877  
FXUS61 KBOX 141726  
AFDBOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
126 PM EDT MON APR 14 2025  
   
SYNOPSIS  
 
HIGH PRESSURE BUILDS OVER SOUTHERN NEW ENGLAND TODAY, BRINGING A  
RETURN TO SUNNY WEATHER AND RATHER MILD TEMPERATURES. A WARM  
FRONT BRINGS INCREASED CLOUDINESS AND PASSING LIGHT SHOWERS  
AGAIN FOR TONIGHT. THEN A RATHER STRONG UPPER LEVEL DISTURBANCE  
BRINGS UNSETTLED CONDITIONS AGAIN FOR TUESDAY AFTERNOON.  
SCATTERED POP- UP SHOWERS LIKELY FOR INTERIOR SOUTHERN NEW  
ENGLAND, SOME CAPABLE OF LIGHTNING AND PERHAPS SOME SMALL HAIL  
OR GRAUPEL. GENERALLY DRY PATTERN BY MIDWEEK WITH COOL AND  
WINDY CONDITIONS WEDNESDAY THAT SLIGHTLY IMPROVE THURSDAY.  
TEMPERATURES CONTINUE TO INCREASE INTO SATURDAY. RAIN CHANCES  
RETURN SATURDAY WITH WARM SECTOR AIR SETTLING OVER THE REGION  
BEFORE A COLD FRONT MOVES THROUGH SATURDAY NIGHT.  
 
 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/  
 
330 AM UPDATE:  
 
KEY MESSAGES:  
 
* LOCALIZED FOGGY AREAS IN EASTERN MA DISPERSES BY SUNRISE.  
 
* SUNNY AND WARMING UP INTO THE 60S, PERHAPS A FEW SPOT 70S?  
 
* COOLER SEABREEZES NEAR SOUTHERN AND EASTERN COASTS.  
 
DETAILS:  
 
THE PESKY, VERTICALLY-STACKED CIRCULATION RESPONSIBLE FOR THIS  
WEEKEND'S CRUMMY AND RAW CONDITIONS IS NOW FINALLY ESCAPING INTO  
GEORGES BANK. OTHER THAN SOME STRAGGLING STRATUS OVER THE OUTER  
CAPE, MOST AREAS HAVE GONE MOSTLY CLEAR AS WEAK SFC HIGH  
PRESSURE RIDGE NOSES IN. GOOD RADIATIONAL COOLING HAS DEVELOPED  
IN MOST AREAS, WHICH HAS DONE A COUPLE THINGS. FIRST, IT'S LED  
TO DEVELOPMENT OF LOCALIZED PATCHES OF FOG, GENERALLY OCCURRING  
INSIDE OF EASTERN MA AND PORTIONS OF RI WHERE TEMPERATURE-  
DEWPOINT SPREADS ARE THE NARROWEST COMING OUT OF THE WEEKEND RAW  
CONDITIONS. VSBYS HAVE BEEN AS LOW AS A QUARTER MILE IN SOME  
AREAS SUCH AS BEDFORD, BUT WE FELT THE COVERAGE WAS TOO SPARSE  
TO WARRANT ANY FOG STATEMENTS. EXPECT FOGGY AREAS TO IMPROVE  
SHORTLY AFTER SUNRISE. IT'S ALSO PARTLY CONTRIBUTED TO A RATHER  
WIDE RANGE IN TEMPS, FROM THE UPPER 20S IN ORANGE MA TO THE LOW  
TO MID 40S CAPE AND ISLANDS AND MOST OF THE CITIES.  
 
