Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 141803 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 203 PM EDT SUN SEP 14 2014 .SYNOPSIS... HIGH PRESSURE OVER THE GREAT LAKES BUILDS INTO NEW ENGLAND THROUGH MONDAY...BRINGING DRY WEATHER ALONG WITH MILD AFTERNOONS AND CHILLY NIGHTS. A COLD FRONT WILL LIKELY BE ACCOMPANIED BY A PERIOD OF SHOWERS LATE MONDAY NIGHT INTO TUESDAY. MAINLY DRY BUT COOLER THAN NORMAL WEATHER FOLLOWS NEXT WEDNESDAY THROUGH FRIDAY. TEMPERATURES THEN LIKELY MODERATE TO NEAR NORMAL BY NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 2 PM UPDATE...TEMPERATURES HAVE REBOUNDED INTO THE UPPER 50S TO MID 60S ACROSS SOUTHERN NEW ENGLAND THIS AFTERNOON UNDER SUNNY SKIES. NORTHWESTERLY WINDS CONTINUE TO GUST MAINLY ACROSS THE EASTERN HALF OF THE REGION AS HIGH PRESSURE FINISHES PUSHING INTO THE REGION. TONIGHT...HIGH PRESSURE SHOULD BE CENTERED OVER SOUTHERN NEW ENGLAND TONIGHT PROVIDING IDEAL RADIATIONAL COOLING CONDITIONS. CLEAR SKIES...CALM WINDS...AND A VERY DRY ATMOSPHERE WILL ALLOW TEMPERATURES TO DROP INTO THE MID 30S TO UPPER 40S. OPTED TO USE THE COOLER MOS GUIDANCE FOR OVERNIGHT LOWS. WILL BE LOOKING TO EXPAND THE FROST ADVISORY INTO NORTHWESTERN MA AND INTO HILLSBOROUGH COUNTY IN NH WITH THE AFTERNOON FORECAST PACKAGE. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... MONDAY...ANOTHER CHILLY START BUT HIGH PRESSURE OVER THE REGION WILL KEEP SUNNY SKIES OVER THE REGION. TEMPERATURES EXPECTED TO BE SIMILAR TO TODAY...POSSIBLY A COUPLE OF DEGREES WARMER IN PLACES. SEA BREEZES ARE LIKELY TO DEVELOP WITH A WEAK PRESSURE GRADIENT IN PLACE OVER THE REGION. MONDAY NIGHT...DRY WEATHER IS EXPECTED THROUGH ABOUT MIDNIGHT AS HIGH PRESSURE MOVES OFFSHORE. LOW PRESSURE IN QUEBEC WILL BRING A COLD FRONT TOWARDS THE REGION RESULTING IN SHOWERS MOVING IN FROM WEST TO EAST AFTER MIDNIGHT. WITH MORE HUMIDITY...CLOUDS...AND RAIN EXPECT LOW TEMPERATURES TO BE SIGNIFICANTLY WARMER THAN THE PREVIOUS TWO NIGHTS. THERE IS ALSO POTENTIAL FOR SOME AREAS OF FOG. && .LONG TERM /TUESDAY THROUGH SUNDAY/... HIGHLIGHTS... * A PERIOD OF SHOWERS LIKELY LATE MON NIGHT/TUE * DRY WEATHER AND BELOW NORMAL TEMPS NEXT WED-FRI * PATTERN CHANGE FOR NEXT WEEKEND OVERVIEW... OVERALL MODEL GUIDANCE IS IN AGREEMENT WITH A BROAD TROUGH OVER THE EASTERN HALF OF THE CONTINENT AND A FULL-LATITUDE RIDGE OVER WESTERN NORTH AMERICA. THUS FAR A VERY PROGRESSIVE PATTERN TO START...THEN THE FLOW DOES BEGIN TO BECOME MORE AMPLIFIED AS A DEEP TROUGH INVADES SOUTHERN NEW ENGLAND. HIGH CONFIDENCE THIS WILL OCCUR THANKS TO A VERY NEGATIVE AO. OVER THE WEEKEND...A TROUGH WILL DIG OVER THE EASTERN PACIFIC LEADING TO A RIDGE IN THE CENTRAL CONUS....ABOUT WHEN THE NAO BECOMES MORE NEUTRAL. ANTICIPATE A POSSIBLE CHANGE IN THE PATTERN BY NEXT WEEKEND/OR EARLY NEXT WEEK. ONLY MAJOR WEATHER MAKER TO WATCH FOR IS THE SHORTWAVE PASSING THROUGH MONDAY NIGHT/TUESDAY BRINGING SHOWERS TO THE REGION. LOW CONFIDENCE ON EXACT SPECIFICS BUT CONFIDENCE IS INCREASING THAT PRECIP WILL OCCUR. OTHERWISE HIGH PRESSURE WILL PREVAIL WITH TEMPS AT OR BELOW AVERAGE FOR THIS TIME OF YEAR. IN FACT MID TO LATE NEXT WEEK MAY NEED TO WATCH FOR FROST HEADLINES ACROSS THE DISTANT INTERIOR. DETAILS... TUESDAY... THE NEXT SHOT FOR PRECIPITATION WILL BE LATE MONDAY NIGHT INTO TUESDAY AS A