Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 012307 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 707 PM EDT SUN MAY 1 2016 .SYNOPSIS...
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A WARM FRONT APPROACHES FROM THE SOUTH TONIGHT WITH WAVES OF LOW PRESSURE RIDING ALONG IT. THE FRONT LIFTS INTO THE REGION ON MONDAY...THEN SLIDES BACK TO THE SOUTH AND STALLS MONDAY NIGHT ALONG THE SOUTH COAST. LOW PRESSURE TRAVELS UP ALONG THE FRONT TUESDAY. THIS WILL BRING ANOTHER PERIOD OF RAIN TO THE REGION. YET ANOTHER LOW PRESSURE AREA DROPS THROUGH THE GREAT LAKES WEDNESDAY AND STALLS OVER THE WATERS SOUTH OF NEW ENGLAND FOR THURSDAY THROUGH THE WEEKEND.
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&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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7 PM UPDATE... SCATTERED SHOWERS ACROSS THE AREA HAVE BEEN WEAKENED BY THE DRY AIR NEAR THE SURFACE. EVENING DEW POINT DEPRESSIONS RANGED FROM 5 DEGREES IN THE SOUTH TO 25 DEGREES IN THE NORTH. AS A RESULT PCPN AMOUNTS TODAY HAVE RANGED FROM A TRACE TO ONE- TENTH INCH...MOSTLY CLOSER TO THE LOWER END OF THE RANGE. SURFACE LOW OFF ATLANTIC CITY WILL MOVE PAST THE SOUTH COAST TONIGHT. AS IT MOVES TO THE EAST OF US THE MAIN AREA OF SHOWERS WILL ALSO MOVE EAST. MOST SHOWERS SHOULD END 04Z-06Z. FOG AND DRIZZLE IS POSSIBLE ALONG THE SOUTH COAST WHERE DEPRESSIONS ARE LOWEST AND THE AIR CLOSEST TO SATURATION. FARTHER NORTH AND INLAND WHERE THE AIR IS DRIEST...FOG WILL BE RATHER DIFFICULT. BUT THERE MAY BE SOME PATCHES FORMING AFTER MIDNIGHT. OVERNIGHT TEMPS WILL DROP DOWN INTO THE 40S...WITH UPPER 40S ACROSS THE MASS EAST COAST AS WINDS REMAIN OUT OF THE EAST. PREVIOUS DISCUSSION...SCATTERED SHOWERS CONTINUE TO MOVE ACROSS THE REGION THIS AFTERNOON AS LOW LEVELS CONTINUE TO SATURATE. HAD REPORTS OF SOME SLEET MIXED IN WITH LIGHT SHOWERS. BELIEVE THE CHANCE WILL CONTINUE TO TONIGHT UNTIL 850 MB TEMPS WARM ABOVE 0C. OTHERWISE CHILLY DAY ACROSS THE REGION AS TEMPERATURES STAY IN THE LOW TO MID 50S. SURFACE LOW WILL MOVE SOUTH OF THE REGION EARLY THIS EVENING DRAGGING A WARM FRONT OUT AHEAD OF IT. APPROACHING UPPER LEVEL WAVE ALONG THE FRONT WILL SPREAD STEADY RAIN ACROSS THE SOUTH COAST THIS EVENING. PRECIP WILL COME TO AN END BETWEEN 04-06Z AS MID-LEVEL DRY MOVES INTO THE AREA BETWEEN SYSTEMS. HOWEVER LOW LEVELS ARE QUITE SATURATED PER MODEL CROSS SECTIONS RESULTING IN FOG AND DRIZZLE OVERNIGHT ACROSS THE ENTIRE CWA.
