993
FXUS61 KBOX 241459
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
1059 AM EDT MON MAR 24 2025
SYNOPSIS
A FRONTAL SYSTEM MOVING IN THIS MORNING WILL BRING A ROUND OF
INTERIOR SNOW TO WINTRY MIX, WITH ALL RAIN EXPECTED FOR THE
COASTAL PLAIN. A MINOR ACCUMULATION OF SNOW AND SLEET IS
EXPECTED WITH VERY LIMITED IMPACTS BEFORE TRANSITIONING OVER TO
ALL RAIN ACROSS INTERIOR SOUTHERN NEW ENGLAND. DRYING OUT FOR
TUESDAY, BUT THERE IS POTENTIAL FOR ANOTHER ROUND OF SHOWERS
MID-WEEK AS A SYSTEM TRACKS TO THE SOUTHEAST OF NEW ENGLAND.
THURSDAY TRENDS DRIER WITH TEMPERATURES NEAR TO SLIGHTLY BELOW
NORMAL. A WEAK SYSTEM BRINGS CHANCES FOR SCATTERED SHOWERS
THURSDAY NIGHT INTO EARLY FRIDAY.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES...
* WARM FRONTAL PRECIPITATION MOVES IN THIS MORNING IN THE FORM
OF BOTH RAIN AND SNOW; VERY LIGHT IF ANY ACCUMULATIONS
EXPECTED OUTSIDE OF THE HIGH ELEVATIONS.
* SNOW CHANGES TO RAIN FOR MOST BY MID MORNING, FOR THE HIGHEST
ELEVATIONS BY MID AFTERNOON.
MAIN CHANGE TO THE FORECAST THIS MORNING WAS TO LIMIT THE AMOUNT
OF SNOW AND FREEZING RAIN GOING INTO THIS AFTERNOON.
TEMPERATURES AT MOST LOCATIONS WERE ALREADY AT OR ABOVE
FREEZING, AND EVEN HIGHER TEMPERATURES EXPECTED INTO THIS
AFTERNOON. ALSO TWEAKED FORECAST TIMING OF PRECIPITATION CHANCES
INTO THIS EVENING.
PREVIOUS DISCUSSION...
REGIONAL RADAR ALREADY SHOWS RETURNS MOVING INTO WESTERN CT AT
THIS HOUR, BUT IT IS A BIT DECEIVING. BUFKIT SOUNDINGS SHOW SOME
VERY DRY AIR IN THE LOW LEVELS AND SURFACE OBS INDICATE A
DEWPOINT DEPRESSION 15 TO 20 DEGREES. THUS, WE'RE NOT SEEING ANY
OF THIS PRECIPITATION MAKING IT TO THE GROUND UNTIL AS FAR WEST
SW PA AND CENTRAL NJ. AS SOUTHERLY FLOW PICKS UP OVER THE NEXT
SEVERAL HOURS THIS WILL SERVE TO BOTH INCREASE SURFACE MOISTURE
AND TEMPERATURES. THUS, AS THE BOUNDARY LAYER SATURATES WE'LL
EVENTUALLY SEE RAIN AND INTERIOR SNOW MAKE IT TO THE GROUND AS
WE GET CLOSER TO SUNRISE. THE BIGGEST IMPEDIMENT TO SEEING AN
IMPACTFUL SNOWFALL WILL BE THAT DRY AIR DELAYING PRECIP ONSET,
ALLOWING MORE TIME FOR WARMING LOW LEVELS. REGARDLESS, SOUTHERLY
FLOW AND THE DIURNAL TEMPERATURE CURVE WILL LEAD TO MOST
LOCATIONS CHANGING TO RAIN BY MID TO LATE MORNING SO IMPACTS ARE
EXPECTED TO BE MINIMAL. THE HIGHEST ELEVATIONS OF THE
BERKSHIRES AND WORCESTER HILLS WILL BE TOUGHEST TO SCOUR OUT
THAT SUBFREEZING AIR AND THE LAST TO CHANGE, SO EXPECTING THE
MOST ACCUMULATION THERE, UP TO AN INCH OR SO. MODEL SOUNDINGS DO
INDICATE POTENTIAL FOR A WINTRY MIX (INCLUDING A BRIEF PERIOD
OF SLEET OR FREEZING RAIN) GIVEN A 900 MB WARM NOSE, BUT ANY
OCCURRENCE SHOULD BE ISOLATED IN NATURE. ELSEWHERE SOME NON
ACCUMULATING FLAKES TO A QUICK COATING IS POSSIBLE BEFORE BEING
WASHED AWAY BY RAIN.
