Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Graphics & Text | 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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBOX 230847 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 447 AM EDT TUE SEP 23 2014 .SYNOPSIS... HIGH PRESSURE WILL BRING DRY WEATHER ALONG WITH MILD DAYS AND COOL NIGHTS THROUGH WEDNESDAY. A DISTANT COASTAL LOW PRESSURE MAY GRAZE SE NEW ENGLAND WITH THE LOW RISK FOR FEW SHOWERS WEDNESDAY NIGHT INTO THURSDAY. HIGH PRESSURE RETURNS FRIDAY INTO EARLY NEXT WEEK WITH DRY WEATHER AND UNSEASONABLY WARM AFTERNOON/S. ITS POSSIBLE A FEW RECORD HIGH TEMPS ARE CHALLENGED THIS WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
CANCELLED THE FROST ADVISORY EARLY. LOW LEVEL DRY AIR DID NOT ARRIVE QUICKLY ENOUGH TO PERMIT WIDESPREAD AREAS OF FROST. THERE WERE A FEW SPOTS IN SOUTHERN NH AND NORTHWEST MA WHICH ARE CLOSE TO THE FROST FORMATION TEMPERATURES ALREADY THIS MORNING. SO WE CANNOT COMPLETELY RULE OUT AT LEAST SOME FROST THIS MORNING. TODAY... HIGH PRESSURE CRESTS ACROSS SOUTHERN NEW ENGLAND. THIS MEANS MOSTLY SUNNY SKIES AND A PREDOMINANTLY LIGHT WEST WIND. SOME OF THE HIGH RESOLUTION GUIDANCE IS HINTING AT A SEABREEZE DEVELOPING ALONG THE COAST THIS AFTERNOON. THE LATEST RUNS OF THE RAP...ALONG WITH BOTH CORES OF THE HI-RES NAM DO DECREASE WINDS WHERE A SEABREEZE WOULD BE POSSIBLE...BUT KEEP THE BOUNDARY JUST OFF THE EAST COAST. THE ONLY MODEL/GUIDANCE SOURCE WHICH HAS CONSISTENTLY DEVELOPED A SEABREEZE IS THE HRRR. LIKE THE PREVIOUS FORECASTER...AM WARY ABOUT THE POSSIBILITY OF A SEABREEZE DEVELOPING. WITH THE HIGH PRESSURE ARRIVING LATER IN THE DAY...AM THINKING THE OFFSHORE PRESSURE GRADIENT SHOULD REMAIN JUST STRONG ENOUGH TO HOLD IT OFFSHORE...BUT IT WILL BE SOMETHING WHICH WILL NEED TO BE WATCHED.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... TUESDAY NIGHT... HIGH PRESSURE BUILDS TO THE NORTH WITH A CONTINUATION OF CLEAR SKIES AND A LIGHT NE WIND DEVELOPING OVERNIGHT. WE USED A BLEND OF THE GUIDANCE WHICH YIELDS MIN TEMPERATURES MOSTLY IN THE 40S. WENT HIGHER ALONG THE EAST COAST OF MA AS WELL AS THE LARGER URBAN CENTERS. WEDNESDAY... LARGE HIGH PRESSURE CENTERED OVER NORTHERN NEW ENGLAND WILL RESULT IN DRY/PLEASANT WEATHER FOR LATE SEPTEMBER. GIVEN THE POSITIONING OF THIS HIGH PRESSURE...STILL EXPECTING EASTERLY WINDS AT THE SURFACE. SO LOWEST TEMPERATURES WILL BE FOUND NEAR THE EASTERN MA COAST. HIGHS SHOULD RANGE FROM MAINLY THE 60S...TO PERHAPS NEAR 70 IN THE LOWER CT RIVER VALLEY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... HIGHLIGHTS... * COOL NIGHTS/MILD DAYS THU * LOW RISK OF A FEW SHOWERS NEAR THE SOUTH COAST WED NIGHT INTO THU * UNSEASONABLY WARM AFTERNOON/S THIS WEEKEND PERHAPS INTO MONDAY * DRY WITH NO APPRECIABLE RAINFALL IN SITE DETAILS... WEDNESDAY NIGHT THROUGH THURSDAY NIGHT... WE WILL HAVE TO KEEP AN EYE ON A LOW PRESSURE SYSTEM THAT WILL BE EMERGING OFF THE MID ATLANTIC COAST. HOWEVER...WEAK UPPER LEVEL FLOW AND A SURFACE HIGH NEARBY ARE NOT FAVORABLE FOR ALLOWING THE LOW PRESSURE SYSTEM TO TRACK UP THE COAST. IN ADDITION...WEAK BAROCLINICITY WILL ALSO LIMIT NORTHWEST AXIS OF QPF SHIELD. NONETHELESS...THE GFS AND ITS ENSEMBLES INDICATE AT LEAST A LOW RISK FOR A FEW BRIEF SHOWERS ACROSS OUR SOUTHERN ZONES. WHETHER OR NOT THIS COMES TO FRUITION REMAINS TO BE SEEN...BUT CERTAINLY DO NOT EXPECT ANY APPRECIABLE RAINFALL. AS FOR HIGH TEMPS ON THURSDAY...ONSHORE FLOW WILL RESULT IN HIGHS IN THE 60S TO NEAR 70. AGAIN...MILDEST READINGS WILL BE FOUND ACROSS