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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 170010
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
810 PM EDT SUN JUN 16 2013

.SYNOPSIS...
A COLD FRONT FROM THE GREAT LAKES WILL SLIDE ACROSS SOUTHERN NEW
ENGLAND TONIGHT. A SECOND COLD FRONT MAY STALL ACROSS THE REGION
MONDAY...THEN SLOWLY MOVE OFFSHORE LATE TUESDAY OR TUESDAY NIGHT.
LARGE HIGH PRESSURE WILL BRING MAINLY DRY AND SEASONABLE CONDITIONS
WEDNESDAY THROUGH FRIDAY...THEN WILL ANCHOR SOUTH OF NEW ENGLAND
SATURDAY. A WEAK FRONT MAY BRING WIDELY SCATTERED SHOWERS NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --
800 PM UPDATE...
MOST OF THE PRECIP AHEAD OF APPROACHING COLD FRONT HAS DISSIPATED
AND MOVED OFFSHORE. NOTING ANOTHER AREA OF LIGHT RAIN SHOWERS
ALONG S COAST OF RI/S MA AT 00Z...BUT SHOULD MOVE THROUGH THE CAPE
AND ISLANDS OVER THE NEXT HOUR OR TWO. LITTLE IF ANY PRECIP NOTED
OVER NY STATE AND MOST OF PA.

BASED ON LATEST RADAR TRENDS...HAVE LOWERED POPS ACROSS THE REGION
AND HAVE PRETTY MUCH ENDED PRECIP. MAY SEE A COUPLE OF POCKETS OF
VERY LIGHT SHOWERS ACROSS EASTERN AREAS THROUGH 03Z AS INSTABILITY
MOVES OFFSHORE. HAVE CONTINUED TO BRING IN PATCHY FOG AS DEWPTS
REMAIN ON THE HIGH SIDE THROUGH MOST OF THE NIGHT. MAY ALSO SEE
SOME LOW CLOUDS WORK INTO PORTIONS OF CAPE COD AND THE
ISLANDS...BUT SHOULD MOVE OFFSHORE OVERNIGHT.

HAVE ALSO UPDATED REMAINING GRIDS TO BRING CONDITIONS CURRENT.

PREVIOUS DISCUSSION...

OVERNIGHT...
CLEARING IS ENTERING FAR WESTERN NY BUT WITH PLENTY OF LOW LEVEL
MOISTURE IN THE FORM OF CUMULUS CLOUDS OVER SOUTHERN ONTARIO.
EXPECT THIS CLEARING TO MOVE INTO SOUTHERN NEW ENGLAND AFTER
MIDNIGHT. THE LOW LEVEL MOISTURE AND DIMINISHED WIND MAY ALLOW FOG
PATCHES TO FORM OVERNIGHT. DEWPOINTS UPSTREAM ARE 55-60...WHICH IS
A GOOD TARGET FOR OVERNIGHT MIN TEMPS. WE USED A BLEND OF MOS
VALUES.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MONDAY...
ONE SURFACE LOW MOVES OFF THROUGH THE MARITIMES. THE UPPER TROUGH
LINGERS OVER QUEBEC AND EXTENDS THROUGH THE NORTHEAST USA. A 105
KNOT UPPER JET MOVES THROUGH THE TROUGH WITH THE RIGHT ENTRANCE
REGION OVER SOUTHERN NEW ENGLAND DURING THE DAY. MEANWHILE A
SHORTWAVE MOVES THROUGH THE CYCLONIC FLOW AND DRIVES A SECOND COLD
FRONT THROUGH THE ST LAWRENCE VALLEY INTO NEW ENGLAND/NY.

STABILITY PARAMETERS TELL A FAVORABLE STORY WITH LI AT
-1/-2...TOTALS 46-50...SBCAPE REACHING 200-500 J/KG. THIS SHOULD
SUPPORT SHOWERS/SCATTERED TSTMS DEVELOPING INLAND DURING THE
AFTERNOON AND SPREADING SOUTH/EAST DURING THE EVENING. TEMPS AT
850 MB 12-14C AND GOOD MIXING DURING THE MORNING/AFTERNOON SHOULD
SUPPORT MAX TEMPS IN THE LOW TO MID 80S.

MONDAY NIGHT...
THE COLD FRONT MOVES ACROSS THE REGION MONDAY NIGHT. DIURNAL
INSTABILITY WILL BE FADING...BUT WE WILL CONTINUE TO HAVE THE
UPPER JET NEARBY WITH FAVORABLE UPPER VENTING TO MAINTAIN SOME
SUPPORT FOR CONVECTION. WE HAVE MAINTAINED CHANCE POPS THROUGH THE
NIGHT.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...

