Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 042037 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 437 PM EDT MON MAY 4 2015 .SYNOPSIS...
-- Changed Discussion --
MILD WEATHER PREVAILS THIS EVENING AND OVERNIGHT AHEAD OF AN APPROACHING COLD FRONT. THIS BOUNDARY MAY TRIGGER ISOLATED TO WIDELY SCATTERED SHOWERS TUESDAY. HIGH PRESSURE BUILDS IN BEHIND THIS FRONT WED...PROVIDING MILD TEMPERATURES BUT LOWER HUMIDITY THAN TUESDAY. WARMER WEATHER FOLLOWS THU AND FRI AS THE HIGH SLIPS SOUTH AND THEN EAST OF NEW ENGLAND. A COLD FRONT LATE THIS WEEKEND INTO EARLY NEXT WEEK MAY YIELD SCATTERED SHOWERS. OTHERWISE DRY... WARM AND MORE HUMID WEATHER PREVAILS THIS WEEKEND.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
430 PM UPDATE... TEMPERATURES HAVE WARMED INTO LOW TO MID 80S ACROSS MUCH OF SOUTHERN NEW ENGLAND EARLY THIS AFTERNOON...WHICH IS THE WARMEST IT HAS BEEN SINCE LAST OCTOBER. MUCH OF SOUTH COAST...CAPE COD AND ISLANDS HAVE BEEN HOLDING IN UPPER 50S AND LOWER 60S DUE TO INFLUENCE OF COLDER OCEAN. TONIGHT... HIGH PRESSURE CONTINUES TO MOVE OFFSHORE...WHICH WILL PERMIT A COLD FRONT TO APPROACH FROM THE WEST AFTER MIDNIGHT. THIS FRONT IS NOT PARTICULARLY POTENT...AND HAS A LOT OF DRY AIR TO OVERCOME. ANY SHOWERS WILL HOLD OFF UNTIL VERY LATE TONIGHT...AND BE CONFINED PRIMARILY TO NORTHWEST MA. THE INCREASING CLOUDS AND RELATIVELY WARM STARTING POINT WILL KEEP MINIMUM TEMPERATURES WELL ABOVE NORMAL OVERNIGHT...MAINLY IN THE 50S.
-- End Changed Discussion --
&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
A WEAKENING COLD FRONT WILL PROVIDE A FOCUS FOR ISOLATED TO SCATTERED SHOWERS ACROSS SOUTHERN NEW ENGLAND. INSTABILITY IS NOT GREAT...BUT CANNOT COMPLETELY RULE OUT THE POSSIBILITY OF AN ISOLATED THUNDERSTORM OR TWO. THE MOST LIKELY SCENARIO IS FOR SCATTERED SHOWERS...ESPECIALLY DURING THE MORNING HOURS. THE FRONT CONTINUES TO WEAKEN DURING THE AFTERNOON...WITH WEAK RIDGING ARRIVING DURING TUESDAY EVENING AND OVERNIGHT. THIS SHOULD MEAN A SLOW DRYING TREND TUESDAY NIGHT. TEMPERATURES WILL STILL BE SLIGHTLY ABOVE NORMAL TUESDAY AND TUESDAY NIGHT.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY THROUGH MONDAY/... 348 PM UPDATE... HIGHLIGHTS... * SPRING TO SUMMER-LIKE TEMPS MUCH OF THE PERIOD * MAINLY DRY WEATHER WED THRU SAT WITH INCREASING RISK OF SHOWERS SUN/MON SYNOPTIC OVERVIEW AND MODEL/GUIDANCE EVALUATION... 