Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 051442 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1042 AM EDT TUE MAY 5 2015 .SYNOPSIS... A WEAK COLD FRONT MAY BRING A FEW BRIEF SHOWERS TODAY...BUT DRY WEATHER AND MILD TEMPERATURES WILL DOMINATE. LITTLE CHANGE IS EXPECTED THROUGH THE WEEKEND...WITH MILD TO WARM AFTERNOON/S AND MAINLY DRY WEATHER PERSIST. A SLOW MOVING FRONT MAY BRING A FEW SHOWERS LATE THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1041 AM UPDATE... WEAK COLD FRONT STILL CROSSING THE REGION. THIS FRONT EXTENDED FROM JUST EAST OF KLWM...TO NEAR KORH...TO JUST SOUTH OF KBDL. 05/12Z CHH SOUNDING SHOWED AN IMPRESSIVE SURFACE-BASED INVERSION. KBOX 88D SHOWING THE MAJORITY OF THE SHOWERS MOVING OVER THE COASTAL WATERS EAST OF MA MID-MORNING. LATEST RUNS OF THE HRRR AND RAP PREDICTING MORE SHOWERS DEVELOPING FARTHER WEST LATE THIS MORNING...THEN MOVING ACROSS PORTIONS OF RI AND SOUTHEAST MA. THIS IS ALSO STARTING TO SHOW IN THE RADAR DATA...SO RELIED HEAVILY ON A HRRR/RAP COMBINATION TO UPDATE RAINFALL CHANCES THROUGH THE REST OF TODAY. TEMPERATURES WILL BE TRICKY. LOTS OF CLOUD COVER THIS MORNING. VISIBLE SATELLITE DATA SHOWING PLENTY OF CLEARING THOUGH BEHIND THE COLD FRONT...AT LEAST FOR NOW. OPEN-CELLULAR STRATOCUMULUS CLOUDS STARTING TO POP ACROSS SOUTHERN VT AND SOUTHERN NH. FULLY EXPECT THIS TREND TO CONTINUE ACROSS SOUTHERN NEW ENGLAND LATER TODAY...ONCE THIS COLD FRONT MOVES COMPLETELY OFFSHORE. KEPT TEMPERATURES WELL ABOVE NORMAL...BUT NOT QUITE AS HIGH AS YESTERDAY. PREVIOUS DISCUSSION... PLENTY OF MID LEVEL CLOUDINESS WILL BE AROUND DURING THE MORNING... BUT STILL EXPECT PEEKS OF SUN. AS THE AFTERNOON WEARS ON...EXPECT SUNSHINE TO BECOME MORE PREVALENT AS DRIER AIR WORKS IN BEHIND THE COLD FRONT. GIVEN VERY MILD START...HIGH TEMPS IN MOST LOCALES SHOULD CLIMB WELL UP INTO THE 70S. IT/S NOT OUT OF THE QUESTION THAT A SPOT LOCATION OR TWO HITS 80. HOWEVER...ACROSS THE IMMEDIATE COAST WEAKENING PRESSURE GRADIENT BEHIND THE COLD FRONT WILL ALLOW COOLING SEA BREEZES TO DEVELOP. IN THESE LOCATIONS...MILD LATE MORNING TEMPS WILL PROBABLY FALL BACK INTO THE UPPER 50S AND LOWER 60S...INCLUDING BOSTON. JUST INLAND FROM THE COAST THOUGH IT WILL REMAIN QUITE MILD EVEN BEHIND THE FRONT. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... TONIGHT AND WEDNESDAY... DRY AND PLEASANT WEATHER EXPECTED FOR MOST OF TONIGHT AS HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT. LOW TEMPS WILL MAINLY BE IN THE 40S...TO LOWER 50S. A MOISTURE STARVED SHORTWAVE WILL DROP DOWN IN WEST TO NORTHWEST FLOW ALOFT WED MORNING. NOT SURE IF IT WILL TRACK FAR ENOUGH NORTHWEST TO RESULT IN A BRIEF PERIOD OF SCATTERED SHOWERS ACROSS ANY PORTION OF OUR REGION. BEST SHOT IS NORTHERN CT...AND PERHAPS EVEN INTO PART OF RHODE ISLAND AND SOUTHEAST MA FOR A SHORT TIME. REGARDLESS...EVEN IF A FEW SHOWERS OCCUR THEY WILL BE SHORT-LIVED AND NOT AMOUNT TO MUCH. MORE IN THE WAY OF SUNSHINE SHOULD DEVELOP FROM NORTH TO SOUTH THROUGH WED AFTERNOON. HIGHS SHOULD GENERALLY REACH WELL INTO THE 70S IN MOST LOCATIONS...WITH THE WARMEST READINGS NORTH OF THE PIKE WHERE THE MOST SUNSHINE IS EXPECTED. ITS ALSO POSSIBLE THAT AREAS NEAR THE SOUTH COAST DO NOT REACH 70 ON WEDNESDAY...IF CLOUDS HANG ON LONGER THEN EXPECTED. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... HIGHLIGHTS... * SPRING TO SUMMER-LIKE TEMPERATURES THROUGH EARLY NEXT WEEK * HIGH PRESSURE WILL KEEP MAINLY DRY CONDITIONS INTO THIS WEEKEND * A SLOW MOVING FRONT MAY BRING SCATTERED SHOWERS SUN INTO MON OVERVIEW AND MODEL PREFERENCES... 00Z GEFS/12Z ECENS REMAIN IN GOOD AGREEMENT WITH OVERALL UPPER LEVEL STEERING FLOW IN KEEPING AMPLIFIED PATTERN ACROSS THE LOWER 48 THROUGH MOST OF THIS FORECAST PERIOD. NOTING LONG WAVE TROUGHING WITH A FEW CUTOFF SHORT WAVES DIVE S INTO THE BASE OF THE TROUGH INTO THIS WEEKEND WHILE LONG WAVE RIDGE SLOWLY BUILDS E AS IT NOSES N THROUGH EASTERN QUEBEC TO LABRADOR. ALSO NOTING NEARLY STATIONARY CUTOFF LOW OFF THE SE U.S. COAST WITH SURFACE LOW/POSSIBLE SUBTROPICAL SYSTEM LATE IN THE WEEK OR THIS WEEKEND. WHILE THIS SYSTEM WILL NOT DIRECTLY AFFECT THE REGION... IT COULD CAUSE THE RIDGE TO HOLD IN PLACE AND SLOW AN APPROACHING COLD FRONT FOR LATE THIS WEEKEND INTO NEXT MONDAY. 00Z MODEL SUITE ALSO IN FAIRLY GOOD AGREEMENT INTO THIS WEEKEND... THEN THE GFS LOOKS TO BREAK DOWN RIDGING FASTER THAN GGEM/ECMWF... MAINLY DUE TO SHORT WAVE TRYING TO WORK OUT OF CENTRAL CANADA WHICH FLATTENS OUT THE RIDGE. WITH OVERALL BLOCKING PATTERN IN PLACE ACROSS NORTH AMERICA AND FURTHER E ACROSS THE ATLC...FEEL THIS WILL BE SLOW TO BREAK DOWN SO THINK THE SLOWER GUIDANCE IS THE WAY TO GO FOR SUN-MON. HOWEVER...WITH THE WIDE MODEL SOLUTIONS...HAVE LOW CONFIDENCE FROM SATURDAY INTO EARLY NEXT WEEK. LEANED TOWARD A BLEND OF MODEL GUIDANCE INTO THIS WEEKEND...THEN BLENDED TOWARD THE ENSEMBLES FOR SUN-MON WHICH WAS CLOSE TO THE HPC GUIDANCE. THIS YIELDED GOOD CONTINUITY TO THE PREVIOUS FORECAST. DETAILS... WEDNESDAY NIGHT...EXPECT STALLED FRONT NEAR THE S COAST TO TEND TO WASH OUT AS IT SHIFTS A BIT FURTHER S AS HIGH PRES AT THE SURFACE AND ALOFT SLOWLY PUSHES ACROSS THE REGION. WILL SEE GENERALLY DRY CONDITIONS WITH LIGHT/VRBL WINDS. THURSDAY-FRIDAY...RIDGING BUILDS E ACROSS NEW ENGLAND INTO EASTERN CANADA DURING THIS TIMEFRAME. EXPECT LIGHT/VRBL WINDS EARLY THU TO BECOME S-SW. THIS WILL KEEP MILD TEMPS IN PLACE EXCEPT ALONG THE S COAST WHERE THEY WILL BE TEMPERED WITH THE GENERAL ONSHORE WIND FLOW. MAY ALSO SEE BRIEF SEA BREEZES ALONG THE E COAST MAINLY ON FRIDAY. ALSO...DUE TO SEA SURFACE TEMPS RUNNING IN THE MID-UPPER 40S AND MILD TEMPS DURING THE NIGHTTIME HOURS...MAY SEE OVERNIGHT PATCHY FOG DEVELOP MAINLY ALONG THE COAST WHILE INCREASING DEWPTS MAY ALSO MEAN BRIEF PATCHY FOG ACROSS THE NORMALLY