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&& .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... MONDAY INTO MONDAY NIGHT... COMPLEX SYSTEM TOMORROW AND INTO TOMORROW NIGHT. SEVERAL WAVES WILL MOVE THROUGH THE SOUTHWEST UPPER LEVEL FLOW RESULTING IN PERIODS OF SHOWERY WEATHER. STILL SOME UNCERTAINTY ON THE EXACT TIMING AND PLACEMENT OF THE HEAVIEST RAINFALL. FIRST SHORTWAVE WILL PUSH A LOW PRESSURE SYSTEM EITHER OVER OR JUST NORTH AND WEST OF SNE...WHERE THE BETTER DYNAMICS ARE LOCATED. HIGHEST CONFIDENCE FOR PRECIP WILL BE NORTH OF ROUTE 2 AS HEAVIEST PRECIP WILL REMAIN ACROSS NORTHERN NEW ENGLAND BUT CANNOT RULE OUT THE POTENTIAL FOR PRECIP TO REACH SOUTH OF THE PIKE. THIS LOW MAY LIFT THE STALLED FRONT NORTHWARD RESULTING IN TEMPS WARMING INTO THE LOW 60S ACROSS THE SOUTH COAST. BUT OVERALL CONFIDENCE IS LOW AS PLACEMENT OF THE FRONT IS SPREAD AMONGST GUIDANCE...WITH THE GFS BRINGING THE FRONT WELL INTO SOUTHERN NEW ENGLAND WHILE THE NAM AND EC KEEP IS CLOSER TO THE SOUTH COAST/PIKE. ANOTHER BREAK IN THE PRECIP LATE MONDAY AFTERNOON AS WEAK RIDGING MOVES INTO THE REGION. PRECIP LOOKS TO PICK BACK UP AGAIN AS ANOTHER SHORTWAVE PASS THROUGH THE FLOW. THIS WAVE WILL SPREAD PRECIP FROM SW TO NE ALONG THE STALLED FRONTAL SYSTEM...DEPENDING ON WHERE IT STALLS DURING THE DAY. RIGHT NOW HAVE HIGHEST CONFIDENCE ACROSS THE SOUTH COAST FOR MEASURABLE PRECIP AS HIGH PRESSURE BUILDS IN ACROSS NORTHERN NEW ENGLAND. STILL PLENTY OF ROOM FOR THE WAVE TO BRING PRECIP NORTHWARD. && .LONG TERM /TUESDAY THROUGH SUNDAY/... BIG PICTURE... LONGWAVE PATTERN MAINTAINS A TROUGH OVER THE EASTERN USA THROUGH THE COMING WEEK. THREE SHORTWAVES MOVE THROUGH THIS PATTERN TUESDAY THROUGH THURSDAY. THE THIRD SHORTWAVE CARVES OUT A CLOSED LOW OVER THE MID ATLANTIC STATES WHICH THEN DRIFTS EAST OVER THE WATERS SOUTH OF NEW ENGLAND LATE WEEK. THIS ENTIRE PERIOD WILL FEATURE CLOUDS AND SHOWERS WITH A SLOW WARMING TREND. THE DAILIES... TUESDAY... AS NOTED...SHORTWAVE RACES ACROSS NEW ENGLAND. THE ASSOCIATED JET GENERATES A WAVE ALONG THE COLD FRONT MOVING TO OUR SOUTH...AND THAT WAVE MOVES UP THE FRONT TUESDAY. THIS WAVE FOCUSES A 35-KNOT SOUTH JET TO OVERRUN THE LOW LEVEL NORTHEAST FLOW OVER NEW ENGLAND...RESULTING IN LOW LEVEL LIFT THAT MOVES ACROSS DURING THE MORNING. THE BEST LIFT WILL BE ACROSS THE SOUTHERN COAST AND ISLANDS...WE WILL FEATURE THE HIGHEST POPS IN THIS AREA. THE NORTHEAST FLOW SHOULD KEEP TEMPS IN THE UPPER 40S AND 50S WITH WARMEST TEMPS IN WESTERN MASS/CT. CLOUDS AND NORTHEAST FLOW WILL KEEP TUESDAY NIGHT TEMPS IN THE 40S. WEDNESDAY... SIGNS IN THE UPPER DATA THAT ANOTHER SHORTWAVE...THIS ONE FROM THE SOUTHERN PLAINS...CRUISES PAST AND GENERATES ANOTHER WAVE ON THE FRONT. LESS OF A FOCUSED LOW LEVEL JET AND RESULTING LIFT...BUT FORCING FROM THE UPPER JET SHOULD BE ENOUGH FOR ANOTHER CHANCE OF SHOWERS. THIS WILL BE IN TWO PARTS. ONE AREA WILL BE ALONG THE CAPE AND ISLANDS NEAREST THE OFFSHORE WAVE...THE SECOND WILL BE IN THE INTERIOR UNDER THE RIGHT ENTRANCE REGION OF THE UPPER JET. THURSDAY THROUGH SUNDAY... CLOSED UPPER LOW MOVES INTO PLACE OVER THE MID ATLANTIC STATES WITH SURFACE LOW OFF DELMARVA. UPPER FLOW IS SOUTHERLY BRINGING MILDER AIRMASS THROUGH THE WEEKEND. THE UPPER JET IN THAT SOUTH FLOW WILL ALIGNED JUST EAST OF NEW ENGLAND WITH OUR AREA UNDER THE LEFT EXIT REGION OF THE JET. THIS SHOULD ALLOW FORCING OF SCATTERED OR WIDELY SCATTERED SHOWERS THROUGH THE WEEKEND. WE TREND MAX TEMPS A LITTLE MILDER EACH DAY BUT MAINTAIN MINS IN THE 40S EACH NIGHT. && .AVIATION /00Z MONDAY THROUGH FRIDAY/...
