304
FXUS61 KBOX 281730
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
130 PM EDT THU MAY 28 2026
WHAT HAS CHANGED
A GALE WATCH HAS BEEN ISSUED FOR ALL OF THE COASTAL AND OUTER
WATERS FOR SATURDAY. GUSTY NORTHERLY WINDS ARE POSSIBLE WITH THE
PASSAGE OF A STRONG LOW PRESSURE SYSTEM.
KEY MESSAGES
- COOLER TODAY WITH SCATTERED SHOWERS DEVELOPING IN THE AFTERNOON,
ESPECIALLY ACROSS EASTERN WITH A LOW RISK OF AN ISOLATED T-STORM.
- UNSETTLED CONDITIONS FRIDAY THROUGH EARLY NEXT WEEK WITH
PERIODS OF SHOWERS. GUSTY NORTHERLY WINDS POSSIBLE SATURDAY.
DISCUSSION
KEY MESSAGE 1...COOLER TODAY WITH SCATTERED SHOWERS DEVELOPING IN
THE AFTERNOON, ESPECIALLY ACROSS EASTERN MA WITH A LOW RISK OF
AN ISOLATED T-STORM.
COOLER TEMPERATURES ARE EXPECTED TODAY WITHIN THE POST-FRONTAL
AIRMASS. 925MB TEMPERATURES RANGE 11-13C, SUPPORTING HIGHS IN THE
LOW TO MID 70S FOR MOST WHILE ONSHORE FLOW WILL HOLD HIGHS IN THE
UPPER 60S ALONG THE EAST MA COAST. A SHORTWAVE TROUGH DROPS
SOUTHWARD ACROSS THE REGION ACCOMPANIED BY A SLIGHT UPTICK IN
MOISTURE. WEAK ASCENT WITH THE WAVE SHOULD BE SUFFICIENT ENOUGH TO
TRIGGER LIGHT SCATTERED SHOWERS AFTER LATE MORNING THROUGH THE
EVENING. SURFACE FLOW FIELDS SHOW INDICATIONS OF A COASTAL FRONT OFF
THE EASTERN MA COAST EXTENDING SOUTHWARD WITH E/NE FLOW OFFSHORE
AND N/NNW WINDS NOT FAR INLAND. THIS SHOULD ACT TO ENHANCE MOISTURE
CONVERGENCE ALONG THE COASTAL AND NEAR-COASTAL AREAS THUS FAVORING
THOSE AREAS FOR THE GREATER RISK FOR SCATTERED SHOWERS. ENOUGH
INSTABILITY MAY BE PRESENT FOR THE LOW RISK FOR AN ISOLATED
T-STORM OR TWO...BUT NOT EXPECTING ANY SEVERE WEATHER.
KEY MESSAGE 2...UNSETTLED CONDITIONS FRIDAY THROUGH EARLY NEXT WEEK
WITH PERIODS OF SHOWERS. GUSTY NORTHERLY WINDS POSSIBLE SATURDAY.
THERE IS A GOOD CONSENSUS AMONG ENSEMBLE GUIDANCE FOR A BLOCKY UPPER
LEVEL PATTERN TO SET UP OVER THE NORTHEAST FEATURING UPPER TROUGHING
FRIDAY THROUGH EARLY NEXT WEEK. SEVERAL SHORTWAVES MOVES THROUGH THE
BROAD CYCLONIC FLOW ALOFT BRINGING PERIODIC CHANCES FOR
SHOWERS/RAIN.
THE FIRST WAVE FEATURES A CLOSED UPPER LOW THAT DROPS SOUTH ACROSS
SOUTHERN NEW ENGLAND LATE FRIDAY INTO SATURDAY. THERE IS STILL SOME
SPREAD AMONGST GUIDANCE ON THE EXACT TIMING OF THE WAVE AND
ARRIVAL OF SHOWERS. SOME GUIDANCE (GFS/AIGFS) INDICATES SHOWERS
ARRIVING AS EARLY AS LATE FRIDAY AFTERNOON, WHILE OTHERS LEAN
LATER (FRI NIGHT). SHOWERS CONTINUE THROUGH SATURDAY, WITH
SHOWERS GRADUALLY DIMINISHING IN THE AFTERNOON/EVENING. WITH
LIMITED MOISTURE, RAIN AMOUNTS AREN'T EXPECTED TO BE HEAVY WITH
ENSEMBLES GENERALLY SHOWING A MORE LIKELY RANGE OF 0.20" TO
0.80" WITH THE HIGHER AMOUNTS FAVORED IN NORTHEAST MA.
