Area Forecast Discussion
Issued by NWS Boston, MA

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656 FXUS61 KBOX 031834 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 134 PM EST WED FEB 3 2016 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL MOVE ACROSS THE REGION TONIGHT. AHEAD OF THE FRONT...EXPECT WIDESPREAD RAIN WITH POSSIBLY A RUMBLE OF THUNDER. THE COLD FRONT WILL STALL JUST OFF THE COAST THURSDAY AND LINGER THERE UNTIL FRIDAY AFTERNOON. HIGH PRESSURE BRINGS DRY WEATHER SATURDAY AND SUNDAY. A DEVELOPING COASTAL STORM MAY AFFECT THE REGION BY TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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130 PM UPDATE...RAIN HAS BEEN RELATIVELY SLOW TO PROGRESS EASTWARD THROUGH SOUTHERN NEW ENGLAND. RAIN REMAINS ROUGHLY WEST OF A BEVERLY MA TO WORCESTER MA TO HARTFORD CT LINE. CURRENT MOVEMENT TO THE NORTH AND EAST SHOWS VERY LITTLE EASTWARD PROGRESSION. RAINFALL: AS THE COLD FRONT APPROACHES FROM THE WEST LATE THIS AFTERNOON WE ANTICIPATE HEAVY RAINFALL. HIGH PWATS AROUND 1.3 INCHES...ABOUT 4 TO 6 SD ABOVE NORMAL...AND A STRONG SOUTHERLY LOW-LEVEL JET...3-4 SD ABOVE NORMAL...IN CONJUNCTION WITH A HIGH AMPLITUDE LONGWAVE TROF TAPPING INTO GULF MOISTURE...ALL POINT TOWARDS THE POTENTIAL OF A GOOD SLUG OF RAINFALL DURING THE AFTERNOON. FORECAST RAINFALL AT THIS TIME IS 1 TO 1.5 INCHES. ANTICIPATE HEAVIEST RAINFALL WILL OCCUR BETWEEN 21-00Z. WIND: 925 MB JET INCREASES BETWEEN 60-70 KTS AHEAD OF THE APPROACHING COLD FRONT. LAPSE RATES ARE POOR ACROSS THE REGION LIMITING ANY MIXING POTENTIAL. SOUNDINGS ALSO SUPPORT 50-60 KTS BETWEEN 2 AND 3 KFT WITH AN INVERSION. HOWEVER...IF HEAVIER RAIN IS ABLE TO TAP INTO THE LLJ...IT COULD MIX DOWN STRONG GUSTY WINDS. WIND GUSTS COULD REACH BETWEEN 30-40 MPH ACROSS THE COASTAL PLAIN LATE THIS AFTERNOON/EVENING. TEMPERATURES: TEMPS HAVE BEEN STRUGGLING TO GET TO 50 THIS AFTERNOON AS THE WARM FRONT SLOWLY PUSHES NORTHWARD. THERE ARE EVEN STILL TEMPERATURES IN THE 30S ACROSS NORTHERN MASSACHUSETTS. APPEARS THAT THE WARMEST TEMPS WILL OCCUR AFTER 21-00Z AHEAD OF THE COLD FRONTAL PASSAGE.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... TONIGHT... COLD FRONT WILL BEGIN TO PUSH THROUGH THE REGION DURING THE EVENING AND INTO THE OVERNIGHT HOURS. AS MENTIONED BEFORE...APPEARS THAT THE COLD FRONT WILL SLOW DOWN BY EARLY THURSDAY AM THANKS TO NORTH ATLANTIC RIDGE. BULK OF THE PRECIP WILL BE ONGOING AROUND 00Z BUT WILL BEGIN TO PUSH OFFSHORE BY 06Z. PRECIP WILL LINGER ACROSS THE CAPE AND ISLANDS TOWARDS THE MORNING HOURS ON THURSDAY. HAVE CONTINUED THE MENTION FOR THUNDER