING FOG...GRADUALLY IMPROVING TO MVFR.
LOCALIZED HEAVY RAIN COULD LEAD TO MVFR/IFR CONDITIONS AGAIN BY
AFTERNOON. MORE WIDESPREAD RAIN IS EXPECTED OVERNIGHT TONIGHT...
WITH MORE WIDESPREAD MVFR/IFR.

FRIDAY...MODERATE CONFIDENCE. MVFR-IFR CONDITIONS WILL CONTINUE
FOR THE FIRST PART OF THE DAY DUE TO SHOWERS AND THUNDERSTORMS.
SOME IMPROVEMENT MAY OCCUR DURING THE AFTERNOON AND EVENING FROM
SOUTH TO NORTH.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. CONFIDENT IN OVERALL
TRENDS HOWEVER LOW CONFIDENCE IN TIMING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. EXPECT SOME LATE NIGHT
MVFR CONDITIONS GIVING WAY TO VFR. LOWER CONFIDENCE IN EXACT
TIMING. 

OUTLOOK...SATURDAY THROUGH MONDAY...

MODERATE CONFIDENCE. VFR CONDITIONS LIKELY DOMINATE...BUT BOUTS
OF SCATTERED SHOWERS/THUNDERSTORMS WILL RESULT IN LOWER CONDITIONS
AT TIMES. PATCHY FOG/LOW CLOUDS AT TIMES ALSO ARE POSSIBLE LATE AT
NIGHT INTO EARLY MORNING...ESPECIALLY TOWARD THE CAPE AND ISLANDS
AS WELL AS PORTIONS OF THE CT RIVER VALLEY.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT-TERM THROUGH FRIDAY...HIGH CONFIDENCE.

THURSDAY...QUIET BOATING WEATHER IS EXPECTED OUTSIDE OF ANY
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY OVERNIGHT. LOCALIZED
LIGHTNING...HEAVY RAIN AND GUSTY WINDS POSSIBLE IN ANY STORMS.

THURSDAY NIGHT INTO FRIDAY...MORE WIDESPREAD SHOWERS AND HEAVY
RAINFALL...COMBINED WITH SOUTHERLY FLOW REACHING 20-25 KT BY EARLY
EVENING. HAVE ISSUED A SCA FOR BOTH WIND AND SEAS TIL FRIDAY
EVENING. HAVE UNDERCUT WNA WAVE GUIDANCE AGAIN TO ACCOUNT FOR ITS
SOUTHERLY BIAS.

OUTLOOK...SATURDAY THROUGH MONDAY...

BERMUDA HIGH WILL RESULT IN PERSISTENT SOUTH TO SOUTHWEST WINDS
ACROSS THE WATERS THROUGH THIS PERIOD. IN ADDITION...PERSISTENT
LONG SOUTHWEST FETCH WILL RESULT IN SEAS AT OR ABOVE 5 FT ACROSS
THE SOUTHERN OUTER COASTAL WATERS AND OUR OUTER-ATLANTIC WATERS
FOR MOST...IF NOT ALL...OF THIS PERIOD. IN ADDITION...SPORADIC
STRONG THUNDERSTORMS AND PATCHY DENSE FOG WILL BE A HAZARD TO
MARINERS.

&&

.HYDROLOGY...
A BACKDOOR COLD FRONT WILL LIKELY STALL OVER SOUTHERN NEW ENGLAND
TODAY AS A STRONG LOW PRESSURE APPROACHES FROM THE WEST. WITH
THIS FRONTAL BOUNDARY AND ABUNDANT MOISTURE IN PLACE LATE TODAY
INTO TONIGHT...THERE IS THE THREAT FOR HEAVY RAINFALL WITH SLOW-
MOVING...AND POTENTIALLY TRAINING...CONVECTION BEGINNING THIS
AFTERNOON AND CONTINUING INTO TONIGHT.

WILL NEED TO ESPECIALLY WATCH REGIONS OF HIGHER TERRAIN WHERE
UPSLOPE COULD ENHANCE THE RAINFALL AS WELL AS URBANIZED AREAS...
WHERE CONVECTIVE HEAVY RAIN MAY LEAD TO URBAN FLOODING. GIVEN
ALL OF THIS...A FLASH FLOOD OR FLOOD WATCH REMAINS IN EFFECT FOR
MOST OF SOUTHERN NEW ENGLAND THIS AFTERNOON INTO TONIGHT.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR CTZ002>004.
MA...FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR MAZ002>021-026.
NH...FLASH FLOOD WATCH FROM 5 PM EDT THIS AFTERNOON THROUGH FRIDAY 
     AFTERNOON FOR NHZ011-012-015.
RI...FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR RIZ001>007.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM TO 8 PM EDT FRIDAY FOR ANZ235-
     237.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 PM EDT 
     FRIDAY FOR ANZ255-256.

&&

$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK/DUNTEN/RLG
SHORT TERM...DUNTEN
LONG TERM...BELK
AVIATION...BELK/DUNTEN
MARINE...BELK/DOODY
HYDROLOGY...