Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 051144 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 744 AM EDT WED AUG 5 2015 .SYNOPSIS... A FEW SHOWERS OR THUNDERSHOWERS ARE POSSIBLE THIS AFTERNOON...FOLLOWED BY DRIER WEATHER INTO THURSDAY. A PERIOD OF UNSETTLED WEATHER IS POSSIBLE LATE FRIDAY INTO THIS WEEKEND...BUT CONFIDENCE REMAINS LOW REGARDING THE TIMING AND COVERAGE OF ANY POTENTIAL WET WEATHER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 743 AM UPDATE... MUCH MORE TRANQUIL WEATHER THIS MORNING. NO MAJOR CHANGES TO THE FORECAST...JUST TWEAKS TO BRING THE NEXT FEW HOURS BACK IN LINE WITH OBSERVED TRENDS. PREVIOUS DISCUSSION... CONVECTION CONTINUES WITHIN A BAND OF HIGHER THETA-E/LOWER STATIC STABILITY TO THE S OF A WEAKENING COLD FRONT CURRENTLY SITUATED NEAR THE S COAST THIS MORNING. BULK OF THE ACTIVITY SHOULD REMAIN OUTSIDE OF THE BOX/OKX COASTAL WATERS DUE TO SLIGHT TURNING TOWARD THE LOWER STABILITY FURTHER S. EVEN THE CI/ANVIL REMAINS OFFSHORE. OTHERWISE...WITH CYCLONIC FLOW CONTINUES ACROSS MOST OF NEW ENGLAND TODAY WITH YET A FINAL STRONG SHORTWAVE EXPECTED TO MOVE ACROSS THE REGION DURING THE LATE MORNING/AFTERNOON HOURS. THIS IS WITHIN A REGIME WHERE H5 HEIGHTS ARE GENERALLY 2-3 STD DEVIATIONS BELOW NORMAL AND H5 TEMPS DROP BETWEEN -13C AND -15C. DRIER AIR DOES CONTINUE TO INVADE THE COLUMN BEHIND THE EXITING FRONT...SO THIS LIMITS THE LAPSE RATES IN SPITE OF THE COLD TEMPS ALOFT. STILL...LOOKS LIKE ENOUGH DIURNALLY DRIVEN AFTERNOON INSTABILITY TO SUPPORT SOME MODEST CONVECTIVE SHRA/T-STORMS. THE COLD TEMPS SUGGEST RISK FOR SMALL HAIL...BUT THE DRIER AIR NEAR THE SFC COULD SUPPORT SOME GUSTY WINDS AS WELL. THEREFORE...HAVE ADDED THIS WORDING TO THE FORECAST WITH THIS UPDATE. HIGHEST RISK WILL BE N...WHERE COLDEST TEMPS AND OVERALL MOISTURE RESIDES...HENCE THE MARGINAL RISK ACROSS NRN NEW ENGLAND. THEREFORE...FOCUS IS N OF THE MASS PIKE...BUT RISK IS NON-ZERO EVERYWHERE. WITH THE DRY AIR...NOT EXPECTING ACTIVITY TO BE AS STRONG OR WIDESPREAD AS TUESDAY...BUT STILL WORTH WATCHING THE SKIES THROUGH THE DAY. OTHERWISE...TEMPS REMAIN WARM TODAY AS THE COLDEST AIR IN THE LOW LVLS STILL LAGS THE FRONT A BIT. EXPECT HIGHS MAINLY IN THE MID- UPPER 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... TONIGHT... SUSPECT ANY SHOWERS/STORMS WILL DISSIPATE RATHER QUICKLY AFTER SUNSET...AS IT WILL REQUIRE THE SFC WARMING TO MAINTAIN. SUSPECT AN END BETWEEN 00Z-02Z. WITH SKIES CLEARING AND SFC PRES GRADIENT WEAKENING SOMEWHAT...TEMPS ARE LIKELY TO COOL INTO THE 50S BY THE EARLY MORNING HOURS. CERTAINLY MUCH MORE COMFORTABLE THAN PREVIOUS NIGHTS. THU... WEAK RIDGE OF HIGH PRES WILL BUILD ACROSS THE REGION. IN SPITE OF LAST BIT OF CYCLONIC CURVATURE ALOFT...SUSPECT MAINLY DRY CONDITIONS AS BEST LIFT/MOISTURE REMAINS WELL TO THE N. H85 TEMPS SLIGHTLY BELOW NORMAL SUGGESTS HIGHS BELOW NORMAL. MAINLY THE LOW 80S. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... HIGHLIGHTS... * UNSETTLED WEATHER REMAINS POSSIBLE FRIDAY INTO THIS WEEKEND * TEMPERATURES TRENDING BELOW NORMAL THROUGH MOST IF NOT THE ENTIRE PERIOD OVERVIEW AND MODEL PREFERENCES... TREND OF THE 05/00Z GUIDANCE IS TO TAKE A COASTAL LOW PRESSURE FARTHER OFFSHORE THAN PREVIOUS RUNS. ECMWF REMAINS A LITTLE FASTER...AND ALSO TRACKS CURVES THIS LOW PRESSURE CLOSER TO SHORE LATER THIS WEEKEND THAN THE GFS. CONFIDENCE IS GROWING IN A DRIER FORECAST...AT LEAST FOR FRIDAY...OWING TO THE CONSENSUS TREND OFFSHORE. STILL NEED TO RESOLVE DETAILS FOR SATURDAY. SINCE THE GUIDANCE HAS NOT BEEN VERY CONSISTENT WITH THIS STORM OVER THE PAST FEW DAYS...WILL STICK WITH THE CONSENSUS APPROACH FOR NOW. PATTERN SHIFTS FROM A CLOSED MID LEVEL LOW OVER EASTERN CANADA... TO A FLATTER PATTERN EARLY NEXT WEEK...BEFORE ANOTHER TROUGH ARRIVES TOWARD MID WEEK. DETAILS... THURSDAY NIGHT THROUGH SATURDAY...COASTAL LOW PRESSURE EXPECTED TO MOVE SLIGHT FARTHER OFFSHORE THAN PREVIOUSLY THOUGHT. THIS SHOULD BE FAR ENOUGH TO KEEP MOS OF SOUTHERN NEW ENGLAND DRY. GREATEST RISK FOR SHOWERS WILL BE TOWARDS THE SOUTH COAST...AND ESPECIALLY CAPE COD AND THE ISLANDS. DID NOT HAVE ENOUGH CONFIDENCE IN THE DETAILS TO GO AS DRY AS SOME OF THE GUIDANCE WAS SUGGESTING. WILL SIMPLY TREND THE FORECAST RAINFALL CHANCES DOWN AT THIS TIME. SUNDAY THROUGH WEDNESDAY...MUCH OF THIS FORECAST CONTINUES TO DEPEND UPON THE FRI-SAT PATTERN SETS UP. AT THIS POINT...LOOKS LIKE IT SHOULD BE MAINLY DRY BUT COOL ON SUNDAY. MODELS SIGNALING ANOTHER SERIES OF COLD FRONTS COMBINED WITH A MID LEVEL LONGWAVE TROUGH EARLY NEXT WEEK. MAY SEE PERIODS OF SCATTERED SHOWERS FROM TIME TO TIME DURING THIS TIMEFRAME...BUT LOW CONFIDENCE ON TIMING AND PLACEMENT REMAINS. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH THURSDAY/... TODAY...MODERATE CONFIDENCE. MAINLY VFR THROUGHOUT THE DAY...ALTHOUGH SCT SHRA/TSRA WITH SMALL HAIL AND GUSTY WINDS ARE POSSIBLE THIS AFTERNOON. NOT AS WIDESPREAD AS YESTERDAY. W WINDS WITH GUSTS APPROACHING 20 KT AT TIMES. TONIGHT INTO THU...HIGH CONFIDENCE. WEAK HIGH PRES WILL SLOWLY BUILD ACROSS THE REGION. MAINLY VFR CONDITIONS EXPECTED. KBOS TERMINAL...HIGH CONFIDENCE IN TAF...LOW CONFIDENCE IN A SHOWER OR STORM THIS AFTERNOON. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/... THURSDAY NIGHT THROUGH SATURDAY...LOW CONFIDENCE ON TIMING AND COVERAGE...HIGHER CONFIDENCE ON TRENDS. MVFR-IFR CONDITIONS IN AREAS OF RAIN SOMETIME DURING THIS PERIOD. VFR BEFORE AND AFTER PERIODS OF RAIN. SUNDAY...LOW CONFIDENCE MAINLY FOR TIMING. MAY SEE LEFTOVER SHOWERS WITH BRIEF MVFR CONDITIONS EARLY...THEN VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH THURSDAY/... THROUGH TODAY...MODERATE CONFIDENCE. W WINDS GENERALLY REMAIN BELOW SCA CONDITIONS...WITH SEAS GRADUALLY RECEDING THROUGH THE MORNING. SMALL CRAFT ADVISORIES REMAIN IN PLACE THROUGH MID MORNING ALONG S WATERS...BUT WILL LIKELY BE GONE BY MID DAY. A FEW SHOWERS OR T-STORMS POSSIBLE MAINLY NEAR COASTLINES THIS AFTERNOON. TONIGHT INTO THU...HIGH CONFIDENCE. WEAK HIGH PRES BRINGS MAINLY QUIET BOATING WEATHER TO THE REGION. OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/... THURSDAY NIGHT...HIGH CONFIDENCE. WINDS AND SEAS BELOW SMALL CRAFT CRITERIA. LOCALLY REDUCED VSBYS IN LIGHT RAIN THU NIGHT. FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE. EASTERLY WINDS GUSTING UP TO 20 KT. WITH ONSHORE WINDS...SEAS LOOK TO BUILD UP TO 5-6 FT HIGHEST ACROSS THE EASTERN OUTER WATERS. RAIN POSSIBLE FRIDAY NIGHT THROUGH SATURDAY NIGHT...LIMITING VISIBILITIES AT TIMES... THEN SHOULD IMPROVE DURING SUNDAY. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ235- 237-254>256. && $$ SYNOPSIS...BELK/DOODY NEAR TERM...BELK/DOODY SHORT TERM...DOODY LONG TERM...BELK AVIATION...BELK/DOODY MARINE...BELK/DOODY

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