SHAPING UP TO BE A BEAUTIFUL START TO THE WORKWEEK AS RIDGING  
BOTH SFC AND ALOFT CREST OVER SOUTHERN NEW ENGLAND. THIS WILL  
SUPPLY US WITH PLENTIFUL SUNSHINE AND SHOULD FAVOR QUITE A WARM-  
UP TO TEMPS WITH GOOD MIXING AND AS WINDS TURN TOWARD THE SW. A  
STREAM OF HIGH CLOUDS MAY ARRIVE LATE IN THE DAY BUT THE WARM  
FRONTAL FEATURE RESPONSIBLE FOR IT WON'T ARRIVE UNTIL LATER  
TONIGHT. THE SOUTHERN AND EASTERN COASTS DO LOOK LIKE THEY WILL  
DEVELOPS SEABREEZES; ALTHOUGH SOME OF THE LATEST HIGH RES  
GUIDANCE, INCLUDING THE HRRR WHICH OFTEN SHOWS ITS DEVELOPMENT,  
HAS STARTED TO BACK OFF ON THE EASTERN MA SEABREEZE. HIGHS  
SHOULD SOAR INTO THE 60S AWAY FROM THE COAST AND A FEW SPOT 70  
DEGREE READINGS ARE POSSIBLE GIVEN MIXING TO 850 MB AND 925 MB  
TEMPS WARMING TO AROUND +10 TO +12C. DEWPOINTS SHOULD ALSO MIX  
LOWER AND SUPPORT RHS IN THE MID 20S PERCENT, BUT NO FIRE  
WEATHER CONCERNS ARE EXPECTED COMING OUT OF THE DAMP WEEKEND.  
 
 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/  
 
330 AM UPDATE:  
 
KEY MESSAGES:  
 
* INCREASING CLOUDS TONIGHT, WITH LIGHT SHOWERS AGAIN POSSIBLE AFTER  
MIDNIGHT, BUT WILL BE PROGRESSIVE.  
 
* EARLY OVERCAST TUE AM TRENDS TO PARTLY/MOSTLY CLOUDY CONDITIONS  
TUE AFTN. AFTERNOON HIT-OR-MISS SHOWERS MORE LIKELY WEST OF I-495,  
SOME COULD BE CAPABLE OF LIGHTNING AND GRAUPEL/SMALL HAIL?  
 
* HIGHS MID 50S TO LOWER-MID 60S TUE.  
 
DETAILS:  
 
TONIGHT:  
 
A WARM FRONT, WHICH AS OF EARLY MONDAY MORNING WAS LOCATED OVER  
EASTERN OH AND THE WESTERN APPALACHIANS WILL PROGRESS THROUGH  
SOUTHERN NEW ENGLAND TONIGHT. THIS IS ASSOCIATED WITH A RATHER  
STRONG FRONTAL SYSTEM AND UPPER TROUGH OVER THE UPPER MIDWEST.  
EXPECT AT LEAST INCREASED CLOUDINESS TO OVERCAST AGAIN THRU  
MIDNIGHT. THERE MAY BE SOME SHOWERS ASSOCIATED WITH THE WARM FRONT'S  
ADVANCE THROUGH SOUTHERN NEW ENGLAND TOO, AND OFFERED CHANCE POP FOR  
THOSE AS GUIDANCE UP UNTIL RECENTLY HAS BEEN MORE BEARISH ON THE  
COVERAGE. RECENT GUIDANCE HAS PERKED UP SOME WITH RESPECT TO THE  
AREAL COVERAGE, AND LATER SHIFTS MAY NEED TO CONSIDER INCREASING  
POPS TO REFLECT A BETTER CHANCE FOR RAINS PENDING TRENDS IN  
GUIDANCE. EITHER WAY, IT IS PROGRESSIVE AND NOT EXPECTED TO BE A  
WASHOUT. LOOKING AT A RATHER MILD EVENING BY EARLY APRIL MEASURES  
WITH LOWS FALLING ONLY INTO THE MID TO UPPER 40S GIVEN OVERCAST AND  
THE WARM SECTOR MOVING IN.  
 
