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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBOX 250745 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 345 AM EDT SAT APR 25 2015 .SYNOPSIS... UNSEASONABLY COOL WEATHER CONTINUES THROUGH THIS WEEKEND WITH SPOTTY SHOWERS OR SPRINKLES. PERIODS OF UNSETTLED WEATHER AND BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH MOST OF NEXT WEEK AS WELL. && .NEAR TERM /THROUGH TODAY/... LATEST SATELLITE DATA INDICATES SKIES ARE NOW MOSTLY CLEAR OVER SOUTHERN NEW ENGLAND. MESONET TEMPERATURES ARE STARTING TO REFLECT THIS AS WELL...WITH MORE THAN A FEW READINGS AROUND FREEZING...OR LOWER. CURRENT FREEZE WARNINGS WILL CONTINUE THIS MORNING. THE UPPER LEVEL COLD POOL SHIFTS SLIGHTLY FURTHER AWAY FROM OUR REGION TODAY....BUT STILL CLOSE ENOUGH TO HAVE SOME INFLUENCE ON OUR WEATHER. THE MAIN CHANGES WILL BE SLIGHTLY LESS CLOUDS... PARTICULARLY TOWARD SOUTHWEST NEW ENGLAND. THE SURFACE LAYER WILL BE DRIER...SO MOST ATTEMPTS AT PRECIPITATION SHOULD EVAPORATE ON THE WAY DOWN. DECENT MIXING...SO WE SHOULD SEE ANOTHER GUSTY DAY WITH PEAK GUSTS AROUND 20 KT/25 MPH. MORE SUNSHINE SHOULD MEAN SLIGHTLY HIGHER MAX TEMPERATURES THAN FRIDAY. && .SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/... WEAK RIDGE BUILDS OVER SOUTHERN NEW ENGLAND TONIGHT...PROVIDING CLEARING SKIES AND LIGHT WINDS. RADIATIONAL COOLING WITH DEW POINTS IN THE 30S...SO MINIMUM TEMPERATURES SHOULD BE IN THE 30S ONCE MORE. FOR SUNDAY...THE UPPER LOW IS EXPECTED TO MOVE SLIGHTLY CLOSER TO OUR REGION. THUS WE WILL BE IN A MORE FAVORABLE POSITION FOR DIURNAL CLOUDS AND SHOWERS. SO...AS HAS BEEN THE CASE OVER THE LAST SEVERAL DAYS...SKIES SHOULD START OFF PARTLY TO MOSTLY SUNNY. THEN CLOUDS DEVELOP ALONG WITH A FEW SPOTTY SHOWERS...ESPECIALLY NEAR AND NORTH OF THE MASS PIKE. EXPECTING MAX TEMPERATURES TO BE MAINLY IN THE 50S. IF A LITTLE MORE SUNSHINE WORKS THROUGH THE CLOUDS ACROSS THE LOWER CT VALLEY...READINGS MAY TOUCH 60 IN A FEW SPOTS THERE. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... HIGHLIGHTS... * BELOW NORMAL TEMPERATURES THROUGH AT LEAST THE MIDDLE OF NEXT WEEK * SCATTERED DIURNAL SHOWERS THIS WEEKEND INTO MID-NEXT WEEK * LOW CONFIDENCE ON COASTAL SYSTEM THU OR FRI OVERVIEW AND MODEL PREFERENCES... PERSISTENT UPPER LEVEL BLOCKING PATTERN REMAINS IN PLACE ACROSS THE LOWER 48 WITH FEW CHANGES EXPECTED INTO THE MIDDLE OF NEXT WEEK. HOWEVER...NOTING SOME SUBTLE CHANGES TOWARD NEXT THU/FRI WHICH ARE SHOWING UP AT LEAST ON THE LAST COUPLE OF MEDIUM RANGE OPERATIONAL RUNS OF BOTH THE GFS AND ECMWF THAT ARE STARTING TO SIGNAL THE BREAKING DOWN OF THE UPPER TROUGH PATTERN. THE GEFS AND EC ENSEMBLES CONTINUE TO KEEP SLOW PROGRESSION OF SYSTEMS...SO STILL QUITE A BIT OF TIMING AND TRACK ISSUES TO CONTEND WITH THIS FORECAST CYCLE. NEGATIVE NAO/AO PATTERN REMAINS IN PLACE...KEEPING BELOW NORMAL TEMPS AND PERIODS OF UNSETTLED WEATHER THROUGH AT LEAST THE MIDDLE OF NEXT WEEK AS CUTOFF H5 LOW PRES CONTINUES TO SIT AND SPIN ACROSS THE NORTHEAST INTO EASTERN QUEBEC AND THE MARITIMES. MODELS SIGNALING A STRONGER SHORT WAVE THAT WILL DROP S ACROSS THE REGION OUT OF EASTERN CANADA IN THE UPPER FLOW WILL DROP ACROSS THE REGION BRINGING A BETTER CHANCE FOR SHOWERS ALONG WITH AN ENHANCED N-NE WIND FLOW. ONCE THIS SHORT WAVE MOVES S...THE UPPER SYSTEM MAY START TO SHIFT E BUT TIMING IS STILL VERY MUCH IN QUESTION DUE TO WIDE MODEL SOLUTION SPREAD BEYOND TUESDAY. ANOTHER QUESTION AT THIS POINT IS THE POTENTIAL COASTAL SYSTEM THAT WORKS OFF THE SE U.S. COAST LATE WED OR THU. THE 12Z MODEL RUNS CONTINUE TO KEEP THE BLOCKING ACROSS THE NORTHEAST WHICH MAY ACTUALLY SHUNT THE COASTAL SYSTEM S OF THE REGION. NOTING A RATHER STRONG SYSTEM ON THE 12Z