000
FXUS61 KBOX 182037
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
437 PM EDT TUE JUN 18 2013

.SYNOPSIS...
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS ANTICIPATED THROUGH
THIS EVENING AS A COLD FRONT MOVES ACROSS THE REGION. LARGE HIGH
PRESSURE WILL FOLLOW...BRINGING MAINLY DRY AND SEASONABLE 
CONDITIONS WEDNESDAY THROUGH SATURDAY. WARMER AND MORE HUMID
WEATHER IS EXPECTED THIS WEEKEND AS HIGH PRES ANCHORS JUST SOUTH
OF NEW ENGLAND. SHOWERS AND THUNDERSTORMS POSSIBLE SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

...THUNDERSTORMS WILL HEAVY RAINFALL AND LOCALIZED FLOODING WILL
CONTINUE INTO THIS EVENING...

LINE OF SHOWERS/SCT TSTMS MOVING SLOWLY BUT STEADILY S ACROSS E
MA/N RI/SE MA AT 20Z AS SEEN ON KBOX 88D RADAR. HAVE HAD SEVERAL
REPORTS OF FLASH FLOODING...AS WELL AS REPORTS OF UP TO 2 INCHES
OF RAIN IN 90 MINUTES OR LESS.

NOTING ANOTHER AREA OF RAINFALL MOVING ACROSS N NJ/WESTERN LONG
ISLAND...WHICH WILL KEEP RAINFALL THROUGH THIS EVENING ACROSS NE
CT/RI/SE MA AS LOW PRES MOVES ALONG THE FRONT AS IT PUSHES
OFFSHORE THIS EVENING. PRETTY LIGHT PRES GRAD EXCEPT IN TSTMS
WHERE GUSTS UP TO 25 KT POSSIBLE. 

EXPECT ANY THUNDER TO END BY AROUND MIDNIGHT AS THE LOW PASSES S
OF NANTUCKET...BUT SHOWERS COULD LINGER ON THE CAPE AND ISLANDS
THROUGH THE NIGHT. MAY ALSO SEE PATCHY FOG DEVELOP PRIOR TO THE
DRIER AIR WORKING IN...BUT SHOULD IMPROVE FROM S-N AS DEWPTS DROP. 

WILL BE A CHILLY NIGHT ACROSS INTERIOR S NH AND N MA AS TEMPS FALL
BACK TO THE UPPER 40S TO AROUND 50...RANGING TO THE MID 50S ALONG
THE S COAST.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
TONIGHT...

THE COLD FRONT WILL SLOW AS IT PUSHES OFFSHORE AS A WEAK WAVE LIFTS 
ALONG THE FRONT FROM THE MID-ATLANTIC. EXPECTING WIDESPREAD RAIN 
WITH EMBEDDED HEAVIER SHOWERS AND THUNDERSTORMS TO LINGER OVER THE 
SOUTH COAST AND ADJACENT WATERS. CONCERNS WILL STILL BE PRESENT FOR 
LOCALIZED URBAN FLOODING AND PONDING OF WATER ALONG ROADWAYS...BUT 
LOW CONFIDENCE ON SEVERE WEATHER THREATS AS INSTABILITY IS EXPECTED 
TO BE MINIMAL. LOWS DOWN TO AROUND LOW 50S. 

WEDNESDAY...

COOLER AIRMASS BUILDING SOUTH SHOULD ALLOW SIGNIFICANT BOUNDARY 
LAYER MIXING OF AROUND 4-6 KFT. SUBSEQUENTLY...ANTICIPATING THE MIX-
DOWN OF FASTER MOMENTUM AND DRIER AIR. NOT LOOKING AT ANY FIRE 
WEATHER HEADLINES WITH RECENT RAINS. DEWPOINTS DOWN TO AROUND 50 
DEGREES...SOME GUSTY NORTHERLY WINDS MAINLY ACROSS EASTERN NEW 
ENGLAND. EXPECTING DIURNAL SCATTERED TO BROKEN FAIR-WEATHER CUMULUS 
ACROSS INTERIOR NEW ENGLAND.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
  * HIGH PRESSURE WILL LEAD TO QUIET WEATHER THU AND FRI
  * HIGH PRES S OF SNE BRINGS WARM...HUMID CONDITIONS THIS WEEKEND
  * SHOWERS AND THUNDERSTORMS POSSIBLE SATURDAY

