190
FXUS61 KBOX 140336
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
1136 PM EDT THU MAR 13 2025
SYNOPSIS
TURNING MILDER FRIDAY INTO THIS WEEKEND, ESPECIALLY AWAY FROM THE
SOUTH COAST, WITH UNSEASONABLY MILD AND WINDY CONDITIONS SUNDAY. A
STRONG COLD FRONT WILL BRING THE POTENTIAL FOR HEAVY RAIN AND STRONG
SOUTHERLY WIND GUSTS SUNDAY NIGHT INTO MONDAY MORNING. MAINLY DRY
TUESDAY AND WEDNESDAY WITH UNSEASONABLY MILD TEMPERATURES RETURNING
WEDNESDAY. AN APPROACHING COLD FRONT MAY BRING A RISK OF SHOWERS
NEXT THURSDAY.
NEAR TERM /THROUGH FRIDAY/
MAIN CHANGES THIS EVENING WERE TO SKY COVER. LOWER CLOUDS AND
MADE IS FAR NORTH AS THE MASS PIKE. BASED ON LATEST NEAR-TERM
GUIDANCE, NOT EXPECTING THESE CLOUDS TO DISSIPATE MUCH THE REST
OF TONIGHT. MINOR TWEAKS TO TEMPERATURES AS WELL TO ACCOUNT FOR
THE INCREASED CLOUD COVER.
PREVIOUS DISCUSSION...
LOW PRES SOUTH OF NEW ENG TRACKS SOUTH OF THE BENCHMARK TONIGHT.
LOW RISK FOR A FEW SHOWERS OVER THE OUTER CAPE AND ACK.
OTHERWISE, DRY TONIGHT. LOW LEVEL MOISTURE INCREASES WITH
PERSISTENT EASTERLY FLOW AND SOME LOWER CLOUDS MAY EXPAND NORTH
AND WEST ACROSS EASTERN HALF OF SNE WITH HIGHEST PROBABILITY
OVER EASTERN MA AND RI. LOWS RANGE FROM THE MID- UPPER 20S
INTERIOR MA TO MID 30S ALONG THE IMMEDIATE COAST.
SHORT TERM /FRIDAY NIGHT/
BROAD RIDGING ALOFT AHEAD OF MIDWEST UPPER LOW MOVES ACROSS NEW
ENG WITH SURFACE RIDGING REMAINING IN PLACE ACROSS SNE. THE
COLUMN IS DRY ABOVE 900 MB, BUT PERSISTENT LOW LEVEL MOISTURE
WILL ALLOW LOW CLOUDS TO LINGER ACROSS SE MA AND ESPECIALLY
CAPE/ISLANDS INTO THE EARLY AFTERNOON BEFORE CLEARING.
OTHERWISE, MOSTLY SUNNY IN THE INTERIOR FRIDAY. THEN LOW CLOUDS
MAY REDEVELOP ACROSS THE REGION FRI NIGHT. GENERALLY LIGHT NE
WINDS FRI WITH SEA-BREEZES DEVELOPING ALONG THE COAST, BECOMING
NEAR CALM FRI NIGHT.
FRIDAY HIGHS WILL BE IN THE 50S, AND AROUND 60 IN THE CT
VALLEY, BUT HOLDING IN THE UPPER 40S ALONG THE EASTERN MA
COAST. LOWS MAINLY IN THE 30S FRI NIGHT.
LONG TERM /SATURDAY THROUGH THURSDAY/
KEY MESSAGES:
* A SPRING-LIKE DAY WITH MILD TEMPERATURES EXPECTED ON SATURDAY WITH
A LOW CHANCE OF A SPOT SHOWER OR TWO LATE AFTERNOON AND EVENING.
* HEAVY RAIN AND STRONG TO DAMAGING WINDS POSSIBLE SUNDAY EVENING
INTO MONDAY
* DRYING OUT TUESDAY, CALMER CONDITIONS GOING INTO WEDNESDAY
DETAILS...
SATURDAY & SATURDAY NIGHT...
THE FIRST-HALF OF THE WEEKEND IS QUIET WITH MID-LEVEL RIDGING ACROSS
THE REGION. WAA DUE TO SW FLOW CONTINUES THE WARMING TREND INTO THE
AFTERNOON ON SATURDAY AND WILL LITTLE CHANGE, LEADS TO A MILD NIGHT
AS WELL. THE WAA WILL INCREASE PWATS UP TO 0.6", WHILE THIS DOES NOT
SOUND SIGNIFICANT, IT IS ROUGHLY 160% OF THE CLIMATOLOGICAL NORMAL
FOR MID-MARCH. DESPITE THE CLOUDS, WILL HAVE ABOVE NORMAL DAYTIME
HIGHS AND NIGHTTIME LOWS. NEAR THE COAST IT WILL BE NOTICEABLY
COOLER DUE TO THE SOUTHWEST FLOW COMING OFF THE RELATIVELY COLDER
OCEAN, BUT STILL WARMER THE NORMAL IN THE UPPER 40S TO THE LOW 50S.