TUESDAY:  
 
THE WARM FRONT FROM MON NIGHT WILL BE PROGRESSING OFFSHORE EARLY  
TUE. WE'LL LIKELY START THE DAY WITH OVERCAST SKIES IN MOST AREAS,  
BUT WE DO EXPECT SOME DECREASE IN CLOUD COVER TO MORE OF A PARTLY  
SUNNY TO MOSTLY CLOUDY LOOK AS WE MOVE INTO THE AFTERNOON. HIGHS IN  
THE MID 50S TO LOWER 60S.  
 
THE FOCUS THEN TURNS TO THE AFTERNOON, AS THE UPPER LOW NOW OVER THE  
MIDWEST MOVES TO NORTHWEST NY BY TUE AFTN. THIS FEATURE WILL BRING A  
COMBO OF SEASONABLY-STRONG MID TO UPPER LEVEL WINDS/DIFFLUENCE AS  
WELL AS STEEP 850-500 MB LAPSE RATES TO AROUND 7 TO 8 C/KM,  
ASSOCIATED WITH A DEEP COLD POOL OF AIR ALOFT. MAJORITY OF MODEL  
SOLUTIONS SHOW A RATHER GENEROUS COVERAGE OF AT LEAST SCATTERED  
CONVECTIVE SHOWERS, WITH CONVECTIVE-PERMITTING NWP OUTPUT SHOWING  
EITHER INDIVIDUAL CELLS OR BROKEN LINEAR CONVECTIVE SEGMENTS. OPTED  
FOR SCATTERED AFTN SHOWERS MAINLY FOR AREAS NEAR AND WEST OF I-495,  
BUT ALSO MADE MENTION OF ISOLATED THUNDERSTORMS FOR THAT SAME AREA.  
WILL HAVE TO SEE IF THIS ACTIVITY MAKES IT INTO EASTERN MA. BUFKIT  
PROFILES SHOW LOW-TOPPED "COLD-POOL-ALOFT" TYPE CONVECTIVE PROFILES  
WITH EQUILIBRIUM LEVELS AROUND 17K, WELL ABOVE THE LIGHTNING  
GENERATION LAYER. A FEW STRONG CELLS COULD BE CAPABLE OF A FEW  
LIGHTNING STRIKES AS WELL AS PRODUCE GRAUPEL OR SMALL SUB-SEVERE  
HAIL GIVEN THE LAPSE RATES AND STRONG MID/UPPER FLOW. THE MAIN  
UNCERTAINTY THAT WILL DICTATE THIS POTENTIAL IS HOW MUCH SFC HEATING  
CAN WE REALIZE THROUGH CONTINUED PARTLY/MOSTLY CLOUDY SKIES; THERE  
SHOULD SOME HEATING, BUT IT DOESN'T SEEM LIKE WE'LL FULLY CLEAR. THE  
COLDER AIR ALOFT AND DIFFLUENCE ALOFT SHOULD OFFSET THAT TO AN  
EXTENT, AND THERE IS SOME MOST-UNSTABLE CAPE (AROUND 500 J/KG IN  
MOST BULLISH SOLUTIONS, MOST ARE LESS THAN THAT). ACTIVITY SHOULD  
DISSIPATE SHORTLY AFTER SUNDOWN.  
 
 
   
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/  
 
KEY MESSAGES:  
 
* COLD FRONT TUESDAY NIGHT LEAVES COOL AND WINDY CONDITIONS IN ITS  
WAKE WEDNESDAY  
 
* TEMPERATURES STEADILY INCREASE HEADING INTO THE WEEKEND  
 
* PRECIPITATION CHANCES RETURN SATURDAY BEFORE POSSIBLE CLEARING  
SUNDAY  
 
DETAILS...  
 
