Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 080003 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 802 PM EDT TUE JUL 7 2015 .SYNOPSIS... WARM AND MUGGY NIGHT THANKS TO A TROPICAL AIRMASS OVER THE REGION. A COLD FRONT MOVES ACROSS THE AREA TOMORROW BRINGING SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY DOWNPOURS. THE FRONT MOVES SOUTH OF NEW ENGLAND WEDNESDAY NIGHT BRINGING SHOWERS. COOLER TEMPERATURES EXPECTED ON THURSDAY BEHIND A COLD FRONT...WITH A RISK FOR A PERIOD OF SHOWERS MAINLY LATE THURSDAY AND THURSDAY NIGHT TO THE SOUTH OF THE MASSACHUSETTS TURNPIKE. HIGH PRESSURE WILL THEN BRING DRY AND WARM WEATHER FRIDAY...SATURDAY AND PROBABLY INTO MUCH OF SUNDAY. A PERIOD OR TWO OF UNSETTLED WEATHER MAY ARRIVE EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 730 PM UPDATE... SCATTERED SHOWERS AND THUNDERSTORMS ARE BEGINNING TO WANE THIS EVENING AS SHORTWAVE OVER NYC PUSHES EASTWARD. SEVERAL REPORTS OF FLOODING AND SOME WIND DAMAGE...SO THE POTENTIAL FOR STRONG STORMS IS POSSIBLE FOR TOMORROW. A FEW SCT SHOWERS MAY LINGER TIL 10 PM AS THE STORMS DIE OFF...HOWEVER THE RISK FOR STRONG STORMS SEEMS LOW AFTER 8 PM. ESPECIALLY SINCE SHORTWAVE ALOFT WILL BE PUSHING DRY AIR INTO THE REGION AS WELL AS THE LOST OF INSTABILITY. SOUTHERN NEW ENGLAND WILL CONTINUE TO BE IN THE WARM SECTOR SO FOG POTENTIAL IS STILL THERE...JUST A LOW CONFIDENCE ON WHETHER DENSE FOG WILL OCCUR. OTHERWISE WIND GUSTS WILL BEGIN TO WEAKEN OVER THE NEXT HOUR AS MIXING COMMENCES. PREVIOUS DISCUSSION... MOSTLY CLOUDY SKIES OVERNIGHT AND DEWPOINTS IN THE 70S WILL NOT ALLOW FOR TEMPS TO COOL VERY MUCH. IN FACT MANY SITES WILL STRUGGLE TO GET BELOW 70F. STILL SOME MIXING COULD OCCUR...ESP ACROSS THE COASTAL REGIONS WHICH COULD LIMIT FOG POTENTIAL. STILL CANT RULE IT OUT AS WELL AS LOW STRATUS. LOW CONFIDENCE ON HOW WIDE SPREAD IF/IT WILL GET SO FOR NOW BELIEVE THAT PATCHY FOG MAY OCCUR. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... ***FLASH FLOOD WATCH ISSUED FOR LATE WEDNESDAY MORNING INTO WEDNESDAY EVENING FOR ALL OF RHODE ISLAND AND MOST OF SOUTHEAST MASSACHUSETTS*** 8 PM UPDATE... HAVE DECIDED TO HOIST A FLASH FLOOD WATCH FOR ALL OF RHODE ISLAND AND SOUTHEAST MA LATE WEDNESDAY MORNING INTO WEDNESDAY EVENING. A NUMBER OF THINGS HAVE US CONCERNED INCLUDING 2+ INCH PWATS...K INDEX VALUES AROUND 36...ALONG WITH CAPE VALUES LIKELY TO REACH OR EXCEED 1000 J/KG WITH DAYTIME HEATING. COMBINED ALL THOSE FACTORS OVER THE HIGHLY URBANIZED AREAS...FELT IT WAS WORTH A FLASH FLOOD WATCH. LATER SHIFTS MAY HAVE TO EXPAND IT A BIT FURTHER NORTHWEST DEPENDING ON WHAT THE LATEST GUIDANCE DEPICTS. TOMORROW... ANOTHER SHORTWAVE WILL MOVE ACROSS WESTERN NEW ENGLAND TOMORROW. THIS WILL BRING A COLD FRONT ACROSS THE REGION. THERE IS STILL A LARGE SPREAD IN GUIDANCE ON TIMING OF THE FRONT WITH THE HI-RES/NAM FASTER VS THE GFS/EC/RGEM. WENT CONSERVATIVE AND PLAYED DOWN THE MIDDLE OF THE ROAD FOR TIMING. SOUTHWEST FLOW CONTINUING INTO THE MORNING HOURS...AND WITH A COLD FRONT APPROACHING COULD SEE SCT SHOWERS AND THUNDERSTORMS