THE DISTANT INTERIOR. LOW TEMPS WED NIGHT AND THU NIGHT SHIELD BE IN THE 40S...TO THE LOWER 50S. FRIDAY THROUGH MONDAY... ANOMALOUS UPPER LEVEL RIDGING TAKES HOLD OF THE NORTHEAST U.S. FROM FRI INTO EARLY NEXT WEEK. THIS WILL RESULT IN DRY WEATHER WITH UNSEASONABLY WARM AFTERNOON/S. NEAR RECORD HIGH TEMPS POSSIBLE THIS WEEKEND. ANOTHER FACTOR THAT MAY HELP IN THIS PROCESS IS THE VERY DRY GROUND...WHICH MAY ALLOW HIGH TEMPS TO GET A DEGREE OR SO HIGHER THAN THEY NORMALLY WOULD IN THIS SET UP. GUIDANCE NUMBERS HAVE LIKELY TRENDED TOO MUCH TOWARDS CLIMATOLOGY. HIGH TEMPS FRI...SHOULD BE WELL UP INTO THE 70S. SAT/SUN LOOKS LIKE THE WARMEST DAYS...WHERE HIGHS WILL PROBABLY REACH 80+ ACROSS THE LOWER ELEVATIONS AND AREAS AWAY FROM THE COAST. LOW CONFIDENCE ON HIGH TEMPS FOR MONDAY...WILL DEPEND WHETHER OR NOT A BACKDOOR COLD FRONT COOLS US OFF A BIT LIKE THE 12Z ECMWF DEPICTS. GFS IS STILL QUITE WARM...BUT OBVIOUSLY WERE A WEEK OUT SO THAT IS UNCERTAIN. AS LAST SHIFT POINTED OUT...DRY AIRMASS WILL KEEP HUMIDITY IN CHECK SO AFTERNOON/S WILL BE NICE FOR OUTDOOR ACTIVITIES. RECORD HIGH TEMPS THIS WEEKEND INTO NEXT MONDAY: SAT 9/27...SUN 9/28...MON 9/29... BOS...86...1998 BOS...90...1881 BOS...88...1952 BDL...88...1998 BDL...83...1959 BDL...86...1945 PVD...86...1998 PVD...84...1943 PVD...87...1945 ORH...85...1933 ORH...84...1916 ORH...84...1952 && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY/... HIGH CONFIDENCE VFR. LOW PROBABILITY OF A SEABREEZE THIS AFTERNOON. KBOS TERMINAL...HIGH CONFIDENCE. LOW PROBABILITY OF A SEABREEZE THIS AFTERNOON. KBDL TERMINAL...HIGH CONFIDENCE. OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY... HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD...OTHER THAN BRIEF LATE NIGHT/EARLY MORNING PATCHY GROUND FOG IN THE TYPICALLY PRONE LOCALES. THERE IS A LOW RISK FOR A BRIEF PERIOD OF MVFR CONDITIONS NEAR THE SOUTH COAST/CAPE AND ISLANDS WED NIGHT INTO THU NIGHT. THIS WILL DEPEND UPON WHETHER A FEW SHOWERS CAN MAKE IT THAT FAR NORTH WITH AN OFFSHORE LOW PRESSURE SYSTEM. && .MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE. WINDS AND SEAS CONTINUE TO DIMINISH ACROSS ALL COASTAL WATERS TODAY AS HIGH PRESSURE MOVES IN. MADE SOME TWEAKS TO TIMING OF SMALL CRAFT ADVISORIES THIS MORNING BASED ON OBSERVED TRENDS. RATHER TRANQUIL BOATING CONDITIONS EXPECTED THROUGH WEDNESDAY. SEAS MAY BUILD ABOVE 5 FEET ACROSS THE SOUTHERN OUTER COASTAL WATERS LATE WEDNESDAY...BUT THE TIMING IS NOT CERTAIN. OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY... MODERATE TO HIGH CONFIDENCE... THE MAIN CONCERN WILL BE A LOW PRESSURE SYSTEM THAT WILL TRACK NEAR OR SOUTHEAST OF THE BENCHMARK WED NIGHT INTO THU. IT WILL LIKELY RESULT IN ENOUGH SWELL FOR SCA SEAS TO DEVELOP ACROSS THE SOUTHERN OPEN WATERS WED NIGHT. SCA SWELL MAY PERSIST ACROSS THE OUTER WATERS RIGHT INTO FRI AFTERNOON BEFORE DIMINISHING. WINDS SHOULD GENERALLY REMAIN BELOW SCA THRESHOLDS THROUGH THE PERIOD. HOWEVER...A PERIOD OF NORTHEAST WIND GUSTS OF 20 TO 25 KNOTS ARE POSSIBLE ACROSS THE SOUTHERN WATERS WED NIGHT/THU IF COASTAL LOW PRESSURE TRACKS CLOSE ENOUGH TO OUR REGION. VISIBILITIES SHOULD BE GOOD THROUGH MOST IF NOT ALL OF THE PERIOD.
-- End Changed Discussion --
&& .BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ250. SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ254>256.
-- End Changed Discussion --
&& $$ SYNOPSIS...BELK/EVT NEAR TERM...BELK SHORT TERM...BELK LONG TERM...EVT AVIATION...BELK/EVT MARINE...BELK/EVT

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