DURING THE LATE AFTERNOON INTO THE EVENING HOURS AS GUIDANCE CONTINUES TO INDICATE ELEVATED INSTABILITY. THE POTENTIAL FOR CONVECTION WILL ALSO INCREASE THE RAINFALL AMOUNTS AS WELL AS BRING DOWN ANY GUSTY WINDS. LLJ WILL CONTINUE TO STRENGTHEN OVERNIGHT AHEAD OF THE COLD FRONTAL PASSAGE. IN FACT 925 MB JET STRENGTHENS BETWEEN 60-70 KTS. AGAIN SOUNDINGS CONTINUE TO SHOW STRONG INVERSION EVEN OVER THE WATERS. GUSTY WINDS WILL CONTINUE ACROSS THE REGION...BETWEEN 20-30 MPH. HOWEVER GUSTS WILL BEGIN TO DISSIPATE AFTER 06Z. FINALLY TEMPERATURES MAY WARM RIGHT AROUND 00-03Z WHEN THE WARMEST 925 MB TEMPS OCCUR. USED A NON-DIURNAL TREND TONIGHT FOR TEMPERATURES AS CAA WONT TRULY TAKE PLACE UNTIL AFTER 06-09Z. && .LONG TERM /THURSDAY THROUGH WEDNESDAY/... BIG PICTURE... LONGWAVE SCALE SHOWS A TROUGH OVER THE MIDWEST AND RIDGE ALONG THE PACIFIC COAST LATE THIS WEEK...ALL SHIFTING EAST OVER THE WEEKEND AND EARLY NEXT WEEK. ONE RIDGE LINGERS OVER THE WEST ATLANTIC WHILE ANOTHER RIDGE BUILDS OVER THE WESTERN USA. MEANWHILE MULTIPLE SHORTWAVES MOVE THROUGH A TROUGH OVER THE MIDWEST. THE SECOND SHORTWAVE MOVES OFF THE CAROLINA COAST SUNDAY...SWINGING WELL OFFSHORE AND THEN NORTH INTO NOVA SCOTIA. THE THIRD SHORTWAVE AMPLIFIES THE MIDWEST TROUGH EARLY NEXT WEEK AND BRINGS THE FLOW EAST OF THE TROUGH AXIS UP THE EAST COAST. THIS PATTERN SUGGESTS LINGERING SHOWERS ALONG THE SOUTH/EAST NEW ENGLAND COASTLINE THURSDAY-FRIDAY...WITH POTENTIAL FOR A MORE SUBSTANTIAL STORM MONDAY NIGHT-TUESDAY. TEMPERATURES COOL BACK TO SEASONABLE LEVELS AS THE UPPER TROUGH SHIFTS EAST. THE DAILIES... THURSDAY-FRIDAY...MODERATE CONFIDENCE. UPPER FLOW REMAINS SOUTHWEST THROUGH FRIDAY AFTERNOON. SHORTWAVE MOVING THROUGH THE UPPER TROUGH THEN CROSSES SOUTHERN NEW ENGLAND AND TURNS THE UPPER FLOW WESTERLY. THE SOUTHWEST FLOW WILL ALIGN WITH AND STALL THE COLD FRONT JUST OFFSHORE UNTIL THE SHORTWAVE MOVES THROUGH. MEANWHILE THE LEFT ENTRANCE REGION OF THE UPPER JET WILL MOVE OVERHEAD DURING THURSDAY AND EARLY FRIDAY. THIS WILL INDUCE A WAVE ALONG THE STALLED FRONT...PUSHING THE PCPN SHIELD BACK ACROSS EASTERN MASS AND RI. TEMPS FOR THE MOST PART WILL SUPPORT RAIN RATHER THAN SNOW...BUT COOLING EARLY FRIDAY MORNING MAY BRING A PERIOD OF SNOW OR MIXED RAIN/SNOW THAT COULD LEAVE A COATING TO AN INCH. SATURDAY-SUNDAY...MODERATE CONFIDENCE. HIGH PRESSURE BUILDS OVER THE REGION FRIDAY NIGHT AND SATURDAY BRINGING DRY AND SEASONABLY COOL WEATHER. A SECOND SHORTWAVE WILL MOVE ACROSS THE REGION SUNDAY. THIS WILL DRIVE A CLIPPER LOW ACROSS EASTERN CANADA AND A COLD FRONT ACROSS NEW ENGLAND. MOST OF THE MOISTURE AND DYNAMIC