SHORTWAVE MOVES THROUGH THE FLOW. OVERALL GUIDANCE HAS TRENDED TO BE ON THE WETTER SIDE SO CONFIDENCE IS INCREASING THAT PRECIP WILL OCCUR. RIGHT NOW IT LOOKS AS IF DROUGHT STRICKEN RI AND SE MASS HAVE THE BETTER SHOT FOR THE HIGHER QPF AMOUNTS. ALTHOUGH THE EC CONTINUES TO SHOW A QPF BULLS- EYE FOR THE REGION...NOTICED THAT THE GFS HAS TICKED UP. OVER 0.25 TO 0.5 INCHES OF RAIN IS NOT OUT OF THE QUESTION...ESPECIALLY SINCE PWAT VALUES DO NOSE IN AT ABOUT 1.5 INCHES. THIS IS ALSO ALONG THE SAME THINKING OF HPC. INSTABILITY LOOKS FAIRLY LIMITED...SO WILL NOT INCLUDE THUNDER IN THE FORECAST AT THIS TIME. HIGHS SHOULD BE IN THE 60S TO AROUND 70. END OF THE WORK WEEK... A LARGE AREA OF HIGH PRESSURE THEN BUILDS SE FROM CENTRAL CANADA THROUGH THE END OF THE WEEK. A DRY COLD FRONTAL PASSAGE WED NIGHT INTO THU MORNING WILL REINFORCE THE DRY...COOL AIR ALREADY IN PLACE. THERE IS STILL SOME UNCERTAINTY ON EXACT TIMING OF THE FRONT BUT EITHER WAY...BELOW AVERAGE TEMPERATURES ARE ANTICIPATED. APPEARS THAT WE MAY NEED TO BEGIN TO WATCH FOR THE RISK FOR SOME FROST IN SOUTHWEST NH/NORTHWEST MA...WHERE WINDS CAN DECOUPLE. NEXT WEEKEND... GUIDANCE AS WELL AS THE TELECONNECTIONS ARE SHOWING THAT A CHANGE IN THE PATTERN IS POSSIBLE BEGINNING NEXT WEEKEND. THIS MAY LEAD TO A MORE AMPLIFIED PATTERN AND TEMPS BACK TO NORMAL. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. HIGH CONFIDENCE THRU MONDAY. MODERATE CONFIDENCE MONDAY NIGHT. THROUGH 00Z...VFR. TONIGHT...VFR ALONG WITH LIGHT WINDS. LOW RISK OF PATCHY MVFR INLAND IN FOG. MONDAY...VFR WITH LIGHT WINDS INTERIOR AND SEABREEZES ALONG THE COAST. MONDAY NIGHT...MAINLY VFR. BRIEF MVFR/IFR CONDITIONS IN SHOWERS AFTER MIDNIGHT. LOW RISK OF PATCHY MVFR FOG INLAND. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. VERY LOW PROBABILITY OF A BRIEF SEA BREEZE LATE THIS AFTERNOON. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...TUESDAY THROUGH THURSDAY...HIGH CONFIDENCE. TUESDAY...SHOWERS BEGIN IN THE EARLY MORNING HOURS WITH MVFR CONDITIONS EXPECTED. THEN BECOMING VFR AS SHOWERS EXIT IN THE MID AFTERNOON HOURS. WEDNESDAY AND THURSDAY...VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. FORECAST CONFIDENCE IS HIGH THROUGH MONDAY. TODAY...NNW WINDS GUSTING UP TO 25 FROM ABOUT 5 AM TO 11 AM THEN DIMINISHING THEREAFTER. GOOD VSBY AS WELL. TONIGHT AND MONDAY...LIGHT WINDS AND GOOD VSBY. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... MONDAY NIGHT INTO TUE MORNING...MODERATE TO HIGH CONFIDENCE. HIGH PRESSURE NEARBY WILL RESULT IN A WEAK PRESSURE GRADIENT KEEPING WINDS/SEAS BELOW SCA THRESHOLDS. TUESDAY AFTERNOON INTO WEDNESDAY...MODERATE CONFIDENCE. SWELLS BEGIN TO BUILD TO BETWEEN 5 AND 7FT BEHIND THE DEPARTING LOW PRESSURE SYSTEM AND COLD FRONT. THIS IS ABOVE SCA LEVELS AND THEREFORE A SCA MAY BE NEED. THURSDAY...AS NEXT HIGH PRESSURE SYSTEM APPROACHES WITH WEAKER PRESSURE GRADIENT...EXPECT SWELLS TO DIE DOWN DURING THE DAY TO BELOW SCA THRESHOLD. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...FROST ADVISORY FROM 3 AM TO 7 AM EDT MONDAY FOR NHZ011. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ250- 254. && $$ SYNOPSIS...NOCERA/DUNTEN NEAR TERM...RLG SHORT TERM...RLG LONG TERM...DUNTEN AVIATION...DUNTEN/RLG MARINE...NOCERA/DUNTEN

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