Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 140629 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 229 AM EDT MON APR 14 2014 .SYNOPSIS...
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GUSTY SOUTHWEST WINDS WILL BRING MILD TEMPERATURES TODAY AND TUESDAY. A SLOW MOVING COLD FRONT WILL BRING A SOAKING RAIN TUESDAY BEFORE MOVING THROUGH NEW ENGLAND EARLY TUESDAY NIGHT. DRIER AND MUCH COOLER CONDITIONS EXPECTED FOR THE MIDDLE AND END OF THIS WEEK.
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&& .NEAR TERM /UNTIL 6 AM THIS MORNING/...
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&& .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
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MONDAY NIGHT AND TUESDAY....LATEST GUIDANCE CONTINUES TO INDICATE THE DEVELOPMENT OF SEVERAL WAVES ALONG A SLOW MOVING COLD FRONT. THIS WILL ALLOW FOR MULTIPLE CHANCES FOR MODERATE TO HEAVY RAINFALL. AN AMPLIFYING LONGWAVE TROUGH OVER THE CENTRAL USA WILL SEND A COLD FRONT TOWARD NEW ENGLAND LATE TUESDAY A FEW SHOWERS MAY DEVELOP AHEAD OF THE FRONT MONDAY NIGHT...BUT BELIEVE THAT GUIDANCE IS PICKING UP MORE ON THE FOG AND DRIZZLE POTENTIAL DUE TO THE MARITIME AIR BEING ADVECTED ONSHORE FROM STRONG SOUTHERLY WINDS. THIS COLD FRONT SHOULD APPROACH BY LATE TUESDAY MORNING...PUSHING HEAVY RAINFALL FROM WEST TO EAST THROUGHOUT THE DAY. EXPECTING RAINFALL TO BE HEAVY AT TIMES AS A +4 STANDARD DEVIATION SOUTHERLY LOW-LEVEL JET TRANSPORTS ATLANTIC/GULF MOISTURE NORTH. PRECIPITABLE WATER VALUES ARE NEAR 1.5 INCHES...WHICH IS ABOUT +3 STANDARD DEVIATIONS ABOVE NORMAL. THUS THE INGREDIENTS ARE IN PLACE FOR A DECENT SOAKING.
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&& .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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HIGHLIGHTS... * STRONG COLD FRONTAL PASSAGE TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING * BELOW AVERAGE TEMPERATURES FOR THE REMAINDER OF THIS WORK WEEK * MODERATING TEMPERATURES FRIDAY MODELS AND CONFIDENCE...OVERALL...13/12Z GUIDANCE REMAINS IN VERY GOOD AGREEMENT WITH THE HANDLING OF A SLOW MOVING COLD FRONT LATE MONDAY NIGHT INTO EARLY WEDNESDAY MORNING...AS WELL AS THE HIGH PRESSURE TO FOLLOW. BIGGER DIFFERENCES ARISE TOWARDS NEXT WEEKEND...WITH THE ECMWF DEPICTING A STRONGER SOUTHERN STREAM MID LEVEL TROUGH MOVING THROUGH THE EASTERN USA THAN THE GFS. THE GFS PLACES IS EMPHASIS ON A STRONGER CUTOFF IN THE NORTHERN STREAM INSTEAD. HAVE HIGH CONFIDENCE WITH RESPECT TO MOST OF THE DETAILS THROUGH FRIDAY...WITH LOWER THAN NORMAL CONFIDENCE IN THE DETAILS FOR NEXT WEEKEND. DISCOUNTED SOME OF THE WRF-BASED GUIDANCE...INCLUDING THE 13/15Z SREF...AS THEY APPEAR TO BE TOO SLOW MOVING THE COLD FRONT TROUGH OUR REGION. GENERALLY FAVORED A CONSENSUS SOLUTION OTHERWISE...TO SMOOTH OVER THE MINOR DIFFERENCES THROUGH FRIDAY. GAVE MORE