SUPPORT WILL STAY WELL TO OUR NORTH. SO EXPECT A DRY FROPA WITH PATCHY CLOUDS. MONDAY-TUESDAY...LOW CONFIDENCE. TWO SHORTWAVES CURRENTLY OVER THE PACIFIC WILL GO FEET-DRY...THE FIRST TONIGHT AND THE SECOND FRIDAY NIGHT. THE FIRST SHORTWAVE FORMS LOW PRESSURE ALONG THE SOUTHEAST USA COAST AND THEN CARRIES IT WELL OFFSHORE SUNDAY NIGHT-MONDAY. ITS MAIN EFFECT ON NEW ENGLAND WOULD BE TO COMBINE WITH CANADIAN LOW PRESSURE TO BRING AN EAST FLOW ONSHORE OVER SOUTHERN NEW ENGLAND WITH CLOUDS AND POSSIBLY SOME LIGHT PCPN. THE SECOND SHORTWAVE DIVES ACROSS THE MIDWEST AND DIGS A DEEP TROUGH OVER THE EASTERN USA BY MONDAY. BOTH THE GFS AND ECMWF SHOW A PRIMARY SURFACE LOW OVER THE MIDWEST AND ANOTHER DEVELOPING COASTAL LOW TUESDAY. THIS WOULD BRING PCPN INTO SOUTHERN NEW ENGLAND PRIMARILY ON TUESDAY. THE FASTEST MODEL QPF REACHES OUR AREA AFTER MIDNIGHT AND MAINLY ON TUESDAY AND THE SLOWER ONSET ON TUESDAY. WITH HIGH PRESSURE AND COLD AIR OVER EASTERN CANADA THERE IS POTENTIAL FOR INITIAL SNOW WITH A CHANGE TO RAIN IN THE COASTAL PLAIN. IN ANY CASE...THAT/S A LOT OF DETAILS FOR A SYSTEM STILL OVER THE PACIFIC OCEAN. BECAUSE IT IS SO FAR OUT IN SPACE AND TIME...CONFIDENCE REMAINS LOW. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY/...MODERATE CONFIDENCE. THROUGH 00Z...HAVE A WIDE RANGE OF CONDITIONS ACROSS THE REGION WITH VFR CIGS/VSBYS ACROSS MUCH OF SOUTHEASTERN MASSACHUSETTS... MVFR CIGS ACROSS RI/EASTERN CT/CENTRAL MA...AND IFR CIGS IN WESTERN MA/CT. EXPECT CONDITIONS TO CONTINUE TO DETERIORATE THROUGH THIS EVENING AS RAIN OVERSPREADS SNE. ISOLD TSRA PSBL AFTER 21Z INTO TONIGHT ESP ALONG THE SOUTH COASTS OF RI/MA. SE WIND GUSTS 25-35 KTS. LLWS IS LIKELY DUE TO INVERSION. TONIGHT...MVFR/IFR CONDITIONS CONTINUE WITH RAIN SLOWLY COMING TO AN END FROM NORTHWEST TO SOUTH EAST. RAIN WILL LIKELY CONTINUE THROUGH THE NIGHT ALONG THE SOUTH COAST...CAPE...AND ISLANDS. WILL SEE SOME IMPROVEMENT TO VFR ACROSS THE NORTHWESTERN TERMINALS TOWARDS 12Z. POTENTIAL FOR ISOLD TSRA ALONG THE SOUTH COASTS OF RI/MA CONTINUES. THURSDAY...QUICK IMPROVEMENT TO VFR ACROSS THE REMAINDER OF THE AREA THROUGH 15Z THOUGH CLOUDS WILL LINGER THROUGH MUCH OF THE DAY. KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN TIMING OF WINDS/PRECIP. KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN TIMING OF WINDS/PRECIP. OUTLOOK /THURSDAY NIGHT THROUGH MONDAY/...MODERATE CONFIDENCE THURSDAY NIGHT-FRIDAY... VFR...EXCEPT MVFR/IFR CAPE COD/ISLANDS/SOUTH COAST IN RAIN AND SNOW SHOWERS. SATURDAY-SUNDAY...VFR. SOUTHWEST WINDS GUSTING TO 20 KNOTS SATURDAY AND NORTHWEST WINDS GUSTING TO 20 KNOTS SUNDAY.
