Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 221411
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1011 AM EDT FRI AUG 22 2014

.SYNOPSIS...
THE THREAT FOR SHOWERS WILL CONTINUE...ESPECIALLY ACROSS THE WEST
THROUGH TONIGHT. DRIER AND COOLER WEATHER FOLLOWS THIS WEEKEND. A
WARM-UP IS POSSIBLE NEXT WEEK PRIOR TO AN UNSETTLED PATTERN AHEAD
OF A FRONTAL BOUNDARY SWEEPING SOUTH OUT OF CANADA.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
MID LEVEL TROF AXIS HANGING ACROSS NORTHERN NEW ENG WITH WEAK
IMPULSES ROTATING AROUND THE TROF. MORNING SHOWER ACTIVITY HAS
DECREASED IN COVERAGE WITH JUST A FEW SHOWERS REMAINING OVER THE
OUTER CAPE AND SE MA. HI RES GUIDANCE INDICATING MAIN FOCUS FOR
ADDITIONAL SHOWERS THIS AFTERNOON WILL BE ACROSS W NEW ENG WHERE
DEEPER MOISTURE EXISTS. NO SFC INSTABILITY TO SPEAK OF AS SNE
REMAINS UNDER INFLUENCE OF MARITIME AIRMASS WITH HIGH PRES NOSING
DOWN FROM E CANADA. INSTABILITY AXIS WILL REMAIN WELL TO THE WEST.
IT WILL BE A COOL DAY UNDER THE CLOUD COVER WITH TEMPS REMAINING
MOSTLY IN THE 60S IN THE INTERIOR...BUT LOW 70S IN THE LOWER CT
VALLEY AND PORTIONS OF RI/SE MA WHERE SOME THINNING OF CLOUD
COVER POSSIBLE.


&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
AM NOTING SIMILAR SETUP AS THU NIGHT. ANOTHER WEAK SHORTWAVE WILL
PUSH N-S ACROSS THE REGION AND PHASE WITH OFFSHORE LONGWAVE TROF
CONNECTED TO CUTOFF IN ATLANTIC CANADA. TWO CONDITIONS ARE
DIFFERENT HOWEVER...PWATS ARE A BIT LOWER /1.0-1.25 INCHES AS
OPPOSED TO 1.5/ AND K INDEX VALUES ARE LOWER AS DRIER AIR INTRUDES
THROUGH THE COLUMN FROM THE TOP DOWN. THEREFORE...SAVE FOR THE
ADVECTION OF LEFTOVER CONVECTION FROM THE W...SUSPECT THAT -SHRA
ARE LIKELY TO BE A BIT WEAKER AND LESS WIDESPREAD THAN THU NIGHT.
HOWEVER...WILL STILL MAINTAIN AT LEAST CHANCE POPS ESPECIALLY FOR
W AND NW PORTIONS OF THE FORECAST AREA.

ONE OTHER ISSUE IS FOG AND/OR LOW CIGS MOVING INTO E PORTIONS OF
THE FORECAST AREA. GUIDANCE CONTINUES TO NOTE AN AREA OF MOISTURE
BACKING IN FROM THE GULF OF MAINE OVERNIGHT THANKS TO CONTINUED
ELY COMPONENT OF THE FLOW. DO NOTE IN BUFKIT PROFILES THAT THERE
IS A LAYER OF DRY AIR ABOVE THE SFC WHICH MAY NEGATE FOG
DEVELOPMENT...ESPECIALLY IF STRATUS BACKS IN...LIMITING RADIATIVE
PROCESSES. THEREFORE...WILL MAINLY MENTION LOW CLOUDS...BUT MAY
NEED TO MONITOR FOR DRIZZLE WITH DRIER MOVING IN OVER MOISTURE
POOLING IN THE LOW-MID LVLS. SHOULD SOME AREAS RADIATE...FOG
REMAINS A RISK.

SAT...
ONE LAST PARTING SHOT FOR SHOWERS SAT AS SHORTWAVE ENERGY FORCES
SOME DIGGING AND SOUTHWARD PROGRESSION OF THE OFFSHORE LONGWAVE
TROF. LEFTOVER MOISTURE COMBINED WITH COOLING TEMPS ALOFT ARE
LIKELY TO LEAD TO A FAIR AMOUNT OF CLOUD COVER DURING THE EARLY
HALF OF THE DAY...ALONG WITH SHOWERS ESPECIALLY FROM PORTIONS OF
THE MERRIMACK VALLEY E AND POINTS SE. HOWEVER...IMPROVEMENT BY THE
AFTERNOON LOOKS POSSIBLE THANKS TO GRADUALLY RISING HEIGHTS FROM
THE S SHIFT IN THE TROF. THIS WILL ALLOW SFC INVERTED RIDGING TO
GRADUALLY REGAIN CONTROL ACROSS THE REGION TOWARD EVENING. IN
FACT...DESPITE THE CLOUDY START TO THE DAY...ITS POSSIBLE MANY
LOCATIONS STILL GET TO SEE THE SUNSET /EVEN IN THE E WHICH WILL
LIKELY TAKE THE LONGEST TO BREAK OUT/. HIGHS REMAIN ON THE COOL
SIDE OF NORMAL THANKS TO THE EARLY CLOUD COVER LIMITING DIURNAL
INFLUENCE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...

