Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 110822
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
422 AM EDT FRI APR 11 2014

.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE ACROSS NEW ENGLAND TODAY AND STALL
ALONG THE SOUTH COAST TONIGHT. A WAVE OF LOW PRESSURE WILL MOVE
ALONG THE FRONT AND PASS SOUTH OF NEW ENGLAND...BRINGING A CHANCE
OF SHOWERS TONIGHT. DRY AND PROGRESSIVELY MILDER CONDITIONS ARE
EXPECTED OVER THE WEEKEND AND MONDAY. A SLOW MOVING FRONT WILL
BRING A SOAKING RAIN SOMETIME TUESDAY AND WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THROUGH 12Z/8AM
SURFACE COLD FRONT IS MOVING THROUGH EASTERN AND CENTRAL NEW YORK.
ONE AREAS OF CLOUDS LED THE FRONT INTO NEW ENGLAND AND BROUGHT
SPRINKLES. THE MAIN AREA OF CLOUDS AND SHOWERS IS ALONG THE FRONT
AND MOVING EAST. TIMING ON THESE CLOUDS/SHOWERS WOULD BRING THEM
TO THE BERKSHIRES 5-6 AM/WORCESTER 6-7AM/BOSTON-PROVIDENCE 7-8 AM.
EXPECT SOUTH-SOUTHWEST WINDS TO CONTINUE THROUGH SUNRISE.

TODAY...
BROAD AREA OF SPRINKLES/LIGHT RAIN IN CENTRAL/WESTERN NY. ONCE THE
SHOWERS MOVE IN...EXPECT OCCASIONAL SPRINKLES THROUGH THE MORNING
AND MIDDAY. THE COLD FRONT BECOMES MORE ALIGNED WITH THE UPPER
FLOW TODAY AND SLOWS AS IT MOVES OVER OUR AREA. CROSS SECTIONS
SHOW A DEEP COLUMN OF MOISTURE AND PW VALUES AROUND AN INCH. THIS
SUGGESTS ENOUGH MOISTURE FOR SHOWERS. A GOOD 850 MB
CONVERGENCE/250 MB DIVERGENCE COUPLET MOVES ACROSS LATE IN THE
DAY...WHICH WOULD ALSO SUPPORT SHOWERS. WE WILL BRING INCREASING
POPS DURING THE LATTER PART OF THE AFTERNOON.

TEMPS AT 850 MB WILL BE 4-6C. WITH FULL MIXING TO 850 MB
TEMPERATURES WOULD REACH THE MID AND UPPER 60S. CLOUDS SHOULD BE
THICK ENOUGH TO HOLD BACK FULL MIXING...SO WE WILL FORECAST LOW TO
MID 60S. WITH MORE SUNSHINE AND DEEPER MIXING 70 MAY BE
POSSIBLE...BUT THIS IS A LOWER PROBABILITY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
UPPER SHORTWAVE MOVES FROM THE GREAT LAKES THIS EVENING TO NEW
ENGLAND BY SUNRISE SATURDAY. UPPER JET SUPPORTING THE SHORTWAVE
MOVES ACROSS NEW ENGLAND OVERNIGHT WITH SOUTHERN NEW ENGLAND IN
THE RIGHT ENTRANCE REGION OF THE JET. THIS WILL GENERATE UPPER
VENTING OVER OUR AREA AND ESPECIALLY OVER THE STALLED COLD
FRONT...AND HELP GENERATE A WAVE OF LOW PRESSURE ALONG THE FRONT.
SUFFICIENT LIFT AND MOISTURE TO GENERATE RAIN/SHOWERS ACROSS OUR
AREA WITH PREFERENCE FOR CT/RI/SE MASS. HIGHEST POPS WILL BE IN
THE VICINITY OF THE STALLED FRONT WITH MAX VALUES 60-65 PCT. THE
WAVE AND ITS UPPER SUPPORT MOVE EAST OF CAPE COD BY 12Z...SO POPS
SHOULD BE DIMINISHING BY THAT TIME.

SATURDAY...
HIGH PRESSURE BUILDS OVER THE REGION BRINGING CLEARING AND DRY
WEATHER. MIXING SHOULD REACH TO 850 MB...WHERE TEMPS WILL BE
AROUND 3C. THIS SHOULD SUPPORT MAX TEMPS IN THE LOW TO MID 60S.
EVEN A DEEPER MIXING TO 800 MB WOULD SUPPORT MID 60S. WIND FIELDS
WILL BE LIGHT...WHICH WOULD ALLOW SEABREEZES TO DEVELOP NEAR THE
COASTS. TEMPS IN THESE AREAS SHOULD BE IN THE UPPER 40S AND 50S.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...

HIGHLIGHTS...