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&& .MARINE...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE. BOTH WIND AND SEAS WILL BEGIN TO BUILD THIS MORNING AHEAD OF A STRONG WEATHER SYSTEM PUSHING A COLD FRONT ACROSS THE WATERS BY TONIGHT. STRONG SOUTHERLY LLJ WILL HELP SEAS BUILD CLOSE TO 8-10 FEET ACROSS THE OUTER WATERS. THIS POTENT JET WILL ALSO ALLOW FOR SOUTHERLY GALE FORCE GUSTS. HIGHEST CONFIDENCE IS ACROSS EASTERN WATERS. WENT AHEAD AND ISSUED A GALE WARNING FOR THE SOUTHERN WATERS AS WELL AS GUSTS WILL BE 35 KTS FOR SEVERAL HOURS DURING THE AFTERNOON/EVENING HOURS. SCA FOR THE REMAINDER OF THE WATERS. THIS SYSTEM WILL BRING HEAVY RAIN ACROSS THE WATERS LIMITING VSBYS...THERE IS ALSO THE POTENTIAL FOR EMBEDDED THUNDER THIS EVENING. OUTLOOK /THURSDAY THROUGH MONDAY/...MODERATE CONFIDENCE... THURSDAY-FRIDAY...WINDS BELOW 20 KNOTS EACH DAY. SEAS 5-7 FEET ON THE RI WATERS THURSDAY AND THE OUTER WATERS BOTH DAYS. SMALL CRAFT ADVISORY MAY BE NEEDED FOR THOSE ROUGH SEAS. SATURDAY-SUNDAY...SOUTHWEST WINDS BELOW 25 KT SATURDAY. A COLD FRONT MOVES THROUGH ON SUNDAY. WIND SHIFT TO A NORTH-NORTHWEST WIND WITH GUSTS 25-30 KNOTS BY EVENING. SEAS BELOW 5 FEET BOTH DAYS. A SMALL CRAFT ADVISORY MAY BE NEEDED LATE SUNDAY.
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&& .CLIMATE... RECORD HIGHS FOR FEB 3RD - 4TH... BOS...59/1991 - 64/1991 BDL...61/1991 - 64/1991 PVD...60/1991 - 66/1991 ORH...57/1909 - 61/1991 && .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. MA...NONE. RI...NONE. MARINE...GALE WARNING UNTIL 4 AM EST THURSDAY FOR ANZ231-232-255-256. SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR ANZ233>235- 237. SMALL CRAFT ADVISORY UNTIL 4 AM EST THURSDAY FOR ANZ230-236. GALE WARNING UNTIL 4 AM EST THURSDAY FOR ANZ250-251-254.
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&& $$ SYNOPSIS...WTB/DUNTEN NEAR TERM...DUNTEN/RLG SHORT TERM...DUNTEN LONG TERM...WTB AVIATION...WTB/RLG MARINE...WTB/DUNTEN CLIMATE...STAFF

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