Area Forecast Discussion
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000
FXUS61 KBOX 302328
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
728 PM EDT SAT MAY 30 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SLOWLY SOUTH ACROSS THE REGION
SUNDAY...THEN STALL SOUTH OF NEW ENGLAND EARLY NEXT WEEK. THIS
WILL BRING NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS
SUNDAY...AND A PERIOD OF RAIN EARLY NEXT WEEK. A COLD FRONT WILL
STALL SOUTH OF NEW ENGLAND EARLY IN THE WEEK. A DISTURBANCE
TRAVELLING ALONG THE FRONT WILL BRING SHOWERS TO THE REGION ON
MONDAY AND TUESDAY. HIGH PRESSURE BUILDS OVER THE REGION WITH FAIR
WEATHER FOR WEDNESDAY THROUGH FRIDAY. A COLD FRONT CROSSES NEW
ENGLAND SATURDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
7 PM UPDATE...
CONVECTION HAS REMAINED WEST AND NORTH OF THE REGION THROUGH THE
EVENING. CAPE WAS FAVORABLE OVER WESTERN MASS THROUGH THE EVENING
BUT STABILITY AND MOISTURE WERE MORE FAVORABLE FARTHER WEST. WE
HAVE MAINTAINED A SLIGHT CHANCE OVER THE EAST SLOPES OF THE
BERKSHIRES THROUGH EARLY NIGHT BASED ON LINGERING INSTABILITY AND
EVENING CONVECTION IN THE CATSKILLS.

NO FOG AND STRATUS ON SATELLITE AT SUNSET BUT ACK REPORTING SOME
AT 2313Z. COOLING TEMPS AT SUNSET SHOULD ALLOW THE FOG/STRATUS TO
EXPAND AGAIN. HAVE SLOWED THE TIMING OF ONSET MOST PLACES BY A
FEW HOURS...BUT EXPECT FOG/STRATUS ALONG AT LEAST THE SOUTH COAST
AND PROBABLY ACROSS MUCH OF RI AND SE MASS.

DEWPOINTS IN THE LOW TO MID 60S SO MIN TEMP FORECAST IN THIS RANGE
LOOKS GOOD.

PREVIOUS DISCUSSION...
COLD FRONT WILL BE DROPPING SOUTH ACROSS NORTHERN NEW ENG
OVERNIGHT. MAINLY DRY CONDITIONS ARE EXPECTED THROUGH THIS
EVENING...BUT A FEW SHOWERS AND AN ISOLD TSTM POSSIBLE AFTER
MIDNIGHT...MAINLY INTERIOR AS FRONT APPROACHES FROM THE NORTH AND
LOW LEVEL THETA-E RIDGE AXIS MOVES INTO THE REGION. DO NOT EXPECT
MUCH RAINFALL OVERNIGHT AS HEAVIER RAIN WILL BE CONFINED TO THE
NORTH WITH THE ACTUAL FRONT.

WITH SW FLOW PERSISTING KEEPING HIGHER DEWPOINTS ACROSS THE
REGION...EXPECT STRATUS TO EXPAND NORTH FROM THE COASTAL WATERS
AND OVERSPREAD MUCH OF SNE OVERNIGHT. AREAS OF FOG SHOULD BE
CONFINED MOSTLY TO SE NEW ENG. LOW TEMPS REMAINING IN THE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SUNDAY...
AS COLD FRONT MOVES SOUTH INTO SNE...SHOWERS WILL INCREASE IN
COVERAGE ALONG WITH SCT TSTMS. TIMING OF FRONT WILL BE 15-18Z
ACROSS N ZONES...REACHING THE S COAST 21-00Z SO SHOWERS AND TSTMS
WILL BE FOCUSED IN THE NORTH DURING THE MORNING AND EARLY
AFTERNOON SHIFTING S OF THE PIKE DURING THE AFTERNOON.

