Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 271100 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 700 AM EDT MON JUL 27 2015 .SYNOPSIS...
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RISK OF SHOWERS AND THUNDERSTORMS CONTINUES THROUGH TUESDAY. STORMS MAY PRODUCE HEAVY RAIN AND A FEW MANY BECOME STRONG TO SEVERE. HOT AND HUMID TUESDAY THROUGH THURSDAY. A COLD FRONT MAY BRING SCATTERED THUNDERSTORMS LATE THURSDAY AND THURSDAY NIGHT. WARM AND DRY WEATHER IS EXPECTED FRIDAY INTO NEXT WEEKEND.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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7 AM UPDATE... SHOWERS/STORMS HAVE BEEN FOCUSED NEAR S COAST EARLY THIS MORNING WHICH IS ALIGNED WITH AXIS OF K-INDEX AND NOSE OF INSTABILITY ALOFT. SO FAR LOCALLY HEAVY RAIN HAS BEEN MAIN THREAT WITH SOME LOCATIONS REPORTING A QUICK INCH OR SO OF RAIN IN AN HOUR. HIGH-RES MODELS HAVE DONE A GOOD JOB IN PINPOINTING THIS AREA AS FAVORED LOCATION FOR CONVECTION. TREND SHOULD BE FOR THIS ACTIVITY TO BUILD SLOWLY N WITH TIME...REACHING INTO MASS PIKE CORRIDOR BY MIDDAY OR EARLY AFTERNOON WITH FOCUS PROBABLY ACROSS EASTERN MA AS OPPOSED TO W NEW ENGLAND. ENVIRONMENTAL PARAMETERS FAVOR HEAVY RAIN AS CONTINUED PRIMARY THREAT DUE TO DECENT INSTABILITY BUT LOW SHEAR WHICH FAVORS SLOW STORM MOTION. ALSO HAVE POTENTIAL FOR SMALL HAIL...GUSTY WINDS AND FREQUENT LIGHTNING. OVERALL SEVERE THREAT IS LOW BUT ONE OR TWO STORMS COULD PRODUCE DAMAGING WINDS OR MARGINALLY SEVERE HAIL THIS AFTERNOON. PREVIOUS FORECAST HAD THESE TRENDS HANDLED WELL SO ONLY MADE MINOR CHANGES TO MATCH RADAR TRENDS. HIGHS IN 70S AND LOWER 80S LOOK GOOD.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... TONIGHT... A REPEAT OF LAST NIGHT ANTICIPATED. SCATTERED SHOWER / THUNDERSTORM ACTIVITY WILL SHIFT E/SE WITH THE MEAN WIND SLOWLY. WHILE DAYTIME HEATING CONCLUDES...THERE STILL IS A LOT OF INSTABILITY AVAILABLE WITHIN THE LOW-MID LEVELS ALOFT WHERE LAPSE RATES ARE CONDITIONALLY UNSTABLE. THREATS OF HEAVY RAIN AND FREQUENT LIGHTNING CONTINUE AND WITH THE SLOW MOVEMENT OF THE STORM THERE IS A CONCERN FOR LOCALIZED FLOODING. A MUGGY NIGHT IN STORE WITH LOWS IN THE MID- TO UPPER- 60S. STORM ACTIVITY MAY DISSIPATE TOWARDS MORNING. TUESDAY... CONTINUED MID-LEVEL ENERGY THROUGH THE BROADER CYCLONIC FLOW ON WHAT APPEARS TO BE NNW-SSE FRONTAL BOUNDARY WHEN EVALUATING THE LOW- TO MID-LEVEL THERMAL PROFILE. SEEMS TO BE SOME LEVEL OF ENHANCED ASCENT THROUGH THE ATMOSPHERIC LAYER. COLLOCATED JET STREAK AND DECENT NNW- SSE UNIDIRECTIONAL BULK SHEAR WITH LAPSE RATES EXCEEDING 6C/KM. SURFACE REFLECTION OF A CONVERGENT BOUNDARY ALONG THE E-COASTLINE OF NEW ENGLAND APPEARS