Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 062213 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 613 PM EDT FRI MAY 6 2016 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLC REGION WILL WEAKEN SATURDAY AS IT MOVES SOUTH OF NEW ENGLAND. A COLD FRONT WITH A BAND OF SCATTERED SHOWERS LIKELY CROSSES THE REGION SUNDAY MORNING FOLLOWED BY A DRY...MILD BUT WINDY AFTERNOON. MUCH OF NEXT WEEK LOOKS SEASONABLE WITH MILD AFTERNOON/S. THERE STILL REMAINS THE LOW RISK FOR A PERIOD OF COOL AND WET WEATHER SOMETIME TUESDAY INTO WEDNESDAY...BUT THE LATEST DATA HAS BACKED OFF ON THAT A BIT. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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***NUMEROUS SHOWERS THIS EVENING NEAR AND WEST OF A PROVIDENCE TO WORCESTER LINE DIMINISH TO A FEW SHOWERS AFTER MIDNIGHT*** 610 PM UPDATE... NUMEROUS SHOWERS CONTINUE TO AFFECT AREAS NEAR AND WEST OF A PROVIDENCE TO WORCESTER LINE EARLY THIS EVENING. THIS A RESULT OF VERTICALLY STACKED LOW OVER THE MID ATLANTIC AND ASSOCIATED COLD POOL ALOFT/SHORTWAVE ENERGY. THE PRIMARY FOCUS FOR THE SHOWERS THIS EVENING WILL REMAIN ACROSS WESTERN/CENTRAL MA...NORTHERN CT AND RI CLOSER TO THE BETTER FORCING. HOWEVER...A PERIOD OF SCATTERED SHOWERS WILL STILL LIKELY OCCUR THIS EVENING ACROSS EASTERN MA. CANT RULE OUT AN ISOLD TSTM WESTERN ZONES AS MID LEVEL TEMPS COOL WHICH WILL STEEPENING THE LAPSE RATES WITH TT INCREASING INTO THE LOWER 50S. STRONGER FORCING/DEEPER MOISTURE LIFTS NORTH OF OUR REGION BY MIDNIGHT...SO SHOULD SEE ACTIVITY DIMINISH TO A FEW SPOT SHOWERS OVERNIGHT. ALSO...EXPECT AREAS OF LOW CLOUDS AND FOG TO DEVELOP LATER TONIGHT ALONG WITH PATCHY DRIZZLE GIVEN ABUNDANT LOW LEVEL MOISTURE IN PLACE. TEMPS WILL REMAIN IN THE 40S.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... SATURDAY ... VERTICALLY STACKED LOW WILL GRADUALLY WEAKEN AS IT DRIFTS EAST OVER THE OCEAN AND BECOMES AN OPEN WAVE. SYNOPTIC FORCING IS WEAK...BUT 500 MB TEMPS AROUND -21C WITH MID LEVEL LAPSE RATES 7-7.5 C/KM SUPPORTS SCT SHOWERS DEVELOPING WITH ISOLD TSTMS POSSIBLE BUT MOST OF THE TIME IT WILL BE DRY. GIVEN LOW WBZ HEIGHTS CANT RULE OUT SMALL HAIL. MID LEVELS DRY OUT AFT 18Z WHICH WILL LIMIT CONVECTION THREAT LATER IN THE DAY. THERE REMAINS CONSIDERABLE LOW LEVEL MOISTURE SATURDAY SO LOW CLOUDS AND FOG WILL LINGER THROUGH MUCH OF THE MORNING AND WHILE THERE MAY BE SOME BREAKS OF SUN IN THE AFTERNOON...CONFIDENCE IS LOW. TEMPS REACHING LOWER 60S SOUTH OF THE PIKE WITH 50S TO THE NORTH. SATURDAY NIGHT... NORTHERN STREAM SHORTWAVE APPROACHING FROM THE GT LAKES WILL ACT AS A KICKER AND FINALLY PUSH MID LEVEL LOW EAST. HOWEVER...THE ATTENDING COLD FRONT WILL BE MOVING INTO W NEW ENG TOWARD 12Z. DEEP MOISTURE AXIS PRECEDING THE FRONT ALONG WITH LEFT EXIT REGION OF THE UPPER LEVEL JET WILL LEAD TO A FRONTAL BAND OF SHOWERS WHICH WILL MOVE INTO W NEW ENG TOWARD DAYBREAK...BUT SHOULD BE DELAYED UNTIL SUNDAY MORNING FOR AREAS FURTHER EAST. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGHLIGHTS... * SHOWERS SUN AM BUT TURNING PARTLY SUNNY/WINDY DURING THE AFTERNOON * DRY AND MILD MONDAY AFTERNOON BUT IT WILL BE BREEZY * MODELS BACKING OFF ON COOL/WET WEATHER TUE/WED BUT NOT SET IN STONE * SEASONABLE TO EVEN ABOVE NORMAL TEMPS LIKELY NEXT THU/FRI DETAILS... SUNDAY... MOST GUIDANCE HAS HAS A COLD FRONT CROSSING THE REGION SUNDAY MORNING. ENOUGH FORCING/LOW LEVEL MOISTURE WITH THE FRONT THAT WILL LIKELY SEE A BAND OF SCATTERED SHOWERS WORK ACROSS THE REGION. MARGINAL ELEVATED INSTABILITY WILL BE IN PLACE AHEAD OF THE FRONT...SO THERE IS A LOW RISK FOR A FEW EMBEDDED THUNDERSTORMS. CONFIDENCE WAS NOT HIGH ENOUGH TO INSERT INTO THE FORECAST AT THIS TIME...BUT SOMETHING WILL NEED TO WATCH. IT APPEARS THAT THE FRONT WILL BE OFF THE COAST SUNDAY AFTERNOON...RESULTING IN SKIES BECOMING PARTLY SUNNY. THIS SHOULD ALLOW HIGH TEMPS TO REACH THE MID 60S IN MOST LOCATIONS. BUFKIT SOUNDINGS SHOW EXCELLENT MIXING WITH WESTERLY WIND GUSTS OF 25 TO 40 MPH EXPECTED TO DEVELOP BY MID TO LATE AFTERNOON. MONDAY... WESTERLY FLOW ALOFT AND AT THE SURFACE CONTINUES ON MONDAY AND MODEL CROSS SECTIONS INDICATE AT LEAST PARTIAL SUNSHINE. ALTHOUGH 850T ARE ONLY BETWEEN +2C AND +4C...WESTERLY FLOW AND SOME SUN THIS TIME OF YEAR SHOULD ALLOW AFTERNOON HIGH TEMPS TO REACH WELL INTO THE 60S TO PERHAPS EVEN SOME LOWER 70S. IT WILL BE BREEZY THOUGH WITH WESTERLY WIND GUSTS OF 20 TO 30 MPH. TUESDAY AND WEDNESDAY... THERE HAS BEEN A CONSIDERABLE SHIFT WITH THE AFTERNOON MODEL GUIDANCE. LAST NIGHT/S 00Z MODELS DEPICTED A WAVE OF LOW PRESSURE TRACKING JUST SOUTH OF OUR REGION...RESULTING IN RAW EASTERLY WINDS AND A PERIOD OF COOL/WET WEATHER. MOST OF THE 12Z GUIDANCE HAS BACKED AWAY FROM THAT...AS THEY NOW SHOW CANADIAN HIGH PRESSURE FORCING THE LOW WELL TO OUR SOUTH. THE RESULT WOULD BE PARTLY SUNNY SKIES WITH JUST THE LOW RISK FOR A FEW BRIEF SHOWERS AND MILD AFTERNOONS. WE DID NOT WANT TO MAKE A DRASTIC ADJUSTMENT BASED ON JUST THE 12Z GUIDANCE 4 TO 5 DAYS IN THE FUTURE...BUT DID TREND MILDER AND LOWERED POPS. A FEW 12Z GEFS MEMBERS ALONG WITH THE CMC STILL INDICATE THE POTENTIAL FOR A PERIOD OF COOL/WET WEATHER. SO TO SUMMARIZE...ITS TOO EARLY TO LOCK IN A DRY/MILD SOLUTION BUT DID TREND A BIT MORE IN THAT DIRECTION. THURSDAY AND FRIDAY... SEASONABLE TO EVEN ABOVE NORMAL TEMPERATURES EXPECTED. DRY WEATHER LIKELY THURSDAY...BUT A COLD FRONT MAY BRING A PERIOD OF SHOWERS SOMETIME FRIDAY AND/OR FRIDAY NIGHT. && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY NIGHT/... TONIGHT...MODERATE CONFIDENCE. MAINLY MVFR CONDITIONS THIS EVENING LOWERING TO IFR/LIFR IN STRATUS AND FOG. SHOWERS MOST PREVALENT IN THE EVENING...CENTRAL/W NEW ENG AND CANT RULE OUT A RUMBLE OF THUNDER. SATURDAY...MODERATE CONFIDENCE. IFR/LIFR IN THE MORNING GRADUALLY IMPROVING DURING THE AFTERNOON...BUT TIMING IS VERY MUCH UNCERTAIN. SCT SHOWERS DEVELOPING AND ISOLD TSTMS POSSIBLE. SATURDAY NIGHT...MODERATE CONFIDENCE. CONDITIONS LOWERING TO IFR/LIFR AGAIN IN STRATUS AND PATCHY FOG. FRONTAL BAND OF SHOWERS MOVE INTO W NEW ENG 09-12Z. KBOS TERMINAL...MODERATE CONFIDENCE. WILL LIKELY SEE IFR CIGS/VSBYS DEVELOPING TONIGHT. TIMING UNCERTAIN. KBDL TERMINAL...MODERATE CONFIDENCE. CIGS LOWERING TO IFR. TIMING UNCERTAIN. OUTLOOK /SUNDAY THROUGH WEDNESDAY/... SUNDAY...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS WITH A BAND OF SCATTERED SHOWERS SUNDAY MORNING SHOULD IMPROVE TO VFR DURING THE AFTERNOON. WESTERLY WINDS WILL INCREASE DURING THE AFTERNOON WITH 25 TO 35 KNOT GUSTS EXPECTED. SUNDAY NIGHT AND MONDAY...HIGH CONFIDENCE IN VFR CONDITIONS. TUESDAY AND WEDNESDAY...LOW CONFIDENCE. WILL DEPEND ON THE TRACK/STRENGTH OF LOW PRESSURE APPROACHING FROM THE WEST. LATEST INDICATIONS DO FAVOR VFR CONDITIONS WITH LOW STAYING WELL TO OUR SOUTH.