SUSCEPTIBLE INLAND LOCATIONS EACH NIGHT. HIGHS BOTH DAYS AWAY FROM THE S COAST WILL BE IN THE 70S... POSSIBLY UP TO AROUND 80 ACROSS PORTIONS OF THE CT VALLEY BOTH DAYS. SATURDAY THROUGH MONDAY...AS MENTIONED ABOVE...MODEL SOLUTIONS WIDEN. HAVE MENTIONED ONLY SLIGHT CHANCE POPS MAINLY N OF THE MASS PIKE SAT AFTERNOON/NIGHT. INCREASED POPS TO ONLY LOW CHANCE FOR SUN/MON FOR MOST AREAS...BUT WILL DEPEND UPON TIMING OF THE APPROACHING FRONT. EXPECT MILD TEMPS TO REMAIN IN PLACE THROUGH THIS WEEKEND WITH HIGHS IN THE 70S /EXCEPT COOLER ALONG IMMEDIATE S COAST/. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TODAY THROUGH WEDNESDAY/... TODAY...HIGH CONFIDENCE. EXPECT VFR CONDITIONS...THOUGH CIGS WILL LOWER TO 4-5KFT ALONG FRONT INVOF BAND OF SHOWERS AS IT MOVES S OUT OF CENTRAL MA THROUGH MIDDAY. MAY SEE BRIEF LOCAL MVFR CONDITIONS IN ANY HEAVIER SHOWERS. TONIGHT AND WEDNESDAY...HIGH CONFIDENCE. MAINLY VFR CONDITIONS. A BRIEF PERIOD OF ISOLATED TO SCATTERED SHOWERS MAY AFFECT NORTHERN CT AND POSSIBLY A PART OF RI/SOUTHEAST MA FOR A TIME WED AM. THIS MAY RESULT IN VERY BRIEF LOCALIZED MVFR CONDITIONS IF ANY OCCUR. KBOS TAF...HIGH CONFIDENCE IN TAF. SEA BREEZES EXPECTED TO DEVELOP THIS AFTERNOON AS A RESULT OF A WEAKENING PRESSURE GRADIENT BEHIND A COLD FRONT. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY... HIGH CONFIDENCE THROUGH THE PERIOD. VFR AND DRY CONDITIONS. LOW RISK FOR PATCHY FOG EACH NIGHT FROM AROUND MIDNIGHT THROUGH SUNRISE WITH LOCAL MVFR-IFR CIGS/VSBYS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TODAY THROUGH WEDNESDAY/... TODAY THROUGH WEDNESDAY...HIGH CONFIDENCE. MARGINAL SMALL CRAFT SEAS WILL CONTINUE TO DIMINISH ACROSS THE OUTER COASTAL WATERS INTO THIS AFTERNOON. WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH WEDNESDAY UNDER A WEAK RIDGE OF HIGH PRESSURE. OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE THROUGH THE PERIOD. WEDNESDAY NIGHT...LIGHT/VRBL WINDS BECOME S-SW AROUND OR AFTER MIDNIGHT AT 15 KT OR LESS. SEAS 3 FT OR LESS. THURSDAY...W-SW WINDS UP TO 15 KT ACROSS THE OPEN WATERS DURING THE AFTERNOON. SEAS REMAIN BELOW 5 FT. THURSDAY NIGHT THROUGH SATURDAY...SW WINDS 15 KT OR LESS WITH SEAS 2-4 FT. LOW CHANCE OF 5 FT SEAS ON THE EASTERN OUTER WATERS SAT AFTERNOON/NIGHT. && .FIRE WEATHER... MAINLY DRY WEATHER WITH LITTLE APPRECIABLE RAINFALL WILL CONTINUE THROUGH AT LEAST SATURDAY IF NOT INTO SUNDAY/MONDAY. WHILE WINDS FOR THE REST OF THE WORK WEEK WILL PROBABLY NOT BE STRONG ENOUGH FOR FIRE WEATHER HEADLINES...WE MAY HAVE TO BE MORE CONCERNED BY SATURDAY. THERE WILL BE AT LEAST A BIT MORE POTENTIAL FOR SOME MARGINAL FIRE WEATHER HEADLINE WIND GUSTS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANK/EVT NEAR TERM...BELK/FRANK/EVT SHORT TERM...FRANK LONG TERM...EVT AVIATION...BELK/FRANK/EVT MARINE...BELK/FRANK/EVT FIRE WEATHER...STAFF

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