00Z ECENS/EPS AND 12Z GEFS ENSEMBLES IN GOOD AGREEMENT ON THE LARGE SCALE FLOW THIS PERIOD WHICH FEATURES AN ANOMALOUS CLOSED LOW EVOLVING OVER THE NORTHWEST ATLANTIC OF ABOUT -3 STD DEVIATIONS FROM CLIMO...ALONG WITH A RIDGE CENTERED OVER THE GREAT LAKES AND OHIO VALLEY. THIS PLACES NEW ENGLAND IN A DRY NORTHWEST FLOW REGIME WED THRU FRI. BY THE WEEKEND THE UPPER AIR PATTERN BECOMES SOMEWHAT PROGRESSIVE WITH THE CLOSED LOW MOVING INTO THE CENTRAL ATLANTIC ALLOWING GREAT LAKES RIDGE/HEIGHT ANOMALY TO ADVECT EASTWARD INTO NEW ENGLAND...CONTINUING THE DRY WEATHER INTO AT LEAST THE FIRST HALF OF THE WEEKEND. THEN BY LATE IN THE WEEKEND AND ESPECIALLY EARLY NEXT WEEK THE QUESTION BECOMES HOW QUICKLY DOES THE RIDGE ERODE AS UPSTREAM TROUGH APPROACHES. IN ADDITION...RIDGE BECOMES SOMEWHAT OF A DIRTY RIDGE WITH MOISTURE FROM REMNANT CLOSED LOW OVER THE SOUTHEAST STATES ADVECTING NORTHWARD UP THE EASTERN SEABOARD. AS EXPECTED AT THIS TIME RANGE THE DETERMINISTIC RUNS OF THE 12Z ECMWF AND 12Z GFS HANDLE THIS DIFFERENTLY ALONG WITH ENSEMBLES. THUS FORECAST CONFIDENCE BECOMES LOW ON SHOWER POTENTIAL LATER THIS WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES... BRIEF COOL DOWN OR BETTER LABELED AS NOT AS WARM WED /LOW TO MID 70S/ IN THE POST FRONTAL AIRMASS ALONG WITH LOWER DEW PTS /30S/. HOWEVER AS SURFACE HIGH SLIPS SOUTH OF NEW ENGLAND THU...SURFACE WINDS BECOME WSW AND THIS WILL SUPPORT TEMPS WARMING TO 75 TO 80 AND POTENTIALLY CLIMBING INTO U70S AND L80S BY FRI. WARM WEATHER CONTINUES SAT WITH HIGHS IN THE L80S AWAY FROM THE SOUTH COAST. IN ADDITION WITH SSW SURFACE WINDS DEW PTS WILL CLIMB INTO THE 50S. STILL COMFORTABLE BUT THIS WILL RESULT IN NIGHTLY TEMPS NOT AS COOL ALONG WITH PATCHY FOG. SUNDAY...TRICKY AS POTENTIAL BACKDOOR FRONT IMPACTS EASTERN MA AND POSSIBLY RI. NOT AS WARM EARLY NEXT WEEK GIVEN LIKELY CLOUD COVER...SOUTHERLY FLOW AND RISK OF SHOWERS. HOWEVER TEMPS WILL STILL AVERAGE WARMER THAN NORMAL. PRECIPITATION... AS MENTIONED ABOVE DRY PATTERN PREVAILS WED THRU FRI AND PROBABLY INTO SAT. RISK OF SHOWERS INCREASES SUNDAY AS UPSTREAM TROUGH APPROACHES ALONG WITH REMNANT MOISTURE OFFSHORE FROM CLOSED LOW OVER THE SOUTHEAST STATES LATER THIS WEEK. HOWEVER GREATEST RISK OF SHOWERS APPEARS TO BE EARLY NEXT WEEK AS UPSTREAM TROUGH GETS CLOSER TO THE REGION AND BEGINS TO INTERACT WITH DEEPER MOISTURE ALONG AND OFF THE EASTERN SEABOARD. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. HIGH CONFIDENCE THROUGH TUE NIGHT. SW WINDS MAY BRING SOME 20-25KT GUSTS THROUGH EARLY EVENING ACROSS INTERIOR...OTHERWISE VFR THROUGH TONIGHT. VFR CIGS TUE AS COLD FRONT DROPS THROUGH SOUTHERN NEW ENGLAND...WITH SCATTERED SHOWERS POSSIBLE. MAY SEE SOME MVFR CIGS NEAR S COAST TUE AFTERNOON. VFR TUE NIGHT. KBOS TAF...HIGH CONFIDENCE IN TAF. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK...WEDNESDAY THROUGH SATURDAY... 348 PM UPDATE... HIGH CONFIDENCE FOR VFR AND DRY WEATHER. LOW RISK FOR PATCHY FOG EACH NIGHT BETWEEN MIDNIGHT AND SUNRISE WITH LOCAL IFR CIGS/VSBYS. && .