SBCAPES ARE FORECAST TO INCREASE TO AROUND 1000 J/KG AROUND 18Z
WITH AXIS OF HIGHEST INSTABILITY NEAR THE MASS PIKE. 0-6KM SHEAR
REMAINS WEAK WITH HIGHER SHEAR VALUES TO THE NORTH IN THE MORE
STABLE POST FRONTAL AIRMASS. HOWEVER...THERE MAY BE A NARROW
CORRIDOR WHERE MAX INSTABILITY OVERLAPS SHEAR VALUES 20-25 KTS
NEAR THE MASS PIKE SO CANT RULE OUT A STRONG TO ISOLD SEVERE
STORM...WITH BEST CHANCE FROM N CT AND RI TO THE MASS PIKE
REGION. GIVEN HIGH PWAT VALUES NEAR 1.75" AND THE POTENTIAL FOR
SOME TRAINING WITH UPPER FLOW NEARLY PARALLEL TO THE
FRONT...HEAVY RAINFALL WILL BE THE PRIMARY THREAT.

MAX TEMPS SHOULD REACH THE 70S BEFORE THE FROPA WITH A FEW
LOCATIONS S OF THE PIKE POSSIBLY NEAR 80 IF WE CAN GET ANY
SUNSHINE...BUT CONFIDENCE IN SUNSHINE IS LOW. BEHIND THE
FRONT TEMPS WILL FALL SHARPLY INTO THE 50S. THIS WILL OCCUR
AROUND MIDDAY OR EARLY AFTERNOON N OF THE PIKE BUT THE COOLER AIR
WILL BE DELAYED UNTIL LATE AFTERNOON FURTHER S. IN
ADDITION...A PERIOD GUSTY NE WINDS TO 30 MPH IS POSSIBLE ACROSS
NE MA IN THE AFTERNOON.

SUNDAY NIGHT...
COLD FRONT MOVES S OF THE COAST WITH COOL MOIST NE FLOW ACROSS
SNE. MORE SHOWERS ARE EXPECTED...BUT HEAVIEST RAINFALL WILL
LIKELY BE CONFINED ACROSS UPSTATE NY AND N NEW ENG ASSOCD WITH
GOOD LOW LEVEL FRONTOGENESIS AND CONVERGENCE WITH THE 850 MB
BOUNDARY WHICH SETS UP TO THE NORTH. BEST CHANCE OF SHOWERS WILL
BE ACROSS N AND W ZONES CLOSEST TO THE BEST FORCING AND WE WILL
HAVE HIGHEST POPS IN THIS AREA. A MUCH COOLER NIGHT WITH TEMPS
UPPER 40S TO LOWER 50S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE...

CHANGEABLE PATTERN MUCH OF NEXT WEEK. AN UPPER TROUGH SLOWLY CROSSES
THE NORTHEAST USA EARLY IN THE WEEK. AN UPPER RIDGE FROM THE WESTERN
USA THEN SHIFTS EAST OVER THE EASTERN USA FOR THE LATE WEEK. EARLY
INDICATIONS FOR THE END OF THE WEEK SHOW POTENTIAL INTERACTION
BETWEEN NORTHERN AND SOUTHERN STREAM SHORTWAVES THAT COULD BRING
SHOWERS TO NEW ENGLAND.

MODELS DIFFER MONDAY-TUESDAY REGARDING PLACEMENT OF FEATURES THAT
WOULD FOCUS RAIN/SHOWERS AND BRING HIGHER AMOUNTS. BUT THE LONG
RANGE MODELS ARE SIMILAR REGARDING LARGER SCALE FEATURES AND THE
GENERAL FLOW OF WEATHER THROUGH THE WEEK. WE USED A BLEND OF THE
MODELS TO GENERATE OUR GRID DATA.

THE DAILIES...

MONDAY-TUESDAY...

COLD FRONT STALLS SOUTH OF NEW ENGLAND. HIGH PRESSURE BUILDS OVER
EASTERN CANADA. THIS WILL BRING AN INCREASING EAST-NORTHEAST WIND
ACROSS THE GULF OF MAINE AND INTO SOUTHERN NEW ENGLAND. THE PRESSURE
GRADIENT WILL GENERATE A 20-25 KNOT FLOW AROUND 2000 FEET. WHILE
SURFACE WINDS WILL BE LESS...THIS STILL SUGGESTS A STIFF WIND OFF
THE GULF INTO EAST COASTAL MASS. EXPECT A COOL MOIST ENVIRONMENT
ESPECIALLY IN EASTERN MASS.