WHILE FURTHER INLAND AND AWAY FROM THE INFLUENCE OF THE COLDER SEA
SURFACE TEMPERATURES AFTERNOON HIGHS TOP OUT IN THE UPPER 50S AND
LOW 60S. AND WITH THE ABUNDANT CLOUD COVER AND CONTINUED WAA THE
OVERNIGHT LOWS RANGE FROM THE LOW 40S NEAR THE COAST AND UPPER 40S
ACROSS AWAY FROM THE COAST/INLAND LOCATIONS. AS FOR PRECIPITATION,
NO WASHOUTS SATURDAY OR SATURDAY NIGHT DUE TO THE LACK OF SENSIBLE
FORCING. GLOBAL GUIDANCE HAS A SUBTLE SHORTWAVE PASSAGE SOMETIME
LATE AFTERNOON AND EARLY EVENING, A SPOTTY SHOWER OR TWO CANNOT BE
RULED OUT DURING SAID TIME FRAME.
SUNDAY & MONDAY...
SOUTHERLY FLOW CONTINUES TO DOMINATE SUNDAY AS THE UPPER-LEVEL RIDGE
MOVES EAST AND OUT OVER THE WATERS. WARM, MOIST AIR IS EXPECTED TO
BRING UNSEASONABLY WARM TEMPERATURES TO THE AREA SUNDAY AND SUNDAY
NIGHT. ENSEMBLE PROBABILITIES REMAIN ABOVE 85 PERCENT FOR HIGHS OVER
60F SUNDAY IN URBAN CENTERS, WITH ONLY 65 PERCENT OVER THE WORCESTER
FOOTHILLS. WHILE HIGH WINDS ARE EXPECTED THROUGHOUT SUNDAY, THE MORE
SIGNIFICANT LLJ MOVES OVER THE REGION SUNDAY EVENING THAT COULD LEAD
TO SOME STRONG TO DAMAGING WIND GUSTS ACROSS SOUTHERN NEW ENGLAND.
ENSEMBLE GUIDANCE HAS CONTINUED TO INDICATE A 60 TO 75 KT LLJ. WINDS
AT THIS SPEED WILL LIKELY NOT REACH THE SURFACE, BUT GUSTS TO 45 MPH
OVER THE HIGHER TERRAIN ARE POSSIBLE, WITH MOST OTHER PARTS OF THE
REGION (ESPECIALLY EAST OF THE I-95 CORRIDOR) EXPERIENCING 35-40 MPH
GUSTS.
ASIDE FROM THE WINDS, A PERIOD OF HEAVY RAIN SUNDAY NIGHT INTO
MONDAY IS EXPECTED. ANOMALOUSLY STRONG SOUTHERLY FLOW CONTINUES TO
ADVECT SIGNIFICANT MOISTURE FROM THE ATLANTIC INTO THE REGION,
ELEVATING PWAT VALUES. THE LATEST NAEFS GUIDANCE HAS INCREASED PWAT
VALUES TO NEAR OR JUST ABOVE 1.3" ACROSS MOST OF SOUTHERN NEW
ENGLAND. RAINFALL TOTALS COULD BE IN THE 1.5" TO 2" RANGE WITH THE
GEPS AND ECMWF ENS CONTINUING TO INDICATE A 20 PERCENT CHANCE THAT
24 HOUR RAINFALL MAY EXCEED 2" ALONG THE SOUTHERN SHORES OF RI AND
MA. THE GEFS, MUCH LIKE THE DETERMINISTIC GFS, CONTINUES TO RUN
SLIGHTLY DRIER THAN OTHER GUIDANCE; PROBS FOR EXCEEDING 2" OVER 24
HOURS ONLY REACH AROUND 10 PERCENT OVER RI AND SOUTHERN CT, WITH
LESS THAN 10 PERCENT FOR SOUTHERN MA.
GIVEN THE LIKELIHOOD OF HEAVY RAIN THIS WEEKEND, ALONG WITH ANY
REMAINING SNOWMELT ACROSS NORTHERN NEW ENGLAND, WE ARE CONTINUING TO
MONITOR THE POSSIBILITY OF RISES ALONG THE LARGER RIVERS ACROSS
SOUTHERN NEW ENGLAND, MAINLY THE CONNECTICUT RIVER. AT THIS TIME,
THERE IS AT LEAST A 30 PERCENT CHANCE OF EXCEEDING MINOR FLOOD STAGE
ALONG THE CONNECTICUT RIVER FROM NORTHAMPTON TO HARTFORD, AND AT
LEAST 70 PERCENT CHANCE OF EXCEEDING MINOR FLOOD STAGE SOUTH OF
HARTFORD. WE MAY ALSO SEE SOME SLIGHTLY HIGHER WATER LEVELS ALONG
THE SOUTHERN SHORES DURING THE SUNDAY NIGHT HIGH TIDE, INCLUDING THE
NARRAGANSETT BAY, WITH THE PROLONGED SOUTHERLY FLOW THROUGH THE
WEEKEND.
