Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 231109
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
709 AM EDT SAT MAY 23 2015

.SYNOPSIS...

HIGH PRESSURE WILL BUILD TO THE MID ATLANTIC STATES TODAY...
BRINGING COOLER AIR TO THE REGION. WARM AND MUGGY CONDITIONS
TO BUILD ACROSS THE REGION BENEATH HIGH PRESSURE INTO NEXT WEEK.
SHOULD REMAIN MOSTLY DRY WITH THE BETTER CHANCES FOR WET-WEATHER
TO REMAIN MAINLY NORTH AND WEST OF OUR AREA PRIOR TO THE FOLLOWING
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...

7 AM UPDATE...

FROST / FREEZE HEADLINES HAVE BEEN DISCONTINUED. WITH ABUNDANT
SUNSHINE PER LATEST SATELLITE TRENDS...TEMPERATURES HAVE BEGUN TO
REBOUND ABOVE THE FREEZING MARK FOR INTERIOR LOCATIONS.

HIGH PRESSURE WILL BUILD TO MID ATLANTIC COAST TODAY...RESULTING
IN DRY W/NW FLOW ACROSS SOUTHERN NEW ENGLAND. FORECAST SOUNDINGS
SHOW POTENTIAL FOR DEEP MIXING TO AROUND 825 MB THIS AFTERNOON...
WHICH WILL BRING 20-25 MPH GUSTS /ESPECIALLY THROUGH MIDDAY BEFORE
WINDS ALOFT WEAKEN/. MIXING WILL ALSO BRING DRY AIR DOWN TO
SURFACE...SO LOWERED DEWPOINTS INTO TEENS IN COLLABORATION WITH
NEIGHBORING OFFICES AS OPPOSED TO 20S OFFERED BY GUIDANCE. ONLY
NAM MOS SEEMS TO HAVE A HANDLE ON THIS.

DESPITE SUNSHINE AND W FLOW...HIGHS WILL ONLY TOP OUT IN UPPER 50S
TO MID 60S.

&&

.SHORT TERM /SUNDAY/...

SW FLOW GETS UNDERWAY TONIGHT AS HIGH PRESSURE BECOMES POSITIONED
OFFSHORE. SHOULD SEE SOME MID LEVEL CLOUDINESS TONIGHT IN
ASSOCIATION WITH WEAK SHORT WAVE PASSING THROUGH...BUT LOWER
LEVELS REMAIN BONE DRY SO NO RAINFALL IS EXPECTED. LOWS SHOULD
FALL BACK INTO 40S AND LOWER 50S.

WARMUP STARTS SUN WITH INCREASING SW FLOW AND SUBSIDENCE IN WAKE
OF DEPARTING SHORT WAVE. MODEL 2M TEMPERATURES SUPPORT HIGHS WELL
INTO 70S OR AROUND 80 AWAY FROM S COAST...WHERE TEMPERATURES
SHOULD BE HELD IN 60S TO NEAR 70.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

*/ HIGHLIGHTS...

 - LOOKING GOOD FOR MEMORIAL DAY
 - WET-WX CHANCES ACROSS N/W-PORTIONS OF THE NE CONUS THRU THE WEEK
 - WARM AND MUGGY PATTERN EVOLVING
 - THE RETURN OF AN ACTIVE WET-WEATHER PATTERN BY NEXT WEEKEND

*/ DISCUSSION...

LONG-TERM PATTERN MORE APPARENT WITH RUN-TO-RUN CONSISTENCY OF MODEL
FORECAST GUIDANCE. RIDGE ENHANCES OVER THE E-CONUS AHEAD OF AN OPEN-
WAVE W-CONUS TROUGH. WITH THE BERMUDA HIGH MAINTAINED THE LOW-TO MID-
LEVEL CONVERGENT FLOW UP AGAINST THE N-CANADA VORTEX IS KEPT N/W OF
S NEW ENGLAND THRU WHICH MID-LEVEL ENERGY STRETCHES PROVIDING
FORCING OF SW-ISENTROPIC ASCENT OF THE WARM-MOIST CONVEYOR BELT.
SUBSIDENCE AND DRY-AIR BENEATH ANTICYCLONIC FLOW IS AFFIRMED FOR S
NEW ENGLAND. ANTICIPATING A WARM-MUGGY-DRY PATTERN THROUGH THE END
OF THE WEEK PRIOR TO THE RIDGE ERODING UP AGAINST THE CUT-OFF
RETROGRADING LOW THROUGH THE NW-ATLANTIC. WITH THE RIDGE ERODING
IT IS MORE LIKELY THAT MID-LEVEL ENERGY AND CONVERGENT FLOW CAN
SLIP SOUTHWARD PUTTING S NEW ENGLAND IN AN ACTIVE WEATHER PATTERN
PERHAPS BY NEXT WEEKEND.