A COLD FRONT MOVES THROUGH THE REGION TUESDAY NIGHT GOING INTO  
WEDNESDAY, USHERING IN NORTHWEST FLOW AND DRIER AIR. THIS IS  
EXPECTED TO LIMIT THE CHANCES FOR ANY PRECIPITATION FOR THE WEEK.  
THE COOLER AIR ALOFT WILL MIX DOWN, ALONG WITH GUSTY WINDS DURING  
THE DAY. GUSTS TO 30 MPH COULD BE POSSIBLE IN THE AFTERNOON HOURS  
HIGHS WEDNESDAY ARE ONLY EXPECTED TO BE IN THE UPPER 40S TO LOW 50S  
ACROSS THE REGION. FORECAST SOUNDINGS INDICATE A SIMILAR STORY FOR  
THURSDAY, ALBEIT A BIT WARMER DUE TO LESS CLOUD COVER AND CONTINUED  
DIURNAL MIXING. GUSTS OF 25-30 MPH WILL BE POSSIBLE THURSDAY AS WELL.  
 
RIDGING BUILDS IN FROM THE WEST AS THE TROUGH RESPONSIBLE FOR THE  
UNSETTLED WEATHER EARLIER IN THE WEEK (ALONG WITH THE COLDER  
TEMPERATURES MIDWEEK) EXITS THE REGION. AS THE RIDGE AXIS BUILDS  
OVER SOUTHERN NEW ENGLAND, TEMPERATURES WILL LIKELY INCREASE TO THE  
LOW 60S. WINDS WILL ALSO DIMINISH WITH THE SLACKENING OF THE  
PRESSURE GRADIENT THAT WILL HAVE BEEN OVER THE REGION SINCE  
WEDNESDAY. WITH FLOW SHIFTING MORE S TO SW TOWARDS THE AFTERNOON  
HOURS, IT'S POSSIBLE SOME CLOUDS MAY DEVELOP FROM MOISTURE BEING  
ADVECTED IN.  
 
A WARM FRONT MOVES OVER SOUTHERN NEW ENGLAND GOING INTO SATURDAY,  
PUTTING THE WARM SECTOR OVER THE REGION TO START THE WEEKEND.  
GUIDANCE INDICATES SATURDAY BEING WARMER THAN NORMAL, WITH ENSEMBLES  
HAVING 925 HPA TEMPERATURES SITTING AROUND 15C FOR THE MEAN; SOME OF  
THE DETERMINISTIC GUIDANCE HAS THESE VALUES UP TO 20C. ASIDE FROM  
THE GEPS, WHICH IS RUNNING A BIT WARMER, OTHER ENSEMBLES HAVE AROUND  
A 50 PERCENT PROBABILITY OF EXCEEDING 15C AT THIS LEVEL. HIGHS ARE  
CURRENTLY FORECAST AT THE MID TO UPPER 60S WITH SOME SPOTS AROUND  
70F. CLOUDY AND SHOWERY CONDITIONS THROUGHOUT THE DAY FROM CONTINUED  
WARM AIR AND MOISTURE ADVECTION MAY HELP LIMIT TEMPERATURES FROM  
GETTING MUCH HIGHER.  
 
FOLLOWING THIS AIRMASS, A COLD FRONT IS EXPECTED TO MOVE THROUGH  
SATURDAY NIGHT INTO SUNDAY. A DRIER AND COLDER AIRMASS SETTLES IN  
ITS WAKE. CLOUDS ARE CLEARED OUT OF THE REGION, WINDS SHIFT  
NORTHWEST, AND TEMPERATURES ALOFT RETURN TO AROUND 0C BY SUNDAY  
MORNING. LOWS SATURDAY NIGHT SINK BACK DOWN TO THE LOW TO MID  
40S.  
 
 
   
AVIATION /17Z MONDAY THROUGH FRIDAY/  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
18Z TAF UPDATE: HIGH CONFIDENCE, THEN MODERATE CONFIDENCE TUE.  
 
