749
FXUS61 KBOX 160923
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
423 AM EST MON DEC 16 2024
SYNOPSIS
A MIXTURE OF LIGHT SNOW & LIGHT FREEZING RAIN/FREEZING DRIZZLE WILL
IMPACT PORTIONS OF SOUTHWEST MASSACHUSETTS, CONNECTICUT AND RHODE
ISLAND INTO MID MORNING WHICH MAY RESULT IN ICY TRAVEL. THIS
PRECIPITATION SHOULD NOT GET MUCH FURTHER EAST THAN THOSE AREAS AND
PRETTY MUCH COME TO AN END BY LATE MORNING. A PERIOD OF STEADY RAIN
IS EXPECTED LATE TONIGHT INTO EARLY TUESDAY MORNING WITH THE
REST OF THE DAY TURNING OUT DRY AND UNSEASONABLY MILD. THERE IS
THE POTENTIAL FOR MORE UNSETTLED WEATHER LATE WEDNESDAY/WEDNESDAY
AND PERHAPS LATE FRIDAY INTO EARLY SATURDAY...FOLLOWED BY A SHOT
OF VERY COLD AIR.
NEAR TERM /UNTIL 6 PM THIS EVENING/
420 AM UPDATE
* LIGHT WINTRY MIX/LIGHT ICING NEAR & SOUTHWEST OF A BAF-PVD LINE
* TEMPS RISE ABOVE 32 BY LUNCHTIME
* DRY WEATHER DOMINATES LATER THIS MORNING INTO THE AFTERNOON
* AFTERNOON HIGHS MAINLY IN THE 30S FOR THE INTERIOR, 40-45 NEAR I-95
A SHORTWAVE WAS APPROACHING FROM THE WEST EARLY THIS MORNING...BUT
RUNNING INTO A MID LEVEL RIDGE AXIS. THIS IS CAUSING THE SHORTWAVE
TO WEAKEN AS IT ENTERS OUR REGION. NONETHELESS...THERE IS STILL
ENOUGH FORCING LEFT FOR A MIXTURE OF LIGHT SNOW & LIGHT FREEZING
RAIN/FREEZING DRIZZLE EARLY THIS MORNING ACROSS SOUTHWEST MA, MUCH
OF CT AND RI. LITTLE IF ANY PRECIPITATION WILL GET MUCH FURTHER EAST
AS THE SHORTWAVE CONTINUES TO WEAKEN.
WHILE THE PRECIPITATION ACROSS SOUTHWEST MA, CT AND RI WILL BE
RATHER LIGHT THIS MORNING...TEMPS ARE NEAR OR BELOW FREEZING.
THERMAL PROFILES ARE RIGHT ON THE CUSP BETWEEN LIGHT SNOW AND LIGHT
FREEZING RAIN/FREEZING DRIZZLE. ANY SNOW ACCUMULATIONS SHOULD BE
JUST A DUSTING TO PERHAPS UP TO 1" IN A FEW SPOTS...BUT THE MAIN
CONCERN IS THE POTENTIAL FOR A LIGHT GLAZE OF ICE. THE GREATEST RISK
FOR THIS IS IN THE HARTFORD TO PROVIDENCE METRO AREAS...WHERE THERE
IS A STRONGER WARM NOSE ALOFT. IN FACT...EVEN WHERE TEMPS ARE A FEW
DEGREES ABOVE FREEZING ICY TRAVEL MAY STILL DEVELOP BECAUSE OF THE
COLD GROUND TEMPS FROM OUR RECENT WEATHER.
SO TO SUMMARIZE...A WINTER WEATHER ADVISORY IS IN EFFECT FOR
SOUTHWEST MA, CT AND INTO RI THROUGH 11 AM THIS MORNING MAINLY FOR A
LIGHT GLAZE OF ICE. THE PRECIPITATION SHOULD NOT MAKE IT TOO MUCH
FURTHER EAST...BUT A BRIEF PERIOD OF A LIGHT WINTRY MIX CAN NOT BE
COMPLETELY RULED OUT FOR INTERIOR SOUTHEAST MA.
