913
FXUS61 KBOX 202017
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
317 PM EST WED NOV 20 2024
SYNOPSIS
HIGH PRESSURE PROVIDES DRY AND COOL CONDITIONS THROUGH THIS EVENING
AND MUCH OF TONIGHT. A SLOW-MOVING AND WELL-DEVELOPED AREA OF LOW
PRESSURE LOOKS TO SPREAD WELCOMED RAINS TO SOUTHERN NEW ENGLAND
EARLY THURSDAY INTO FRIDAY. RAIN COULD MIX WITH WET SNOW ABOVE 1500
FEET ELEVATION BY EARLY FRIDAY MORNING, BUT LITTLE IF ANY IMPACTS
ARE EXPECTED. DRYING OUT THIS WEEKEND, ALTHOUGH WITH CONSIDERABLE
CLOUDINESS, BLUSTERY NORTHWEST WINDS AND SEASONABLY COOL
TEMPERATURES, ALTHOUGH SUNDAY LOOKS TO OFFER MORE SUNSHINE THAN
SATURDAY. THEN MOSTLY SUNNY AND DRY MONDAY, BUT MONITORING POSSIBLE
RAIN SHOWERS MONDAY NIGHT AND/OR TUESDAY.
NEAR TERM /UNTIL 8 PM THIS EVENING/
WE'RE ENJOYING ONE MORE DAY OF CLEAR SKIES AND DRY WEATHER BEFORE
SOME MUCH NEEDED RAIN ARRIVES OVERNIGHT. THROUGH THE REST OF THIS
AFTERNOON AND EARLY EVENING HIGH PRESSURE WILL CONTINUE TO KEEP
THINGS DRY WITH LIGHT EASTERLY WINDS. SATELLITE IMAGERY SHOWS LOW
CLOUDS OFFSHORE AND OVER THE CAPE/ISLANDS THAT WILL ADVECT
WESTWARD MOVING FURTHER ONSHORE TOWARD 8PM WHILE AT THE SAME
TIME LOW CLOUDS FROM THE INCOMING SYSTEM MOVE INTO WESTERN CT.
SHORT TERM /8 PM THIS EVENING THROUGH THURSDAY NIGHT/
TONIGHT THROUGH THURSDAY NIGHT WILL BE THE MAIN FOCUS OF THE
FORECAST, ESPECIALLY FOR THOSE WITH INTEREST IN SEEING DIMINISHED
FIRE ACTIVITY. THE PATTERN MAKES A SWITCH AS THE UPPER LOW OVER THE
GREAT LAKES AND ITS SURFACE REFLECTION SINK INTO THE MID-ATLANTIC.
THIS SPAWNS A SECONDARY LOW PRESSURE CENTER ALONG THE FRONTAL
BOUNDARY JUST OFF THE EAST COAST WHICH SUBSEQUENTLY DEEPENS AS IT
LIFTS DIRECTLY OVER SOUTHERN NEW ENGLAND ON THURSDAY AND RETROGRADES
BACKS TOWARD EASTERN NEW YORK THURSDAY NIGHT. A DEEP PLUME OF
MOISTURE WILL ACCOMPANY THIS SYSTEM WITH PWATS ON THE ORDER OF ONE
INCH. STRONG DYNAMIC LIFT (35-45KT LLJ AND 500 MB PVA) WITH THE
AFOREMENTIONED MOISTURE WILL LEAD TO A BLOSSOMING PRECIPITATION
SHIELD THAT OVERSPREADS SNE FROM 2AM (WEST) TO 10AM (EAST) AND
CONTINUES ALL OF THURSDAY AND THE FIRST HALF OF THURSDAY NIGHT
BEFORE A DRY SLOT WORKS ITS WAY NORTH INTO THE REGION. THEREAFTER
SHOWERS BECOME MORE SCATTERED IN NATURE WITH THE LOW CONTINUING TO
BE JUST TO OUR WEST.
RAINFALL AMOUNTS CONTINUE TO LOOK SOLID FOR A MEANINGFUL RAINFALL,
WITH 1 TO 1.75 INCHES POSSIBLE; THE HEAVIEST AMOUNTS WILL BE IN THE
HIGH ELEVATIONS OF WESTERN MA WHERE EASTERLY UPSLOPE FLOW ASSISTS.
AS FOR SNOW POTENTIAL, THERE WILL BE ENOUGH COLD AIR ALOFT AND
MOVING IN ON THE BACK SIDE OF THE SYSTEM TO BRING SOME WET FLAKES TO
THE UPPER REACHES OF THE BERKSHIRES, MAINLY ABOVE 1500 FT. HOWEVER,
NOT EXPECTING EFFICIENT ACCUMULATION; A SLUSHY INCH OR TWO ARE MOST
LIKELY.