* ABOVE AVERAGE TEMPERATURES ARE EXPECTED ON SUNDAY/MONDAY
* STRONG COLD FRONTAL PASSAGE NEXT TUES/WED
* BELOW AVERAGE TEMPERATURES RETURN FOR THE REMAINDER OF THE WORK
  WEEK

MODELS AND CONFIDENCE...
HAVE HIGH CONFIDENCE IN THE WARMING TREND IN THE FORECAST OVER
THE WEEKEND WITH A MODERATE CONFIDENCE FOR THE TIMING POTENTIAL
FOR THE SYSTEM NEXT WEEK. INCREASING CONFIDENCE THAT PRECIP WILL
OCCUR OVER THE MID-WEEK SYSTEM BUT THE EXACT TIMING AND LOCATION
OF MODERATE RAINFALL ARE STILL UNCERTAIN. FINALLY BELIEVE THAT
TEMPS WILL DROP BELOW AVERAGE BY WEDNESDAY/THURSDAY. STILL SOME
UNCERTAINTY LEADING UP TO NEXT WEEK AS STRONG TROUGH DIGS TOWARDS
THE NORTHEAST.

OVERALL 00Z MODEL GUIDANCE IS IN GOOD AGREEMENT. THE RE-
AMPLIFICATION OF THE UPPER PATTERN WILL TAKE SHAPE LATE THIS
WEEKEND INTO NEXT WEEK. UPPER RIDGING WILL BUILD OVER SE ALASKA/NW
CANADA AS WELL AS ACROSS THE NORTHEAST...FAVORING DIGGING
TROUGHING OVER THE CENTRAL CONUS. THIS WILL SUPPORT A
STRENGTHENING SURFACE FRONTAL BOUNDARY THAT WILL SLOWLY MARCH
EASTWARD TOWARDS NEW ENGLAND BY TUES/WED. THE DETERMINISTIC AND
ENSEMBLE GUIDANCE CONTINUE TO SHOW BETTER AGREEMENT ON THE
EVOLUTION OF THIS SYSTEM...WITH BOTH THE DETERMINISTIC GFS/EC IN
GOOD AGREEMENT. IN THE WAKE OF THIS FRONT HIGH PRESSURE SHOULD
SETTLE OVER/NEAR NEW ENGLAND WITH ENOUGH GRADIENT SURROUNDING IT
TO SUPPORT BREEZY CONDS AWAY FROM THE HIGH CENTER. TEMPS SHOULD
MODERATE TO WITHIN 10F OF NORMAL BY LATE NEXT WEEK. HAVE TRENDED
THIS FORECAST TOWARDS PREVIOUS FORECAST AND WPC.

DETAILS...

SATURDAY NIGHT INTO MONDAY...
HIGH PRESSURE WILL EXIT OFFSHORE BY SUNDAY MORNING AS A FRONTAL
SYSTEM TO THE NORTH OF THE REGION BEGINS TO MOVE TOWARDS SOUTHERN
NEW ENGLAND. THIS FRONT WILL STALL BEFORE REACHING SOUTHERN NH AND
THEN MOVE NORTHWARD BY MONDAY AS A WARM FRONT.

RETURN FLOW TO THE REGION WILL ALLOW FOR GOOD WAA ON BOTH SUNDAY AND
MONDAY. DURING THE DAY...A GOOD AMOUNT OF MIXING WILL OCCUR AND
WITH 850MB TEMPS AT 8C ON SUNDAY AND 12C ON MONDAY...HIGH
TEMPERATURES WILL FLIRT WITH 70F ON SUNDAY TO MID TO UPPER 70S ON
MONDAY. IF THE ATMOSPHERE IS SUPER ADIABATIC THEN TEMPERATURES MAY
REACH 80F ON MONDAY. ON CAVEAT IS FOR THOSE ALONG THE SOUTH
COASTLINE...SOUTHERLY WINDS WILL BRING THE COOL MARITIME AIR
ONSHORE KEEP TEMPS IN THE 50S TO LOW 60S ON BOTH DAYS. BECAUSE OF
THE MIXING...WINDS WILL BE GUSTY...NEAR 20-30 MPH. ONCE THE WINDS
LIGHTEN UP DURING THE OVERNIGHT HOURS...COMBINED WITH THE
SOUTHERLY WINDS...ANTICIPATE FOG DEVELOPMENT ESP ALONG THE SOUTH
COAST.

FINALLY THERE IS A LOW PROBABILITY THAT A FEW SHOWERS MAY DEVELOP
ACROSS THE HIGH TERRAIN ON MONDAY DUE TO DIABATIC HEATING. AM NOT
ANTICIPATING ANY STRONG OR SEVERE STORMS BUT PERHAPS A RUMBLE OF
THUNDER OR TWO. BECAUSE OF THIS UNCERTAINTY LEFT IT OUT OF THE
FORECAST FOR NOW BUT IT IS SOMETHING THE BEARS WATCHING.