PLAUSIBLE. WITH A WARM MUGGY AIRMASS STILL IN PLACE MAY BE DEALING WITH SHOWER / THUNDERSTORM ACTIVITY ACROSS E- HALF OF NEW ENGLAND...POTENTIALLY LINE-CONVECTION ALONG THE LEADING EDGE OF THE MID-LEVEL IMPULSE. CONSIDERING SHEAR / INSTABILITY / INVERTED-V PROFILES WITHIN THE BOUNDARY-LAYER COULD BE LOOKING AT A MULTI-THREAT OUTCOME WITH ANY CONVECTION AS IT WOULD APPEAR. GOING TO HAVE TO TAKE A LOOK AT THIS MORE CLOSELY OVER THE NEXT 24-HOURS. COLLABORATING WITH OTHER WEATHER FORECAST OFFICES...WILL GO WITH ENHANCED WORDING OF HEAVY RAIN / GUSTY WINDS / SMALL HAIL. GOOD DEEP- LAYER FORCING AND NEAR A LOBE OF H5 COLDER AIR DROPPING S WITH THE MID-LEVEL VORTEX. WITH ANTICIPATED WEATHER / CLOUD COVER PERHAPS SOME ISSUES WITH HIGH TEMPERATURES. MAYBE AN ONSHORE FLOW ALONG THE E-COAST IF THE ZONE OF CONVERGENCE HOLDS OVER THE E-HALF OF NEW ENGLAND. WILL LEAN COOLER IN THIS AREA BUT GO INTO THE UPPER-80S TO THE W. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * TRIPLE-H WEATHER WED/THU WITH HIGHS IN 90S. * SCATTERED STORMS THU/THU NIGHT. * DRIER BUT STILL VERY WARM FRI THRU SUN. LARGE SCALE PATTERN FEATURES BUILDING RIDGE OVER NORTHEAST WED/THU WHICH WILL BRING OUR NEXT SHOT OF HEAT AND HUMIDITY. HOWEVER THIS SHOULD BE RELATIVELY SHORT LIVED AS UPPER LOW DIGS ACROSS CANADIAN PRAIRIES AND EVENTUALLY BECOMES CENTERED NEAR HUDSON BAY...RESULTING IN MORE IN WAY OF CYCLONIC FLOW FOR LATER THIS WEEK INTO NEXT WEEKEND. STILL LOOKS SUMMERLIKE BEYOND THU BUT CHANGE IN UPPER AIR PATTERN SHOULD BREAK HUMIDITY AND KEEP TEMPERATURES CLOSER TO AVERAGE FOR LATE JULY. WED INTO THU...HIGH CONFIDENCE. RISING HEIGHTS SHOULD SUPPRESS CONVECTION WED SO AM CONTINUING WITH DRY FORECAST. NAM SUGGESTION OF DEVELOPMENT ALONG SEA BREEZE FRONT IS POSSIBLE BUT IS OUTLIER AT THIS POINT. HIGHS SHOULD TOP OUT IN LOW TO MID 90S AWAY FROM S COAST BUT WITH DEWPOINTS IN MID 60S TO AROUND 70 HEAT INDICES WILL PROBABLY FALL SHORT OF ADVISORY CRITERIA /100F FOR 2+ HOURS/. ANOTHER HOT/HUMID DAY EXPECTED THU BUT HIGHS SHOULD BE SLIGHTLY LOWER THAN WED GIVEN INCREASING CLOUD COVER AHEAD OF COLD FRONT APPROACHING FROM GREAT LAKES. DECENT CAPE/0-6KM SHOULD BE PRESENT ALONG WITH MARGINAL MID LEVEL LAPSE RATES...SO BETTER CHANCE OF SHOWERS/STORMS DURING AFTERNOON AND EVENING AS FRONT PROVIDES FOCUS FOR LIFT. FRI THROUGH SUN...MODERATE CONFIDENCE. HIGH PRESSURE BUILDS ACROSS NORTHEAST AS UPPER FLOW BECOMES MORE CYCLONIC. THIS WILL BRING SOME RELIEF FROM HEAT/HUMIDITY BUT HIGHS SHOULD STILL TOP OUT WELL INTO 80S AWAY FROM S COAST. GOING WITH DRY FORECAST AS ENSEMBLES SHOW FAIRLY LOW PROBABILITIES OF MEASURABLE RAINFALL DURING THIS TIME FRAME. && .AVIATION /12Z MONDAY THROUGH FRIDAY/...
