Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Graphics & Text | 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 281136 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 736 AM EDT THU MAY 28 2015 .SYNOPSIS... A COLD FRONT MAY BRING A FEW STRONG TO SEVERE THUNDERSTORMS TO THE REGION THIS AFTERNOON. A WIDESPREAD/SOAKING RAINFALL IS NOT EXPECTED. ON FRIDAY...HIGH PRESSURE WILL BRING DRY CONDITIONS. FOR THIS WEEKEND...A SLOW MOVING FRONT WILL BRING ARE GREATER CHANCE FOR SHOWERS...WITH SOME THUNDERSTORMS. THIS FRONT MAY LINGER NEAR OUR AREA INTO THE BEGINNING OF THE NEXT WEEK...WITH HIGH PRESSURE RETURNING BY MIDWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ** A FEW STRONG TO MARGINALLY SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON/EARLY EVENING ACROSS SOUTHERN NEW ENGLAND *** 736 AM UPDATE... SOUTHERN NEW ENGLAND REMAINS IN THE WARM...MOIST AIRMASS EARLY THIS MORNING. STRATUS WAS ACROSS MOST OF SOUTHERN NEW ENGLAND. ALREADY SEEING TRENDS IN THE SATELLITE AND CLOUD HEIGHT DATA WHICH SUGGESTS A RELATIVELY QUICK DISSIPATION OF THE STRATUS... ESPECIALLY AWAY FROM THE SOUTH COAST. TWEAKED NEAR-TERM FORECAST TO BRING IT BACK IN LINE WITH OBSERVED TRENDS. PREVIOUS DISCUSSION... TODAY... WARM...MUGGY CONDITIONS CONTINUE FOR TODAY. SOUTHWESTERLY WINDS WILL GUST BETWEEN 20-30 KTS AS 850MB TEMPS WARM INTO 14-15C. THIS WILL LEAD TO HIGH TEMPS INTO THE MID TO UPPER 80S AWAY FROM THE SOUTH COAST. STABLE MARINE AIR WILL CONTINUE TO PUSH THROUGH KEEPING THE SOUTH COAST...CAPE AND ISLANDS IN THE MID 60S TO MID 70S. SOUTHWESTERLY WINDS WILL GUST TO NEAR 20-30 MPH AHEAD OF THE FRONT. UPPER LEVEL SHORTWAVE WILL PASS THROUGH NORTHERN NEW ENGLAND TODAY PUSHING A PRE-FRONTAL TROUGH/COLD FRONT ACROSS THE REGION. 00Z GUIDANCE SHOWS THE FRONT PUSHING THROUGH BY THE AFTERNOON/EVENING HOURS WHICH WILL BE THE SOURCE OF LIFT FOR ANY CONVECTION. APPEARS THAT THE BETTER UPPER LEVEL DYNAMICS WILL BE NORTH OF THE REGION. HOWEVER CAPE VALUES WILL RANGE BETWEEN 1000-2000 J/KG AND WITH 35 KTS OF SHEAR BELIEVE THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE. MID-LEVEL LAPSE RATES REALLY DO NOT STEEPEN TIL THE LATER HALF OF THE AFTERNOON...AND WITH DRY AIR ALOFT PUSHING THROUGH...COULD LIMIT THE COVERAGE. ITS ALL ABOUT PERFECT TIMING. THEREFORE BELIEVE SHOWERS AND THUNDERSTORMS WILL BEGIN TO PUSH THROUGH THE REGION BY THE LATE MORNING HOURS ACROSS THE NW AND OVER THE I-95 CORRIDOR BY 20-23Z. NOT EXPECTING A WIDESPREAD EVENT...BUT MORE SCATTERED IN NATURE. MAIN THREAT WITHIN ANY STORM WILL BE DAMAGING WINDS AND HEAVY RAINFALL. BECAUSE TEMPS ALOFT ARE SO WARM BELIEVE THE THREAT FOR HAIL IS LOW...BUT IF ANY STORMS SHOW ROTATION...SMALL HAIL CANNOT BE RULED OUT. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... TONIGHT... COLD FRONT WILL MOVE OFFSHORE TONIGHT...BUT STALL JUST SOUTH OF THE ISLANDS AS BERMUDA HIGH STILL DOMINATES THE WATERS. ALONG THIS FRONT COULD SEE SOME PATCHY FOG AND STRATUS DEVELOP. OTHERWISE EXPECT A LITTLE RELIEF IN THE WARM AND MUGGY CONDITIONS AS THE FRONT IS WEAK AND WASHES OUT. OVERNIGHT TEMPS WILL RANGE FROM THE MID 50S TO LOW 60S IN METRO BOS/PVD. TOMORROW... HIGH PRESSURE WILL MOVE OVERHEAD ON FRIDAY YIELDING TO DRY WEATHER FOR THE DAY. WITH MOIST SOUTHWESTERLY FLOW ALOFT ANTICIPATE DIURNAL CLOUDS TO DEVELOP DURING THE DAY. OTHERWISE WEAK WINDS ALOFT WILL ALLOW FOR SEA BREEZES TO DEVELOP ALONG THE COASTLINES. TEMPS WILL STILL BE ABOVE AVERAGE...WITH HIGHS REACHING INTO THE LOW TO MID 80S WITH 70S ALONG BOTH COASTLINES. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... FRIDAY NIGHT...UPPER LEVEL RIDGING...AND A RESURGENCE OF HIGH PRESSURE OVER THE NORTH ATLANTIC...WILL KEEP MAINLY DRY WEATHER ACROSS SOUTHERN NEW ENGLAND. SATURDAY...SURFACE HIGH PRESSURE MOVES FARTHER OFFSHORE... ENABLING SOUTHWEST FLOW TO BRING INCREASING MOISTURE/HUMIDITY TOWARDS OUR AREA. A COLD FRONT APPROACHES OUR REGION FROM THE WEST LATE IN THE DAY. WE COULD SEE SCATTERED SHOWERS/THUNDERSTORMS DURING SATURDAY AFTERNOON ACROSS WESTERN MA AND NORTHERN CT...WITH SHOWER/THUNDERSTORM CHANCES EXTENDING EASTWARD SATURDAY NIGHT AS THIS COLD FRONT PUSHES FARTHER INTO OUR AREA. WITH PRECIPITABLE WATER INCREASING TO OVER 1.5 INCHES AHEAD OF THIS FRONT...LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE. SUNDAY...COLD FRONT SLOWLY MOVES THROUGH OUR REGION. EXPECTING NUMEROUS SHOWERS TO CROSS OUR AREA DURING THE DAY...WITH A LOWER RISK OF THUNDERSTORMS. THIS FRONT MAY REACH THE SOUTH COAST BY SUNDAY NIGHT...BUT THERE IS SOME UNCERTAINTY AS TO WHETHER IT STALLS NEAR OUR AREA FOR A PERIOD OF TIME. WILL GRADUALLY LOWER POPS SUNDAY NIGHT. MONDAY AND TUESDAY...THERE CONTINUES TO BE UNCERTAINTY ON HOW FAR SOUTH OF OUR REGION A FRONT GETS PUSHED. THIS WILL AFFECT OUR CHANCES FOR SHOWERS. 28/00Z ECMWF REMAINS LESS PROGRESSIVE THAN THE 28/00Z GFS IN MOVING THIS FRONT FAR ENOUGH AWAY WHERE THERE WOULD NOT BE A CHANCE OF SHOWERS ANYWHERE IN SOUTHERN NEW ENGLAND. GIVEN THE UNCERTAINTY WITH THE MID LEVEL FLOW EVOLUTION...WILL KEEP AT LEAST A LOW CHANCE OF SHOWERS IN THE FORECAST...WITH THE GREATEST POPS TOWARD THE SOUTH COAST. DRIER WEATHER SHOULD BE MORE PREVALENT TUESDAY. THUNDERSTORMS LOOK LESS PROBABLE FOR THIS TIMEFRAME. WEDNESDAY...MODELS ARE SHOWING SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING...BRINGING MAINLY DRY CONDITIONS TO OUR AREA. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. TODAY...MODERATE CONFIDENCE. ANY LOWER CLOUDS AND FOG SHOULD DISSIPATE BY LATE MORNING...AT THE LATEST. OTHERWISE...VFR BUT A COLD FRONT/PRE-FRONTAL TROUGH MAY BRING A FEW STRONG THUNDERSTORMS THIS AFTERNOON RESULTING IN BRIEFLY LOWER CONDITIONS. SOUTHWEST WINDS COULD GUST BETWEEN 20-30 KTS. TONIGHT INTO TOMORROW...MODERATE CONFIDENCE. COLD FRONT PASSES THROUGH SWITCHING WINDS TO THE NW TONIGHT. EXPECT VFR CONDITIONS TO START...WITH THE POTENTIAL FOR MVFR VSBYS DUE TO RADIATION FOG. OTHERWISE VFR FOR TOMORROW WITH SEA BREEZES ALONG THE MASS COASTLINE. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. MAY SEE BRIEF MVFR/IFR CONDITIONS WITHIN ANY STRONG THUNDERSTORM THIS AFTERNOON. KBDL TERMINAL...HIGH CONFIDENCE IN TAF TRENDS. MODERATE CONFIDENCE IN TIMING. STRATUS COULD LINGER LONGER THAN CURRENT EXPECTATIONS THIS MORNING. OTHERWISE COULD SEE BRIEF MVFR/IFR CONDITIONS WITHIN ANY STRONG THUNDERSTORM THIS AFTERNOON. OUTLOOK...SATURDAY THROUGH MONDAY...MODERATE CONFIDENCE. SATURDAY...PATCHY EARLY MORNING FOG WITH MVFR-IFR CONDITIONS... WILL IMPROVE. SCT SHRA/TSRA SAT AFTERNOON THROUGH SAT NIGHT... WITH LOCAL MVFR-IFR CONDITIONS. SUNDAY...NUMEROUS SHOWERS WITH ISOLD/SCATTERED TSTMS POSSIBLE DURING THE DAY. MAY SEE BRIEF MVFR CONDITIONS. MONDAY...CONDITIONS MAINLY VFR...EXCEPT MVFR WITH SCT SHOWERS SOUTH COASTAL MA/RI. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TODAY INTO FRIDAY/... TODAY...MODERATE TO HIGH CONFIDENCE. ANOTHER ROUND OF NEAR SHORE SOUTHWEST WIND GUSTS OF 25 KNOTS EXPECTED THIS AFTERNOON. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THIS POTENTIAL. IN ADDITION...A FEW STRONG THUNDERSTORMS WITH GUSTY WINDS AND HAIL ARE POSSIBLE LATE THURSDAY AFTERNOON AND EVENING. TONIGHT INTO FRIDAY...HIGH CONFIDENCE. COLD FRONT WILL STALL ACROSS THE ISLANDS AND WASH OUT. THIS COULD YIELD TO FOG AND STRATUS TONIGHT. OTHERWISE HIGH PRESSURE WILL DOMINATE THE WATERS KEEPING SEAS AND WINDS BELOW SCA. OUTLOOK...SATURDAY THROUGH MONDAY...MODERATE CONFIDENCE. SATURDAY-SUNDAY...SW WINDS MAY BRIEFLY GUST TO 25 KT DURING SAT ON THE EASTERN WATERS...AS A COLD FRONT APPROACHES THE WATERS. OTHERWISE...EXPECTING GUSTS UP TO 20 KT. SEAS BUILD AGAIN TO AROUND 5 FT ACROSS THE OUTER WATERS. MONDAY...A COLD FRONT MAY LINGER NEAR THE WATERS DURING THIS TIMEFRAME...WITH SEAS UP TO 5 FEET AND GUSTS TO 20 KT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ231>234. SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM EDT THIS EVENING FOR ANZ230-236-251. SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ235- 237-250-254>256. && $$ SYNOPSIS...BELK/DUNTEN NEAR TERM...BELK/DUNTEN SHORT TERM...DUNTEN LONG TERM...BELK AVIATION...BELK/DUNTEN MARINE...BELK/DUNTEN

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