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 231418 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1018 AM EDT THU OCT 23 2014 .SYNOPSIS...
-- Changed Discussion --
A POWERFUL EARLY SEASON COASTAL STORM WILL PASS SOUTHEAST OF NANTUCKET THIS EVENING. RAIN WILL BECOME MORE SHOWERY THIS AFTERNOON BUT STRONG WINDS WILL CONTINUE TO AFFECT EASTERN NEW ENGLAND. SHOWERS CONTINUE TO DIMINISH FRIDAY AS THE STORM SLOWLY PULLS AWAY FROM NEW ENGLAND. SHOWERS POSSIBLE AGAIN SATURDAY EVENING AND OVERNIGHT AS LOW PRES MOVES INTO SOUTHERN QUEBEC. DRY AND SEASONABLY COOL WEATHER RETURNS SUNDAY INTO EARLY NEXT WEEK.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
* URBAN/SMALL STREAM FLOODING...STRONG WINDS AND COASTAL FLOODING * FORECAST LARGELY IN GOOD SHAPE. MINOR ADJUSTMENTS MADE TO MATCH CURRENT RADAR/OBS TRENDS. SATELLITE SHOWS CLOSED LOW S OF NEW ENGLAND...WHICH WILL SLOWLY BRING SURFACE LOW SE OF NANTUCKET THIS EVENING. 1) URBAN/SMALL STREAM FLOODING RADAR SHOWED MAIN BAND OF HEAVY RAIN...ASSOCIATED WITH MID LEVEL DEFORMATION ZONE...SLOWLY SHIFTING INTO CENTRAL AND WESTERN NEW ENGLAND. FOCUS THROUGH MIDDAY WILL BE ACROSS SW NH AND W MA WHERE SEVERAL FLOOD WARNINGS HAVE BEEN POSTED...BUT THIS SHOULD PUSH OUT OF NEW ENGLAND EARLY THIS AFTERNOON. RAINFALL WILL DIMINISH ACROSS MERRIMACK VALLEY WHERE FLOOD AND FLASH FLOOD WARNINGS REMAIN POSTED AS WELL. ACROSS REST OF SOUTHERN NEW ENGLAND...HIGH-RES MODELS SHOW POTENTIAL FOR ADDITIONAL SCATTERED SHOWERS/ISOLATED THUNDER THROUGH AFTERNOON. ALREADY SEEING EVIDENCE OF THIS S OF NEW ENGLAND...AND SOME OF THIS SHOULD AFFECT CAPE COD AND ISLANDS WHERE MODELS SHOW FEW HUNDRED J/KG OF ML/MU CAPE THIS AFTERNOON. STILL HAVE POTENTIAL FOR LOCALLY HEAVY RAINFALL BUT NOT ENOUGH OF WIDESPREAD THREAT TO KEEP FLOOD WATCH GOING. 2) STRONG WINDS: STILL SEEING STRONG WINDS /NEAR 40KT/ FROM BOSTON TO NE MA. WIND FIELD ALOFT DIMINISHES THROUGH EARLY AFTERNOON...BUT REMAINS HIGH ENOUGH TO JUSTIFY ADVISORY GIVEN IMPACT ON FULLY LEAVED TREES. SHOULD SEE ANOTHER ROUND OF STRONG WINDS ARRIVE LATER THIS AFTERNOON AND EVENING. 3) COASTAL FLOODING: SEE TIDES/COASTAL FLOODING SECTION BELOW.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... TONIGHT... OCCLUDED LOW SLOWLY MOVES SEAWARD. HOWEVER LIGHTER COMMA-HEAD RAINS WILL LIKELY IMPACT THE REGION MUCH OF THE NIGHT. HOWEVER THE FLOOD THREAT APPEARS TO DIMINISH. GUSTY NORTHEAST WINDS SHOULD BEGIN TO SLACKEN LATER IN THE EVENING AS THE LOW LEVEL JET WEAKENS. FRIDAY... FURTHER IMPROVEMENT ESPECIALLY DURING THE AFTERNOON FROM WEST TO EAST AS COMMA-HEAD EXITS AND MOVES OFFSHORE. RISK FOR SHOWERS WILL BE HIGHEST IN THE MORNING WITH BEST CHANCE OF DRYING AND LATE DAY SUNSHINE IS ACROSS THE CT RVR VLY. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... * SHOWERS POSSIBLE AGAIN SATURDAY AS LOW PRES MOVES INTO QUEBEC * MAINLY DRY AND SEASONABLE WEATHER EARLY NEXT WEEK OVERALL THE 12Z MODEL SUITE IS IN FAIRLY GOOD AGREEMENT THROUGH THE LONG TERM. THERE ARE SOME DISCREPANCIES IN THE MESOSCALE DETAILS BUT OTHERWISE THEY ARE IN GOOD AGREEMENT. AFTER THE COASTAL STORM CURRENTLY AFFECTING THE REGION MOVES AWAY FROM SOUTHERN NEW ENGLAND...THE WEATHER STARTS TO DRY OUT AND BECOME MORE SEASONABLE. THERE ARE A COUPLE OF COLD FRONTS EXPECTED TO MOVE THROUGH THE REGION AND EACH OF THESE MAY BRING SOME SHOWERS WITH THEM. SATURDAY...ANOTHER UPPER LEVEL TROUGH MOVES OVER THE NORTHEAST WITH LOW PRESSURE MOVING THROUGH SOUTHERN QUEBEC AND INTO THE MARITIMES. THE MODELS DON/T SHOW A WHOLE LOT OF MOISTURE OR A BIG WIND SHIFT WITH THIS FRONT BUT WE COULD SEE SOME SHOWERS. THE GFS HAS A STRONGER LOW LEVEL JET THAN THE ECMWF WHICH COULD ENHANCE THE AMOUNT OF RAINFALL BUT THERE IS STILL MUCH TO BE SEEN WITH THIS SYSTEM. SUNDAY THROUGH TUESDAY...HIGH PRESSURE STARTS TO BUILD INTO SOUTHERN NEW ENGLAND BRINGING DRY AND SEASONABLE WEATHER. TEMPERATURES BEGIN TO CLIMB AND MAY WARM TO WELL ABOVE NORMAL BY TUESDAY. WEDNESDAY...LOW PRESSURE MOVING THROUGH THE GREAT LAKES AND INTO QUEBEC MAY BRING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND. ANOTHER CHANCE OF SOME SHOWERS POSSIBLE WITH THIS FRONT BUT PLENTY OF UNCERTAINTY. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THU/... TODAY... BAND OF HEAVY RAIN WITH EMBEDDED T-STORMS WILL SLOWLY LIFT NORTHWARD. MARGINAL IFR/MVFR CONDITIONS CONTINUE. GUSTY NE WINDS CONTINUE WITH STRONGEST WINDS FOCUSED ACROSS NORTHEAST MA. SOME VFR CAPE/ISLANDS GRADUALLY DIMINISH AGAIN LATER THIS MORNING. TONIGHT... IFR EASTERN MA WITH MVFR ELSEWHERE. SLOW IMPROVEMENT WITH SHOWERS BECOMING LESS NUMEROUS AND WINDS SLOWLY EASING. FRIDAY... MVFR BUT TRENDING TOWARD VFR LATE. SCATTERED SHOWERS BECOMING LESS NUMEROUS AS THE DAY PROGRESSES. NNW WINDS 10-20 KT. KBOS...HIGH CONFIDENCE IN TAF ON TRENDS BUT LOWER CONFIDENCE ON EXACT TIMING OF DETAILS. KBDL...HIGH CONFIDENCE IN TAF ON TRENDS BUT LOWER CONFIDENCE ON EXACT TIMING OF DETAILS. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY... SATURDAY THROUGH MONDAY...MODERATE CONFIDENCE. VFR. LOW PROBABILITY OF SCATTERED SHOWERS SATURDAY. && .MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY/... *** DANGEROUS COASTAL STORM IMPACTS THE NEW ENGLAND WATERS *** THIS AFTERNOON... COASTAL STORM SOUTH OF NEW ENGLAND WILL BRING NE GALES AND DANGEROUS SEAS TO THE MASSACHUSETTS AND RHODE ISLAND WATERS. STRONGEST WINDS AND LARGEST SEAS WILL OCCUR OVER THE NORTHERN MA INTO NH COASTAL WATERS. WINDS AND SEAS NOT QUITE AS INTENSE THIS AFTERNOON BUT NEVERTHELESS DANGEROUS SEA CONDITIONS. HEAVY RAIN SQUALLS WITH EMBEDDED STORMS MAINLY CONFINED TO THE NORTHERN MA WATERS THROUGH MIDDAY...WITH MORE SCATTERED SHOWERS AND STORMS ELSEWHERE. TONIGHT... LOW SLOWLY WEAKENS AND MOVES SEAWARD WITH WINDS BECOMING SUBGALE AS THE NIGHT PROGRESSES. ALSO ANY LINGERING RAIN SQUALLS NOT AS INTENSE AS THIS MORNING. FRIDAY... SLOW IMPROVEMENT CONTINUES WITH WINDS BECOMING MORE NNW AND SHOWERS BECOMING LESS NUMEROUS LATE IN THE DAY AND AT NIGHT. OUTLOOK...SATURDAY THROUGH MONDAY... SATURDAY AND SUNDAY...MODERATE CONFIDENCE. AFTER A BRIEF LULL...SEAS AND WINDS WILL INCREASE AHEAD OF A COLD FRONT. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR AT LEAST A PORTION OF THE WATERS. MONDAY...MODERATE CONFIDENCE. WINDS AND SEAS DIMINISH AS HIGH PRESSURE BUILDS OVER THE WATERS.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING... LAST NIGHT/S HIGH TIDE YIELDED A STORM SURGE OF 1.5 FT TO 2.0 FT. THIS COMBINED WITH LARGE WAVE ACTION RESULTED IN WIDESPREAD MINOR COASTAL FLOODING/INUNDATION FROM PLYMOUTH COUNTY NORTHWARD. BOTH ETSS AND ESTOFS ARE ABOUT 50% TOO LOW WITH THEIR SURGE VALUES WHEN COMPARED TO CURRENT OBSERVATIONS. THUS HAVE INCREASED GUID BY 50 PERCENT. WE ARE NOW RAMPING UP TO THE LATE MORNING/MIDDAY HIGH TIDE CYCLE. PRIOR STORM SURGE FORECAST LOOKS GOOD AND HAVE NOT CHANGED. AT 0945 EDT THE SURGE WAS RUNNING AT 2 FEET AT BOS...ABOUT TWICE AS HIGH AS THE GUIDANCE. WAVES JUST OFFSHORE RUNNING 16 TO 18 FEET. THE NNE GRADIENT APPEARS TO BE RETIGHTENING FOR A PERIOD AS ADVERTISED BY SHORT TERM MODELS AND THINK WAVES WILL HOLD AT THESE HEIGHTS OR POSSIBLY EVEN INCREASE ANOTHER FOOT OR TWO BEFORE SUBSIDING THIS EVENING. THE ASTRONOMICAL TIDE IS ABOUT A HALF FOOT HIGHER TODAY THAN LAST NIGHT AND WILL ALLOW WAVE ACTIVITY TO RUNUP SOMEWHAT FURTHER ALONG THE BEACH. HENCE...THE IMPACT COULD BE A LITTLE HIGHER THAN WHAT WAS EXPERIENCED LAST NIGHT. ALSO...WE HAVE THE ISSUE OF THIS BECOMING A FAIRLY LONG DURATION EVENT WITH CONTINUED EROSION OF THE DUNE SLOPES ALONG SANDY BEACH AREAS. WILL KEEP THE COASTAL FLOOD ADVISORY IN PLACE FOR SALISBURY TO CAPE ANN AND HULL TO PLYMOUTH. OUR GREATEST CONCERN CONTINUES TO BE BEACH EROSION IN THE SALISBURY AND PLUM ISLAND AREA. THERE MAY BE SOME SPLASHOVER AND MINOR BEACH EROSION FOR THE HIGH TIDE TONIGHT BUT DO NOT BELIEVE IT WILL REACH AN ADVISORY LEVEL. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR CTZ004. MA...WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR MAZ005>007- 012>021. COASTAL FLOOD ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MAZ007-019. NH...WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR NHZ012. RI...WIND ADVISORY UNTIL 11 PM EDT THIS EVENING FOR RIZ001>007. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ231>234-236-254-255. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR ANZ230-250-251- 256. GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR ANZ235-237. && $$ SYNOPSIS...NOCERA NEAR TERM...JWD SHORT TERM...NOCERA LONG TERM...RLG AVIATION...NOCERA/DOODY/RLG MARINE...NOCERA/RLG/JWD TIDES/COASTAL FLOODING...THOMPSON

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