766
FXUS61 KBOX 090528
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
1228 AM EST FRI JAN 9 2026
WHAT HAS CHANGED
INCREASED CONFIDENCE IN PATCHY FREEZING DRIZZLE/FOG THAT MAY RESULT
IN ICY CONDITIONS ON UNTREATED SURFACES TONIGHT INTO FRIDAY
MORNING.
KEY MESSAGES
- AREAS OF FREEZING FOG TONIGHT INTO FRIDAY MORNING. LIGHT RAIN
OVERNIGHT FRIDAY.
- A LOW-PRESSURE SYSTEM BRINGS A SOAKING RAINFALL
SATURDAY, WITH RAIN POSSIBLY LINGERING INTO SUNDAY.
- A COLD FRONT BRINGS COOL AND BLUSTERY CONDITIONS
BACK TO THE REGION LATE SUNDAY INTO MONDAY.
DISCUSSION
KEY MESSAGE 1...PATCHES OF FREEZING FOG TONIGHT INTO FRIDAY
MORNING. LIGHT RAIN OVERNIGHT FRIDAY.
SURFACE HIGH PRESSURE MOVES OFFSHORE OVERNIGHT. LIGHT RETURN FLOW
ALLOWS DEW POINT TEMPERATURES TO RISE INTO THE UPPER 20S/ LOWER 30S.
BUFKIT SOUNDINGS SHOW IDEAL CONDITIONS FOR FOG WITH AN INVERSION
NEAR THE SURFACE ALONG WITH A SATURATED LAYER UP TO ABOUT 1 KFT.
GIVEN THE SURFACE TEMPERATURES ARE BELOW FREEZING, PATCHY FREEZING
FOG IS LIKELY LATE TONIGHT INTO FRIDAY MORNING. THANKFULLY, THE
FREEZING FOG THREAT WILL QUICKLY DIMINISH AFTER 12Z FRIDAY AS
SURFACE TEMPERATURES WARM ABOVE FREEZING. STRENGTHENING SOUTHWEST
WINDS ALOFT RESULT IN STRONG WAA WITH 850MB TEMPERATURES RISING
BETWEEN +4C TO +6C FRIDAY AFTERNOON. AS A RESULT, IT SHOULD BE A
WARMER DAY WITH HIGHS CLIMBING INTO THE MID AND UPPER 40S FOR MOST
OF THE REGION. NBM EVEN SHOWS AREAS OF SOUTHERN MASSACHUSETTS
AND RHODE ISLAND TOUCHING 50F. SURFACE WARM FRONT MOVES THROUGH
SOUTHERN NEW ENGLAND FRIDAY NIGHT INTO EARLY SATURDAY MORNING.
GUIDANCE STILL SHOWS A BROKEN BAND OF SHOWERS WITH QPF BETWEEN
0.10 AND 0.25 INCHES, CERTAINLY NOT A WASHOUT. HIGHEST TOTALS
WILL BE FURTHER TO THE NORTH ACROSS NORTHERN NEW ENGLAND, WITH
THE PARENT LOW PRESSURE SYSTEM. NO P-TYPE ISSUES EXPECTED WITH
THIS EVENT AS TEMPERATURES FRIDAY NIGHT REMAIN IN THE LOW-40S AT
THE COAST AND UPPER 30S ACROSS INTERIOR LOCATIONS.
KEY MESSAGE 2...A LOW-PRESSURE SYSTEM BRINGS A SOAKING RAINFALL
SATURDAY, WITH RAIN POSSIBLY LINGERING INTO SUNDAY.
SHORTWAVE ENERGY ARRIVES WELL AHEAD OF THE PARENT SHORTWAVE BACK
OVER THE NORTHERN GREAT PLAINS ON SATURDAY. THIS ALLOWS SEVERAL
WEAK SURFACE LOWS TO SPIN UP ALONG THE NEARSHORE BAROCLINIC ZONE AND
BRING RAIN TO THE REGION ON SATURDAY. WITH A WARM AIRMASS IN PLACE
AND EXTRA MOISTURE FLOWING IN FROM THE MID-ATLANTIC, PWATS SURGE TO
AROUND 0.9 TO 1.1 INCHES. BEST FORCING AND MOISTURE WILL BE NEAR
THE SOUTH COAST AS THE WAVE OF LOW PRESSURE PASSES JUST OFFSHORE.