THIS SHORTWAVE WILL SLIDE TO OUR SOUTHEAST BY MID-LATE
MORNING...BRINGING AN END TO MOST OF THE LIGHT PRECIPITATION. TEMPS
SHOULD RISE ABOVE FREEZING ACROSS MOST OF THE REGION BY LATE
MORNING/LUNCH TIME. OTHER THAN A FEW SPOT SHOWERS...MUCH OF THE TIME
LATER THIS MORNING AND AFTERNOON WILL FEATURE DRY WEATHER. IT WILL
REMAIN CLOUDY TODAY WITH HIGHS REMAINING IN THE 30S ACROSS MUCH OF
THE INTERIOR...TO BETWEEN 40 AND 45 NEAR THE I-95 CORRIDOR.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/
KEY MESSAGES...
* A PERIOD OF STEADY RAIN...MAINLY LATE TONIGHT INTO EARLY TUE AM
* RISING TEMPS INTO THE 40S/LOWER 50S OVERNIGHT
* DRY/UNSEASONABLY MILD THE REST OF TUE WITH HIGHS WELL INTO THE 50S
DETAILS...
TONIGHT AND TUESDAY...
THE NEXT SHORTWAVE TROUGH ACROSS THE GREAT LAKES WILL MOVE EASTWARD
INTO NORTHERN NEW ENGLAND/QUEBEC TONIGHT INTO TUE. WHILE THE BETTER
DYNAMICS WILL BE PASSING TO OUR NORTH...IT WILL INDUCE A MODEST
SOUTHWEST LLJ OF 45 TO 60 KNOTS. IN RESPONSE...THE FORCING FOR
ASCENT WILL INCREASE TONIGHT AS A WARM FRONT CROSSES THE REGION. WE
EXPECT A FEW SHOWERS DURING THE EVENING...BUT THE BEST FORCING WILL
SLIDE ACROSS THE REGION LATE TONIGHT INTO EARLY TUESDAY MORNING. THE
RESULT SHOULD BE A 3-5 HOUR PERIOD OF STEADY RAIN MOVING ACROSS THE
REGION FROM WEST TO EAST. TEMPERATURES SHOULD RISE BEHIND THE WARM
FRONTAL PASSAGE OVERNIGHT INTO THE 40S/LOWER 50S BY DAYBREAK TUE.
THIS SYSTEM IS PROGRESSIVE...SO THE LAST OF THE RAIN SHOULD BE
EXITING THE CAPE/ISLANDS BY EARLY-MID MORNING ON TUE. WEST TO
SOUTHWEST FLOW SHOULD ALLOW FOR PARTIAL SUNSHINE TO DEVELOP BY TUE
AFTERNOON. THE AIRMASS WILL NOT COOL OFF TOO QUICKLY WITH 925T STILL
NEAR +5C/+6C TOWARDS LUNCHTIME. THIS WILL RESULT IN ABOVE NORMAL
HIGHS WELL INTO THE 50S. IN FACT...IT IS POSSIBLE A FEW SPOTS TOUCH
60 DEGREES.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
KEY MESSAGES:
* UNSETTLED/ACTIVE WEATHER PATTERN THROUGH THE WEEKEND FEATURING THE
PASSAGE OF SEVERAL SYSTEMS ACCOMPANIED BY PERIODS OF
PRECIPITATION.
* ARCTIC AIR MOVES INTO REGION BY END OF WEEK BRINGING BELOW NORMAL
TEMPERATURES FOR THE WEEKEND.
THE EXTENDED PERIOD FEATURES UPPER LEVEL RIDGING TO THE WEST AND
MAINLY A TROUGH PATTERN ACROSS THE EAST, AMPLIFYING LATER IN THE
WEEK. SEVERAL SHORTWAVE TROUGHS MOVE THROUGH THE FLOW ACROSS
SOUTHERN NEW ENGLAND SUPPORTING AN ACTIVE/UNSETTLED PATTERN WITH A
COUPLE CHANCES AT PRECIPITATION. ARCTIC AIR ARRIVES TOWARD THE END
OF THE WEEK BRINGING BELOW NORMAL TEMPERATURES.
