Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBOX 272259 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 659 PM EDT SAT SEP 27 2014 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE OVER SOUTHERN NEW ENGLAND TONIGHT AND TOMORROW BRINGING SUMMERLIKE WARMTH. A BACK DOOR FRONT WILL MOVE ACROSS NEW ENGLAND BRINGING A SLIGHT CHANCE OF SHOWERS MONDAY NIGHT INTO TUESDAY. A COASTAL LOW PRESSURE SYSTEM WILL DEVELOP BUT STAY TO THE SOUTH OF THE REGION DURING THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
7 PM UPDATE... CLEAR SKIES AND LIGHT WINDS ARE ALLOWING TEMPS TO DROP OFF QUICKLY THIS EVENING. MODIFIED T/TD GRIDS TO REFLECT CURRENT TRENDS...OTHERWISE FORECAST ON TRACK. PREVIOUS DISCUSSION... *PATCHY DENSE FOG TONIGHT* HIGH PRESSURE OVERHEAD WILL CONTINUE TO DOMINATE THE REGION OVERNIGHT. TEMPS WILL RADIATE OUT OVERNIGHT SINCE WINDS WILL BE LIGHT AND CLEAR SKIES. MOISTURE WAS ON THE INCREASE TODAY SO BELIEVE THAT PATCHY DENSE FOG WILL BE MORE WIDESPREAD TONIGHT COMPARED TO LAST NIGHT. HIGHEST CONFIDENCE IS ACROSS VALLEY REGIONS. TEMPS WILL DROP DOWN ONLY TO THE LOW TO MID 50S WITH A FEW UPPER 40S POSSIBLE.
-- End Changed Discussion --
&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... TOMORROW AND TOMORROW NIGHT... HIGH PRESSURE WILL CREST OVER THE REGION TOMORROW BEFORE EXITING THE REGION TOMORROW NIGHT. MIXING WILL REACH UP TO 900MB TOMORROW...AND WITH TEMPS WARMER ALOFT THEN TODAY ADDED 3 DEGREES TO TODAYS HIGHS. THEREFORE ANTICIPATE TEMPS TO REACH THE MID TO UPPER 80S WHICH COULD MAKE A RUN AT SEVERAL RECORDS...ESP AT PVD AND BDL. ANTICIPATE A WEAK SEA BREEZE AGAIN TOMORROW ON BOTH COASTLINES. AS HIGH PRESSURE SLIDES OFFSHORE SUNDAY NIGHT...AS WINDS WILL BE MORE OUT OF THE WEST BUT STILL LIGHT. HIGH LEVEL CLOUDS WILL STREAM INTO THE REGION WHICH MAY LIMIT RADIATIONAL COOLING AS WELL AS THE FOG POTENTIAL. MIN TEMPS MAY DROP INTO THE MID TO UPPER 50S. && .LONG TERM /MONDAY THROUGH SATURDAY/... HEADLINES... *A CHANCE OF SHOWERS MONDAY NIGHT INTO TUESDAY *UNCERTAIN FORECAST AFTER MONDAY *COASTAL LOW MAY DEVELOP MIDWEEK OFF SOUTHEAST COAST OVERVIEW... THE GENERAL PATTERN BEGINS WITH SPLIT FLOW AROUND A CUTOFF LOW PRESSURE SYSTEM IN THE WESTERN US. THIS IS THE WESTERN EDGE OF A WAVE TRAIN. IN THE EASTERN US...A TROUGH EXISTS. AS THE PATTERN EVOLVES...THE RIDGE MOVES EAST INTO THE EASTERN US WITH A TROUGH OVER THE WESTERN US FOR A VERY HIGH AMPLITUDE PATTERN WITH STRONG BLOCKING IN EASTERN CANADA. THE MODELS ARE HAVING TROUBLE HANDLING THE TIMEFRAME FROM TUESDAY ON THROUGH THE END OF THE PERIOD. A COASTAL LOW FORMS OFF THE MID ATLANTIC COAST...BUT DISCREPANCIES OCCUR IN THE TRACK AND INTENSITY DEPARTMENTS MAINLY BECAUSE THE MODELS AREN/T HANDLING THE LOCATION AND INTENSITY OF THE RIDGE OVER SOUTHEASTERN CANADA. DAILIES... MONDAY...A COLD FRONT APPROACHES FROM SOUTH CANADA. BY TUESDAY MORNING UPPER LEVEL TEMPERATURE GRADIENTS BECOME LESSENED INDICATING A DYING FRONT AND LACKING PRECIPITATION. 700 MB RH IS VERY LOW AS WELL. HAVE ALLOWED FOR SLIGHT CHANCE OF PRECIPITATION...BUT THE RECENT DROUGHT MAY HAVE SOMETHING TO SAY ABOUT THAT. TUESDAY THROUGH THURSDAY...AS THE ENERGY FROM MONDAY/S COLD FRONT MOVES INTO THE UNITED STATES...ENERGY FROM THE SOUTHEASTERN US AND THAT COLD FRONT INTERACT TO CREATE A COASTAL LOW PRESSURE SYSTEM. HOWEVER...VERY DIFFERENT SOLUTIONS ENSUE. THE 00Z ECMWF HAS CUTOFF THE ENERGY AS IT IS WONT TO DO WHILE THE 6Z GFS/00Z CANADIAN HAVE NOT AND HAVE THE LOW PRESSURE SYSTEM FURTHER SOUTH. AM LEANING AWAY FROM