* SCATTERED SHOWERS/ISOLATED TSTMS DURING TUESDAY AS FRONT SLOWLY
  MOVES ACROSS REGION.
* DRY AND SEASONABLE WEATHER FOR THE MIDDLE AND END OF THE WEEK

OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS SIGNALING BROAD UPPER LEVEL LOW PRES ACROSS
QUEBEC AT THE START OF THE LONG TERM PERIOD...KEEPING A LONG WAVE
TROUGH ACROSS NY STATE INTO PA WITH WEAK SHORT WAVES RIDING
THROUGH THE BASE OF THIS LOW. GENERAL W-SW FLOW WILL CAUSE A COLD
FRONT TO ONLY SLOWLY CROSS THE REGION...BUT SHOULD MOVE OFF AS THE
UPPER LEVEL SYSTEM WEAKENS AND SHIFTS E BY ABOUT MID WEEK. LOOKS
LIKE A DRY W-NW FLOW ALONG WITH LARGE SURFACE HIGH PRES WILL BRING
SEVERAL DAYS OF DRY CONDITIONS WITH NEAR SEASONABLE TEMPS. NOTING
INCREASING VARIANCE IN MODEL SOLUTIONS AS THE HIGH BUILDS OFF THE
MID ATLC COAST AROUND NEXT WEEKEND AS THEIR HANDLING OF ANOTHER
APPROACHING FRONT. WENT ALONG WITH WPC GUIDANCE IN KEEPING THE
FRONT TO THE NW OF THE REGION...WHICH MEANS MODERATING TEMPS WITH
INCREASING HUMIDITY AT THIS POINT.

DETAILS...

TUESDAY-TUESDAY NIGHT...
SECOND FRONT TENDING TO RUN PARALLEL TO THE W-SW UPPER FLOW IN
PLACE...SO WILL BE SLOW TO CLEAR THE REGION. KEPT CHANCE POPS
GOING. WILL ALSO SEE MARGINAL INSTABILITY...SO KEPT MENTION OF
ISOLD TSTMS AS WELL. DOES LOOK LIKE THE UPPER LEVEL SYSTEM WILL
SHIFT E LATE TUE/TUE NIGHT...SO FRONT SHOULD MOVE OFFSHORE AS HIGH
PRES MOVES OUT OF THE GREAT LAKES. SKIES SHOULD CLEAR FROM NW-SE
TUE NIGHT...THOUGH MAY LINGER INTO WED ALONG THE S COAST...CAPE
COD AND THE ISLANDS.

WEDNESDAY THROUGH FRIDAY...
LARGE HIGH PRES WILL BUILD ACROSS THE REGION OUT OF NY STATE.
EXPECT DRY CONDITIONS DURING THIS TIMEFRAME. HIGHS WILL START OFF
CLOSE TO OR A LITTLE BIT BELOW SEASONAL NORMS FOR WED...THEN WILL
REBOUND TO THE LOWER 80S BY FRIDAY. THE HIGH WILL BUILD OFFSHORE
DURING FRIDAY...SO WINDS WILL START TO SHIFT TO S-SW WHICH WILL
HELP TO BRING MILDER AIR TO THE REGION.

MAY SEE ISOLD SHOWER/TSTM ACTIVITY DURING THE AFTERNOON/EVENING ON
FRI AS WEAK TROUGH TRIES TO MOVE THROUGH BUT WEAKENS. MAY BE JUST
ENOUGH LL MOISTURE TO KICK OFF DIURNAL CONVECTION. ONLY MENTIONED
SLIGHT CHANCE POPS AT THIS POINT.

SATURDAY-SUNDAY...
WITH INCREASING SOLUTION SPREAD AMONG THE MODELS...NOT QUITE AS
CONFIDENCE WITH THIS PORTION OF THE FORECAST. WITH RETURN SW FLOW
IN PLACE AND INCREASING HUMIDITIES...COULD SEE WIDELY SCT DIURNAL
SHOWERS DEVELOP ON SATURDAY. FOR NEXT SUNDAY...MAY SEE NEXT
FRONTAL SYSTEM APPROACH. AGAIN...KEPT ONLY SLIGHT CHANCE POPS
GOING BUT TIMING IS IN QUESTION.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS...

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

OVERVIEW...HIGH CONFIDENCE THROUGH MONDAY NIGHT.

TONIGHT...
MOST OF LINGERING SHOWERS WILL PUSH OFFSHORE BY 02Z. COLD FRONT
MOVES ACROSS SOUTHERN NEW ENGLAND AROUND 06Z WITH CLEARING BEHIND.
THE CLEARING MAY ALLOW FOR SOME PATCHY MVFR FOG ESPECIALLY ALONG
THE SOUTH COAST REGION. MAY ALSO SEE BRIEF IFR CIGS AS LOW CLOUDS
MOVE IN OFF THE OCEAN ACROSS OUTER CAPE COD AND NANTUCKET...BUT
SHOULD MOVE OFFSHORE AS THE DRIER AIR WORKS IN.