TUESDAY INTO WEDNESDAY....
GUIDANCE IS BEGINNING TO CLUSTER MORE TOGETHER ON THE TIMING AND
INTENSITY OF THE APPROACHING COLD FRONTAL SYSTEM. THE LATEST 00Z
MODELS INDICATE THAT A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE
SLOW MOVING COLD FRONT BY TUESDAY NIGHT FOLLOWED BY STRONG HIGH
PRESSURE BY WED NIGHT.

ANTICIPATE A FEW SHOWERS TO DEVELOP AHEAD OF THE FRONT MONDAY NIGHT
INTO TUESDAY. BUT AS SOON AS THE FRONT APPROACHES...EXPECT
MODERATE TO POSSIBLY HEAVY PRECIP TO FALL. THIS PRECIP MAY CAUSE
URBAN AND POOR DRAINAGE FLOODING...BUT MAY ALSO HELP ELEVATED THE
RIVERS IF EVERYTHING LINES UP. HOWEVER WE WILL NEED TO MONITOR
THIS POTENTIAL CLOSELY. BOTH AHEAD AND BEHIND THE FRONT...A VERY
STRONG LLJ WILL DEVELOP WHICH WILL NOT ONLY AID IN THE MOISTURE
TRANSPORT ALONG THE FRONT BUT WILL ALSO CREATE GUSTY WINDS THROUGH
THE PERIOD. WIND GUSTS OF 20 TO 30 MPH ARE EXPECTED AHEAD OF THE
FRONT BUT PERHAPS EVEN STRONGER GUSTS COULD OCCUR AS 925MB WINDS
SPEEDS STRENGTHEN TO 60-80KTS. THIS WILL RESULT IN A POSSIBLE WIND
ADV IF WE MIX ALL THE WAY TO 925MB. VERY STRONG CAA WILL OCCUR AS
THE FRONT PASSES THROUGH BY WED. APPEARS THAT THE COLD AIR WILL
RUSH INTO THE AREA WITH PRECIP LINGERING BEHIND THE SYSTEM. THIS
WILL RESULT IN SOME P-TYPE ISSUES ESP ACROSS THE BERKSHIRES AND
IN SOUTHERN NEW HAMPSHIRE. LASTLY WITH THE STRONG ONSHORE FLOW
FROM THE SOUTH...WE WILL NEED TO WATCH FOR THE POTENTIAL FOR SOME
MINOR SPLASHOVER ALONG THE SOUTH SHORE AND INTO NARRAGANSETT BAY.
TIDES ARE SLOWLY INCREASING WITH HIGH ASTRONOMICAL TIDE PEAKING
NEXT FRIDAY/SATURDAY.

AS ONE CAN SEE THERE ARE A LOT OF HAZARDS THAT THIS STORM CAN
POTENTIALLY DEVELOP. ALTHOUGH CONFIDENCE IS STILL A LITTLE
UNCERTAIN...ESP SINCE THIS STORM IS STILL 5 DAYS AWAY...IT IS
LOOKING LIKE A POTENT SPRING STORM WILL AFFECT THE EASTERN STATES
NEXT WEEK.

THURSDAY...
STRONG HIGH PRESSURE WILL QUICKLY USHER INTO THE REGION BEHIND
THE COLD FRONT. TEMPERATURES WILL DROP WELL BELOW AVERAGE WITH
HIGH JUST REACHING 50F.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH FRIDAY NIGHT/...

THROUGH 12Z...CLOUDS MOVING IN AHEAD OF A COLD FRONT...BUT BASES
ARE ABOVE 8000 FEET. THIS SHOULD CONTINUE THROUGH SUNRISE. ANY
PCPN WILL BE LIGHT WITH LITTLE OR NO VSBY RESTRICTIONS. SOUTHWEST
WINDS A 2000-3000 FEET WITH SPEEDS OF 40-50 KNOTS...WHICH COULD
CAUSE LOW LEVEL WIND SHEAR. THESE WINDS WILL MOVE OFFSHORE TOWARD
MORNING.

TODAY...VFR IN CLOUDS AND LIGHT SHOWERS. A BRIEF PERIOD OF MVFR
CIGS/VSBYS POSSIBLE IN SHOWERS LATE IN THE DAY ESPECIALLY OVER CT
AND RI.

TONIGHT...A PERIOD OF 2000 FOOT CIGS AND 4-5 MILE VSBYS IS
POSSIBLE IN RAIN SHOWERS...MOSTLY ACROSS CT/RI/SE MASS. THERE IS A
LOW CHANCE OF DENSE FOG FORMING ALONG THE SOUTH COAST.