TUESDAY NIGHT - THURSDAY
CONDITIONS BRIEFLY DRY OUT INTO WEDNESDAY WITH WEAK RIDGING ALOFT
AND HIGH PRESSURE BUILDING IN. A WEAK COLD FRONT SHIFTS THROUGH
TUESDAY NIGHT, RESULTING IN COOLER TEMPERATURES FOR WEDNESDAY IN THE
MID TO UPPER 40S. THIS IS STILL A TOUCH ABOVE NORMAL FOR MID-
DECEMBER.
NO TIME TO WASTE WITHIN THIS ACTIVE PATTERN. THE NEXT FRONTAL SYSTEM
PUSHES ACROSS THE REGION WEDNESDAY EVENING INTO THURSDAY AS A
SHORTWAVE TROUGH MOVES EAST FROM THE GREAT LAKES. THE SYSTEM WILL BE
ON THE PROGRESSIVE SIDE BRINGING A QUICKER WAVE OF WEAK LIFT COUPLED
WITH ABOVE NORMAL MOISTURE. IN OTHER WORDS, ANOTHER SHOT OF
PRECIPITATION. DETAILS SUCH AS TIMING AND TRACK ARE COMING INTO
BETTER AGREEMENT AMONG MODEL GUIDANCE WITH MAINLY SUBTLE DIFFERENCES
IN THE LOW TRACK. ALTHOUGH SUBTLE, THIS WILL HAVE IMPACT ON HOW MUCH
COLD AIR THERE WILL BE. MORE COLDER AIR IN PLACE WILL RESULT IN
HIGHER CHANCES FOR LIGHT SNOW, RAIN/SNOW MIX FOR THE HIGHER
ELEVATIONS OF THE MA INTERIOR/BERKS. MORE INLAND TRACK WILL SUPPORT
MORE WAA AND THUS RESULTING IN LOWER PROBABILITY FOR SNOW. EITHER
WAY, IMPACTS WILL BE MINOR AT WORST AND CONFINED TO THE HIGHER
ELEVATIONS. ELSEWHERE WILL GET A DECENT RAINFALL WITH ENSEMBLE MEANS
RANGE FROM A QUARTER OF AN INCH TO A LITTLE OVER A HALF AN INCH. THE
MAIN BATCH OF PRECIPITATION LIKELY EXITS BY THURSDAY AFTERNOON WITH
CONDITIONS CLEARING BEHIND IT. TEMPERATURES THURSDAY HOVER CLOSER TO
NORMAL.
FRIDAY - WEEKEND:
ENSEMBLE GUIDANCE SHOWS A STRONG SIGNAL FOR A DEEP TROUGH TO
POSITION ACROSS THE NORTHEAST FRIDAY THROUGH MUCH OF THE WEEKEND.
THIS WILL SUPPORT AN ARCTIC AIRMASS SETTLING INTO THE REGION. THIS
WILL SUPPORT TEMPERATURES AROUND 7 TO 15 DEGREES BELOW NORMAL BY THE
END OF THE WEEKEND. POTENTIALLY COLDER!
ENSEMBLE GUIDANCE STILL POINTS TO A CONTINUED ACTIVE PATTERN. THERE
IS A CONSENSUS ON SHORTWAVE ENERGY MOVING ACROSS THE GREAT LAKES
REGION INTO THE NORTHEAST FRIDAY INTO SATURDAY BRINGING PRECIP
CHANCES. THERE IS NOTABLE SPREAD AMONG SOLUTIONS WITH REGARDS TO AN
OFFSHORE LOW PRESSURE DEVELOPING AND MOVING UP THE COAST IN THE
WEEKEND TIMEFRAME. THIS IS SHOWN BY THE ENSEMBLE MEANS; HOWEVER,
TRACKING IS QUITE VARIABLE AMONG THEIR INDIVIDUAL MEMBERS. WE'LL
NEED MORE CONSISTENCY WITH MODELS/SOLUTIONS BEFORE WE CAN TALK
AMOUNTS, BUT GIVEN THE ANOMALOUSLY COLD AIRMASS IN PLACE, SNOW ISN'T
OUT OF THE QUESTION.