THE ECMWF ON THIS FORECAST. AM ALSO NOTING THAT THE GEFS SHOWS VERY LOW PROBABILITY OF PRECIPITATION...WHICH MAY BE FROM SPREAD...BUT ALSO FROM MOST MEMBERS SHOWING NO PRECIPITATION. WITH A STRONGER RIDGE TO THE NORTH ESPECIALLY INDICATED IN THE GFS BY THE LOW RH AT 700 MB...BELIEVE THAT MOST OF THE PRECIPITATION WILL STAY SOUTH...BUT COULD STILL HAVE A CHANCE OF PRECIPITATION ESPECIALLY ALONG THE SOUTH COAST OF SOUTHERN NEW ENGLAND. THIS IS ENFORCED BY THE NEW 12Z ECMWF THAT CAME IN DRY FOR THE REGION. AGREE WITH PREVIOUS FORECASTER IN SAYING THE ONLY AGREEABLE PORTIONS OF THIS FORECAST IS THAT NORTHEAST WINDS WILL DEVELOP ALLOWING FOR CLOUDS AND COOLER TEMPERATURES DURING THIS PERIOD. FRIDAY...WITH THE COASTAL LOW NOW OUT TO SEA...HIGH PRESSURE OCCURS AHEAD OF AN APPROACHING COLD FRONT. HAVE GONE AWAY FROM DETERMINISTIC GUIDANCE FOR FRIDAY AND SATURDAY. SATURDAY...ANOTHER TROUGH APPROACHES FROM THE WEST AND A COLD FRONT LOOKS TO MOVE OVER THE REGION. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...HIGH CONFIDENCE THROUGH SUNDAY NIGHT. TONIGHT...MAINLY VFR...BUT ANOTHER ROUND OF LOCALIZED IFR/LIFR IN PATCHY DENSE FOG TONIGHT ESP ACROSS THE CT RIVER VALLEY AND NORMALLY PRONE FOG LOCALES. SUNDAY AND SUNDAY NIGHT...CONTINUED VFR CONDITIONS WITH LIGHT S-SW FLOW...ALTHOUGH SEA BREEZES ARE POSSIBLE ALONG E MA COAST BY SUN AFTERNOON. ANOTHER ROUND OF FOG IS POSSIBLE BUT NOT AS WIDESPREAD AS TONIGHT. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. LOW CONFIDENCE ON SEA BREEZE SUN BUT POSSIBLE AROUND 15Z. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. LOW CONFIDENCE ON IF FOG WILL IMPACT THE TERMINAL TONIGHT. OUTLOOK...MONDAY THROUGH WEDNESDAY... MONDAY NIGHT-TUESDAY...MODERATE CONFIDENCE. VFR. COLD FRONT MAY BRING SCATTERED SHOWERS WITH LOCAL MVFR CIGS/VSBYS POSSIBLE. AREAS WHERE RAIN FALLS COULD ALSO SEE FOG FORM. NE WINDS MAY PICK UP ALONG THE IMMEDIATE E COAST OVERNIGHT...GUSTS TO AROUND 20 KT POSSIBLE FROM KBOS TO KBVY. TUESDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE. MAINLY VFR... THOUGH COULD SEE PATCHY MVFR CIGS ESPECIALLY ALONG THE COAST WITH PERSISTENT ONSHORE WINDS. WIDELY SCT SHOWERS MAY LINGER ACROSS REGION WITH THE MOIST AIRMASS IN PLACE.
-- End Changed Discussion --
&& .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...HIGH CONFIDENCE THROUGH SUN NIGHT. HIGH PRESSURE BUILDS OVER WATERS TONIGHT AND TOMORROW BEFORE EXITING THE REGION TOMORROW NIGHT. ANTICIPATE LIGHT WINDS AND CALM SEAS. SEA BREEZES MAY DEVELOP ALONG BOTH COASTLINES TOMORROW. OUTLOOK...MONDAY THROUGH THURSDAY... MONDAY NIGHT...MODERATE CONFIDENCE. COLD FRONT MOVES S INTO THE REGION. GUSTY NE WINDS MOVE IN ACROSS THE EASTERN WATERS WITH GUSTS UP TO 25 KT POSSIBLE. SEAS MAY ALSO BUILD ON THE OPEN WATERS...POSSIBLY UP TO 5-6 FT E OF CAPE ANN TO E OF BOSTON HARBOR. SCA MAY BE NEEDED THERE. TUESDAY THROUGH THURSDAY...MODERATE CONFIDENCE. PERSISTENT NE WINDS REMAIN IN PLACE AS POSSIBLE COASTAL LOW DEVELOPS OFF THE MID ATLC COAST. SEAS WILL BUILD UP TO 5-7 FT...HIGHEST ON THE OUTER WATERS LATE TUE NIGHT AND WED. VSBY RESTRICTIONS POSSIBLE ON THE SOUTHERN OUTER WATERS IN SCT SHOWERS AND PATCHY FOG. && .CLIMATE... RECORD HIGH TEMPERATURES FOR TOMORROW 9/28 BOS 90F ON 1881* BDL 83F ON 1959 PVD 84F ON 1943 ORH 84F ON 1916 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...DUNTEN/HR NEAR TERM...KJC/DUNTEN SHORT TERM...DUNTEN LONG TERM...HR AVIATION...KJC/DUNTEN/HR MARINE...DUNTEN/HR CLIMATE...

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.