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/... 4430 PM UPDATE... TONIGHT INTO TOMORROW...MODERATE CONFIDENCE. THE SW FLOW WILL SLOWLY GIVE WAY TO W FLOW AS A COLD FRONT CROSS THE WATERS DURING THE TUE EVENING HOURS. WITH THE PERSISTENT SW FLOW TODAY...SOME CONCERN WIND-DRIVEN SEAS COULD APPROACH 5 FT ON THE OCEAN WATERS. IT IS MARGINAL...BUT DID HAVE ENOUGH CONFIDENCE TO ISSUE A SMALL CRAFT ADVISORY ACROSS THE OUTER COASTAL WATERS. THE MAIN RISK WILL BE ROUGH SEAS...BUT COULD SEE A FEW GUSTS TO 25 KT AS WELL AHEAD OF A COLD FRONT. CONDITIONS IMPROVE TUESDAY AFTERNOON. SOME SHOWERS...WITH POSSIBLY EVEN A THUNDERSHOWER. TUESDAY NIGHT...WINDS AND SEAS CONTINUE TO DIMINISH. OUTLOOK...WEDNESDAY THROUGH SATURDAY... 348 PM UPDATE... WEDNESDAY...HIGH PRES OVER THE WATERS WITH TRANQUIL/DRY WEATHER AND GOOD VSBY. HIGH FORECAST CONFIDENCE. THURSDAY...HIGH SLIPS SOUTH OF NEW ENGLAND WITH WINDS BECOMING SSW. TRANQUIL/DRY WEATHER WITH GOOD VSBY CONTINUES. FRIDAY...HIGH PRES MOVES EAST OF NEW ENGLAND. DRY/TRANQUIL WEATHER CONTINUES.
-- End Changed Discussion --
&& .FIRE WEATHER...
-- Changed Discussion --
RED FLAG WARNING REMAINS POSTED PRIMARILY FOR THE TERRAIN INFLUENCE IN WESTERN MASSACHUSETTS. TEMPERATURES IN THE UPPER 70S AND LOWER 80S WILL COMBINE WITH DEWPOINTS IN THE UPPER 30S AND LOW 40S TO YIELD MIN RH VALUES AROUND 20 PERCENT THIS AFTERNOON. SW WINDS 10 TO 15 MPH WILL OCCASIONALLY GUST TO 20-25 MPH THROUGH 7 PM. SCATTERED SHOWERS EXPECTED TUE...BUT RAINFALL AMOUNTS SHOULD BE UNDER 0.25 INCH. LIGHT W/NW WINDS EXPECTED WITH MORE CLOUD COVER. 348 PM UPDATE... THURSDAY...LOW RISK OF ELEVATED FIRE WEATHER CONCERNS WITH MIN RH VALUES DIPPING TO 25 TO 30 PERCENT ALONG WITH WSW WIND GUSTS UP TO 20 MPH. SUSTAINED WINDS WILL BE LESS 10-15 MPH BUT AGAIN GUSTS UP TO 20 MPH AND PERHAPS 25 MPH ARE POSSIBLE. WHILE ISOLATED OR WIDELY SCATTERED SHOWERS ARE POSSIBLE TUE MOST OF THE REGION WILL BE DRY WITH ANY RAINFALL LIKELY LESS THAN 0.25 INCHES.
-- End Changed Discussion --
&& .BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE. MA...RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR MAZ002>004- 008>012-026. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 9 AM EDT TUESDAY FOR ANZ235. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 9 AM EDT TUESDAY FOR ANZ250. SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 3 PM EDT TUESDAY FOR ANZ254. SMALL CRAFT ADVISORY FROM 1 AM TO 3 PM EDT TUESDAY FOR ANZ255- 256.
-- End Changed Discussion --
&& $$ SYNOPSIS...NOCERA NEAR TERM...BELK/JWD SHORT TERM...BELK LONG TERM...NOCERA AVIATION...NOCERA/JWD MARINE...BELK/NOCERA FIRE WEATHER...STAFF

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