Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 241523 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1123 AM EDT SUN MAY 24 2015 .SYNOPSIS... SOUTHWEST WINDS WILL BRING WARMER AIR INTO SOUTHERN NEW ENGLAND BEGINNING TODAY. WARM AND MUGGY CONDITIONS BUILD INTO MIDWEEK AHEAD OF INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS. COULD REMAIN WET ALL THE WAY THROUGH INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... 11 AM UPDATE... OTHER THAN A FEW BRIEF PUFFY CUMULUS CLOUDS THAT DEVELOPED AND DISSIPATED ACROSS N CENTRAL AND NE MA OVER THE LAST FEW HOURS... SKIES HAVE BEEN MAINLY CLEAR THROUGH LATE THIS MORNING. PRETTY GOOD W-SW FLOW IN PLACE ESPECIALLY NEAR THE COAST AND...WITH GOOD MIXING...NOTING GUSTS UP TO AROUND 25 KT MAINLY OVER THE NEAR SHORE WATERS. TEMPS HAVE RESPONDED NICELY AS WELL. READINGS AT 15Z MAINLY IN THE LOWER-MID 70S EXCEPT LOWER-MID 60S ALONG THE IMMEDIATE S COAST WITH THE ONSHORE FLOW. NEAR TERM FORECAST IN GOOD SHAPE BUT HAVE UPDATED TO BRING CONDITIONS CURRENT. PREVIOUS DISCUSSION... EXPECT WINDS TO DIMINISH TOWARD EVENING AS BOUNDARY LAYER BEGINS TO STABILIZE...ASIDE FROM S COAST WHERE IT WILL TAKE A BIT LONGER. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM MONDAY/... SW FLOW PERSISTS TONIGHT AND MON AS MODELS BRING WARM FRONT THROUGH UPSTATE NY AND NORTHERN NEW ENGLAND...WHICH SHOULD BE FOCUS FOR ANY SHOWERS OR STORMS. 00Z GFS SEEMS OVERDONE IN BRINGING PRECIPITATION THIS FAR E...ESPECIALLY GIVEN RISING 500 MB HEIGHTS AND LACK OF DEEP MOISTURE OR APPRECIABLE LIFT OVER OUR AREA. AS A RESULT WE DO EXPECT TO SEE AN INCREASE IN CLOUDINESS /MAINLY MID LEVEL/ WITH PERHAPS AN ISOLATED SHOWER OR STORM MON ACROSS NW MA. LOWS WILL DROP BACK INTO 50S TONIGHT AND ONCE AGAIN CLIMB INTO 70S/LOWER 80S MON EXCEPT 60S ON S COAST...CAPE COD AND ISLANDS. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... */ HIGHLIGHTS... - WARM MUGGY AND DRY TUESDAY INTO TUESDAY NIGHT - INCREASING SHOWER / THUNDERSTORM POTENTIAL WEDNESDAY - THURSDAY - PERHAPS A LULL IN THE WEATHER ON FRIDAY - LOOKING POTENTIALLY WET AND ACTIVE FOR NEXT WEEKEND */ DISCUSSION... FORECAST GUIDANCE STRUGGLING WITH BOTH STRENGTH AND INFLUENCE OF RIDGING ACROSS THE E-CONUS AND SUBSEQUENT ALLOWANCE OF N-STREAM ENERGY TO SLIP S. AS BEEN THE TREND THE LAST SEVERAL DAYS...THE RIDGE DEAMPLIFIES SUBSEQUENT TO THE FLATTENING MARITIME FLOW AND RETROGRADING LOW PULLING COOLER AIR CYCLONICALLY SW. THERE IS NOT MUCH SUPPORT IN MAINTAINING A RIDGING PATTERN. SO EXPECTATION THRU THE WEEK IS FOR N-STREAM ENERGY TO HAVE THE ABILITY TO TROUGH S SHIFTING THE CONVERGENT SW-FLOW ALONG WITH THETA-E / INSTABILITY AXES INTO NEW ENGLAND. ANTICIPATING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS ESP ACROSS THE INTERIOR. SHEAR NOT IMPRESSIVE COMPARED TO INSTABILITY...SO ECHO PRIOR FORECASTER WITH CONCERN OF HEAVY RAIN AS A THREAT. WILL KEEP TUESDAY INTO TUESDAY NIGHT DRY. THOUGH THE WARM AND MUGGY CONDITIONS POTENTIALLY EXCEEDING CONVECTIVE-TEMPERATURES ACROSS THE N AND W MAY YIELD THUNDERSTORMS THAT WOULD PUSH E WITH THE STEERING FLOW...FEEL DRY AIR AND SUBSIDENCE WILL ERODE / WEAKEN ANY ACTIVITY INTO NEW ENGLAND. THE BETTER FORCING AND SW-CONVERGENT FLOW OF MOIST- INSTABILITY AXES IS WELL NW AT THIS TIME. LOW-90S POSSIBLE ACROSS INTERIOR VALLEYS. EXPECT MARINE STRATUS / FOG ALONG THE S/SE-COAST PERHAPS DEVELOPING AS EARLY AS MONDAY NIGHT INTO TUESDAY. WEDNESDAY INTO