TEMPERATURES TREND BELOW NORMAL SATURDAY IN THE UPPER 50S TO LOW
60S. THE PRESSURE GRADIENT TIGHTENS AS A SURFACE LOW TRACKS
ACROSS THE REGION WHICH WILL PROMOTE A PERIOD OF GUSTY N-NE
WINDS SATURDAY. THE EXPECTED GUSTS WILL DEPEND ON THE TRACK OF
THE LOW, BUT IF THE LOW TRACKS NEARBY GUSTS 30-40 MPH ARE
POSSIBLE, ISOLATED 45 MPH CAN'T BE RULED OUT. THE ECMWF ENSEMBLE
LEANS TOWARD WIDESPREAD GUSTY WINDS WITH MODERATE TO HIGH PROBS
FOR GUSTS GREATER THAN 40 MPH. HOWEVER, THE GEFS SHOWS WEAKER
WINDS OVERALL AND CONFINES LOW-MODERATE PROBABILITIES FOR 40
MPH+ TO THE CAPE AND WATERS. SOMETHING WE WILL KEEP MONITORING.
SUNDAY TRENDS DRIER AND MORE SEASONABLE WITH A
MIX OF SUN AND CLOUDS.
A FEW MORE WAVES MOVE THROUGH THE FLOW BEYOND SUNDAY INTO EARLY NEXT
WEEK. THERE IS STILL SPREAD IN THE DETAILS OF THE WAVES SUCH AS THE
TIMING, BUT THEY MAY SUPPORT PERIODIC CHANCES FOR SHOWERS. THERE IS
A BETTER CONSENSUS FOR A ROUND OF SHOWERS SOMETIME MONDAY AND
ANOTHER TUESDAY. 850MB TEMPERATURES ANOMALIES LEAN BELOW NORMAL
EARLY NEXT WEEK LIKELY YIELDING TEMPERATURES IN THE 60S AND LOW 70S
THROUGH WEDNESDAY. THERE ARE SIGNS OF THE BLOCKY PATTERN BREAKING
DOWN LATER NEXT WEEK WHICH SHOULD HELP WARM TEMPERATURES BACK
UP.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE...
TODAY...HIGH CONFIDENCE.
VFR OUTSIDE BRIEF SCATTERED SHOWERS THROUGH THE REST OF THE AFTERNOON
ESPECIALLY ACROSS EASTERN MA. LOW RISK FOR AN ISOLATED T-STORM
OR TWO...BUT CERTAINLY NORTHING WIDESPREAD. WINDS WILL BECOME
N-NW WINDS AT 10-15 KTS WITH GUSTS OF 20+ KTS FOR THE INTERIOR
TERMINALS AND E-NE 7-13 KTS NEAR THE EASTERN MA COAST.
TONIGHT...HIGH CONFIDENCE.
VFR. LIGHT N-NW WIND.
KBOS...HIGH CONFIDENCE IN TAF. THE MAIN RISK FOR BRIEF SCATTERED
SHOWERS IN THE VICINITY OF TERMINAL WILL BE AFTER 18Z THROUGH
ABOUT 00Z/01Z. THERE IS A LOW RISK FOR A BRIEF RUMBLE OF
THUNDER AS WELL.
KBDL...HIGH CONFIDENCE IN TAF.
OUTLOOK /FRIDAY THROUGH TUESDAY/...
FRIDAY: VFR. BREEZY. CHANCE SHRA.
FRIDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY WITH
LOCAL GUSTS UP TO 35 KT. CHANCE SHRA, PATCHY BR.
SATURDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY WITH
GUSTS UP TO 35 KT. CHANCE SHRA.
SATURDAY NIGHT: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
SUNDAY: VFR.
SUNDAY NIGHT: VFR. SLIGHT CHANCE SHRA.
MONDAY: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY AND TONIGHT...
WINDS AND SEAS BELOW SCA THRESHOLDS. N WINDS TONIGHT. N-NE WINDS
5-15 KTS TODAY BECOMING N-NW TONIGHT. SCATTERED SHOWERS
DEVELOPING THU AFTERNOON. LOW CHANCE OF AN ISOLATED STORM.
WE ISSUED A GALE WATCH FOR ALL THE WATERS FOR SATURDAY DUE TO
THE POTENTIAL FOR A STRONGER LOW PRESSURE TO TRACK ACROSS THE
REGION BRINGING GUSTY N-NE WINDS. CONFIDENCE IS MODERATE AS THE
GALES WILL DEPEND ON THE TRACK OF THE LOW.
OUTLOOK /FRIDAY THROUGH TUESDAY/...
FRIDAY: WINDS LESS THAN 25 KT. CHANCE OF RAIN SHOWERS.
FRIDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. AREAS OF SEAS APPROACHING 5 FT. RAIN
SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS, PATCHY FOG.
SATURDAY: STRONG WINDS WITH GUSTS UP TO 40 KT. AREAS OF ROUGH
SEAS. CHANCE OF RAIN SHOWERS.
SATURDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
AREAS OF GUSTS UP TO 30 KT. ROUGH SEAS UP TO 11 FT.
SUNDAY: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. SLIGHT CHANCE OF RAIN SHOWERS.
MONDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...GALE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY EVENING FOR
ANZ230-250-251-280.
GALE WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING FOR
ANZ231>237-254>256-281>283.
DISCUSSION...FRANK/MENSCH
AVIATION...FRANK/FT
MARINE...MENSCH
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