OF AN EDGE TO THE ECMWF GUIDANCE TOWARD NEXT WEEKEND...AS IT WAS PREFERRED BY WPC AND THE GFS CUTOFF LOOKS ANOMALOUSLY TOO POTENT. DETAILS... TUESDAY NIGHT AND WEDNESDAY MORNING... WE ANTICIPATE THE EVENING COMMUTE WILL BE THE MOST IMPACTED ACROSS DUE TO THE HEAVIER RAIN AND LOWER VISIBILITY. FINALLY THERE IS THE POSSIBILITY THAT A ISOLATED THUNDERSTORMS COULD DEVELOP ALONG THE LINE AT THE NOSE OF THE STRONG LOW-LEVEL JET. SIGNIFICANTLY COLDER AIR WILL ARRIVE VERY LATE TUESDAY NIGHT INTO WEDNESDAY AS THIS FRONT PASSES TO THE EAST...WITH ANY LINGERING SHOWERS MIXING WITH OR CHANGING BRIEFLY TO SNOW. VERY LITTLE IF ANY ACCUMULATION IS EXPECTED. MINIMUM TEMPERATURES TUESDAY NIGHT SHOULD BE 15-20 DEGREES LOWER THAN THOSE MONDAY NIGHT. MUCH OF SOUTHERN NEW ENGLAND WILL BE AROUND FREEZING EARLY WEDNESDAY MORNING. WEDNESDAY AFTERNOON INTO FRIDAY...STRONG COLD FRONT WILL MOVE OFFSHORE BY WEDNESDAY MORNING. FOLLOWED BY STRONG SUBSIDENCE FROM A HIGH PRESSURE. ANOTHER UPPER LEVEL DIGGING TROUGH WILL BEGIN TO DEVELOP ACROSS THE WESTERN USA...ALLOWING FOR A STRONG RIDGE TO DEVELOP ACROSS THE NORTH ATLANTIC. THIS RIDGE WILL PUSH THE BUILDING HIGH OVER NEWFOUNDLAND AND LABRADOR YIELDING TO EASTERLY FLOW FOR OUR REGION. OVERALL ANTICIPATE DRY WEATHER WITH WELL BELOW NORMAL TEMPERATURES THROUGH THURSDAY NIGHT. TEMPERATURES WILL BE MODERATING FRIDAY DUE TO A BUILDING THERMAL RIDGE TRYING TO PUSH INTO OUR REGION. HOWEVER ALONG THE IMMEDIATE MASS COASTLINE TEMPERATURES WILL STRUGGLE ON ALL THREE DAYS TO GET ABOVE 50F DUE TO THE ONSHORE WIND. SATURDAY AND SUNDAY...OPERATIONAL GUIDANCE AS WELL AS THEIR ENSEMBLES INDICATE A POTENTIAL LOW PRESSURE IMPACTING SOUTHERN NEW ENGLAND NEXT WEEKEND. THERE IS LITTLE AGREEMENT IN THE DETAILS...BUT WE COULD BE LOOKING AT A SOGGY WEEKEND. HOWEVER THIS FAR OUT...HAVE LOW CONFIDENCE.
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&& .AVIATION /06Z MONDAY THROUGH FRIDAY/...
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LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE IN TRENDS BUT MODERATE CONFIDENCE IN TIMING THROUGH 12Z/8 AM... FOG AND LOW CLOUDS DEVELOPING OVERNIGHT. PRIMARY LOCATION SHOULD BE ALONG THE SOUTH COAST AND ISLANDS OF RI AND MASS WITH CIGS BELOW 1000 FEET AND VSBYS 1-3 MILES. PATCHY MVFR VSBYS IN FOG POSSIBLE ELSEWHERE IN SOUTHERN NEW ENGLAND AS HUMIDITY INCREASES. STRONG WINDS JUST OFF THE SURFACE WITH OBSERVED 35-40 KNOTS. THIS WILL CAUSE LOW LEVEL WIND SHEAR. TODAY... AREAS OF FOG AND LOW CLOUDS WILL INITIALLY BRING IFR CONDITIONS ALONG THE SOUTH COAST...BUT THIS SHOULD DISSIPATE DURING THE MORNING. MOST AREAS WILL BE VFR WITH SOME MID AND HIGH CLOUDS. GUSTY SOUTH-SOUTHWEST WIND AT THE SURFACE WITH 30 KNOT WINDS. WINDS AT 2000-3000 FEET WILL INCREASE TO 40-50 KNOTS CONTINUING LOW LEVEL WIND SHEAR THROUGH THE DAY. TONIGHT... THE HUMID ENVIRONMENT WILL ALLOW CLOUDS WITH MVFR CIGS