500
FXUS61 KBOX 020714
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
214 AM EST MON MAR 2 2026
WHAT HAS CHANGED
CONFIDENCE CONTINUES TO INCREASE FOR A WINTRY MIX LATE TUESDAY.
KEY MESSAGES
-ARCTIC AIRMASS KEEPS TEMPS WELL BELOW NORMAL TODAY AND TONIGHT
-A WINTRY MIX OF PRECIPITATION IS LIKELY TUESDAY INTO TUESDAY NIGHT
-REMAINING UNSETTLED BEYOND WEDNESDAY WITH TEMPERATURES TRENDING
ABOVE NORMAL
DISCUSSION
KEY MESSAGE 1...
ARCTIC AIRMASS CENTERS OVER THE REGION TODAY AS A 1040MB HIGH DROPS
DOWN FROM CANADA THIS MORNING. DESPITE THE CLEAR SKIES AND THE
STRONG MARCH SUN ANGLE, HIGH TEMPERATURES WILL REMAIN BELOW FREEZING
TODAY. WHILE WINDS WILL BE LIGHT WNW TODAY, THE WIND CHILL INDEX
WILL MAKE IT FEEL LIKE THE LOW 20S. ARCTIC HIGH BEGINS TO MOVE
OFFSHORE TONIGHT AND 850MB TEMPS BEGIN TO RISE FROM -12C TO -2C
OVERNIGHT. DESPITE WAA ALOFT, THE DENSE COLD AIR WILL STICK TO THE
SURFACE OVERNIGHT AS THE BOUNDARY LAYER DECOUPLES FROM THE SURFACE.
WITH CLEAR SKIES AND CALM WINDS OVERNIGHT, LOW TEMPERATURES WILL
ONCE AGAIN DIP INTO THE LOW TEENS TO HIGH SINGLE DIGITS.
KEY MESSAGE 2...
A WEAK WAVE OF LOW PRESSURE TRAVELS UP THE COAST ON TUESDAY,
BRINGING OUR NEXT ROUND OF WINTRY PRECIPITATION TUESDAY AFTERNOON
INTO TUESDAY NIGHT. WHILE A WARM FRONT WILL BRING TEMPERATURES NEAR
OR ABOVE FREEZING ON TUESDAY, RESIDUAL COLD AIR WILL ALLOW
PRECIPITATION TO START AS A WINTRY MIX OF SNOW/SLEET, THEN
TRANSITION TO FREEZING RAIN BEFORE TURNING TO PLAIN RAIN. CONFIDENCE
REMAINS LOW ON THE TIMING OF THESE PRECIPITATION TYPE CHANGES, WHICH
WILL BE IMPORTANT TO ACCUMULATIONS. SNOW AT THIS TIME APPEARS
LIGHT, MOSTLY LIKELY UNDER AN INCH, WITH SLIGHTLY HIGHER
ACCUMULATIONS POSSIBLE IN THE HIGH TERRAIN. FREEZING RAIN
ACCUMULATION IS LESS CERTAIN AT THIS TIME, AS TEMPERATURES MAY WARM
RAPIDLY ENOUGH TO PREVENT IT OUTSIDE THE HIGH TERRAIN. HREF FRAM
(FREEZING RAIN ACCUMULATION MODEL) SHOWS A WIDESPREAD TRACE OF 0.05
INCHES OF ICE ACCUMULATION AWAY FROM THE COASTS. WINTER WEATHER
ADVISORIES MAY BE NEEDED LATER TUESDAY; HOWEVER, CONFIDENCE IS
CURRENTLY BELOW 50% THAT FREEZING RAIN ACCUMULATION WILL EXCEED A
TRACE AND CAUSE TRAVEL IMPACTS, GIVEN THE WARMING TEMPERATURES AND
THE SWITCH TO RAIN.
KEY MESSAGE 3...
THE PATTERN REMAINS ACTIVE BEYOND WEDNESDAY THIS WEEK, AS THE
JETSTREAM REMAINS ZONAL AND SENDS SEVERAL WAVES OF WEAK SHORTWAVE
ENERGY OUR WAY, WITH A POTENTIALLY STRONGER SHORTWAVE ARRIVING
FRIDAY. HIGH TEMPERATURES WEDNESDAY THROUGH FRIDAY WILL BE WELL
ABOVE FREEZING, IN THE 40S TO 50S, WHILE LOW TEMPERATURES WILL BE
NEAR OR SLIGHTLY BELOW FREEZING. THE TIMING OF THESE DISTURBANCES
WILL BE KEY TO PRECIPITATION TYPE, AS PRECIPITATION DURING THE DAY
WILL FALL AS RAIN, WHEREAS PRECIPITATION ARRIVING AT NIGHT MAY TURN
TO A WINTRY MIX, ESPECIALLY NEAR THE HIGH TERRAIN. LOOKING BEYOND
FRIDAY, THE UPPER-LEVEL RIDGE TAKES AIM FOR THE WEEKEND, POTENTIALLY
BRINGING WELL-ABOVE-NORMAL TEMPERATURES. NBM SHOWS LOW
PROBABILITIES OF REACHING 60°F ON SUNDAY.
AVIATION /07Z MONDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
MONDAY THROUGH TUESDAY MORNING...HIGH CONFIDENCE.
VFR. N/NW-LY WINDS 5-10 KNOTS. WINDS BACK TO WESTERLIES MONDAY
AFTERNOON THEN FURTHER BACK TO SSW MONDAY NIGHT. CLOUDS BEGIN TO
OVERSPREAD THE REGION TUESDAY AHEAD OF A COLD FRONT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT: MAINLY IFR, WITH AREAS MVFR POSSIBLE. BREEZY.
RA, CHANCE FZRA.
WEDNESDAY: VFR. CHANCE RA, CHANCE FZRA.
WEDNESDAY NIGHT: MAINLY VFR, WITH LOCAL IFR POSSIBLE. CHANCE
RA.
THURSDAY: MAINLY VFR, WITH AREAS IFR POSSIBLE. CHANCE RA.
THURSDAY NIGHT: MVFR/IFR CONDITIONS POSSIBLE. RA LIKELY.
FRIDAY: MVFR/IFR CONDITIONS POSSIBLE. BREEZY. RA LIKELY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH TUESDAY MORNING...HIGH CONFIDENCE.
NORTHERLY WINDS OF 25-30 KNOTS WITH SEAS BUILDING TO 5 FEET
ACROSS THE OUTER WATERS WHERE SCA'S CONTINUE THROUGH THIS
AFTERNOON. WIDESPREAD LIGHT TO MODERATE FREEZING SPRAY ACROSS
THE INNER WATERS LINGERS THROUGH LATE THIS MORNING. WINDS, SEAS,
AND SPRAY SUBSIDE LATER THIS AFTERNOON AS HIGH PRESSURE BUILDS
OVERHEAD.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. RAIN. LOCAL VISIBILITY 1 NM OR LESS.
WEDNESDAY THROUGH THURSDAY: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT. CHANCE OF RAIN.
THURSDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. RAIN
LIKELY.
FRIDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. CHANCE OF
RAIN.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...FREEZING SPRAY ADVISORY UNTIL 10 AM EST THIS MORNING FOR
ANZ231>235-237-251-255-256.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ250-
254>256.
DISCUSSION...KP
AVIATION...MCMINN
MARINE...MCMINN
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