Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 310746 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 345 AM EDT THU JUL 31 2014 .SYNOPSIS... A FEW HIT AND MISS SHOWERS/THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND AGAIN FRIDAY AFTERNOON...MAINLY NORTHWEST OF I-95. THE WEEKEND FORECAST REMAINS UNCERTAIN BUT THE POTENTIAL FOR A PERIOD OF WET WEATHER CONTINUES. SEASONABLE TEMPS ARE THEN EXPECTED EARLY NEXT WEEK && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ***A FEW STRONG THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON NORTHWEST OF I-95*** A POTENT SHORTWAVE WILLS MOVE ACROSS NORTHERN NEW ENGLAND TODAY. WHILE THE BEST DYNAMICS/FORCING WILL PASS TO OUR NORTH...STILL EXPECT TO SEE SOME IMPACT...AT LEAST ACROSS OUR NORTHWEST ZONES. LATEST GUIDANCE SHOWS THAT CAPES ON THE ORDER OF 500 TO 1000 J/KG WILL COMBINED WITH 0 TO 6 KM SHEAR VALUES ON THE ORDER OF 40 TO 45 KNOTS. IN ADDITION...500 MB TEMPS DROP TO AROUND -16C IN OUR NORTHWEST ZONES...WHICH IS VERY IMPRESSIVE FOR THIS TIME OF YEAR. EXPECT TO SEE A FEW HIT AND MISS SHOWERS/THUNDERSTORMS DEVELOP NORTHWEST OF I-95 THIS AFTERNOON. A FEW OF THE STORMS MAY BECOME STRONG PRODUCING HAIL AND GUSTY WINDS GIVEN THE ABOVE PARAMETERS. HIGHEST RISK FOR THIS WILL BE ACROSS NORTHWEST MA/SOUTHERN NH BETWEEN NOON AND 6 PM. WE ALSO CAN/T RULE OUT AN ISOLATED SEVERE THUNDERSTORM OR TWO AS SOMETIMES THESE COLD POOLS CAN OVER PERFORM...DESPITE MARGINAL INSTABILITY. MEANWHILE...EXPECT THE WEATHER TO GENERALLY REMAIN DRY SOUTHEAST OF I-95 AS THOSE LOCATIONS WILL BE REMOVED FROM THE BULK OF THE FORCING. A MIXTURE OF CLOUDS AND SUN WILL RESULT IN HIGH TEMPS IN THE UPPER 70S AND LOWER 80S THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... TONIGHT... ANY LEFT OVER SHOWERS/THUNDERSTORMS SHOULD QUICKLY DISSIPATE EARLY THIS EVENING AS SHORTWAVE DEPARTS AND INSTABILITY DIMINISHES. LOW TEMPS WILL MAINLY BE IN THE 50S...TO THE LOWER 60S. FRIDAY... A MIXTURE OF CLOUDS AND SUN ANTICIPATED WITH HIGH TEMPS MAINLY IN THE LOWER 80S. ANOTHER SHORTWAVE SHOULD TRIGGER A FEW HIT AND MISS SHOWERS/THUNDERSTORMS DURING THE AFTERNOON...MAINLY TO THE NORTHWEST OF I-95. SHEAR IS LESS THAN TODAY AND 500 MB TEMPS ARE NOT NEARLY AS COLD...SO STORMS WILL PROBABLY BE WEAKER THAN WHAT IS EXPECTED TODAY. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... HIGHLIGHTS... * VERY UNSETTLED PATTERN FOR THE WEEKEND * SHOWERS AND THUNDERSTORMS POSSIBLE EARLY NEXT WEEK MODELS AND CONFIDENCE... 12Z MODEL GUIDANCE IS STILL IN GOOD AGREEMENT WITH THE FORECAST. A STRONG TROUGH WILL DOMINATE ACROSS THE MIDWEST FOR THE REMAINDER OF THIS WEEK INTO THE WEEKEND. A STALLED FRONT OVER THE EASTERN SEABOARD WILL BE THE FOCUS FOR HEAVY RAIN FOR THE WEEKEND AS SEVERAL WAVES RIDE ALONG THIS FRONT. OUT WEST...AN UPPER LEVEL RIDGE WILL CONTINUE TO BUILD ACROSS THE WESTERN CONUS AND EVENTUALLY MOVE INTO THE PLAINS. THIS WILL ALLOW FOR THE UPPER LEVEL TROUGH TO TURN MORE ZONAL BY THE FIRST HALF OF THE WEEK. BECAUSE OF THE OVERALL AGREEMENT TRENDED TOWARDS A BLEND OF THE MODELS AND PREVIOUS FORECAST FOR THIS PACKAGE. FOR CONFIDENCE LEVEL...HAVE HIGH CONFIDENCE ON TRENDS FOR THIS FORECAST...BUT A LOW CONFIDENCE ON EXACT TIMING. DETAILS... SATURDAY INTO SUNDAY... MAIN FOCUS ON THE FORECAST WAS FOCUS ON THE WEEKEND. GUIDANCE CONTINUES TO SHOW THAT A SLUG OF RAIN WILL IMPACT NEW ENGLAND