DEVELOP BY LATE MORNING LASTING INTO THE EVENING HOURS. BIGGEST THREAT WITH THE STORMS WILL BE HEAVY RAIN LEADING TO LOCALIZED FLOODING. IN FACT IT APPEARS THAT THE FRONT WILL SLOW DOWN ITS SOUTHWARD MOVEMENT AND STALL SOMEWHERE ACROSS THE THE SOUTH COAST. WITH THIS SLOW MOVEMENT AND THE WINDS BEING PARALLEL WITH THE FRONT...COULD SEE TRAINING CELLS. ALSO APPEARS THAT THERE WILL BE GOOD BL MOISTURE CONVERGENCE ALONG THE FRONT.CONSIDERED ISSUING A FLASH FLOOD WATCH FOR TOMORROW AFTER...ESP FOR THE 95 CORRIDOR AND POINTS SOUTH AND EAST FOR 2+ INCH PWATS...COMBINED WITH TRAINING CELLS...BUT HAVE A LOW CONFIDENCE. SOMETHING THE NEXT SHIFT MAY NEED TO THINK ABOUT. CANNOT RULE OUT A FEW STRONG THUNDERSTORMS TOMORROW...BUT HAVE A LOW CONFIDENCE AS SHEAR AND LAPSE RATES ARE STILL WEAK. TEMPS ALOFT BARELY COOL A DEGREE KEEPING THE ATMOSPHERE PRETTY STABLE AND WITH THE FRONT BEING DISPLACED BY THE SHORTWAVE...REALLY LOSING A GOOD AMOUNT OF FORCING. STILL WITH 70F DEWPOINTS CANT DISMISS THE POTENTIAL FOR A QUICK SPIN-UP OR WET MICROBURST. TOMORROW NIGHT... WEAK COLD FRONT WILL STALL SOMEWHERE ACROSS THE SOUTH SHORE OVERNIGHT. A MID-LEVEL WAVE WILL RIDE ALONG THE FRONT DEVELOPING A WEAK LOW PRESSURE SYSTEM. AS THIS SYSTEM MOVES CLOSER...COULD SEE SCT SHOWERS AND PERHAPS A THUNDERSTORM DEVELOP OVERNIGHT. STORM MOTION WILL BE MOVING FORM THE SW TO THE NE AND INCREASE IN AREAL COVERAGE THROUGH THE NIGHT. TEMPS WILL BE COOLER AS FRONTAL PASSAGE WILL BRING IN LOWER DEWS AND TEMPS. A COMFORTABLE NIGHT AHEAD...BUT A FEW SCT SHOWERS. && .LONG TERM /THURSDAY THROUGH TUESDAY/... HIGHLIGHTS... * COOLER THU/THU NIGHT BUT UNCERTAIN IF WE SEE A PERIOD OF SHOWERS * MAINLY DRY AND WARM FRI/SAT AND PROBABLY INTO MUCH OF SUNDAY * A PERIOD OR TWO OF UNSETTLED WEATHER POSSIBLE EARLY NEXT WEEK DETAILS... THURSDAY AND THURSDAY NIGHT... COOLER AND LESS HUMID WEATHER WILL BE USHERED IN ON THURSDAY BEHIND A COLD FRONT. DEPARTING WAVE MAY RESULT IN SOME LEFT OVER MORNING SHOWERS....ESPECIALLY ACROSS SOUTHEAST NEW ENGLAND. OTHERWISE...A LOT OF CLOUDS EXPECTED ON THURSDAY. MAIN UNCERTAINTY IS IF SOME OF OUR AREA IS AFFECTED BY AN MCS LATE THU INTO THU NIGHT. WE WILL BE ON THE COOL SIDE OF THE BOUNDARY WITH BASICALLY NO SURFACE INSTABILITY. MANY TIMES THESE MCS/S TEND TO GRAVITATE TO WHERE THE HIGHEST INSTABILITY RESIDES...WHICH IN THIS CASE WILL BE TO OUR SOUTHWEST. SO WOULD NOT BE SURPRISED IF MUCH OF THE AREA ENDED UP DRY LATE THU/THU NIGHT. NONETHELESS...A PERIOD OF SHOWERS IS CERTAINLY POSSIBLE WITH THE BEST CHANCE SOUTH OF THE MA PIKE AND ESPECIALLY NORTHERN CT. NOT CONCERNED ABOUT THUNDER OR SEVERE WEATHER WITH LIMITED INSTABILITY. HIGH TEMPS ON THU WILL MAINLY BE IN THE 70S...AND MAY STRUGGLE TO REACH 70 ON THE IMMEDIATE EASTERN MA COAST. FRIDAY THROUGH SUNDAY... NORTHWEST FLOW ALOFT SHOULD PROVIDE DRY WEATHER WITH WARM AFTERNOON/S. HIGHS SHOULD REACH INTO THE 80S IN MOST LOCATIONS FRI/SAT AND SUN AWAY FROM THE COAST. ITS POSSIBLE THAT A FEW LOCATIONS FLIRT WITH 90 ON SUNDAY...IF CLOUDS AND ANY SCATTERED PRECIPITATION WITH AN APPROACHING