AVIATION /09Z MONDAY THROUGH FRIDAY/
FORECAST CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY...MODERATE CONFIDENCE (PRECIP TYPE, CIGS. AND EASTWARD
EXTEND OF AM PRECIP)
SHOWERS EXPAND EARLY THIS MORNING, MAINLY FOR THE INTERIOR
TERMINALS. ANY PRECIPITATION LIKELY STARTS AS -SN, THEN
TRANSITIONS TO FZRA TOWARD 12Z ACROSS NORTHERN CT INTO HAMPDEN
COUNTY MA AND INTO RI. ANY SNOW/ICE ACCUMULATION IS EXPECTED TO
BE A GLAZE-LIGHT. PRECIPITATION CHANCES DROP OFF AS YOU GO
FURTHER EAST OF WORCESTER-PROVIDENCE LINE.
LOW END VFR TO MVFR CONDITIONS ACROSS THE INTERIOR, BECOMING IFR
IN THE AFTERNOON. EASTERN/CAPE TERMINALS VFR INTO AFTERNOON.
TONIGHT...HIGH CONFIDENCE
MORE WIDESPREAD MVFR WITH AREAS IFR DEVELOP MONDAY NIGHT. BY
THIS POINT, TEMPERATURES SHOULD BE WELL ABOVE FREEZING,
PRODUCING RAINFALL REGION-WIDE.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF... MODERATE CONFIDENCE
A BRIEF MIXTURE OF LIGHT SNOW AND/OR LIGHT FREEZING
RAIN/FREEZING DRIZZLE IS EXPECTED THIS MORNING. ACCUMULATIONS
FROM A "GLAZE" TO A LIGHT ACCUMULATION OF ICE. TRACE OF SNOW
POSSIBLE BEFORE CHANGES OVER.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT: VFR. BREEZY.
WEDNESDAY: VFR. CHANCE RA.
WEDNESDAY NIGHT: MAINLY MVFR, WITH LOCAL IFR POSSIBLE. BREEZY.
RA.
THURSDAY: VFR. BREEZY. CHANCE RA.
THURSDAY NIGHT: VFR. BREEZY.
FRIDAY: VFR. CHANCE SN, CHANCE RA.
MARINE
FORECASTER CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY...HIGH CONFIDENCE.
HIGH PRESSURE WILL CONTINUE TO MOVE FURTHER EAST AND AWAY FROM THE
WATERS TODAY. IN RESPONSE...SSE WINDS SHOULD INCREASE TO BETWEEN 10
AND 20 KNOTS BY LATE IN THE AFTERNOON BUT THE BULK OF THE SMALL
CRAFT CONDITIONS SHOULD HOLD OFF UNTIL EARLY THIS EVENING.
TONIGHT AND TUESDAY...HIGH CONFIDENCE.
A SHORTWAVE TROUGH PASSING TO OUR NORTH WILL INDUCE A MODEST
SOUTHWEST LOW LEVEL JET TONIGHT INTO TUE. DESPITE THE INVERSION OVER
THE RELATIVELY COOL WATERS...STILL EXPECT SW WIND GUSTS OF 20 TO 30
KNOTS TONIGHT INTO THE MIDDLE OF TUE AFTERNOON BEFORE GRADUALLY
STARTING TO DIMINISH. SMALL CRAFT HEADLINES POSTED MOST WATERS
TONIGHT INTO TUE.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
WEDNESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT. CHANCE OF RAIN.
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS. RAIN.
THURSDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. AREAS OF ROUGH SEAS. CHANCE OF RAIN.
THURSDAY NIGHT: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS.
FRIDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
CHANCE OF RAIN, CHANCE OF SNOW.
BOX WATCHES/WARNINGS/ADVISORIES
CT...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
MAZ009-011.
RI...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
RIZ001>007.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
TUESDAY FOR ANZ231>235-237-251.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
TUESDAY FOR ANZ250.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 1 AM EST
WEDNESDAY FOR ANZ254>256.
SYNOPSIS...FRANK/MENSCH
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...MENSCH
AVIATION...FRANK/MENSCH
MARINE...FRANK/MENSCH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page