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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 TUESDAY/... NUMEROUS SHOWERS/TSTMS NEAR S COAST WITH MVFR/IFR CIGS/VSBYS WILL SLOWLY WORK N INTO MA BY EARLY AFTERNOON...BUT ACTIVITY SHOULD BECOME MORE SCATTERED IN NATURE. OTHERWISE EXPECT VFR CIGS 040-060 TO DOMINATE TODAY WITH LIGHT S/SW WINDS GIVING WAY TO SEA BREEZES NEAR COAST. SCATTERED SHOWERS/TSTMS PERSIST TONIGHT WITH MVFR/IFR CIGS/VSBYS. TUESDAY...LOW-END VFR. FOCUS OVER E-HALF OF S NEW ENGLAND WHERE RENEWED CHANCES OF SHRA/TSRA. THREATS OF SMALL HAIL / WINDS / +RA / LIGHTNING ALL ANTICIPATED. ONSHORE FLOW EXPECTED ALONG E-COAST. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. MAINLY VFR. WEAK SEA BREEZE DEVELOPS LATER THIS MORNING AND VEERS TO S THIS AFTERNOON. BEST CHANCE OF TSTMS ROUGHLY 19Z-22Z. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. MAINLY VFR. BEST CHANCE OF TSTMS IS ROUGHLY 20Z-22Z BUT CONFIDENCE IS LOW ACROSS W NEW ENGLAND. OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/... TUESDAY NIGHT AND WEDNESDAY...HIGH CONFIDENCE. MVFR/IFR IN SCT SHRA/TSRA TUESDAY EVENING...OTHERWISE VFR. THURSDAY...MODERATE CONFIDENCE. MVFR/IFR IN SCT SHRA/TSRA MAINLY DURING AFTERNOON AND EVENING. FRIDAY...MODERATE CONFIDENCE. VFR.
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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 MONDAY NIGHT/...HIGH CONFIDENCE. SCATTERED SHOWERS / THUNDERSTORMS TO PERSIST OVER ALL OF THE S NEW ENGLAND REGION WHICH WILL AT TIMES IMPACT THE WATERS. ANTICIPATE HEAVY RAIN AND FREQUENT LIGHTNING WITH ANY STORMS. CAN NOT RULE OUT THE POSSIBILITY OF SMALL HAIL ALONG WITH GUSTY WINDS...THOUGH THINKING BELOW GALE FORCE. OTHERWISE SEAS REMAINING BELOW 4-FEET AS WINDS PREDOMINANTLY REMAIN OUT OF THE S. OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/... TUESDAY NIGHT AND WEDNESDAY...HIGH CONFIDENCE. WINDS AND SEAS REMAIN BELOW SCA. SCA. MAY SEE LEFTOVER SHOWERS/STORMS ON WATERS DURING EVENING. THURSDAY...MODERATE CONFIDENCE. INCREASING S/SW WINDS EXPECTED AHEAD OF COLD FRONT...BUT GUSTS SHOULD PEAK AROUND 20KT MAINLY ON S COASTAL WATERS. BUILDING S SWELL MAY REACH 5 FT ON OUTER WATERS S OF ISLANDS. MAY SEE THUNDERSTORMS LATER IN DAY AND THU EVENING. FRIDAY...MODERATE CONFIDENCE. HIGH PRESSURE BUILDS OVER WATERS. WINDS AND SEAS BELOW SCA. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...SIPPRELL/JWD NEAR TERM...SIPPRELL/JWD SHORT TERM...SIPPRELL LONG TERM...JWD AVIATION...SIPPRELL/JWD MARINE...SIPPRELL/JWD

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