MONDAY NIGHT THROUGH WEDNESDAY...
A DRYING TREND WORKS IN FOR TUESDAY AND WEDNESDAY AS MID TO UPPER
LEVEL RIDGING BUILDS BACK IN BEHIND THE DEPARTING SHORTWAVE. WINDS
WILL BRIEFLY SHIFT TO THE WNW BEFORE SOUTHWESTERLY FLOW RETURNS WITH
THE RIDGING TUESDAY. GUIDANCE INDICATES A WARMING TREND BOTH DAYS AS
850MB TEMPERATURES CLIMB ABOVE +10C BOTH DAYS. THE NBM HAS WEDNESDAY
AS THE WARMER DAY WITH WIDESPREAD 50-70 PERCENT PROBS OF HIGH
TEMPERATURES RISING ABOVE 60 DEGREES. PROBS ARE HIGHEST ACROSS THE
CT AND MERRIMACK VALLEYS WHERE WEAK DOWNSLOPING MAY RESULT IN
LOCALLY WARMER TEMPERATURES.
AVIATION /04Z FRIDAY THROUGH TUESDAY/
FORECAST CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH TONIGHT...MODERATE CONFIDENCE.
AREAS OF MVFR-IFR STRATUS WILL DEVELOP ACROSS CAPE/ISLANDS AND
EXPAND INLAND ACROSS EASTERN MA AND RI ESPECIALLY. THE WESTWARD
EXTEND OF STRATUS AND HOW LOW CIGS GET IS SOMEWHAT UNCERTAIN.
BEST CHANCE OF IFR WILL BE OVER THE CAPE/ISLANDS. A FEW SHOWERS
POSSIBLE OVER CAPE/ISLANDS AROUND MIDNIGHT. DIMINISHING E-NE
WINDS TONIGHT BECOMING LIGHT.
FRIDAY...HIGH CONFIDENCE.
MVFR-IFR STRATUS LINGERING DURING THE MORNING ACROSS RI AND SE
MA, BECOMING VFR IN THE AFTERNOON. LIGHT E-NE WIND.
FRIDAY NIGHT...MODERATE CONFIDENCE.
AREAS OF MVFR-IFR STRATUS EXPECTED TO REDEVELOP ACROSS SNE BUT
AREAL EXTENT IS UNCERTAIN. LIGHT TO CALM WIND.
KBOS TAF...MODERATE CONFIDENCE IN TAF. EXPECT MVFR CIGS TO
DEVELOP AFTER 06Z IMPROVING TO VFR BY 15Z.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. BREEZY.
SATURDAY NIGHT: MAINLY IFR, WITH AREAS VFR POSSIBLE. BREEZY.
SLIGHT CHANCE RA, PATCHY BR.
SUNDAY: MVFR/IFR CONDITIONS POSSIBLE. WINDY WITH GUSTS UP TO
35 KT. CHANCE RA.
SUNDAY NIGHT: MAINLY MVFR, WITH AREAS IFR POSSIBLE. WINDY WITH
GUSTS UP TO 35 KT. RA.
MONDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. BREEZY. RA
LIKELY.
MONDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE RA.
TUESDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH FRIDAY NIGHT...HIGH CONFIDENCE.
A PERIOD OF NE GUSTS TO 25 KT OVER WATERS S AND E OF ACK TONIGHT
AS LOW PRES PASSES TO THE SOUTH, OTHERWISE WINDS MAINLY BELOW
20 KT THROUGH THE PERIOD. MOSTLY E-NE FLOW THROUGH FRI TURNING
SE-S FRI NIGHT. MARGINAL SCA SEAS WILL PERSIST OVER OUTER WATERS
AS OFFSHORE LOW PRES PASSES, WITH SEAS SUBSIDING BELOW 5 FT FRI
NIGHT.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
SLIGHT CHANCE OF RAIN.
SATURDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT. SLIGHT CHANCE OF RAIN.
SUNDAY: LOW RISK FOR GALE FORCE WINDS WITH GUSTS UP TO 35 KT.
SEAS UP TO 5 FT. SLIGHT CHANCE OF RAIN.
SUNDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 35 KT. ROUGH SEAS
UP TO 12 FT. RAIN.
MONDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. ROUGH SEAS UP TO 12 FT. RAIN.
MONDAY NIGHT: WINDS LESS THAN 25 KT. ROUGH SEAS UP TO 10 FT.
CHANCE OF RAIN.
TUESDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT FRIDAY FOR ANZ254-255.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT FRIDAY FOR ANZ256.
SYNOPSIS...KJC/DOOLEY/MCMINN/FT
NEAR TERM...BELK/KJC
SHORT TERM...KJC
LONG TERM...DOOLEY/MCMINN/FT
AVIATION...BELK/KJC/DOOLEY/MCMINN/FT
MARINE...KJC/DOOLEY/MCMINN/FT
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