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&& .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY NIGHT/...MODERATE CONFIDENCE. TONIGHT...A PERIOD OF EASTERLY GUSTS 20-25 KT ACROSS S COASTAL WATERS WILL DIMINISH THIS EVENING BUT E SWELL WILL KEEP SEAS ABOVE 5 FT OVER THE OUTER WATERS TONIGHT. SCA CONTINUES. VSBYS LOWERING IN AREAS OF FOG. EVENING SHOWERS. SATURDAY...E/NE WINDS LESS THAN 15 KT WILL BECOME LOCALLY ONSHORE IN THE AFTERNOON AS SEABREEZES DEVELOP. LINGERING SWELL OVER THE SOUTH COASTAL WATERS. VSBYS REDUCED IN MORNING FOG. LOW RISK OF SCATTERED SHOWERS WITH ISOLATED T-STORM POSSIBLE. SATURDAY NIGHT...SOUTHERLY WINDS INCREASING LATE AHEAD OF APPROACHING COLD FRONT...BUT BELOW SCA. VSBYS MAY BE REDUCED IN FOG. SHOWERS SHOULD HOLD OFF UNTIL SUN MORNING. OUTLOOK /SUNDAY THROUGH WEDNESDAY/... SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE. WESTERLY WIND GUSTS OF 20 TO 30 KNOTS EXPECTED WITH GOOD MIXING BEHIND THE COLD FRONT. STRONGEST OF THOSE WINDS WILL BE NEAR SHORE...ESPECIALLY MID TO LATE SUNDAY AFTERNOON WHERE THERE IS A LOW RISK A FEW PLACES BRIEFLY APPROACH 35 KNOTS. TUESDAY AND WEDNESDAY...LOW CONFIDENCE. MODELS HAVE BACKED OFF ON LOW PRESSURE TRACKING NEAR SOUTHERN NEW ENGLAND AS CANADIAN HIGH PRESSURE TRIES TO SUPPRESS IT SOUTH. THIS IS STILL NOT SET IN STONE...BUT IF LATER MODEL RUNS HOLD WINDS/SEAS MAY BE BELOW SCA HEADLINES OVER THIS TIME. && .TIDES/COASTAL FLOODING... VERY HIGH ASTRO TIDES TONIGHT /AROUND MIDNIGHT/ WITH BOSTON 12.3 FT AT 1146 PM. MINIMAL SURGE THIS AFTERNOON BUT WITH MODEST ONSHORE WINDS WILL LIKELY SEE A SURGE BELOW 0.5 FT AT HIGH TIDE. THAT/S SUFFICIENT FOR A MODERATE TO HIGH RISK OF MINOR COASTAL FLOODING ENTIRE EASTERN MA COASTLINE SO COASTAL FLOOD ADVISORY WILL CONTINUE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT SATURDAY FOR MAZ007-015-016-019-022-024. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ232>234. SMALL CRAFT ADVISORY UNTIL 8 PM EDT SATURDAY FOR ANZ235-237- 254>256. SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR ANZ250. SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ251. && $$ SYNOPSIS...KJC/FRANK NEAR TERM...FRANK/KJC SHORT TERM...KJC LONG TERM...FRANK AVIATION...KJC/FRANK MARINE...KJC/FRANK TIDES/COASTAL FLOODING...KJC

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