Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 222026
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
426 PM EDT MON SEP 22 2014

.SYNOPSIS...

HIGH PRESSURE WILL BRING DRY WEATHER ALONG WITH MILD DAYS AND
COOL NIGHTS THROUGH WEDNESDAY.  DISTANT COASTAL LOW PRESSURE MAY
GRAZE SE NEW ENGLAND WITH THE LOW RISK FOR FEW SHOWERS WEDNESDAY
NIGHT INTO THURSDAY. HIGH PRESSURE RETURNS FRIDAY INTO EARLY NEXT
WEEK WITH DRY WEATHER AND UNSEASONABLY WARM AFTERNOON/S. ITS
POSSIBLE A FEW RECORD HIGH TEMPS ARE CHALLENGED THIS WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HIGH PRES WILL GRADUALLY BUILD IN FROM THE WEST BRINGING MOCLEAR
SKIES AND A DRY AIRMASS. GUSTY WINDS WILL GRADUALLY DIMINISH
TONIGHT BUT THERE APPEARS TO BE ENOUGH GRADIENT TO LIMIT
RADIATIONAL COOLING SO TEMPS WILL LIKELY STAY ABOVE FROST
THRESHOLDS. STILL A CHILLY NIGHT WITH MINS IN THE MID/UPPER 30S IN
THE INTERIOR...WITH 40S ELSEWHERE. ISOLD FROST POSSIBLE IN THE NW
MA AND SW NH BUT NOT WIDESPREAD ENOUGH TO SUPPORT FROST HEADLINES.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY...
HIGH PRES CRESTS ACROSS THE REGION WHICH WILL BRING MOSUNNY SKIES
AND LIGHT WINDS. SUBSIDENCE INVERSION WILL LIMIT MIXING HEIGHT
BELOW 850 MB. 925 MB TEMPS 10-11C WHICH SUPPORTS TEMPS 65-70
DEGREES...COOLER HIGHER TERRAIN WHICH IS LINE WITH 2M TEMPS. SOME
OF THE HIRES GUIDANCE IS HINTING A SEABREEZE DEVELOPING ALONG THE
COAST IN THE AFTERNOON.

TUESDAY NIGHT...
HIGH PRES BUILDS TO THE NORTH WITH A CONTINUATION OF CLEAR SKIES
AND A LIGHT NE WIND DEVELOPING OVERNIGHT. WE USED A BLEND OF THE
GUIDANCE WHICH YIELDS MINS MOSTLY IN THE 40S.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...

HIGHLIGHTS...

* COOL NIGHTS/MILD DAYS WED AND THU
* UNSEASONABLY WARM AFTERNOON/S THIS WEEKEND PERHAPS INTO MONDAY
* DRY WITH NO APPRECIABLE RAINFALL IN SITE

DETAILS...

WEDNESDAY...

LARGE HIGH PRESSURE CENTERED OVER NORTHERN NEW ENGLAND WILL RESULT
IN DRY/PLEASANT WEATHER FOR LATE SEPTEMBER.  GIVEN THE POSITIONING
OF THE HIGH PRESSURE SYSTEM...EXPECT EASTERLY WINDS AT THE SURFACE
SO COOLEST TEMPS WILL BE FOUND NEAR THE EASTERN MA COAST.  HIGHS
SHOULD RANGE FROM MAINLY THE 60S...TO PERHAPS NEAR 70 IN THE LOWER
CT RIVER VALLEY.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...

WE WILL HAVE TO KEEP AN EYE ON A LOW PRESSURE SYSTEM THAT WILL BE
EMERGING OFF THE MID ATLANTIC COAST.  HOWEVER...WEAK UPPER LEVEL
FLOW AND A SURFACE HIGH NEARBY ARE NOT FAVORABLE FOR ALLOWING THE
LOW PRESSURE SYSTEM TO TRACK UP THE COAST.  IN ADDITION...WEAK
BAROCLINICITY WILL ALSO LIMIT NORTHWEST AXIS OF QPF SHIELD.
NONETHELESS...THE GFS AND ITS ENSEMBLES INDICATE AT LEAST A LOW RISK
FOR A FEW BRIEF SHOWERS ACROSS OUR SOUTHERN ZONES.  WHETHER OR NOT
THIS COMES TO FRUITION REMAINS TO BE SEEN...BUT CERTAINLY DO NOT
EXPECT ANY APPRECIABLE RAINFALL.

AS FOR HIGH TEMPS ON THURSDAY...ONSHORE FLOW WILL RESULT IN HIGHS IN
THE 60S TO NEAR 70.  AGAIN...MILDEST READINGS WILL BE FOUND ACROSS
THE DISTANT INTERIOR.  LOW TEMPS WED NIGHT AND THU NIGHT SHIELD BE
IN THE 40S...TO THE LOWER 50S.

FRIDAY THROUGH MONDAY...

ANOMALOUS UPPER LEVEL RIDGING TAKES HOLD OF THE NORTHEAST U.S. FROM
FRI INTO EARLY NEXT WEEK.  THIS WILL RESULT IN DRY WEATHER WITH
UNSEASONABLY WARM AFTERNOON/S WITH NEAR RECORD HIGH TEMPS POSSIBLE
THIS WEEKEND. ANOTHER FACTOR THAT MAY HELP IN THIS PROCESS IS THE
VERY DRY GROUND...WHICH MAY ALLOW HIGH TEMPS TO GET A DEGREE OR SO
HIGHER THAN THEY NORMALLY WOULD IN THIS SET UP.

