Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 290748 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 348 AM EDT WED JUL 29 2015 .SYNOPSIS...
-- Changed Discussion --
HOT AND HUMID CONDITIONS TODAY THROUGH THURSDAY. A COLD FRONT WILL BRING SCATTERED THUNDERSTORMS LATE THURSDAY AND THURSDAY NIGHT. NOT AS WARM AND LESS HUMID WEATHER IS EXPECTED FRIDAY INTO THE WEEKEND AND PROBABLY INTO EARLY NEXT WEEK. WHILE MUCH OF THIS PERIOD WILL BE DRY...CAN/T RULE OUT AN AFTERNOON AND EVENING THUNDERSTORM EACH DAY.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM THIS MORNING/... 2 AM UPDATE... OVERALL TREND IN THE FORECAST IS ON TRACK. DRY WEATHER PREVAILS AS UPPER LEVEL RIDGING BEGINS TO TAKE HOLD OF THE REGION. TEMPERATURES HAVE DROPPED A DEGREE OR TWO BUT ANTICIPATE LOW TEMPS TO REMAIN IN THE UPPER 60S TO LOW 70S. ANOTHER MILD NIGHT AS DEWPOINTS HAVE REACHED IN THE UPPER 60S TO LOW 70S AS WELL. THIS LOW TEMPS/DEWPOINT SPREAD HAS ALLOWED FOG TO DEVELOP ACROSS SE MASS/RI AND THE ISLANDS. EXPECT FOG TO SLOWLY INCREASE ESP IN REGIONS THAT RECEIVED RAIN TODAY AND ALONG THE SOUTH COAST. MAY NEED TO ISSUE A DENSE FOG ADV IF VSBYS DROP ANY LOWER...RIGHT NOW MANY SITES ARE HOLDING AROUND 2-4SM. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/... ***HOT BUT DRY WEATHER ON WEDNESDAY*** UPPER LEVEL RIDING WILL BUILD ACROSS SOUTHERN NEW ENGLAND. THIS SHOULD RESULT IN PARTLY TO MOSTLY SUNNY SKIES...DESPITE SOME DIURNAL CUMULUS CLOUDS. 850 MB TEMPS AROUND +18C WILL YIELD HIGHS BETWEEN 90 AND 95 ACROSS MOST OF THE REGION. WEAK PRESSURE GRADIENT WILL RESULT IN TEMPS A BIT COOLER ALONG PORTIONS OF THE COAST. WHILE THERE IS A LOW RISK OF A VERY ISOLATED SHOWER/THUNDERSTORM...GIVEN UPPER LEVEL RIDGING OPTED FOR A DRY FORECAST. EVEN IF ONE WERE TO HAPPEN IT PROBABLY WOULD BE VERY BRIEF AND COVER SUCH A SMALL AREA OF OUR REGION...NOT WORTH A MENTION AT THIS POINT. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
-- Changed Discussion --
HIGHLIGHTS... * PATTERN CHANGE TO MORE SEASONABLE TEMPS IS ACCOMPANIED BY SHOWERS AND THUNDERSTORMS THU NIGHT * NOT AS WARM AND HUMID FRIDAY AND BEYOND * MAINLY DRY WEATHER PREVAILS FRIDAY THRU TUESDAY SYNOPTIC OVERVIEW AND MODEL PREFERENCES... IMPRESSIVE AND ANOMALOUS VORTEX CURRENTLY OVER SOUTHERN MANITOBA AS SEEN ON THE LATEST WATER VAPOR IMAGERY WILL BECOME THE MAIN WEATHER FEATURE THIS PERIOD...AS IT EVOLVES INTO A MUCH BROADER CIRCULATION OVER JAMES AND HUDSON BAY THIS WEEKEND AND NEXT WEEK. THIS RESULTS IN A BROAD MEAN LONG WAVE TROUGH SETTING UP ACROSS THE GREAT LAKES AND THE NORTHEAST. THIS WILL SUPPRESS EXCESSIVE HEAT AND HUMIDITY AIRMASS CURRENTLY OVER THE AREA SOUTHWARD BEGINNING FRIDAY AND LASTING THRU THE WEEKEND INTO EARLY NEXT WEEK. GIVEN GOOD MULTI MODEL AGREEMENT AMONG DETERMINISTIC AND ENSEMBLE GUIDANCE REGARDING THE LARGE SCALE FLOW THIS PERIOD...FORECAST CONFIDENCE IS ABOVE AVERAGE. DAILY SENSIBLE WEATHER DETAILS... THURSDAY NIGHT... NORTHERN STREAM SHORT WAVE AND ATTENDING COLD FRONT MOVE ACROSS THE AREA. MODEST SYNOPTIC SCALE FORCING ASSOCIATED WITH THIS FEATURE. WHILE INSTABILITY AND SHEAR IS MARGINAL IN THE PREFRONTAL ENVIRONMENT...PWATS CLIMB TO 2+ INCHES /+2 STD DEVIATIONS ABOVE CLIMO/. THUS GREATER RISK OF HEAVY DOWNPOURS AND LOCALIZED FLOODING. WARM AND MUGGY CONDITIONS PREVAIL AS POST FRONTAL AIRMASS DOESN/T ARRIVE UNTIL FRIDAY. FRIDAY THRU TUESDAY... TREND TOWARD MORE SEASONABLE TEMPERATURES AND LOWER HUMIDITY ARRIVES FRIDAY BEHIND DEPARTING COLD FRONT WITH HIGHS IN THE 80S AND LOWS IN THE 60S. TOO DIFFICULT AT THIS TIME RANGE TO TIME INDIVIDUAL SHORT WAVES EMBEDDED IN THE CYCLONIC FLOW. SO BEST WORDING WOULD BE MANY HOURS OF DRY WEATHER THIS PERIOD BUT CYCLONIC FLOW AND COOLER TEMPS ALOFT WILL RESULT IN THE RISK OF A THUNDERSTORM DURING PEAK HEATING HOURS EACH DAY.
