346
FXUS61 KBOX 170728
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
328 AM EDT FRI APR 17 2026
WHAT HAS CHANGED
GENERAL FORECAST TRENDS REMAIN UNCHANGED FROM THE PREVIOUS
UPDATE.
KEY MESSAGES
- SOME SHOWERS POSSIBLE LATER THIS AFTERNOON. RETURN OF ONSHORE
FLOW AND COOLER TEMPERATURES.
- STRONG COLD FRONT BRINGS A ROUND OF WIDESPREAD SHOWERS LATE
SATURDAY NIGHT INTO SUNDAY, LEAVES COLDER TEMPERATURES AND DRIER
CONDITIONS IN ITS WAKE.
- MAINLY DRY AND UNSEASONABLY COOL MON-TUE, THEN MODERATING
TEMPERATURES TOWARD MIDWEEK. NEXT CHANCE OF SHOWERS WILL BE
TUE NIGHT INTO EARLY WED.
DISCUSSION
KEY MESSAGE 1...SOME SHOWERS POSSIBLE LATER THIS AFTERNOON. RETURN
OF ONSHORE FLOW AND COOLER TEMPERATURES.
COOLER DAY AHEAD OVER THE INTERIOR COMPARED TO YESTERDAY AS THE LOW
ASSOCIATED WITH THE BACKDOOR COLD FRONT BEGINS TO SHIFT OFFSHORE
TODAY. WITH IT SITTING OFFSHORE, ONSHORE FLOW KICKS BACK UP AND
CLOUD COVER BECOMES PERSISTENT ACROSS SOUTHERN NEW ENGLAND. 925 MB
TEMPERATURES ALSO FALL SLIGHTLY FROM JUST OVER 20C IN SOME SPOTS TO
CLOSER TO 10C ACROSS THE REGION AS THE RIDGE BREAKS DOWN AND THE
SHORTWAVE THAT PROVIDED SOME SHOWERS EARLIER THIS MORNING PUSHES
THROUGH THE REGION. HIGHS TODAY WILL MOSTLY BE IN THE 60S AND 70S
ACROSS THE REGION, WITH THE WARMEST TEMPERATURES IN THE MID 70S
POSSIBLE IN THE CT VALLEY AND THE COOLEST TEMPERATURES REMAINING
CLOSER TO THE EASTERN COASTLINE. SOME ISOLATED SHOWERS ARE POSSIBLE
LATER IN THE AFTERNOON WITH A LOW CHANCE (20%) FOR SOME EMBEDDED
THUNDER OVER PARTS OF THE INTERIOR WHERE SOME SURFACE-BASED CAPE 500-
1000 J/KG MAY BE PRESENT. THE SLIGHTLY COOLER CONDITIONS CONTINUE
INTO TONIGHT WITH 925 MB AND 850 MB TEMPERATURES FALLING BELOW 10C
AND FLOW REMAINING N AND NE. LOWS TONIGHT SHOULD BE MORE WIDESPREAD
40S-50S.
KEY MESSAGE 2...STRONG COLD FRONT BRINGS A ROUND OF WIDESPREAD
SHOWERS LATE SATURDAY NIGHT INTO SUNDAY, LEAVES COLDER TEMPERATURES
AND DRIER CONDITIONS IN ITS WAKE.
THE LOW LINGERS OFFSHORE SATURDAY WHILE SURFACE RIDGING TAKES HOLD
IN THE WAKE OF TODAY'S SHORTWAVE. WITH THAT, ONSHORE FLOW CONTINUES
AND DRIER WEATHER PREVAILS. HIGHS SATURDAY SHOULD BE MORE
SEASONABLE, ONLY CLIMBING INTO THE 50S AND 60S.
OUR ATTENTION THEN TURNS TO AN INCOMING STRONG COLD FRONT DURING THE
LATTER HALF OF THE WEEKEND THAT WILL LIKELY BRING A ROUND OF MORE
SHOWERS. THIS FRONT IS PART OF A POTENT UPPER LEVEL TROUGH THAT WILL
BE SHIFTING EAST FROM THE GREAT LAKES THIS WEEKEND. AHEAD OF THIS
FRONT AND TROUGH, PWAT VALUES CLIMB TO AROUND 1.25" SUNDAY MORNING
AFTER DROPPING MOSTLY BELOW AN INCH DURING THE DAY SATURDAY. AS THIS
FRONT PUSHES THROUGH, THE FORCING FROM IT INTERACTING WITH THIS
INCREASED MOISTURE WILL LEAD TO WIDESPREAD SHOWERS FOR SUNDAY. SOME
GUIDANCE IS HINTING AT SOME MUCAPE AROUND 500 J/KG DURING THE DAY
THAT COULD BE A FACTOR IN SOME EMBEDDED THUNDERSTORMS WITH THESE
SHOWERS. COLDER AND DRIER AIR IS LEFT IN THIS FRONTAL PASSAGE'S
WAKE, REINFORCED BY BREEZY W TO NW WINDS STARTING SUNDAY AFTERNOON.
SHOWERS MAY END WITH A MIX OF SOME SNOW IN THE HIGHER ELEVATIONS OF
THE BERKSHIRES SUNDAY EVENING AS THIS COLDER AIR TAKES HOLD, BUT ANY
ACCUMULATIONS ARE NOT EXPECTED AT THIS TIME. LOWS SUNDAY NIGHT MAY
DIP INTO THE UPPER 20S IN THE HIGHEST ELEVATIONS WITH THE REST OF
THE REGION FALLING INTO THE 30S.
