Area Forecast Discussion
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000
FXUS61 KBOX 231746
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
146 PM EDT TUE SEP 23 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING DRY WEATHER ALONG WITH MILD DAYS AND
COOL NIGHTS THROUGH WEDNESDAY. COASTAL LOW PRESSURE WELL SOUTH OF
THE REGION MAY GRAZE SOUTH COASTAL AREAS WITH A LOW RISK FOR FEW
SHOWERS THURSDAY AFTERNOON INTO FRIDAY MORNING. HIGH PRESSURE
RETURNS FRIDAY INTO EARLY NEXT WEEK WITH DRY WEATHER AND
UNSEASONABLY WARM AFTERNOONS. IT IS POSSIBLE A FEW RECORD HIGH
TEMPERATURES MAY BE CHALLENGED THIS WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
145 PM UPDATE...
UPDATED T/TD/WIND GRIDS FOR CURRENT OBS/TRENDS...OTHERWISE
FORECAST ON TRACK. SEABREEZES HAVE DEVELOPED ALONG THE SOUTH COAST
BUT NOT YET ALONG THE EAST COAST. STILL A CHANCE A BRIEF SEABREEZE
COULD DEVELOP THIS AFTERNOON.

PREVIOUS DISCUSSION...
CURRENT FORECAST ON TRACK. HIGH PRES IN CONTROL WILL BRING
SUNSHINE...LIGHT WINDS AND MILD TEMPS. THE ONLY CHANGE TO THE
FORECAST WAS AN UPDATE TO THE WINDS TO INTRODUCE A SEABREEZE ALONG
THE COAST. LOW LEVEL WINDS DECREASE BELOW 10 KT THIS AFTERNOON AND
HIRES GUIDANCE IS SHOWING A SEABREEZE DEVELOPING. MAX TEMPS MOSTLY
65-70 DEGREES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...
HIGH PRESSURE 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 MIN TEMPERATURES MOSTLY IN THE 40S. WENT
HIGHER ALONG THE EAST COAST OF MA AS WELL AS THE LARGER URBAN
CENTERS.

WEDNESDAY...
LARGE HIGH PRESSURE CENTERED OVER NORTHERN NEW ENGLAND WILL
RESULT IN DRY/PLEASANT WEATHER FOR LATE SEPTEMBER. GIVEN THE
POSITIONING OF THIS HIGH PRESSURE...STILL EXPECTING EASTERLY
WINDS AT THE SURFACE. SO LOWEST TEMPERATURES 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.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...

* LOW RISK OF A FEW SHOWERS NEAR THE SOUTH COAST THU INTO FRI
  MORNING
* UNSEASONABLY WARM AFTERNOONS THIS WEEKEND
* DRY WITH NO APPRECIABLE RAINFALL IN SIGHT

OVERVIEW AND MODEL PREFERENCES...

MEDIUM RANGE OPERATIONAL MODELS START OFF IN PRETTY GOOD
AGREEMENT...THEN HAVING DIFFICULTIES RESOLVING LOW PRES OFF THE
MID ATLC COAST AND ITS POSSIBLE SHIFT TO THE N SOMETIME DURING THE
THURSDAY INTO FRIDAY TIMEFRAME. QUESTION IS WHETHER E-W ORIENTED
RIDGE AXIS ACROSS CENTRAL NEW ENGLAND LIFTS FAR ENOUGH N TO ALLOW
MOISTURE TO WORK INTO AT LEAST SOUTHERN PORTIONS OF THE REGION.
DUE TO THE DIFFERENCES...USED A BLEND OF AVAILABLE GUIDANCE AND
ENSEMBLES TO INCORPORATE WIDE RANGE OF POSSIBILITIES...THOUGH
LEANED TOWARD A DRIER SOLUTION.