THERE IS GOOD GENERAL AGREEMENT AMONGST THE MODELS THROUGH MUCH OF 
THE LONG TERM.  THERE ARE SOME MODEL DISCREPANCIES REGARDING THE 
STRENGTH AND EXTENT OF AN UPPER LEVEL RIDGE OVER THE EASTERN U.S. 
THROUGH THIS WEEKEND.  ULTIMATELY THIS WILL AFFECT THE WEATHER IN 
THIS AREA MAINLY IN WHERE AND WHEN SHOWERS AND THUNDERSTORMS ARE 
ABLE TO DEVELOP.  THE CONSENSUS IS WITH THE ECMWF AND THE UPPER 
LEVEL RIDGE OVER THE SE CONUS THURSDAY AND GRADUALLY BUILDING 
NORTHWARD INTO THE OHIO VALLEY BY SATURDAY AND INTO THE NE CONUS 
SUNDAY AND SINKING BACK SOUTH EARLY NEXT WEEK.  OTHERWISE...AM 
EXPECTING FAIRLY QUIET WEATHER WITH MORE SUMMER LIKE TEMPERATURES 
AND A FEW HUMID DAYS THROWN IN THERE AS WELL.  WITH THUNDERSTORMS 
CURRENTLY MOVING OVER SOUTHERN NEW ENGLAND...WILL MAKE WHATEVER 
CHANGES ARE NECESSARY AND BASE MUCH OF THE FORECAST OFF THE PREVIOUS 
FORECAST.

THURSDAY AND FRIDAY...HIGH PRESSURE CRESTS OVER SOUTHERN NEW ENGLAND 
WITH A WARMING TREND IN TEMPERATURES.

SATURDAY...BEST CHANCE FOR SHOWERS AND THUNDERSTORMS AS WARM...MOIST 
AIR BUILDS INTO THE REGION ON SW WINDS.  WE WILL STILL BE ON THE 
PERIPHERY OF THE RIDGE WITH DECENT INSTABILITY NOTED IN STEEP MID 
LEVEL LAPSE RATES.  

SUNDAY THROUGH TUESDAY...HIGH PRES MOVES OFFSHORE AS THE UPPER RIDGE 
SINKS S SLOWLY.  WARM...MOIST AIR REMAINS IN THE REGION ON 
SOUTHWESTERLY WINDS...AND INCREASES INSTABILITY.  HOWEVER...NOT MUCH 
OF A TRIGGER ANY OF THOSE DAYS AND MODELS ARE NOT SHOWING MUCH...IF 
ANY...QPF SO WILL KEEP THUNDERSTORM CHANCES LOW.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

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

NEAR TERM /THROUGH WEDNESDAY NIGHT/...

MODERATE CONFIDENCE FOR TRENDS...LOWER CONFIDENCE FOR TIMING
THROUGH TONIGHT...THEN MODERATE CONFIDENCE WED-WED NIGHT.

THROUGH 00Z...MVFR-IFR CIGS/VSBYS IN SHOWERS/SCT TSTMS ACROSS E
MA/N RI/N CT AS COLD FRONT MOVES SLOWLY S. NOTING BRIEF
TORRENTIAL RAINFALL IN SOME STORMS. MAY SEE LOCAL LIFR CONDITIONS.
THIS WILL SHIFT SLOWLY S TO THE S COAST THIS EVENING. WILL ALSO
SEE LOCAL IFR-LIFR CIGS/VSBYS ALONG S COAST WITH LOW
CLOUDS/PATCHY FOG.

TONIGHT...EXPECT MAINLY VFR CONDITIONS ACROSS N MA/S NH...PATCHY
MVFR-IFR CIGS/VSBYS MAINLY IN THE VALLEYS WITH PATCHY FOG. ACROSS
CENTRAL AND SOUTHERN AREAS...MVFR-IFR CIGS/VSBYS IN LOW
CLOUDS/SHOWERS. MAY SEE SCT TSTMS THROUGH MIDNIGHT. BRIEF LIFR
CONDITIONS POSSIBLE.