VFR THROUGH EARLY TONIGHT BEFORE CIGS LOWER TO MVFR/IFR IN  
SCATTERED SHOWERS OVERNIGHT INTO TUE MORNING. GRADUAL  
IMPROVEMENT BACK TO VFR IS EXPECTED TUE AFTERNOON BUT WITH  
CONTINUED RISK OF SCATTERED SHOWERS. STILL LOOKING AT POTENTIAL  
FOR SOME LATE AFTERNOON THUNDERSTORMS WITH SMALL HAIL,  
ESPECIALLY IN WESTERN/CENTRAL MA AND CT. CLEARING TUE NIGHT.  
 
LOCAL SEA BREEZES EXPECTED FOR A FEW HOURS LATE THIS AFTERNOON,  
OTHERWISE WINDS BACK TO S/SW THROUGH TONIGHT WITH INCREASING SW  
WINDS TUE GUSTING TO 20-25KT AT TIMES. WINDS SHIFT TO W/NW TUE  
NIGHT WITH COASTAL AIRPORTS GUSTING TO 25-30KT TOWARD DAYBREAK  
WED.  
 
KBOS TAF...HIGH CONFIDENCE, INCLUDING SEA BREEZE TIMING LATE  
THIS AFTERNOON. EXPECTING TS TO REMAIN WEST OF AIRPORT LATE TUE  
AFTERNOON.  
 
KBDL TAF...HIGH CONFIDENCE. ISOLATED TS POSSIBLE 20Z-23Z TUE BUT  
CONFIDENCE IS TOO LOW TO INCLUDE IN TAF.  
 
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...  
 
WEDNESDAY: VFR. WINDY WITH GUSTS UP TO 30 KT.  
 
WEDNESDAY NIGHT: VFR. WINDY WITH AREAS OF GUSTS UP TO 35 KT.  
 
THURSDAY: VFR. BREEZY.  
 
THURSDAY NIGHT: VFR.  
 
FRIDAY: VFR. BREEZY.  
 
 
   
MARINE  
 
FORECASTER CONFIDENCE LEVELS:  
 
LOW - LESS THAN 30 PERCENT.  
MEDIUM - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
KEY POINTS:  
* PERIOD OF W/NW GALES POSSIBLE LATE TUE NIGHT INTO WED.  
 
STRONG COLD ADVECTION BEHIND NEXT SYSTEM LATER TUE NIGHT INTO  
WED MOST LIKELY BRINGS GUSTS OF 25-30KT BUT POSSIBLY HIGHER.  
ISSUING A GALE WATCH FOR ALL WATERS FOR W/NW WINDS POTENTIALLY  
GUSTING TO 35-40KT. HIGHEST CONFIDENCE IS ON WATERS AROUND AND  
OFFSHORE OF CAPE COD AND THE ISLANDS BUT WE CANNOT RULE OUT 34KT  
GUSTS ELSEWHERE, INCLUDING BOSTON HARBOR AND NARRAGANSETT BAY.  
 
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...  
 
TUESDAY NIGHT THROUGH WEDNESDAY: LOW RISK FOR GALE FORCE WINDS  
WITH GUSTS UP TO 35 KT. AREAS OF ROUGH SEAS.  
 
WEDNESDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH  
GUSTS UP TO 30 KT. LOCAL ROUGH SEAS.  
 
THURSDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING  
5 FT.  
 
THURSDAY NIGHT THROUGH FRIDAY: WINDS LESS THAN 25 KT.  
 
 
   
BOX WATCHES/WARNINGS/ADVISORIES  
 
CT...NONE.  
MA...NONE.  
RI...NONE.  
MARINE...GALE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY EVENING  
FOR ANZ230>237-250-251-254>256.  
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ250-  
254.  
 
 
 
 
 
SYNOPSIS...LOCONTO/HRENCECIN  
NEAR TERM...LOCONTO  
SHORT TERM...LOCONTO  
LONG TERM...HRENCECIN  
AVIATION...JWD  
MARINE...JWD  
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