BEYOND THIS...MODEL TRENDS CONTINUE TO SHOW HIGH AMPLITUDE H5 RIDGE
CENTERED ACROSS THE CENTRAL U.S. WITH MAIN STORM TRACK ACROSS HUDSON
BAY THROUGH MOST OF THE WEEK. NOTING A H5 SHORT WAVE IN THIS FLOW
DURING NEXT WEEKEND...WITH RIDGING POSSIBLY RETROGRADING TO THE
PLAINS STATES WHILE THE SHORT WAVE WORKS INTO THE GULF OF ST.
LAWRENCE AND SOUTHERN TIP OF GREENLAND. HAVE NOTED THAT THE CPC NAO
GUIDANCE CURRENTLY HAS POSITIVE NAO THAT STARTS TO TREND MORE
NEGATIVE TOWARD THE END OF THE MONTH...AROUND THE TIMEFRAME OF THIS
SHORT WAVE. H5 HEIGHTS MAY LOWER NEXT WEEKEND...WITH A POSSIBLE COLD
FRONT TRYING TO SHIFT S OUT OF QUEBEC.

TOWARD THE END OF THE FORECAST...CONTINUED TO USE A BLEND OF
AVAILABLE GUIDANCE INTO THE WEEKEND...THEN TRENDED TOWARD THE
ENSEMBLE MEANS.

DETAILS...

WEDNESDAY NIGHT...

E-W RIDGE AXIS REMAINS CLOSE TO THE MA/NH/VT BORDER DURING THE
NIGHT WITH GENERAL E-SE WIND FLOW IN PLACE. QUESTION AT THIS POINT
WILL WHETHER MOISTURE STARTS TO WORK N FROM LOW PRES NEAR THE
DELMARVA PENINSULA. MODELS HAVING A VERY DIFFICULT TIME HANDLING
THIS FEATURE...THOUGH 00Z GFS/GGEM ARE MORE AGGRESSIVE IN BREAKING
DOWN THE RIDGE AND PUSHING PRECIP IN...WHILE 00Z ECMWF HOLDS
PRECIP TO THE S. LEANED MORE TOWARD THE DRIER SOLUTION AND HOLDING
THE RIDGE IN. DO INCREASE THE CLOUDS DURING THE NIGHT THOUGH.
EXPECT OVERNIGHT LOWS MAINLY IN THE 40S...THOUGH HOLDING IN THE
LOWER-MID 50S ALONG THE IMMEDIATE COAST.

THURSDAY THROUGH FRIDAY...

CONTINUE TO KEEP A WEARY EYE ON THE PERSISTENT LOW PRES NEAR THE
DELMARVA PENINSULA DURING THIS TIMEFRAME. GFS/GGEM REMAIN
AGGRESSIVE IN BRINGING GOOD SLUG OF PRECIP ACROSS THE REGION
DURING THIS TIMEFRAME. WITH THIS RUN...THE EC IS ALSO BRINGING
SOME PRECIP IN ACROSS SOUTHERN AREAS...BUT KEEPING HEAVIEST QPF TO
THE S. ALL MODELS KEEP THE LOW RATHER WEAK AND NEAR OR S OF 40N
LATITUDE. AGREE WITH PREVIOUS FORECAST...WITH A RATHER WEAK UPPER
FLOW IN PLACE WILL BE TOUGH TO BRING APPRECIABLE PRECIP INTO THE
REGION.

ANOTHER ASPECT TO CONSIDER WILL BE THE POSSIBILITY OF INCREASING
E TO NE WINDS WITH BROAD INVERTED TROUGH THAT MAY DEVELOP AS THE
LOW PASSES. FOR NOW...KEPT STRONGEST WINDS MAINLY OVER THE COASTAL
WATERS...BUT COULD ALSO SHIFT N WITH THE PRECIP.

DID BRING SLIGHT CHANCE POPS INTO N CT/RI/SE MA FOR NOW...BUT
AGAIN WILL NEED TO MONITOR THE PROGRESS OF THIS SYSTEM.