THE REST OF THE DAY IS COOL AND RAW WITH RAIN, LOW CLOUDS, AND
HIGHS ONLY REACHING THE 40S. DRIER AIR ABOVE 850 MB WILL BRING
AN END TO THE RAIN FROM WEST TO EAST BETWEEN 5 PM AND 9 PM.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/
KEY MESSAGES...
* DRY MONDAY NIGHT AND TUESDAY.
* WARMER ON TUESDAY WITH HIGHS IN THE LOW TO MID 50S.
DESPITE THE QUICK ARRIVAL OF THE MID/UPPER LEVEL DRY SLOT MONDAY
EVENING LOW LEVEL MOISTURE GETS TRAPPED UNDER A LOW LEVEL
INVERSION AROUND 925 MB. THIS MEANS THOSE LOW CLOUDS MAY STICK
AROUND ALL NIGHT UNTIL THE INVERSION MIXES OUT TUESDAY MORNING.
THEN, EXPECT MORE SUN, THOUGH DIURNAL MID CLOUDS INCREASE IN THE
AFTERNOON. DESPITE A COOLER AIRMASS OVERHEAD, MORE SUN AND THE
DOWNSLOPE COMPONENT OF THE WESTERLY WINDS SHOULD ALLOW TEMPS TO
BE WARMER THAN MONDAY, IN THE LOW TO MID 50S.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
KEY MESSAGES:
* POTENTIAL FOR SYSTEM TO BRING A ROUND OF SHOWERS WEDNESDAY.
* SCATTERED SHOWERS POSSIBLE THURSDAY NIGHT INTO EARLY FRIDAY.
* MORE UNSETTLED WEATHER POSSIBLE FOR THE WEEKEND.
WEDNESDAY - FRIDAY:
AN UPPER LEVEL TROUGH REMAINS ANCHORED ACROSS THE NORTHEAST WITH
AN EMBEDDED SHORTWAVE TROUGH MOVING THROUGH THE FLOW WEDNESDAY.
THIS WILL TRACK A SYSTEM NEAR THE REGION BRING OUR NEXT SHOT AT
SEEING PRECIPITATION. DETAILS STILL NEED TO BE IRONED OUT,
ESPECIALLY WITH THE TRACK WHICH WILL IMPACT QPF AND
PRECIPITATION CHANCES. ENSEMBLE GUIDANCE SHOWS DECENT AGREEMENT
AMONG MEMBERS WITH THE SURFACE LOW TRACKING SOUTHEAST OF
SOUTHERN NEW ENGLAND. PROBABILITIES FOR >0.10" OF QPF ARE
HIGHEST ACROSS THE CAPE AND ISLANDS WHERE THEY RANGE FROM 50 TO
70 PERCENT ACROSS VARIOUS ENSEMBLE GUIDANCE. RAIN AMOUNTS WILL
DEPEND ON HOW THE SURFACE LOW TRACKS, BUT OVERALL THIS STILL
LOOKS LIKE LIGHTER RAIN EVENT ON MOST GUIDANCE.
THURSDAY WILL FEATURE A BRIEF DRY PERIOD WITH A TRANSIENT AREA
OF HIGH PRESSURE BUILDING IN FROM THE SOUTH. DESPITE THIS, HIGH
TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL IN THE MID 40S TO
UPPER 40S. A WEAK EMBEDDED SHORTWAVE WITHIN TROUGH ALOFT MAY
BRING ANOTHER ROUND OF LOW COVERAGE/SCATTERED SHOWERS LATER
THURSDAY INTO EARLY FRIDAY. THE HIGHER ELEVATIONS OF THE
INTERIOR MAY SEE A FEW SNOW SHOWERS. THERE IS A LOW CHANCE FOR
LIGHT SNOW ACCUMULATION FOR THE HIGH POINTS OF THE BERKSHIRES
OVERNIGHT. BREEZY CONDITIONS FRIDAY WITH HIGHS IN THE UPPER 40S
TO LOWER 50S IN MOST SPOTS.