SOMETIME DURING THE WEEKEND...BUT THERE IS STILL SOME DIFFERENCES IN TIMING. OVERALL A STALLED FRONT WILL BE DRAPED ACROSS THE EASTERN SEA BOARD AS A FEW WAVES RIDE ALONG THIS FRONT BRING UNSETTLED WEATHER TO THE REGION. APPEARS TO BE 2 DIFFERENT MODEL CAMPS...THE GFS/CANADIAN AND THE EC/ECENS/UKMET. THE GFS CAMP BRINGS THE HEAVIEST RAIN ON SUNDAY WHILE THE EC CAMP BRINGS IT IN DURING THE DAY ON SATURDAY. OVERALL UNIFORM SOUTHWESTERLY FLOW THROUGH THE LEVELS WILL ALLOW FOR THE FLOW TO TAP INTO THE GULF MOISTURE INCREASING THE PWATS CLOSE TO 2 INCHES...AND ALMOST 2 STANDARD DEVIATIONS AWAY. BOTH MODELS ARE ALSO SHOWING A GOOD 850 MB LLJ INTO THE FLOW AT RESPECTIVE TIMES FOR HEAVY RAIN TO OCCUR. ALSO BECAUSE OF THE INCREASING LLJ CANNOT RULE OUT A RUMBLE OF THUNDER. CONFIDENCE IS MODERATE TO HIGH THAT HEAVIER RAIN WILL OCCUR...JUST A MATTER OF FINE TUNING THE TIMING OF WHEN IT WILL IMPACT SOUTHERN NEW ENGLAND. WORK WEEK... UPPER LEVEL FLOW WILL BECOME MORE ZONAL BY THE BEGINNING OF THE WORK WEEK. HOWEVER APPEARS THAT THERE MAY BE SOME LINGERING SHOWERS ON MONDAY...WITH A BETTER SHOT ON TUESDAY AS FRONT SLIDES THROUGH THE REGION. HOWEVER TIMING OF THIS SYSTEM MAY CHANGE AS IT IS STILL 6-7 DAYS AWAY. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...TODAY THROUGH FRIDAY... TODAY...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS. A FEW HIT AND MISS SHOWERS/THUNDERSTORMS EXPECTED THIS AFTERNOON...MAINLY TO THE NORTHWEST OF I-95 WITH THE HIGHEST RISK ACROSS NORTHWEST MA/SOUTHWEST NH. THIS ACTIVITY MAY RESULT IN BRIEFLY LOWER CIGS/VSBYS. TONIGHT...MODERATE TO HIGH CONFIDENCE. MAINLY VFR CONDITIONS OTHER THAN PATCHY GROUND FOG POSSIBLE LATE IN THE TYPICALLY PRONE LOCATIONS. FRIDAY...HIGH CONFIDENCE IN MAINLY VFR CONDITIONS. A FEW HIT AND MISS SHOWERS AND THUNDERSTORMS POSSIBLE DURING THE AFTERNOON...MAINLY NORTHWEST OF I-95. THIS ACTIVITY MAY RESULT IN BRIEFLY LOWER CONDITIONS. KBOS TAF...HIGH CONFIDENCE IN VFR CONDITIONS WITH MODERATE CONFIDENCE THAT A SOUTHEAST SEA BREEZE DEVELOPS FOR A FEW HOURS THIS AFTERNOON. VERY LOW PROBABILITY FOR A THUNDERSTORM MOVING OVER THE TERMINAL THIS AFTERNOON. KBDL TAF...HIGH CONFIDENCE IN TAF. LOW PROBABILITY FOR A BRIEF THUNDERSTORM TO MOVE ACROSS THE TERMINAL THIS AFTERNOON. OUTLOOK...FRIDAY NIGHT THROUGH SUNDAY... SATURDAY AND SUNDAY...MODERATE CONFIDENCE. MVFR CIGS/VSBYS IN SCATTERED SHOWERS. POSSIBLE MVFR/IFR CONDITIONS MORE PROBABLE TOWARDS EASTERN MA/RI IN -RA AND ISO THUNDER. MONDAY...MODERATE CONFIDENCE. CONDITIONS IMPROVING TO VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...TODAY THROUGH FRIDAY... HIGH CONFIDENCE. UPPER LEVEL RIDGE JUST EAST OF THE WATERS WILL KEEP WINDS/SEAS BELOW SMALL CRAFT ADVISORY LEVELS THROUGH FRIDAY AFTERNOON WITH GOOD VISIBILITIES. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY... SATURDAY AND SUNDAY...MODERATE CONFIDENCE. WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. HOWEVER...MORE UNSETTLED WEATHER IS LIKELY WITH A STATIONARY FRONT WAVERING OVER THE WATERS. BRING SEVERAL ROUNDS OF RAIN AND ISOLATED THUNDER. MONDAY...MODERATE CONFIDENCE. IMPROVING VSBY CONDITIONS WITH SEAS/WINDS STILL BELOW SCA. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANK NEAR TERM...FRANK SHORT TERM...FRANK LONG TERM...DUNTEN AVIATION...FRANK/DUNTEN MARINE...FRANK/DUNTEN

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