AS FOR THE WINDS ON THURSDAY, IT WILL BE A BLUSTERY AND COOL DAY
WITH THAT LLJ OVERHEAD, EASTERLY WINDS GUSTING 20 TO 30 MPH,
ESPECIALLY ALONG THE COASTS; IT WILL BE A WINDY AND ROUGH DAY ON THE
OUR WATERS AS WELL.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
HIGHLIGHTS:
* CLOUDY AND COOLER WITH PERIODS OF RAIN SHOWERS INTO FRI NIGHT,
WITH WET/SLUSHY SNOW POSSIBLE ABOVE 1500 FT ELEVATION.
* GRADUAL DRYING TREND THIS WEEKEND. BLUSTERY WITH CONSIDERABLE
CLOUDINESS SAT, THEN MORE SUNSHINE SUNDAY. TEMPS SEASONABLY COOL.
* DRY AND MOSTLY SUNNY MON, THEN POSSIBLE RAIN SHOWERS MONDAY
NIGHT/TUESDAY
FRI/FRIDAY NIGHT...
WITH CLOSED LOW WEST OF NEW ENGLAND AND DRY SLOT STREAMING ACROSS
SNE, PRECIP WILL BECOME MORE INTERMITENT AND LIGHTER. THE ONLY
EXCEPTION MAYBE OVER EASTERN MA, WHERE TRAILING SHORT WAVE
ENERGY AND ASSOCIATED MOISTURE PLUME ROTATE AROUND THE LARGE
CIRCULATION ALOFT, POSSIBLY CLIPPING EASTERN MA WITH A PERIOD OF
STEADIER RAINFALL LATER FRI INTO FRI NIGHT. OTHERWISE, BULK OF
RAINFALL OCCURS THU/THU NIGHT. MUCH COOLER THAN PREVIOUS DAYS
COURTESY OF
-32C COLD POOL ALOFT AT 500 MB. THIS COMBINED WITH OVERCAST
CONDITIONS AND ON/OFF LIGHT PRECIP, WILL LIMIT HIGHS TO THE UPPER
40S/LOWER 50S, WHICH IS RIGHT ON TRACK FOR LATE NOV.
THIS WEEKEND...
MODELS HAVE TRENDED MORE AMPLIFIED AND BLOCKY UPPER AIR PATTERN,
WHICH WILL RESULT IN A SLOWER DEPARTURE OF THE CLOSED LOW. THUS,
COLD POOL ALOFT WILL COMBINE WITH CYCLONIC FLOW TO YIELD LOTS OF
CLOUDS SATURDAY AND SCATTERED SHOWERS, ALTHOUGH NOT EXPECTING A
WASHOUT. ANY IMPACTS SATURDAY WILL BE FROM THE GUSTY WINDS, AS THE
STORM MAY RE-INTENSIFY AS IT DEPARTS THE REGION TOWARD THE MARITIMES.
SOME MODEL SOUNDINGS SUPPORT NORTHWEST WINDS 20-30 MPH GUSTING UP TO
50 MPH POSSIBLE ACROSS EASTERN MA, CAPE COD AND ISLANDS SATURDAY.
THEREFORE, MAY NEED WIND HEADLINES WITH LATER FORECAST ISSUANCES.
STAY TUNED. HIGHS 45-50 SAT, UPPER 40S TO LOWER 50S SUNDAY, BUT
FEELING COOLER GIVEN THE BLUSTERY NW WINDS. SHOULD BE MORE SUNSHINE
SUNDAY WITH CORE OF COLD AIR ALOFT AND CYCLONIC FLOW CENTERED ON
SAT.
NEXT WEEK...
SHORT WAVE RIDGING SHOULD PROVIDE QUIET/TRANQUIL WEATHER MONDAY
ALONG WITH MILDER TEMPS, HIGHS 50-55 AND LIGHTER WINDS WITH RIDGE
AXIS ADVECTING ACROSS THE AREA. NEXT NORTHERN STREAM SHORT WAVE AND
ATTENDING COLD FRONT LOOKS TO ARRIVE SOMETIME MONDAY NIGHT/TUE. THIS
FEATURE MAYBE ACCOMPANIED BY SCATTERED RAIN SHOWERS, FOLLOWED BY A
REINFORCING SURGE OF COOLER/BLUSTERY CONDITIONS INTO WED.
AVIATION /20Z WEDNESDAY THROUGH MONDAY/
FORECAST CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
THIS AFTERNOON: HIGH CONFIDENCE.
VFR CONTINUES FOR MOST TERMINALS, WITH A PATCH OF MVFR MARINE
STRATOCU ADVANCING WSW TOWARD CAPE COD. CLOUD COVER STEADILY
INCREASES DURING THE AFTERNOON FROM THE WEST FOR THE REMAINING
TERMINALS. LATE IN THE DAY WE COULD SEE MARINE STRATUS FROM NOVA
SCOTIA. LIGHT N WINDS BECOME NE/ENE BY AFTERNOON WITH SPEEDS
5-10 KT.
