Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 050805 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 405 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 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/... 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 THE WEEKEND * TEMPERATURES TRENDING BELOW NORMAL THROUGH MOST IF NOT THE ENTIRE PERIOD OVERVIEW AND MODEL PREFERENCES... NOTING FAIRLY GOOD AGREEMENT WITH 12Z OPERATIONAL MODELS RUNS INTO FRIDAY...THEN EACH GOES ON THEIR MERRY OWN WAY WHICH LENDS TO LOW CONFIDENCE BEYOND FRIDAY. ONE BIG QUESTION WILL BE HOW THE H5 CUTOFF LOW ACROSS QUEBEC AND MARITIMES FLATTENS OUT...WHICH ALSO FLATTENS OUT THE FLOW ACROSS MOST OF THE NORTHERN STREAM. DEPENDING UPON WHETHER THIS UPPER LEVEL SYSTEM FLATTENS OUT WILL DETERMINE HOW FAR S THE LARGE HIGH PRES RIDGE BUILDS OUT OF CENTRAL CANADA. ALSO NOTING A STALLED FRONT S OF THE REGION WHICH HAS A SHORT WAVE MOVING ALONG IT...WHICH COULD PUSH SOME MOISTURE INTO PORTIONS OF SOUTHERN NEW ENGLAND. ANOTHER FLY IN THE OINTMENT IS THE POSSIBLE AMPLIFICATION OF LONG WAVE TROUGH ACROSS THE MID ATLC REGION THIS WEEKEND. NEEDLESS TO SAY...LOW CONFIDENCE FORECAST BEYOND FRIDAY DUE TO THE WIDE VARIANCE OF OP MODEL RUN SOLUTIONS. WENT ALONG WITH MOST AVAILABLE GUIDANCE /EXCEPT GFS/ THROUGH FRIDAY...THEN TRANSITIONED OVER TO AN ENSEMBLE MODEL BLEND SIMILAR TO WPC GUIDANCE FROM SATURDAY ONWARD. DETAILS... THURSDAY...HIGH PRESSURE BUILDS OUT OF CENTRAL CANADA INTO UPSTATE NY. WEAK SHORT WAVE MOVES ACROSS NORTHERN NEW ENGLAND AND...WITH LACK OF AVAILABLE MOISTURE IN THE GENERAL W-NW FLOW...EXPECT DRY CONDITIONS. HIGHS LOOK TO RUN AROUND 80 DEGREES...SLIGHTLY BELOW SEASONAL NORMS. THURSDAY NIGHT THROUGH SATURDAY...SHORT WAVE MOVING ALONG STALLED FRONT FROM THE OHIO VALLEY. COULD START TO SEE SOME MOISTURE MOVING NE INTO N CT/RI/SE MA OVERNIGHT THU NIGHT THEN PUSH FURTHER N DURING FRI. STILL A LOT OF QUESTION ON HOW FAR THIS RAIN WILL PUSH INTO THE REGION...IF AT ALL. FOR NOW...KEPT CONTINUITY GOING FROM THE PREVIOUS FORECAST WITH MAINLY CHANCE POPS...THOUGH LOW LIKELY IN PLACE ACROSS S COASTAL AREAS FRI INTO FRI NIGHT. HAVE LOWERED POPS TO CHANCE FOR EARLY SATURDAY THEN SHOULD PUSH E DURING THE AFTERNOON INTO SAT EVENING. 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 H5 LONG WAVE TROUGH DIGGING ACROSS EASTERN GREAT LAKES AS H5 LOW TRYING TO CUT OFF AGAIN ACROSS HUDSON BAY. MAY SEE PERIODS OF WIDELY SCT SHOWERS FROM TIME TO TIME DURING THIS TIMEFRAME...BUT LOW CONFIDENCE ON TIMING AND PLACEMENT. && .AVIATION /07Z 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/... THROUGH 12Z...HIGH CONFIDENCE. MAINLY VFR AND DRY. A FEW LOW CLOUDS/FOG MAINLY CAPE/ISLANDS. TODAY...MODERATE CONFIDENCE. MAINLY VFR THROUGHOUT THE DAY...ALTHOUGH SOME 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...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 LIKELY 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...DOODY SHORT TERM...DOODY LONG TERM...BELK AVIATION...BELK/DOODY MARINE...BELK/DOODY

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