THERE IS STILL QUITE A BIT OF SPREAD IN QPF TOTALS, AS ENSEMBLES
SHOW WIDE RANGES IN THE 25TH-75TH PERCENTILES. REGARDLESS, QPF WILL
BE HIGHEST NEAR THE SOUTH COAST, WHERE THE 25TH-75TH PERCENTILE
RANGE IS BETWEEN .35 AND 1.15 INCHES, WHILE FURTHER NORTH, THE RANGE
IS .15 TO 0.55 INCHES.
SATURDAY MORNING SHOULD REMAIN DRY, WITH RAIN MOVING IN FROM SOUTH
TO NORTH IN THE LATE MORNING TO EARLY AFTERNOON. GIVEN THAT RAIN
WILL BEGIN DURING THE DAYTIME HOURS, FREEZING RAIN CONCERNS WILL BE
LIMITED, LIKELY OCCURRING ONLY IN POCKETS OF THE NORTHERN HIGH
TERRAIN WHERE COLD AIR MAY BE TOUGH TO SCOUR OUT.
RAIN ENDS FROM WEST TO EAST LATE SATURDAY EVENING INTO THE
OVERNIGHT. ANOTHER WAVE OF LOW PRESSURE RIDES UP THE STALLED
FRONTAL BOUNDARY OFFSHORE, POSSIBLY BRINGING ANOTHER ROUND OF RAIN
TO THE SOUTH COAST ON SUNDAY. HIGH TEMPERATURES OVER THE WEEKEND
REMAIN MILD, WITH MID TO UPPER 40S ON SATURDAY, THEN UPPER 30S TO
LOW 40S ON SUNDAY.
KEY MESSAGE 3...A COLD FRONT BRINGS COOL AND BLUSTERY CONDITIONS
BACK TO THE REGION LATE SUNDAY INTO MONDAY.
A COLD FRONT MOVES THROUGH THE REGION SUNDAY EVENING, HELPING CLEAR
OUT THE REMAINING RAIN. THE COLD FRONT WILL SQUEEZE OUT THE
REMAINING MOISTURE FROM THE WEEKEND, LEADING TO ISOLATED SNOW
SHOWERS AND POSSIBLY WEAK SNOW SQUALLS SUNDAY EVENING. TEMPERATURES
WILL CRASH SUNDAY NIGHT, BOTTOMING OUT IN THE LOW TO MID 20S. ANY
REMAINING STANDING WATER FROM THIS WEEKENDS RAIN WILL FREEZE BY
MONDAY MORNING, POSSIBLY LEADING TO SOME SLIPPERY CONDITIONS FOR THE
MONDAY AM COMMUTE. HIGH TEMPERATURES ON MONDAY WILL RECOVER INTO
THE LOW TO MID 30S, BUT GUSTY WEST WINDS AT 20-25MPH WILL BRING THE
WIND CHILL INDEX INTO THE LOW 20S.
LOOKING AHEAD INTO NEXT WEEK, COOL AND DRY CONDITIONS PERSIST
THROUGH WEDNESDAY OR THURSDAY, WITH THE PATTERN POSSIBLY TURNING
MORE ACTIVE AGAIN LATE IN THE WEEK INTO NEXT WEEKEND.
AVIATION /06Z FRIDAY THROUGH TUESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH -GREATER THAN 60 PERCENT.
TAF UPDATE: 06Z
THROUGH THIS MORNING... MODERATE CONFIDENCE.
VFR TO START, LOW-LEVEL MOISTURE LEADS TO LOWER VISIBILITY AFTER 03Z-
04Z, BETWEEN 2SM TO 5SM. AREAS OF FOG MAY LEAD TO A SCT TO BKN GROUP
OF IFR CLOUDS, BUT CONFIDENCE IN THIS IS LOWER. WITH BELOW FREEZING
TEMPERATURES EXPECTED, MOISTURE CAN REFREEZE ON UNTREATED SURFACES.
AREAS IN SOUTHEAST MASSACHUSETTS AND RHODE ISLAND HAVE A LOW CHANCE,
LESS THAN 30%, OF VISIBILITY TO LOWER BELOW 1/2 MILE, AND THERE
FREEZING DENSE FOG OR FREEZING DRIZZLE ARE POSSIBLE. INCLUDED PROB30
FOR KPVD. LIGHT SOUTH WIND LESS THAN 5 KNOTS. IMPROVING CONDITIONS
BETWEEN 13Z AND 15Z.