SO WILL CONTINUE WITH HIGHER POP-CHANCES N/W KEEPING A MAJORITY OF
THE FORECAST PERIOD DRY. STEERING FLOW MAINLY W/SW. S-FLOW BENEATH
HIGH PRESSURE/SUBSIDENCE WILL LEAN WITH MUGGY UNSEASONABLY-WARM
TEMPERATURES AS WE GO INTO THE WEEK. MAY HAVE TO DEAL WITH PERIODS
OF MARINE STRATUS/FOG AS S-FLOW ADVECTS HIGHER DEWPOINT AIR N ACROSS
THE COOLER WATERS. FOCUS ON THE OVERNIGHT INTO MORNING PERIODS. WILL
HINT AT A SHIFT IN THE WEATHER PATTERN BY THE END OF NEXT WEEKEND.

&&

.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SUNDAY/...HIGH CONFIDENCE.

12Z UPDATE...NO MAJOR CHANGES.

W/NW WINDS GUST 20-25 KT THROUGH MIDDAY...BEFORE WINDS BACK TO
W/SW AND DIMINISH THIS AFTERNOON AND TONIGHT. SW WINDS GUST TO
20-25 KT SUN...ESPECIALLY NEAR S COAST. VFR THROUGH PERIOD.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. W/NW FLOW.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...

MODERATE CONFIDENCE. MAINLY VFR. LOWEST CIGS MAINLY N/W. SW-WINDS
BLUSTERY AT TIMES DURING DAYTIME PERIODS. LOW CONFIDENCE WITH IFR-
LIFR MARINE STRATUS / FOG ACROSS THE S/SE-COAST OCCURRING DURING THE
OVERNIGHT INTO MORNING PERIODS.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SUNDAY/...HIGH CONFIDENCE.

7 AM UPDATE...NO MAJOR CHANGES.

SCA REMAINS POSTED FOR W/NW WINDS GUSTING TO 25 KT THROUGH MID
MORNING...ESPECIALLY WITHIN A FEW MILES OF SHORE BEFORE
DIMINISHING AND BECOMING W/SW THIS AFTERNOON. LIGHTER SW FLOW
EXPECTED TONIGHT WITH INCREASING SW WINDS SUN WHICH MAY REACH
SCA...ESPECIALLY ON S COASTAL BAYS AND SOUNDS.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY NIGHT...

MODERATE CONFIDENCE. PERSISTENT SW-FETCH WITH DAYTIME GUSTS AROUND
20-25 KTS ESP ALONG THE SHORES AND INNER-WATERS WILL RESULT IN WAVE
HEIGHTS IN EXCESS OF 5-FEET MOSTLY ON THE OUTER WATERS. LOW
CONFIDENCE ON THE POTENTIAL FOR MARINE FOG DURING THE OVERNIGHT INTO
MORNING PERIODS.

&&

.FIRE WEATHER...

W/NW WINDS GUST TO 25 MPH AT TIMES...ESPECIALLY THROUGH MIDDAY
BEFORE DIMINISHING. MINIMUM RH DROPS TO 10 TO 20 PERCENT THIS
AFTERNOON ACROSS MUCH OF SOUTHERN NEW ENGLAND. ALTHOUGH WE ARE
FARTHER ALONG IN GREENUP...DUE TO LACK OF SIGNIFICANT RAINFALL
OVER PAST SEVERAL DAYS AND INFORMATION FROM STATE FIRE OFFICIALS...
WE WILL ISSUE A SPECIAL WEATHER STATEMENT FOR AN ELEVATED FIRE
WEATHER RISK TODAY.

DRY PATTERN MAY PERSIST FOR NEXT FEW DAYS...ALTHOUGH RH WILL BE
SOMEWHAT HIGHER DUE TO SW FLOW.

&&


.BOX WATCHES/WARNINGS/ADVISORIES...

CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
     ANZ230>237-251-255-256.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ250-
     254.

&&

$$

SYNOPSIS...SIPPRELL/JWD
NEAR TERM...SIPPRELL/JWD
SHORT TERM...JWD
LONG TERM...SIPPRELL
AVIATION...SIPPRELL/JWD
MARINE...SIPPRELL/JWD
FIRE WEATHER...
CLIMATE...


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