WITH THE COOL ONSHORE FLOW...EXPECT HIGHS ONLY IN THE 60S TO
AROUND 70 ON THURSDAY...THOUGH COULD WARM TO THE LOWER-MID 70S
AWAY FROM THE COAST ON FRIDAY DEPENDING UPON WHEN THE LOW PASSES
AND WINDS BACK TO A LIGHT NORTHERLY DIRECTION. LOWS THU NIGHT WILL
RANGE FROM THE MID 40S WELL INLAND TO THE MID-UPPER 50S ALONG THE
SHORE.

FRIDAY NIGHT THROUGH MONDAY...

HIGH AMPLITUDE H5 RIDGE REMAINS ACROSS THE EASTERN AND CENTRAL
U.S. THROUGH MOST OF THIS PERIOD. EXPECT DRY CONDITIONS WITH MILD
TEMPERATURES ESPECIALLY DURING THE WEEKEND. MAY SEE RECORD HIGHS
ON SATURDAY AND/OR SUNDAY. MODELS TRY TO LOWER H5 HEIGHTS ACROSS
CENTRAL AND SOUTHERN QUEBEC INTO THE REGION DURING MONDAY ALONG
WITH A COLD FRONT...BUT TIMING IS IN QUESTION. DID HOLD TEMPS BACK
A BIT FOR NOW...MAINLY IN THE 70S.

ONLY QUESTION WILL BE ON MONDAY...AS MODELS TRY TO PUSH A COLD
FRONT OUT OF QUEBEC TOWARD THE REGION. TIMING IS IN QUESTION
THOUGH.

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 /18Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

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

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

VFR...BUT ISOLD FOG POSSIBLE LATE TONIGHT AND WED NIGHT IN THE
INTERIOR VALLEYS. ANY RAIN SHOULD REMAIN S OF NEW ENGLAND THROUGH
WED NIGHT.

KBOS TERMINAL...HIGH CONFIDENCE. STILL A CHANCE A SEABREEZE WILL
DEVELOP BUT CONFIDENCE IS LOW.

KBDL TERMINAL...HIGH CONFIDENCE.

OUTLOOK...THURSDAY THROUGH SATURDAY...

HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE PERIOD.  MAY SEE
TYPICAL 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 LATE WED NIGHT INTO FRIDAY MORNING.
THIS WILL DEPEND UPON WHETHER A FEW SHOWERS CAN MAKE IT INTO
THAT PORTION OF THE REGION WITH OFFSHORE LOW PRESSURE.

&&

.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.

WINDS AND SEAS CONTINUE TO DIMINISH ACROSS ALL COASTAL WATERS
TODAY AS HIGH PRESSURE MOVES IN. SMALL CRAFT ADVISORIES WERE
DISCONTINUED. RATHER TRANQUIL BOATING CONDITIONS EXPECTED
THROUGH WEDNESDAY. SEAS MAY BUILD ABOVE 5 FEET ACROSS THE
SOUTHERN OUTER COASTAL WATERS LATE WEDNESDAY...BUT THE TIMING IS
NOT CERTAIN.

OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...

WEDNESDAY NIGHT...HIGH CONFIDENCE.  WINDS AND SEAS BELOW SMALL
CRAFT...THOUGH MAY BEGIN TO BUILD LATE WED NIGHT ON SOUTHERN
OUTER WATERS.

THURSDAY THROUGH FRIDAY...MODERATE CONFIDENCE. LOW PRES WILL PASS
S OF THE 40N/70W BENCHMARK LATE THU NIGHT OR FRI MORNING. LOOKS
LIKE E TO NE WINDS WILL GUST UP TO 25 KT MAINLY ON THE OUTER
WATERS FROM E OF CAPE COD TO THE SOUTHERN WATERS. SWELLS MAY BUILD
UP TO 6-8 FT. THIS IS DEPENDENT UPON HOW FAR N THE LOW WILL PUSH
BEFORE MOVING OFFSHORE.

FRIDAY NIGHT-SATURDAY...HIGH CONFIDENCE. WINDS BACK TO N AND
DIMINISH. LEFTOVER SEAS OF AROUND 5 FT FRI NIGHT SHOULD SUBSIDE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BELK/EVT
NEAR TERM...KJC
SHORT TERM...BELK
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...BELK/EVT



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