725
FXUS61 KBOX 021800
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
100 PM 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 /18Z MONDAY THROUGH SATURDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
THROUGH 12Z TUESDAY: HIGH CONFIDENCE.
VFR. LIGHT NORTHERLY WINDS BECOME SW LATE IN THE AFTERNOON, AND
BECOME S/SW 5 KT OR LESS THRU TONIGHT.
TUESDAY: MODERATE CONFIDENCE.
VFR SHOULD GENERALLY PREVAIL THRU AT LEAST 17Z TUE, ALTHOUGH
WITH LOWERING CEILINGS. CONDITIONS DETERIORATE TO MVFR AFTER 18Z
WITH WINTRY MIX OF PRECIP TYPES, THEN TO IFR LATE-DAY.
PREDOMINANT SN/FZRA INTERIOR SNE WITH MINOR SNOW/ICE ACCUMS AND
ICY RUNWAYS MORE LIKELY FOR THOSE AIRPORTS; COASTAL SNE AIRPORTS
(PVD, BOS, CAPE) INITIAL LIGHT SNOW MIXED WITH RAIN WITH NIL
ACCUM AND MAINLY WET RUNWAYS, CHANGING TO PLAIN RAIN AFTER 22Z.
WINDS BECOME SE/ESE AROUND 5-10 KT.
TUESDAY NIGHT: MODERATE CONFIDENCE.
IFR/LIFR CEILINGS, WITH FZRA MAINLY HIGHER TERRAIN OF SOUTHERN
NEW ENGLAND AND PLAIN RAIN FOR THE MAJORITY OF SOUTHERN NEW
ENGLAND. PRECIP ENDS FROM WEST TO EAST AFTER 10Z, BUT RAIN MAY
LINGER ALONG THE SOUTH COAST INTO EARLY WED AM. ESE WINDS 5-10
KT LIGHTEN AND SHIFT TO W/WNW AS PRECIP ENDS WEST TO EAST.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. VFR, ESE WINDS 5 KT OR
LESS CONTINUE THRU 22Z BEFORE FLIPPING TO S. THESE CONDITIONS
CONTINUE THRU TUE AM, MVFR DEVELOPS AFTER 19Z TUE, WITH BRIEF
PERIOD OF 4SM -SNRA 21-23Z BEFORE BECOMING RA BY 23Z. NIL ACCUM
AND WET RUNWAYS EXPECTED GIVEN AIR TEMPS 32-35F.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. VFR THRU AT LEAST 16Z
TUE. CEILINGS DETERIORATE TO MVFR/IFR WITH LIGHT SNOW,
TRANSITIONING TO FREEZING RAIN BETWEEN ~21-02Z. IT IS MORE
UNCERTAIN HOW LONG FREEZING RAIN MAY LAST AS TEMPS MAY HOVER
AROUND 31-33F OVERNIGHT.
OUTLOOK /TUESDAY NIGHT THROUGH SATURDAY/...
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 SATURDAY/...
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...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ250-
254>256.
DISCUSSION...KP
AVIATION...LOCONTO
MARINE...MCMINN
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