TODAY AND TONIGHT... MODERATE CONFIDENCE.
VFR, BECOMING MVFR AFTER 20Z AS A WARM FRONT APPROACHES. SOUTH TO
SOUTH-SOUTHWEST WINDS INCREASING, GUSTS 20 TO 25 KNOTS AFTER 18Z.
AREAS OF SHRA MOVE IN FROM WEST TO EAST 22Z-00Z, CONDITIONS BRIEFLY
LOWER TO IFR, SHOWERS DIMINISH BETWEEN 03-06Z, IMPROVING BACK TO VFR
06-09Z, WHILE MVFR LINGERS ON THE CAPE AND ISLANDS THROUGH 09Z-12Z.
WIND SHIFTS TO THE WEST TO WEST-NORTHWEST BETWEEN 04Z-10Z, WINDS
SPEEDS ARE 5 TO 10 KNOTS, SLIGHTLY HIGHER FOR COASTAL TERMINALS.
SATURDAY... MODERATE CONFIDENCE.
VFR TO START, THEN LOWERING TO MVFR FROM SOUTH TO NORTH, ALONG WITH
SHOWERY RAIN, MAINLY AFTER 18Z/21Z. LIGHT NORTH WIND BECOMES EAST AT
5 TO 10 KNOTS.
KBOS TERMINAL... MODERATE CONFIDENCE.
MVFR TO IFR VISIBILITY DEVELOPING TONIGHT, POTENTIAL FOR DENSE FOG
AND IFR CEILINGS 08Z TO 13Z.
KBDL TERMINAL... MODERATE CONFIDENCE.
MVFR TO IFR VISIBILITY DEVELOPING TONIGHT, POTENTIAL FOR DENSE FOG
AND IFR CEILINGS 09Z TO 14Z.
OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...
SATURDAY NIGHT: MAINLY IFR, WITH AREAS MVFR POSSIBLE. RA,
CHANCE FZRA.
SUNDAY: MAINLY VFR, WITH AREAS IFR POSSIBLE. BREEZY. CHANCE RA,
CHANCE FZRA.
SUNDAY NIGHT: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT. CHANCE
RA, SLIGHT CHANCE SN.
MONDAY: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
MONDAY NIGHT THROUGH TUESDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY THROUGH SATURDAY... HIGH CONFIDENCE.
WINDS INCREASES FROM THE SOUTH ON TODAY AS A WARM FRONT LIFTS OVER
THE REGION. STRONGEST GUSTS ARE OVER THE OUTER OCEAN WATERS, 20 TO
25 KNOTS THIS AFTERNOON, THEN 25 TO 30 KNOTS OVERNIGHT. SEAS ARE
INCREASING THIS AFTERNOON AND TONIGHT 4 TO 6 FEET, LOCALIZED AREAS
OF 7 FEET ON THE OUTERMOST SOUTHERN WATERS. SHOWERY RAIN OVERNIGHT,
NOT EXPECTED TO BE AT ALL IMPACTFUL. SATURDAY MORNING WINDS GO LIGHT
AND FLIP TO THE EAST AS A QUASI-STATIONARY FRONT LIFTS FROM THE
SOUTH TO THE NORTH, RAIN ACCOMPANIES THIS FRONT AS WELL DURING THE
EARLY TO MIDAFTERNOON.
OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...
SATURDAY NIGHT: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS. RAIN.
SUNDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. RAIN
LIKELY.
SUNDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 40 KT. AREAS OF
ROUGH SEAS. CHANCE OF RAIN, SLIGHT CHANCE OF SNOW.
MONDAY: STRONG WINDS WITH GUSTS UP TO 35 KT. AREAS OF ROUGH
SEAS.
MONDAY NIGHT THROUGH TUESDAY: LOW RISK FOR SMALL CRAFT ADVISORY
WINDS WITH GUSTS UP TO 25 KT. LOCAL ROUGH SEAS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 3 AM EST
SATURDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
SATURDAY FOR ANZ250-254>256.
DISCUSSION...KP/FT
AVIATION...DOOLEY/MENSCH
MARINE...DOOLEY/MENSCH
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