WEEKEND:
ENSEMBLES SUGGEST THAT THE PARADE OF SHORTWAVES CONTINUE INTO
NEXT WEEKEND. THERE IS THE POTENTIAL FOR YET ANOTHER AREA OF LOW
PRESSURE LATER SATURDAY INTO SUNDAY. ENSEMBLES EVEN SUGGEST A
PERIOD OF WINTRY PRECIPITATION AT THE ONSET, BUT DETAILS ARE FAR
FROM CERTAIN AT THIS TIME.
AVIATION /15Z MONDAY THROUGH FRIDAY/
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY: HIGH CONFIDENCE IN TRENDS.
VFR TO START THEN DECREASING TO IFR LATE THIS MORNING AND
AFTERNOON IN RA. THERE IS A POSSIBILITY FOR A BRIEF PERIOD OF
FZRA ACROSS THE INTERIOR DURING THE TRANSITION FROM SN TO RA.
LITTLE ACCUM OF SN OR FZRA. PRECIP ENDS FROM WEST TO EAST
20-23Z, BUT CEILINGS MAY STILL BE LOW AS DRY SLOT MOVES IN ALOFT
AND TRAPS CLOUD COVER AROUND. SE TO S WINDS 10 TO 15 KT WITH
GUSTS NEAR THE SOUTH COAST AROUND 25 KT. SOME LOW LEVEL SHEAR
POSSIBLE FOR PVD AND THE CAPE AIRPORTS BETWEEN 18 AND 20Z. LOW
LEVEL SHEAR MAY CONTINUE THRU 23Z ACROSS THE CAPE.
TONIGHT: HIGH CONFIDENCE.
INITIAL MVFR-IFR CEILINGS SLOWLY IMPROVE TO MVFR, MAINLY AFTER
MIDNIGHT. SW WINDS DECREASING TO AROUND 5 KT OR LESS.
TUESDAY: HIGH CONFIDENCE.
VFR. WSW WINDS 10-15 KTS GUSTING 15 TO 20 KTS.
BOS TAF...MODERATE CONFIDENCE IN TAF.
BDL TAF...MODERATE CONFIDENCE IN TAF.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT: VFR. SLIGHT CHANCE RA.
WEDNESDAY: VFR. CHANCE RA.
WEDNESDAY NIGHT: VFR.
THURSDAY THROUGH FRIDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
SMALL CRAFT ADVISORIES IN EFFECT INTO TUESDAY.
SE WINDS INCREASE TO AROUND 15-25 KT WITH GUSTS TO 30 KT THIS
MORNING AND CONTINUE INTO THE AFTERNOON. WINDS BECOMING S AND
DECREASING TO AROUND 10-15 KT TONIGHT. SEAS INCREASE THIS
MORNING TO AROUND 4-8 FT, HIGHEST ON THE SOUTHERN OFFSHORE
WATERS. RAIN DEVELOPS THIS MORNING AND CONTINUES INTO EARLY
TONIGHT, WITH VSBYS DECREASING TO 2-4 MILES.
DRY TONIGHT AND TUESDAY. WINDS WILL BE SW 10 TO 15 KT, GUSTING
15 TO 20 KT TUESDAY AFTERNOON.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. SLIGHT CHANCE OF RAIN.
WEDNESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
CHANCE OF RAIN. WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT. SLIGHT CHANCE OF RAIN.
THURSDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
THURSDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. AREAS OF SEAS APPROACHING 5 FT.
FRIDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 25 KT. SEAS UP TO 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ230-
236.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR ANZ231>235-237-
251.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR ANZ254>256.
SYNOPSIS...BW/FT
NEAR TERM...BELK/BW
SHORT TERM...BW
LONG TERM...FT
AVIATION...BELK/BW/FT
MARINE...BW/FT
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