MONDAY AND MONDAY NIGHT...
MAINLY VFR THROUGH THE DAY. ANOTHER WEAK FRONT APPROACHES DURING
THE AFTERNOON AND MOVES THROUGH AT NIGHT. THIS MAY TRIGGER
SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS. AREAS OF MVFR/IFR
POSSIBLE IN FOG MONDAY NIGHT...ESPECIALLY NEAR THE SOUTH COAST.

KBOS TERMINAL...HIGH CONFIDENCE IN OVERALL TAF TRENDS...SLIGHTLY
LOWER CONFIDENCE IN TIMING OF SHOWERS.

KBDL TERMINAL...HIGH CONFIDENCE IN OVERALL TAF TRENDS...SLIGHTLY
LOWER CONFIDENCE IN TIMING OF SHOWERS.

OUTLOOK...TUESDAY THROUGH FRIDAY...

TUESDAY THROUGH TUESDAY NIGHT...MODERATE CONFIDENCE. MVFR POSSIBLE
AT TIMES IN SCT SHOWERS AND TSTMS.

WEDNESDAY THROUGH FRIDAY...HIGH CONFIDENCE. VFR.
-- End Changed Discussion --

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

THROUGH THIS EVENING...
REPORTED WIND GUSTS HAVE BEEN 20 KNOTS OR LESS OVER THE NEAR
SHORE WATERS. WE HAVE OPTED TO DROP SMALL CRAFT HEADLINES IN THOSE
AREAS.

TONIGHT...MODERATE TO HIGH CONFIDENCE.
A COLD FRONT APPROACHES THE WATERS TONIGHT. THE STEADY SOUTHWEST
WIND WILL BUILD SEAS ON THE SOUTHERN/SOUTHEAST OUTER WATERS WITH
HEIGHTS REACHING 5-6 FEET. WINDS AHEAD OF THE FRONT MAY APPROACH
25 KNOTS BUT THIS IS LESS CERTAIN. WE HAVE MAINTAINED THE SMALL
CRAFT ADVISORY FOR THE SOUTHERN WATERS AND EXPANDED IT INTO THE
WATERS EAST OF CAPE COD.

MONDAY...MODERATE TO HIGH CONFIDENCE.
THE COLD FRONT MOVES OFFSHORE AND DISSIPATES. ANOTHER FRONT WILL
APPROACH FROM THE GREAT LAKES LATE IN THE DAY. WEATHER ON THE
WATERS WILL BE QUIET MUCH OF THE DAY WITH DIMINISHING SEAS.
SCATTERED SHOWERS/TSTMS WILL DEVELOP INLAND AND MAY BECOME A
FACTOR ON THE WATERS LATE IN THE DAY/EVENING.

MONDAY NIGHT...MODERATE CONFIDENCE.
SHOWERS/SCATTERED TSTMS WILL AFFECT THE WATERS DURING THE NIGHT.
THE COLD FRONT WILL MOVE TO THE SOUTH NEW ENGLAND COAST BY TUESDAY
MORNING AND STALL. SEAS SHOULD REMAIN BELOW 5 FEET.  WINDS SHOULD
REMAIN BELOW 25 KNOTS EXCEPT IN THE VICINITY OF ANY TSTMS.

OUTLOOK...TUESDAY THROUGH FRIDAY...

MODERATE CONFIDENCE THROUGH THE PERIOD.

WINDS AND SEAS BELOW SMALL CRAFT CRITERIA FOR THE MAJORITY OF THE
PERIOD. N-NE WIND GUSTS MAY APPROACH 25 KT LATE TUE NIGHT AND WED
ON THE OUTER WATERS E AND S OF CAPE COD ALONG WITH MARGINAL 5 FOOT
SEAS.

&&

.HYDROLOGY...
-- Changed Discussion --
DRY WEATHER IS ALLOWING RIVERS ACROSS SOUTHERN NEW ENGLAND TO
CREST AND RECEDE. WE WILL NEED TO MONITOR FOR ANY SHOWERS/TSTMS
MONDAY WHERE RUNOFF COULD CHANGE THE TIMING FOR THE RECEDING
WATERS.

RIVER FORECAST POINTS WHERE FLOOD WARNINGS ARE STILL IN EFFECT AS
OF 800 PM. ALL EXCEPT THE CHARLES RIVER MAY BE ENDED SOMETIME
THIS EVENING OR TONIGHT.

IN CT...
CONNECTICUT RIVER AT MIDDLE HADDAM ABOVE FLOOD STAGE AND FALLING

IN MA...
CHARLES RIVER AT DOVER AT CREST AND STEADY

IN RI...
PAWTUXET RIVER AT CRANSTON ABOVE FLOOD STAGE AND FALLING

IN ADDITION...AN AREAL FLOOD WARNING REMAINS IN EFFECT FOR
SOUTHWESTERN WASHINGTON COUNTY IN RI WHERE THE LOWER PAWCATUCK
RIVER REMAINS IN FLOOD.

REFER TO THE LATEST FLOOD STATEMENTS FOR SPECIFIC FORECASTS.
-- End Changed Discussion --

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT MONDAY FOR ANZ254>256.

&&

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