KEY MESSAGE 3...MAINLY DRY AND UNSEASONABLY COOL MON-TUE, THEN
MODERATING TEMPERATURES TOWARD MIDWEEK. NEXT CHANCE OF SHOWERS WILL
BE TUE NIGHT INTO EARLY WED.
THE UPPER LEVEL TROUGH SETTLES OVERHEAD MONDAY, AND WITH THAT,
TEMPERATURES ALOFT DROP TO UNSEASONABLE VALUES. 925 MB TEMPERATURES
FALL BELOW 0C AND MAY EVEN DIP TO -5C BY MONDAY MORNING; 850 MB
TEMPERATURES MAY APPROACH -10C AS WELL. BREEZY W TO NW WINDS
CONTINUE AS WE SIT IN A CAA PATTERN, AND HIGHS MAY NOT CLIMB OUT OF
THE UPPER 40S AND LOW 50S MONDAY AFTERNOON. THESE WINDS WILL START
TO DIMINISH AS HIGH PRESSURE APPROACHES FROM THE WEST, AND LOWS
MONDAY NIGHT MAY FALL INTO THE 20S FOR MUCH OF SOUTHERN NEW ENGLAND.
THIS HIGH PRESSURE SHOULD KEEP THE REGION DRY FOR THE START OF THE
WEEK BEFORE IT EXITS HEADING INTO WEDNESDAY. SOME SHOWERS ARE A
POSSIBILITY ONCE AGAIN TUESDAY NIGHT INTO WEDNESDAY MORNING,
PARTICULARLY IN NORTHERN MA AS ANOTHER SHORTWAVE PASSES TO THE
NORTH, BUT DRY WEATHER IS EXPECTED TO DOMINATE THE PATTERN FOR MUCH
OF NEXT WEEK.
AVIATION /07Z FRIDAY THROUGH TUESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE:
THROUGH 12Z: MODERATE CONFIDENCE.
MIX OF CEILINGS ACROSS SOUTHERN NEW ENGLAND THIS MORNING.
PERIODS OF LIFR/IFR POSSIBLE EVEN AMIDST VFR DUE TO BR AND
PERIODIC LOWER CLOUDS. EXACT TIMING UNCERTAIN. SHRA WITH SOME
EMBEDDED TS MOVING INTO THE REGION AS OF THE TIME WRITING THIS.
THESE SHOWERS WILL CONTINUE TRACKING NE THIS MORNING, MOST
LIKELY IMPACTING BDL AND ORH, AND POSSIBLY BED AND BOS.
TODAY: MODERATE CONFIDENCE.
MVFR-IFR ALONG THE IMMEDIATE COAST, OTHERWISE CONDITIONS
LOWERING TO MVFR ELSEWHERE AND EVENTUALLY TO IFR EASTERN MA AND
RI DURING THE AFTERNOON. SCATTERED SHOWERS AND A FEW T-STORMS
DEVELOPING. EXACT SPATIAL EXTENT STILL A BIT UNCERTAIN. NORTH
TO NORTHEAST WINDS 5-10 KT.
TONIGHT THROUGH SATURDAY...MODERATE CONFIDENCE.
ANY LINGERING SHOWERS SHOULD DRY UP HEADING INTO TONIGHT. LIGHT
N TO NE WINDS CONTINUE, THEN INCREASE TO AROUND 10 KT DURING THE
DAY SATURDAY. PERIODS OF IFR/MVFR POSSIBLE, ESPECIALLY HEADING
INTO SAT.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. LIFR FOG AND STRATUS
THIS MORNING. LOW CLOUDS CONTINUE, BUT IFR/LIFR CEILINGS MAY
BREAK BRIEFLY IN PERIODS THIS MORNING. IFR LIKELY PERSISTS
THROUGH MUCH OF TODAY. SCATTERED SHOWERS AND POSSIBLY A T-STORM
DEVELOPING AROUND MIDDAY AND INTO THE AFTERNOON.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. SHOWERS WITH EMBEDDED TS
MOVING THROUGH TERMINAL OVER THE NEXT HOUR OR SO (06-07Z).
OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...
SATURDAY NIGHT: MVFR/IFR CONDITIONS POSSIBLE. SLIGHT CHANCE
SHRA.
SUNDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY. SHRA.
SUNDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SHRA.
MONDAY: VFR. BREEZY.
MONDAY NIGHT THROUGH TUESDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THE WEEKEND.
SEAS 2-4 FT AND WINDS LESS THAN 25 KTS. LOCALIZED 5 FT SEAS
POSSIBLE IN THE SOUTHERN WATERS TODAY; NOT EXPECTED TO BE
PERSISTENT ENOUGH FOR SMALL CRAFT ADVISORIES. SW WINDS SHIFT TO
NE LATER TODAY.
PASSAGE OF STRONGER COLD FRONT SUN SHOULD BRING SCA CONDITIONS
TO AT LEAST OUTER WATERS SUN INTO MON. WIND GUSTS MAY LOCALLY
APPROACH 25 KT LATE SUNDAY IN THE OUTER WATERS.
OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...
SATURDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
SUNDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
RAIN SHOWERS LIKELY.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE OF
RAIN SHOWERS.
MONDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
MONDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
TUESDAY: WINDS LESS THAN 25 KT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...HRENCECIN
AVIATION...HRENCECIN
MARINE...HRENCECIN
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