WEDNESDAY...MVFR-IFR CIGS/VSBYS TO START MAINLY S OF THE MASS
PIKE...THEN IMPROVING TO VFR DURING THE MORNING. MVFR VSBYS MAY
LINGER ALONG S COAST INTO THE AFTERNOON.

WEDNESDAY NIGHT...VFR.
 
KBOS TERMINAL...MODERATE CONFIDENCE. RA+/TSRA POSSIBLE FROM AROUND
21Z THROUGH 02Z. 

KBDL TERMINAL...MODERATE CONFIDENCE. RA+/TSRA POSSIBLE THROUGH
23Z-00Z.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY AND FRIDAY...HIGH CONFIDENCE.  VFR.

SATURDAY...MODERATE CONFIDENCE.  MAINLY VFR.  LOW PROBABILITY OF 
SHOWERS AND THUNDERSTORMS BRIEFLY LOWERING CONDITIONS TO MVFR/IFR.

SUNDAY...MODERATE TO HIGH CONFIDENCE.  VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

NEAR-TERM /THROUGH WEDNESDAY/...MODERATE CONFIDENCE. 

WINDS AND SEAS HAVE DIMINISHED PROMPTING THE CANCELING OF SMALL
CRAFT ADVISORIES ON THE SOUTH-SOUTHEAST OUTER WATERS. WILL SEE A
COLD FRONT SLIDE ALONG WATERS OVERNIGHT TONIGHT ALONG WHICH
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE. EXPECT THIS ACTIVITY
TO BE SOUTH OF THE WATERS INTO WEDNESDAY...BEHIND WHICH WINDS WILL
SHIFT OUT OF THE NORTH-NORTHEAST. GUSTS UP TO 25 KTS WILL BE
POSSIBLE SUBSEQUENTLY AMPLIFYING WAVE HEIGHTS OF 5 TO 6 FEET ON
THE OUTER WATERS. 

OUTLOOK...THURSDAY THROUGH SUNDAY...

HIGH CONFIDENCE.

QUIET BOATING WEATHER EXPECTED THROUGH SUNDAY WITH HIGH PRESSURE 
NEAR OR OVER THE WATERS.  THE ONLY EXCEPTION IS SATURDAY WHEN 
SHOWERS AND THUNDERSTORMS MAY LIMIT VISIBILITIES ON THE WATERS.

&&

.HYDROLOGY...
HAVE KEPT FLASH FLOOD WATCH UP THROUGH THIS EVENING ACROSS THE
REGION...THOUGH MAY END IT EARLY ACROSS LOWER CT VALLEY REGION.
HAVE HAD SEVERAL REPORTS OF FLASH FLOODING DUE TO TORRENTIAL RAINS
FROM TSTMS AS THE COLD FRONT SLOWLY MOVES THROUGH. HAVE ALSO
RECEIVED A COUPLE OF REPORTS OF SMALL STREAMS OVERFLOWING THEIR
BANKS. 

AS FOR RIVER FLOODING...THE CHARLES AT DOVER REMAINS JUST ABOVE
FLOOD STAGE. LATEST GUIDANCE INDICATES THAT THIS RIVER WILL ONLY
SLOWLY FALL AND REMAIN IN MINOR FLOOD THROUGH LATE WEDNESDAY NIGHT.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH UNTIL 9 PM EDT THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH UNTIL 9 PM EDT THIS EVENING FOR MAZ009-
     011>013-015>021.
NH...NONE.
RI...FLASH FLOOD WATCH UNTIL 9 PM EDT THIS EVENING FOR RIZ001>007.
MARINE...NONE.

&&

$$
SYNOPSIS...RLG/EVT
NEAR TERM...FRANK/EVT
SHORT TERM...EVT
LONG TERM...RLG
AVIATION...RLG/EVT
MARINE...RLG/EVT
HYDROLOGY...EVT