SHORTWAVE HOLD OFF UNTIL SUN NIGHT OR MON. SUNDAY NIGHT THROUGH TUESDAY... LOW CONFIDENCE FORECAST ESPECIALLY WITH TIMING...BUT A PERIOD OR TWO OF UNSETTLED WEATHER IS CERTAINLY POSSIBLE. THE MODELS DO SHOW A FEW SHORTWAVES DROPPING INTO OUR REGION IN NORTHWEST FLOW ALOFT...SO THE RISK FOR A PERIOD OR TWO OF SHOWERS WITH SOME EMBEDDED THUNDERSTORMS EXISTS. TIMING UNCERTAIN...SO WILL CARRY LOW POPS SUN NIGHT INTO TUE BUT NOT EXPECTING A WASHOUT. SEASONABLE TEMPS MUCH OF THE TIME. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY NIGHT/... TONIGHT...MODERATE CONFIDENCE. VFR TO START WITH WANING SHOWERS/-TSRA. CONDITIONS OVERNIGHT WILL LOWER TO MVFR TO LOCALIZED IFR. SOME GUIDANCE KEEPS STRATUS AT BAY...BUT BELIEVE THAT IS UNDERDONE. MVFR FOG MAY DEVELOP AS WELL ACROSS THE INTERIOR. COULD SEE IFR VSBYS ACROSS COASTAL REGION TONIGHT. WEDNESDAY INTO WEDNESDAY NIGHT...MODERATE CONFIDENCE. APPROACHING COLD FRONT WILL BRING SCT -SHRA AND -TSRA ACROSS THE REGION. ANTICIPATE MVFR/IFR CIGS WITHIN ANY -TSRA AS WELL AS VSBY RESTRICTIONS. OTHERWISE VFR FOR THE DAY. FRONT WILL STALL ACROSS SOUTH SHORE ALLOWING FOR SHOWERS TO OVERSPREAD TOMORROW NIGHT. CIGS COULD DROP TO MVFR. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK...THURSDAY THROUGH SUNDAY... THURSDAY AND THURSDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MAINLY VFR CONDITIONS BUT CAN NO RULE OUT A PERIOD OF MVFR CIGS/VSBYS IN A CLUSTER OF SHOWERS...HIGHEST RISK SOUTH OF MA PIKE LATE THU INTO THU NIGHT. FRIDAY AND SATURDAY...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS. SUNDAY...MODERATE CONFIDENCE. MAINLY VFR BUT MAY SEE MVFR-IFR CONDITIONS DEVELOP ACROSS THE INTERIOR LATE SUN OR SUNDAY NIGHT...BUT THAT IS HIGHLY UNCERTAIN. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE. TONIGHT...MAY SEE LEFTOVER 20-25 KT GUSTS THIS EVENING THEN DIMINISH AFTER SUNSET. PATCHY FOG DEVELOPS WITH REDUCED VSBYS...BELOW 3 MILES. WEDNESDAY...SW WINDS WILL INCREASE...WITH GUSTS UP TO 20 KT ON THE SOUTHERN OUTER WATERS. EXPECT SEAS TO REMAIN BELOW 5 FT...THOUGH MAY BRIEFLY REACH 5 FT AT TIMES. CHANCE OF SHOWERS/THUNDERSTORMS SOME WITH HEAVY RAINFALL. WEDNESDAY NIGHT...FRONT WILL SIT ACROSS THE SOUTH SHORE...WITH A LOW PRESSURE RIDING ALONG IT COULD SEE INCREASE IN SEAS AND WINDS. SHOWERS WILL ALSO INCREASE FOR THE SOUTHERN WATERS. OUTLOOK...THURSDAY THROUGH SUNDAY... WEAK PRESSURE GRADIENT SHOULD KEEP WINDS/SEAS BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH THE WEEKEND. OVERALL...NICE BOATING WEATHER EXPECTED. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...FLASH FLOOD WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR MAZ013-015>022. RI...FLASH FLOOD WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR RIZ001>007. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ231- 251. SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ250. && $$ SYNOPSIS...FRANK/DUNTEN NEAR TERM...DUNTEN SHORT TERM...FRANK/DUNTEN LONG TERM...FRANK AVIATION...FRANK/DUNTEN MARINE...FRANK/DUNTEN

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