TO DEVELOP. SOME PATCHY FOG IS POSSIBLE WITH MVFR VSBYS. CONTINUED STRONG WINDS AT 2000 FEET WITH RESULTING LOW LEVEL WIND SHEAR. TUESDAY... COLD FRONT APPROACHES FROM THE GREAT LAKES WITH SHOWERS DEVELOPING FROM WEST TO EAST. A FEW SHOWERS MAY REACH THE CT VALLEY AROUND SUNRISE...THEN SPREAD EAST THROUGH THE MORNING. EXPECT IFR CIGS/VSBYS IN RAIN AND FOG FROM MIDDAY THROUGH EVENING. ALSO A POTENTIAL FOR SCATTERED OR ISOLATED THUNDERSTORMS TUESDAY AFTERNOON/EVENING. GUSTY SOUTH WINDS 30-35 KNOTS. CONTINUED STRONG WINDS AT 2000 FEET WITH LOW LEVEL WIND SHEAR. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY... TUESDAY NIGHT-WEDNESDAY...HIGH CONFIDENCE IN TRENDS...MODERATE CONFIDENCE IN TIMING. RAIN MAY MIX WITH LIGHT SNOW AND/OR SLEET ACROSS S NH/W MA BEFORE ENDING LATE TUE NIGHT OR WED MORNING. CONDITIONS SHOULD IMPROVE TO VFR FROM W-E DURING WED. THURSDAY AND FRIDAY...HIGH CONFIDENCE. VFR.
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&& .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SUNDAY NIGHT/...HIGH CONFIDENCE. TONIGHT...EXPECT S WINDS TO INCREASE OVERNIGHT. SEAS WILL ALSO BUILD. SMALL CRAFTS IN EFFECT. EXPECT AREAS OF FOG TO DEVELOP OVERNIGHT WITH LOCAL 1/4 MILE OR LESS ON THE SOUTHERN WATERS. PATCHY DRIZZLE ALSO TO DEVELOP. MONDAY...AREAS OF FOG AND DRIZZLE MAY LINGER INTO MID MORNING. EXPECT IMPROVING VSBYS BY MIDDAY OR EARLY AFTERNOON. SOUTH TO S-SW WINDS GUSTING UP TO 25-30 KT. OUTLOOK...MONDAY NIGHT THROUGH FRIDAY... MONDAY NIGHT...HIGH CONFIDENCE. FOG WILL DEVELOP ACROSS THE WATERS. STRONG SOUTHERLY WINDS WILL RESULT IN BUILDING SEAS. SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED. TUESDAY INTO THURSDAY...MODERATE CONFIDENCE. STRONG COLD FRONT WILL MOVE ACROSS THE WATERS TUESDAY INTO WEDNESDAY. EXPECTING GUSTY WINDS BEHIND THIS FRONT DUE TO STRONG COLD AIR ADVECTION. THERE IS A LOW PROBABILITY OF GALES TUESDAY EVENING INTO THE OVERNIGHT HOURS. SEAS WILL BUILD FURTHER IN RESPONSE. WINDS START TO RELAX LATE WEDNESDAY INTO THURSDAY...BUT SEAS WILL TAKE QUITE A BIT LONGER. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED. FRIDAY...HIGH CONFIDENCE. WINDS CONTINUE TO DIMINISH BELOW 25 KT. ROUGH SEAS LINGER ACROSS THE OUTER COASTAL WATERS. && .HYDROLOGY... WATER BEING ROUTED DOWNSTREAM FROM THE UPPER CONNECTICUT RIVER BASIN HAS RESULTED IN MINOR FLOODING AT BOTH HARTFORD AND MIDDLE HADDAM CT. FLOOD WARNINGS CONTINUE FOR THE CT RIVER AT THESE LOCATIONS. THOSE WITH INTERESTS ALONG LOWER REACHES OF CT RIVER SHOULD PAY ATTENTION TO THE LATEST FORECASTS AND CURRENT WATER LEVELS. && .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ230>237-250-251-254>256.
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&& $$ SYNOPSIS...WTB/BELK NEAR TERM...WTB SHORT TERM...EVT LONG TERM...BELK AVIATION...WTB/BELK MARINE...BELK/EVT HYDROLOGY...

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