ECMWF...WHICH TENDS TO DEVELOP AND SLOW THE SYSTEM AS IT PASSES S OF NEW ENGLAND THU NIGHT OR FRIDAY... WHILE THE GFS IS A MORE OPEN WAVE BUT STILL PUSHES OFFSHORE. WILL STILL NEED TO WATCH FUTURE MODEL TRENDS BEFORE WRITING THIS ONE OFF FOR NOW. USED A BLEND OF AVAILABLE GUIDANCE INTO TUESDAY...WHICH SHOWED GOOD CONSISTENCY WITH THE PREVIOUS FORECAST...THEN TRANSITIONED OVER TO ENSEMBLE GUIDANCE THROUGH THE REMAINDER OF NEXT WEEK. DETAILS... * MONDAY THROUGH TUESDAY NIGHT...MODERATE CONFIDENCE. RATHER POTENT H5 SHORT WAVE AND ASSOCIATED BACKDOOR /OF SORTS/ SURFACE REFLECTION ROTATE SW ACROSS THE REGION DURING THIS TIMEFRAME. LOOKS LIKE THE BEST ENERGY AND PRECIP CHANCES WILL PUSH ACROSS MON NIGHT THROUGH INTO TUESDAY NIGHT. WINDS ALSO SHIFT TO N-NE AND INCREASE. GUSTS UP TO AROUND 25 KT POSSIBLE MAINLY ALONG E COASTAL AREAS. MAY SEE SOME APPRECIABLE RAINFALL WITH QPF OF 0.2 TO 0.3 INCHES ALONG THE E COAST AS LOW LEVEL MOISTURE INCREASES WITH THE ONSHORE WIND. * WEDNESDAY THROUGH FRIDAY...LOW CONFIDENCE. STILL QUITE A BIT OF UNCERTAINTY WITH SOUTHERN STREAM SYSTEM THAT MAY MAKE THE TURN UP THE EASTERN SEABOARD. HOWEVER...12Z MODEL TRENDS ARE TENDING TO KEEP THIS SYSTEM TO THE S THANKS TO THE UPPER LEVEL LOW THAT MAY PUSH THE SOUTHERN SYSTEM OFFSHORE. THIS THIS WAS A RECENT TREND THOUGH...DID KEEP CHANCE POPS GOING FROM THU AFTERNOON THROUGH A GOOD PORTION OF FRIDAY DUE TO THE MODEL/S HANDLING OF THE SOUTHERN STREAM UPPER LEVEL SYSTEM. TEMPS ARE ALSO TRYING TO CREEP BACK CLOSER TO SEASONAL LEVELS DURING THIS TIMEFRAME AS WELL. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. .SHORT TERM /THROUGH SUNDAY/... TODAY...HIGH CONFIDENCE. VFR. POSSIBLE BRIEF MVFR IN SPOTTY SHOWERS. NORTHWEST WINDS GUSTING AROUND 20 KNOTS. TONIGHT...HIGH CONFIDENCE. VFR WITH LIGHT WINDS. SUNDAY...HIGH CONFIDENCE. VFR WITH LIGHT WINDS. SEA BREEZES LIKELY. POSSIBLE BRIEF MVFR IN SPOTTY SHOWERS. KBOS TAF...HIGH CONFIDENCE IN OVERALL TAF. KBDL TAF...HIGH CONFIDENCE IN OVERALL TAF. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY... MODERATE CONFIDENCE SUNDAY THROUGH TUESDAY...LOW CONFIDENCE WEDNESDAY. SUNDAY...MAINLY VFR. MAY SEE BRIEF MVFR CONDITIONS IN SCT SHOWERS. SEA BREEZE DEVELOPMENT POSSIBLE ALONG E COAST. MONDAY-TUESDAY...AREAS OF MVFR CIGS/VSBYS POSSIBLE WITH BETTER CHANCE FOR SHOWERS. N-NE WINDS INCREASE ESPECIALLY ALONG E COAST. MAY SEE GUSTS TO 20-25 KT FROM PLYMOUTH COUNTY S TO CAPE COD AND THE ISLANDS MAINLY MON NIGHT AND TUE. WEDNESDAY...VFR WITH MAINLY DRY CONDITIONS. LIGHT N-NW WINDS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... WEST-NORTHWEST WINDS GUST TO 20 KT...WITH A FEW GUSTS TO 25 KT OFFSHORE. SEAS LINGER NEAR 5 FEET ON THE OUTER WATERS THIS MORNING...THEN SUBSIDE. TONIGHT AND SUNDAY...WINDS AND SEAS BELOW SMALL CRAFT ADVISORY CRITERIA. EXPECT NW WINDS TO SHIFT TO NE SUNDAY...BUT REMAIN BELOW 15 KT. SEA BREEZES LIKELY SUNDAY. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE. MONDAY...N-NW WINDS INCREASE BUT REMAIN BELOW SMALL CRAFT. SEAS REMAIN BELOW 5 FT. MONDAY NIGHT THROUGH TUESDAY NIGHT...N-NE WINDS INCREASE...GUSTING TO 25-30 KT. SEAS BUILD UP TO 5-7 FT...HIGHEST ON THE EASTERN OUTER WATERS DURING TUE. MODERATE PROBABILITY FOR SMALL CRAFT. WEDNESDAY...WINDS BECOME NW AND DIMINISH. MAY SEE LEFTOVER GUSTS TO 25 KT EARLY. SEAS WILL REMAIN AOA 5 FT MAINLY ON THE OUTER WATERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR CTZ002>004. MA...NONE. RI...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR RIZ001-003. MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR ANZ250- 256. SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ254-255. && $$ SYNOPSIS...BELK/EVT NEAR TERM...BELK/EVT 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.