THURSDAY THE RIDGE WEAKENS ALLOWING THE FAVORABLE ENVIRONMENT FOR SHOWERS AND THUNDERSTORMS TO SHIFT SE. INCREASING POP CHANCES ACCORDINGLY. SOME QUESTION AS TO HOW EFFECTIVELY WE CAN DESTABILIZE. COULD BE ISSUES WITH CLOUD COVER SHOULD ACTIVITY ON WEDNESDAY EXPECTED MAINLY W DRIFTS E OVERNIGHT INTO THURSDAY. WILL CONTINUE WITH WARM AND MUGGY CONDITIONS. LOW-90S POSSIBLE ACROSS INTERIOR VALLEYS ESPECIALLY WEDNESDAY. CONTINUED POTENTIAL OF MARINE STRATUS / FOG ALONG THE S/SE-COAST. FRIDAY COULD BE A LULL WITH DRY AIR AND HIGH PRESSURE IN PLACE IF YOU BELIEVE THE GFS OVER THE ECMWF. LOW CONFIDENCE. CONSENSUS OF FORECAST GUIDANCE HAS ANOTHER WAVE N PUSHING A FRONTAL BOUNDARY S AND STALLING OVER NEW ENGLAND MAKING IT A FOCUS FOR A PROLONGED PERIOD OF WET-WEATHER. HAVE SOME DOUBTS WITH CONVERGENT MASS-FIELDS N AS SURFACE REFLECTIONS FOCUS S WITH THERMAL-INSTABILITY-MOIST AXES. SHOULD HAVE A BETTER IDEA AS WE GET CLOSER IN TIME. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE. 15Z UPDATE... VFR WITH SW FLOW. 20-25 KT GUSTS INTO EARLY THIS EVENING...MAINLY NEAR COASTAL TERMINALS. CIGS AOA 060 LATE TONIGHT AND MONDAY. LOW PROB OF AN ISOLATED -SHRA/TSRA POSSIBLE ACROSS NW MA MONDAY. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY NIGHT... MONDAY NIGHT INTO TUESDAY NIGHT...MODERATE CONFIDENCE. VFR. BREEZY SW-FLOW WITH 20-25 KT GUSTS. IFR STRATUS / FOG POSSIBLE ACROSS THE S/SE-COAST. WEDNESDAY INTO THURSDAY NIGHT...MODERATE CONFIDENCE. INCREASING CHANCES FOR -SHRA / TSRA. TEMPO MVFR-IFR WITH ANY ACTIVITY. SW-FLOW WITH 20 KT GUSTS AT TIMES. IFR STRATUS / FOG REMAINS POSSIBLE ACROSS THE S/SE-COAST. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE. 11 AM UPDATE... NOTING SEVERAL REPORTS FROM THE FERRIES OUT TO THE ISLANDS OF GUSTS TO AROUND 25 KT AND SEAS UP TO 5 FT...MAINLY ON BUZZARDS BAY AND VINEYARD SOUND ON THE SW WIND. SEAS WILL ALSO BUILD TO AROUND 5 FT ON THE SOUTHERN OPEN WATERS MAINLY S OF NANTUCKET/MARTHAS VINEYARD THIS AFTERNOON. SMALL CRAFT CONTINUES. PREVIOUS DISCUSSION... GUSTS MAY BE MARGINAL ALONG E MA COAST INCLUDING BOS HARBOR BUT DECIDED TO INCLUDE THESE AREAS DUE TO INCREASE IN HOLIDAY RECREATIONAL TRAFFIC. WINDS AND SEAS DIMINISH TONIGHT. SW FLOW PERSISTS MON BUT GUSTS ARE EXPECTED TO REMAIN BELOW SCA. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY NIGHT... MODERATE CONFIDENCE. PERSISTENT SW-FETCH WITH GUSTS AROUND 20-25 KTS AT TIMES. WAVE HEIGHTS IN EXCESS OF 5-FEET MOSTLY ON THE OUTER WATERS BUT GETTING INTO THE S INNER SOUNDS. FOG ANTICIPATED LENDING TO VISIBILITY RESTRICTIONS. && .FIRE WEATHER... 11 AM UPDATE... DEWPTS AWAY FROM THE S COAST ARE A BIT LOWER THAN FORECAST...DOWN TO THE LOWER-MID 30S. WITH TEMPS IN THE LOWER-MID 70S...NOTING MIN RH VALUES DOWN TO 15-25 PERCENT. HOWEVER...WINDS NOT QUITE AS STRONG THERE AS ALONG THE COAST...NOTING GUSTS BELOW 20 KT THERE. STILL HAVE SOME CONCERNS FOR ELEVATED FIRE WEATHER SPREAD THROUGH THIS AFTERNOON. SPECIAL WEATHER STATEMENT REMAINS IN PLACE TO ADDRESS THIS CONCERN. PERSISTENT SW FLOW WILL BRING GRADUAL INCREASE IN HUMIDITY THIS WEEK. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ230>237-250-251. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ254>256. && $$ SYNOPSIS...SIPPRELL/JWD NEAR TERM...SIPPRELL/EVT SHORT TERM...JWD LONG TERM...SIPPRELL AVIATION...SIPPRELL/JWD MARINE...SIPPRELL/EVT FIRE WEATHER...STAFF

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