LOW PRESSURE DEVELOPS OVER THE CENTRAL APPALACHIANS MONDAY. THIS
WILL BRING A SOUTHERLY LOW LEVEL JET OF 20-30 KNOTS UP THE COASTAL
PLAIN INTO EASTERN PARTS OF NY AND PA MONDAY...SHIFTING EAST MONDAY
NIGHT AND TUESDAY. AS THIS RUNS OVER THE LOW LEVEL MARINE AIR IT
WILL GENERATE SUFFICIENT LIFT TO SUPPORT RAIN OR RAIN SHOWERS.
MEANWHILE PRECIP WATER VALUES WILL BE ABOVE NORMAL ALL AREAS AND
AROUND 1.50 INCHES CT-RI-SE MASS. EXPECT THE HEAVIEST RAIN TO BE
NORTH OF US...BUT WITH NOTICEABLE AMOUNTS STILL LIKELY HERE IN THE
SOUTH. THE HEAVIEST RAINFALL HERE IN THE SOUTH SHOULD BE LATE MONDAY
NIGHT INTO TUESDAY AS THE LOW LEVEL JET MOVES ACROSS...FOLLOWED BY
THE SURFACE LOW PASSING OFFSHORE TO THE SOUTH.

WEDNESDAY THROUGH FRIDAY... NORTHERN STREAM SHORTWAVE MOVES EAST OF
THE REGION WEDNESDAY. HIGH PRESSURE BUILDS OVER THE NORTHEAST USA.
THIS WILL FAVOR A DRY PERIOD WITH TEMPS TRENDING WARMER EACH DAY.
THE PREVAILING FLOW WEDNESDAY WILL BE NORTHERLY. LIGHTER WINDS WILL
FAVOR SEA BREEZES ON SOME OR ALL OF THE COASTLINE THURSDAY AND
FRIDAY.

SATURDAY... NORTHERN STREAM SHORTWAVE MAY DRIVE A COLD FRONT INTO
NEW ENGLAND. SHOWERS AHEAD OF THE FRONT MAY REACH PARTS OF OUR
AREA...BUT LOW CONFIDENCE ATTM. WE ARE ALSO WATCHING THE SOUTHERN
STREAM. TROUGH IN THE SOUTHERN FLOW MAY GENERATE A COASTAL LOW LATE
WEEK THAT COULD BRING RAIN UP THE COAST NEXT WEEKEND. STAY TUNED.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

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

TONIGHT...MODERATE CONFIDENCE. EXPECT IFR/LIFR STRATUS AND FOG TO
DEVELOP ALONG THE S COAST FIRST PART OF THE NIGHT.  FOG WILL BE
MAINLY CONFINED TO THE SE COASTAL NEW ENG WITH AREAS OF MVFR/IFR
CIGS WILL EXPAND N ACROSS MUCH OF THE REGION OVERNIGHT. A FEW
SHOWERS AND POSSIBLE A TSTM DEVELOPING OVERNIGHT IN THE INTERIOR.

SUNDAY...MODERATE CONFIDENCE. WIDESPREAD MVFR/IFR CONDITIONS.
NUMEROUS SHOWERS AND TSTMS DEVELOPING AS COLD FRONT DROPS S ACROSS
SNE. MAIN FOCUS WILL BE NEAR THE MASS PIKE. WINDS SHIFTING FROM SW
TO NE BEHIND THE FRONT WITH G25 KT POSSIBLE NE MA IN THE
AFTERNOON. TIMING OF FRONT...15-18Z ALONG AND N OF MASS PIKE
REACHING S COAST 21-00Z.

SUNDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR/IFR
CONDITIONS. SHOWERS LIKELY...ESPECIALLY INTERIOR.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. IFR CONDITIONS LIKELY
DEVELOP SUN AFTERNOON AS WINDS SHIFT TO NE BEHIND THE FRONT.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY AND TUESDAY... EAST TO NORTHEAST FLOW WITH WINDS ALONG THE
MASS EAST COAST 10 TO 15 KNOTS WITH GUSTS 15 TO 20 KNOTS POSSIBLE.
LIGHTER NORTHEAST WINDS FARTHER INLAND. MVFR/IFR CIGS AND VSBYS WITH
BEST CHANCE OVER THE COASTAL PLAIN AND EASTERN SLOPES OF THE
WORCESTER HILLS. SHOWERS POSSIBLE BOTH DAYS.

WEDNESDAY... VFR WITH A NORTH-NORTHWEST WIND.

THURSDAY...VFR. LOCAL SEA BREEZES POSSIBLE.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

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

TONIGHT...WINDS AND SEAS HAVE DIMINISHED OVER THE NEARSHORE WATERS
EXCEPT FOR BOSTON HARBOR WHERE LOGAN AIRPORT WAS GUSTING TO 24
KNOTS AT 7 PM. ALSO NARRAGANSETT BAY WHERE PVD WAS GUSTING TO 24
KNOTS. THESE GUSTS SHOULD DIMINISH AFTER SUNSET. WE WILL END THE
SMALL CRAFT ADVISORY AT THIS TIME OVER MOST WATERS BUT MAINTAIN IT
FOR BOSTON HARBOR/NARRAGANSETT BAY AND MASS BAY UNTIL 10 PM.

OTHERWISE EXPECT SW WINDS BELOW SCA TONIGHT WITH SEAS BUILDING TO
5 FT OVER OUTER WATERS DUE TO INCREASING SWELL. AREAS OF DENSE FOG
EXPECTED TO DEVELOP OVER S COASTAL WATERS RESULTING IN POOR VSBYS.

SUNDAY...SW WINDS WILL SHIFT TO NE ACROSS E MA WATERS IN THE
AFTERNOON. A PERIOD OF GUSTS TO 30 KT EXPECTED OVER NE MA WATERS
AND SCA WILL BE NEEDED. ACROSS S COASTAL WATERS...SW WINDS WILL
PERSIST. EXPECT SHOWERS WITH EMBEDDED THUNDERSTORMS TO DEVELOP.

SUNDAY NIGHT...NE WIND GUSTS TO 25 KT NE MA WATERS IN THE
EVENING...OTHERWISE WINDS DIMINISHING. SW WINDS SHIFTING TO NE
OVER S COASTAL WATERS IN THE EVENING. SCT SHOWERS ALONG WITH
PATCHY FOG REDUCING VSBYS.

OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE CONFIDENCE.

MONDAY-TUESDAY...SMALL CRAFT ADVISORY MAY BE NEEDED ESPECIALLY ON
THE WATERS EAST OF MASSACHUSETTS. NORTHEAST WINDS GUSTING 20 KNOTS
WITH A POTENTIAL TO REACH 25 KNOTS MONDAY. SEAS REACH  TO 9 FEET ON
THE EASTERN MASS WATERS...AND 3 TO 5 FEET ON THE SOUTHERN WATERS.

WEDNESDAY...A SMALL CRAFT ADVISORY MAY BE NEEDED...MAINLY DUE TO
SEAS ON THE EASTERN WATERS AND SOUTHERN OUTER WATERS. DIMINISHING
NORTH TO NORTHWEST WINDS LESS THAN 20 KNOTS. SEAS OF 5 FEET MAY
LINGER ON THE EASTERN OUTER WATERS WEDNESDAY NIGHT.

THURSDAY...NO HEADLINES EXPECTED. HIGH PRESSURE MOVES OVERHEAD.
WINDS AND SEAS WILL BE LESS THAN SMALL CRAFT THRESHOLDS.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ230-
     236-251.
     SMALL CRAFT ADVISORY UNTIL 3 PM EDT SUNDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...WTB/KJC
NEAR TERM...WTB/KJC
SHORT TERM...KJC
LONG TERM...WTB
AVIATION...WTB/KJC
MARINE...WTB/KJC



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