-- End Changed Discussion --
&& .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY AFTERNOON/... TONIGHT...MODERATE CONFIDENCE. VFR FOR MANY SITES...HOWEVER ANTICIPATE PATCHY DENSE FOG TO DEVELOP DROPPING SOME SITES DOWN TO IFR OR EVEN LIFR. BEST SPOT WILL BE ACROSS THE CAPE...ISLANDS AND SOUTH COAST WHERE DEWPOINTS ARE IN THE 70S. WEDNESDAY INTO WEDNESDAY NIGHT...HIGH CONFIDENCE IN VFR CONDITIONS. MAY SEE PATCHY FOG OVERNIGHT DROPPING CONDITIONS TO IFR. THURSDAY...VFR TO START CONDITIONS DROPPING TO MVFR IN -SHRA/TSRA BETWEEN 18-00Z. A FEW STRONG STORMS ARE POSSIBLE. KBOS TERMINAL...HIGH CONFIDENCE. SEA BREEZE DEVELOPS BETWEEN 14-15Z. KBDL TERMINAL...HIGH CONFIDENCE. OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/... THURSDAY NIGHT...MVFR AND IFR IN SCATTERED SHOWERS/T-STORMS AND FOG. MODERATE TO HIGH FORECAST CONFIDENCE. FRIDAY AND SATURDAY...MODERATE TO HIGH CONFIDENCE IN VFR CONDITIONS. VERY LOW RISK FOR AN AFTERNOON T-STORM SATURDAY. SUNDAY...MODERATE CONFIDENCE FOR MAINLY VFR.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TONIGHT THROUGH WEDNESDAY AFTERNOON/...HIGH CONFIDENCE. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH WEDNESDAY AFTERNOON. MAIN CONCERN WILL BE A FEW STRONG TO SEVERE STORMS ACROSS THE ADJACENT SOUTH COASTAL WATERS THROUGH 7 OR 8 PM. LOCALLY STRONG WIND GUSTS AND PERHAPS ISOLATED HAIL ARE THE MAIN CONCERNS. ALSO...SOME PATCHY FOG IS POSSIBLE THIS EVENING NEAR THE ISLANDS BUT VISIBILITIES SHOULD IMPROVE AFTER MIDNIGHT AS WINDS TURN WEST. OUTLOOK /THURSDAY NIGHT THROUGH SATURDAY/... THURSDAY NIGHT...SW WINDS 15 TO 20 KT WITH GUSTS UP TO 25 KT POSSIBLE. ROUGH SEAS ON SOUTH OCEAN WATERS WITH WIND WAVES OF 3 TO 6 FT POSSIBLE. VSBY REDUCED IN SCATTERED SHOWERS/TSTMS AND FOG. MODERATE TO HIGH FORECAST CONFIDENCE. FRIDAY/SATURDAY AND SUNDAY...COLD FRONT SLOWLY MOVES OFFSHORE WITH WIND SHIFT FROM SSW TO WSW. DRY WEATHER AND GOOD VSBY. HIGH FORECAST CONFIDENCE. LEFTOVER SOUTHERLY SWELLS ON SOUTH OCEAN WATERS FROM THU NIGHT LINGER FRI BUT SLOWLY DIMINISH.
-- End Changed Discussion --
&& .BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR CTZ002. MA...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR MAZ017>024. DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MAZ023-024. HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR MAZ011. RI...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR RIZ005>008. MARINE...NONE.
-- End Changed Discussion --
&& $$ SYNOPSIS...NOCERA/DUNTEN NEAR TERM...DUNTEN SHORT TERM...FRANK LONG TERM...NOCERA AVIATION...NOCERA/DUNTEN MARINE...FRANK/NOCERA

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