SATURDAY...SHOWERS AND ANY MVFR CONDITIONS SHOULD MOVE OFFSHORE
EARLY IN THE DAY. CAPE COD AND ISLANDS WOULD BE THE LAST TO
EXPERIENCE THESE CONDITIONS. EXPECT VFR IN CLEARING SKIES. NORTH
TO NORTHWEST WINDS IN THE MORNING SHOULD BECOME LIGHT/VARIABLE BY
AFTERNOON. POTENTIAL SEA BREEZES DEVELOPING IN THE AFTERNOON.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF TONIGHT AND FRIDAY.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF TONIGHT AND FRIDAY.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT...MODERATE CONFIDENCE.
LOW CLOUDS AND PATCHY FOG MAY MOVE ONSHORE ALONG S COAST WITH
LOCAL IFR CIGS/VSBYS.

SUNDAY...MODERATE CONFIDENCE.
MAINLY VFR. LOCAL MVFR-IFR CIGS/VSBYS ALONG S COAST IN LOW OCEAN
CLOUDS AND PATCHY FOG WHICH SHOULD IMPROVE BY MIDDAY. EXPECT S
WINDS TO INCREASE DURING THE AFTERNOON...GUSTING TO AROUND 25 KTS.
MAY SEE LOW CLOUDS/PATCHY FOG RETURN AFTER MIDNIGHT ALONG S COAST
WITH MVFR-IFR CONDITIONS.

MONDAY...MODERATE CONFIDENCE.
LOCAL MVFR-IFR CIGS/VSBYS ALONG S COAST EARLY MON SHOULD
IMPROVE...OTHERWISE VFR ON MONDAY. GUSTY S-SW WINDS IN PLACE...UP
AROUND 30 KTS.

TUESDAY...LOW CONFIDENCE. MAINLY VFR WITH SOME MVFR IN ISOLATED
SHOWER DEVELOPMENT AHEAD OF APPROACHING COLD FRONT.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

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

TODAY...A WEAK COLD FRONT SWINGS ACROSS THE WATERS AND STALLS.
STRONG SOUTHWEST WIND EARLY THIS MORNING WITH GUSTS 20-25 KNOTS.
THE WIND WILL DIMINISH THROUGH THE DAY AND WILL SPEND MOST OF THE
DAY BELOW 25 KNOTS. MEANWHILE SEAS WILL LINGER AT 5-7 FEET ON THE
OUTER WATERS AND PARTS OF THE RI WATERS.

TONIGHT...
STALLED FRONT NEAR THE SOUTH COAST OF MASS AND RI. THE WIND FIELD
NEAR THIS FRONT WILL BE LIGHT. SWELL WILL CONTINUE AROUND 5 FEET
ON THE SOUTHERN OUTER WATERS AND PARTS OF THE RI WATERS. ALSO SOME
POTENTIAL FOR LOW VSBYS IN FOG OVERNIGHT.

SATURDAY...HIGH PRESSURE BUILDS IN WITH A LIGHT WIND FIELD. SWELL
OF 5 FEET WILL STILL LINGER ON THE OUTER WATERS AND SOME OF THE RI
WATERS.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT...HIGH CONFIDENCE.
VSBY RESTRICTION LATE SAT NIGHT ON THE OUTER WATERS IN PATCHY
FOG.

SUNDAY...MODERATE CONFIDENCE.
LIGHT/VRBL WINDS SHIFT TO SE-S DURING SUNDAY. WILL INCREASE...
GUSTING TO AROUND 25 KT. EXPECT SEAS TO BUILD AS WELL. VSBY
RESTRICTIONS IN PATCHY FOG.

MONDAY-TUESDAY...MODERATE CONFIDENCE.
EXPECT S-SW WINDS TO GUST UP TO 30 KT WITH SEAS INCREASING IN
RESPONSE ESP ON THE SOUTHERN OUTER WATERS. VSBY RESTRICTIONS
DURING THE OVERNIGHT AND EARLY MORNING HOURS IN PATCHY FOG...THEN
SHOWERS MOVE IN ON TUE.

&&

.HYDROLOGY...
SNOWMELT AND RUNOFF FROM NORTHERN NEW ENGLAND HAS THE CONNECTICUT
RIVER RUNNING HIGH.  LATEST PROJECTIONS KEEP THE RIVER JUST BELOW
MINOR FLOOD STAGE AT HARTFORD AND AT MIDDLE HADDAM THROUGH THE
MORNING. HOWEVER...IT IS STILL POSSIBLE THAT TIDE FLUCTUATIONS
COULD PUSH THE LOCATIONS INTO VERY BRIEF MINOR FLOODING. NO
HEADLINES WILL BE ISSUED THIS TIME...BUT WILL HAVE TO CONTINUE TO
CLOSELY MONITOR. WORST CASE SCENARIO WOULD BE VERY MINOR FLOODING.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ235-237-
     254>256.
     SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ250.

&&

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



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