GUIDANCE NUMBERS HAVE LIKELY TRENDED TOO MUCH TOWARDS CLIMATOLOGY.
HIGH TEMPS FRI...SHOULD BE WELL UP INTO THE 70S.  SAT/SUN LOOKS LIKE
THE WARMEST DAYS...WHERE HIGHS WILL PROBABLY REACH 80+ ACROSS THE
LOWER ELEVATIONS AND AREAS AWAY FROM THE COAST.  LOW CONFIDENCE ON
HIGH TEMPS FOR MONDAY...WILL DEPEND WHETHER OR NOT A BACKDOOR COLD
FRONT COOLS US OFF A BIT LIKE THE 12Z ECMWF DEPICTS.  GFS IS STILL
QUITE WARM...BUT OBVIOUSLY WERE A WEEK OUT SO THAT IS UNCERTAIN.  AS
LAST SHIFT POINTED OUT...DRY AIRMASS WILL KEEP HUMIDITY IN CHECK SO
AFTERNOON/S WILL BE NICE FOR OUTDOOR ACTIVITIES.

RECORD HIGH TEMPS THIS WEEKEND INTO NEXT MONDAY:

    SAT 9/27...SUN 9/28...             MON 9/29...

BOS...86...1998         BOS...90...1881         BOS...88...1952
BDL...88...1998         BDL...83...1959         BDL...86...1945
PVD...86...1998         PVD...84...1943         PVD...87...1945
ORH...85...1933         ORH...84...1916         ORH...84...1952

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY NIGHT/...

HIGH CONFIDENCE. VFR. N/NW WIND GUSTS TO 25 KT THIS AFTERNOON...
DIMINISHING TONIGHT. LIGHT WINDS TUE AND TUE NIGHT WITH LOW PROB
OF A SEABREEZE TUE AFTERNOON.

KBOS TERMINAL...HIGH CONFIDENCE. LOW PROB OF A SEABREEZE TUE
AFTERNOON.

KBDL TERMINAL...HIGH CONFIDENCE.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD...OTHER THAN
BRIEF LATE NIGHT/EARLY MORNING PATCHY GROUND FOG IN THE TYPICALLY
PRONE LOCALES.  THERE IS A LOW RISK FOR A BRIEF PERIOD OF MVFR
CONDITIONS NEAR THE SOUTH COAST/CAPE AND ISLANDS WED NIGHT INTO THU
NIGHT.  THIS WILL DEPEND UPON WHETHER A FEW SHOWERS CAN MAKE IT THAT
FAR NORTH WITH AN OFFSHORE LOW PRESSURE SYSTEM.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE.

TONIGHT...GUSTY WINDS WILL GRADUALLY DIMINISH TONIGHT WITH GUSTS
DROPPING BELOW SCA THRESHOLDS THIS EVENING. HOWEVER...SOUTHERLY
SWELL WILL KEEP SEAS ABOVE 5 FT OVER THE OPEN WATERS THROUGH THE
NIGHT SO SMALL CRAFT ADVISORIES WILL CONTINUE HERE.

TUE AND TUE NIGHT...LIGHT WINDS BELOW 15 KT WITH SEAS SUBSIDING
BELOW 5 FT DURING TUE OVER THE OPEN WATERS. LIGHT WINDS AND SEAS
TUE NIGHT.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

MODERATE TO HIGH CONFIDENCE...

THE MAIN CONCERN WILL BE A LOW PRESSURE SYSTEM THAT WILL TRACK NEAR
THE BENCHMARK WED NIGHT INTO THU.  IT WILL LIKELY RESULT IN ENOUGH
SWELL FOR SCA SEAS TO DEVELOPING ACROSS THE SOUTHERN OPEN WATERS WED
NIGHT.  SCA SWELL MAY PERSIST ACROSS THE OUTER WATERS RIGHT INTO FRI
AFTERNOON BEFORE DIMINISHING.

WINDS SHOULD GENERALLY REMAIN BELOW SCA THRESHOLDS THROUGH THE
PERIOD.  HOWEVER...A PERIOD OF NORTHEAST WIND GUSTS OF 20 TO 25
KNOTS ARE POSSIBLE ACROSS THE SOUTHERN WATERS IF COASTAL LOW
PRESSURE TRACKS CLOSE ENOUGH TO OUR REGION.  VISIBILITIES SHOULD BE
GOOD THROUGH MOST IF NOT ALL OF THE PERIOD.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...HIGH SURF ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ020>024.
NH...NONE.
RI...HIGH SURF ADVISORY UNTIL 6 PM EDT THIS EVENING FOR RIZ006>008.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
     ANZ231>234.
     SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ230-
     236-251.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ235-237.
     SMALL CRAFT ADVISORY UNTIL 11 AM EDT TUESDAY FOR ANZ250-
     254>256.

&&

$$
SYNOPSIS...KJC/FRANK
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...FRANK
AVIATION...KJC/FRANK
MARINE...KJC/FRANK


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