TONIGHT: HIGH CONFIDENCE IN TRENDS, MODERATE ON THE TIMING.
CONDITIONS DETERIORATE AT ALL TERMINALS WITH THE ARRIVAL OF
STRATUS AND RA, SOONEST FOR EASTERN MA BUT MOST AIRPORTS SHOULD
BE SUB-VFR BY 05Z. LEADING EDGE OF WIDESPREAD RAINS MOVES INTO
WESTERN AIRPORTS AFTER 11Z. NE WINDS AROUND 5-10 KT, WITH
DEVELOPING GUSTS AROUND 20 KT NEAR THE COAST.
THURSDAY: MODERATE CONFIDENCE.
MVFR-IFR CIGS WITH 3-6 SM STEADY -RA/RA DURING THE EARLY
MORNING, GRADUALLY LIFTING NORTHWARD THROUGH THE AFTN. AS
STEADIER RAIN TAPERS OFF TO MORE INTERMITTENT SHOWER LATE IN THE
DAY, IT IS POSSIBLE THAT CEILINGS/VISBYS COULD DETERIORATE TO
SOLID IFR BUT THIS REMAINS UNCERTAIN. E WINDS INCREASE TO 10-15
KT WITH GUSTS 20-25 KT.
THURSDAY NIGHT: MODERATE CONFIDENCE.
RAIN BECOMES MORE SCATTERED IN NATURE THROUGH THE OVERNIGHT
HOURS WITH IFR CONDITIONS BECOMING MVFR THEN VFR FOR EASTERN MA
TERMINALS BETWEEN 06 AND 12Z.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. OCEAN STRATUS AT MVFR
LEVELS COULD SET IN AS SOON AS 00Z BUT MORE LIKELY AFTER 03Z
THURS.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY: MAINLY MVFR, WITH LOCAL IFR POSSIBLE. BREEZY. CHANCE
RA.
FRIDAY NIGHT: MAINLY MVFR, WITH LOCAL IFR POSSIBLE. RA LIKELY.
SATURDAY: MVFR/IFR CONDITIONS POSSIBLE. BREEZY. CHANCE RA.
SATURDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY
WITH LOCAL GUSTS UP TO 30 KT. SLIGHT CHANCE RA.
SUNDAY THROUGH MONDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THIS EVENING THROUGH THURSDAY NIGHT...
CALM/TRANQUIL CONDITIONS THIS EVENING WITH WEAK HIGH PRESSURE
SUPPORTING LIGHT WINDS OVER THE COASTAL WATERS. CONDITIONS
BEGIN TO DETERIORATE OVERNIGHT AS AN AREA OF LOW-PRESSURE MOVES
OVER THE SOUTH COASTAL WATERS. WINDS STRENGTHEN OUT OF THE EAST
TO SPEEDS OF 15 TO 25 KNOTS WITH GUSTS UP TO 30 KNOTS BY
TOMORROW. MODERATE EASTERLY WINDS CONTINUE THROUGH THE DAY
THURSDAY WITH SEAS BUILDING TO 6 TO 8 FEET. A FEW GALE FORCE
GUSTS UP TO 35 KNOTS WILL BE POSSIBLE, ESPECIALLY OVER THE
SOUTHERN MARINE ZONES THROUGH THURSDAY AFTERNOON. HOWEVER,
CONFIDENCE IN A PROLONGED PERIOD OF GALES IS NOT HIGH ENOUGH TO
WARRANT GALE HEADLINES. NONETHELESS, SOLID SCY CONDITIONS WILL
BE PRESENT OVER THE COASTAL WATERS LIKELY THROUGH MUCH OF THE
DAY FRIDAY AND BEYOND.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY THROUGH FRIDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO
5 FT. RAIN.
SATURDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS. RAIN LIKELY.
SATURDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 30 KT. ROUGH SEAS
UP TO 10 FT. CHANCE OF RAIN.
SUNDAY: STRONG WINDS WITH GUSTS UP TO 30 KT. ROUGH SEAS UP TO
10 FT.
SUNDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. AREAS OF ROUGH SEAS.
MONDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THURSDAY TO 1 PM EST FRIDAY
FOR ANZ231>234-251.
SMALL CRAFT ADVISORY FROM 5 AM THURSDAY TO 7 PM EST FRIDAY FOR
ANZ235-237.
SMALL CRAFT ADVISORY FROM 10 AM THURSDAY TO 7 AM EST SATURDAY
FOR ANZ250-254-255.
SMALL CRAFT ADVISORY FROM 5 AM THURSDAY TO 7 AM EST SATURDAY
FOR ANZ256.
SYNOPSIS...BW/NOCERA
NEAR TERM...BW
SHORT TERM...BW
LONG TERM...NOCERA
AVIATION...BW/NOCERA
MARINE...NOCERA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page