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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 MONDAY NIGHT/...MODERATE CONFIDENCE. MAINLY VFR CONDITIONS LOWERING TO MVFR TONIGHT. CONDITIONS WILL CONTINUE TO LOWER TO IFR AFTER 06Z AS STRATUS...PATCHY FOG AND DRIZZLE DEVELOPS. IFR CONDITIONS WILL LINGERING INTO EARLY MON BEFORE CONDITIONS IMPROVE TO MVFR. PERIODS OF RAIN AND DRIZZLE THROUGH THE PERIOD. KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN DETAILS. KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN DETAILS. OUTLOOK /TUESDAY THROUGH FRIDAY/... MODERATE CONFIDENCE TUESDAY-WEDNESDAY... IFR TUESDAY IN AREAS OF RAIN AND FOG. BEST CHANCE FOR THIS WILL BE SOUTH OF THE MASS PIKE. THURSDAY-FRIDAY...AREAS OF MVFR/IFR IN SHOWERS.
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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 MONDAY NIGHT/...HIGH CONFIDENCE. OVERALL QUIET BOATING WEATHER AS WINDS SHIFT MORE TO A EASTERLY DIRECTION. PERIODS OF RAIN...DRIZZLE AND FOG WILL PERSIST THROUGH THE ENTIRE PERIOD. SEAS WILL BUILD ACROSS THE SOUTH COAST TONIGHT TO 5 FEET RESULTING IN SCA. AS THE WINDS TURN MORE NORTHEASTERLY TOMORROW...SEAS ALONG THE EASTERN OCEAN WATERS WILL PICK UP ABOVE 5 FEET. SCA WILL CONTINUE FOR THOSE WATERS AS WELL INTO MONDAY NIGHT. OUTLOOK /TUESDAY THROUGH FRIDAY/... MODERATE CONFIDENCE SURFACE FLOW IS EASTERLY...MOSTLY NORTHEAST...THROUGH THE PERIOD WITH SPEEDS 15 KNOTS OR LESS. EVEN WITH A PERSISTENT DIRECTION SEA HEIGHTS ON MOST OF THE WATERS WILL REMAIN BELOW 5 FEET. THE BEST CHANCE OF 5 FOOT SEAS WILL BE ON THE OUTER WATERS WHERE HEIGHTS WILL VARY BETWEEN 3 AND 5 FEET. VSBYS WILL BE POOR AT TIMES TUESDAY WITH RAIN AND FOG. VSBYS WEDNESDAY THROUGH FRIDAY MAY LOWER AT TIMES IN SHOWERS. && .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 8 AM MONDAY TO 8 AM EDT TUESDAY FOR ANZ250-254. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 5 PM MONDAY TO 2 AM EDT TUESDAY FOR ANZ251. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT MONDAY FOR ANZ256.
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&& $$ SYNOPSIS...WTB/DUNTEN NEAR TERM...WTB/DUNTEN SHORT TERM...DUNTEN LONG TERM...WTB AVIATION...WTB/DUNTEN MARINE...WTB/DUNTEN

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