* QUIET WEATHER EXPECTED THROUGH MUCH OF THIS PERIOD
* UNCERTAINTY INCREASES MIDDLE OF NEXT WEEK WITH AN APPROACHING
  FRONT

21/00Z MODELS ARE IN GOOD AGREEMENT THROUGH ABOUT TUESDAY. THEN
SIGNIFICANT DIFFERENCES ARISE FOR THE LATTER HALF OF NEXT WEEK...
MAKING FOR A LOWER CONFIDENCE FORECAST FROM THE MIDDLE OF NEXT WEEK
ONWARD.

A PERSISTENT UPPER LEVEL TROUGH OVER THE NORTHEAST WILL SLOWLY MAKE
ITS WAY EAST...MOVING JUST OFFSHORE THIS WEEKEND AS AN UPPER LEVEL
RIDGE TRIES TO PUSH NORTHEASTWARD FROM THE SOUTHERN USA. THIS UPPER
TROUGH IS RATHER PERSISTENT THOUGH...WITH EACH SUCCESSIVE MODEL RUN
LINGERING THIS TROUGH OVER THE NORTH ATLANTIC LONGER AND LONGER.

COOLER...LESS SEASONABLE WEATHER IS EXPECTED WHILE HIGH PRESSURE IN
QUEBEC WILL KEEP THINGS RELATIVELY DRY. STILL AGREE WITH THE
PREVIOUS FORECASTER...THINKING 21/00Z GUIDANCE CONTINUES TO STRUGGLE
WITH CONVECTIVE FEEDBACK INTO EARLY NEXT WEEK. AS SUCH...KEPT A DRY
FORECAST ACROSS MOST OF SOUTHERN NEW ENGLAND.

A HIGH PRESSURE WILL SINK SOUTH INTO EARLY NEXT WEEK...EVENTUALLY
MOVING SOUTH AND EAST OF SOUTHERN NEW ENGLAND AND RETURNING US TO A
MORE WESTERLY FLOW. A LOW PRESSURE IN ONTARIO MAY EVENTUALLY MOVE
EAST INTO QUEBEC...SWINGING A COLD FRONT THROUGH SOUTHERN NEW
ENGLAND WEDNESDAY OR THURSDAY. THIS IS WHERE MODELS START TO DIVERGE
MORE SIGNIFICANTLY.

THE ECMWF LOOKS A BIT QUICKER THAN THE GFS WITH THE APPROACH OF THIS
FRONT...BUT NEITHER IS AS PROGRESSIVE AS THE CANADIAN. WILL TAKE A
BLENDED APPROACH WITH THE TIMING FOR NOW.  GIVEN THE STRENGTH OF THE
SURFACE RIDGE EXPECTED TO BE NEAR THE COAST...WOULD NOT BE OVERLY
SURPRISED IF THE ULTIMATE TIMING TURNS OUT TO BE SLOWER THAN THE
GFS. DEPENDING ON AVAILABLE MOISTURE...WE COULD SEE SOME SHOWERS AND
THUNDERSTORMS AHEAD OF THIS FRONT.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM...THROUGH SATURDAY...MODERATE CONFIDENCE.

TODAY INTO TONIGHT...
CONDITIONS IMPROVE TO VFR MOST LOCATIONS THROUGH THE DAY...
ALTHOUGH MVFR CIGS ARE POSSIBLE ESPECIALLY FROM THE WORCESTER
HILLS WESTWARD. SCT SHOWERS POSSIBLE IN THIS REGION AS WELL. BY
TONIGHT...SHOWERS DISSIPATE BUT THERE MAY BE MORE WIDESPREAD FOG
IN THE W AND THE POSSIBILITY OF LOWER CIGS IN THE E.
THEREFORE...COMPLEX OVERNIGHT SCENARIO...WHERE SOME OCCASIONAL
MVFR/IFR CONDITIONS ARE POSSIBLE.

SAT...
CONDITIONS IMPROVE TO VFR ALL LOCATIONS EXCEPT MAYBE AREAS E OF
THE WST-ORH-AFN...WHERE SOME MVFR CONDITIONS MAY LINGER INTO THE
DAY IN LOW CIGS. BY AFTERNOON...LIKELY TO SEE VFR ALL LOCATIONS.

KBOS TERMINAL...MODERATE CONFIDENCE. MAINLY VFR TODAY EXCEPT FOR
OCCASIONAL SHOWERS AND MVFR THIS MORNING. OVERNIGHT...EASTERLY
FLOW COULD YIELD A PERIOD OF LOW CLOUDS WITH MVFR/IFR CIGS
POSSIBLE. SHOULD THESE BE ESTABLISHED...ITS POSSIBLE THEY LINGER
INTO THE MORNING HOURS SAT.

KBDL TERMINAL...MODERATE CONFIDENCE. MVFR/VFR MAY BOUNCE BACK AND
FORTH THROUGH THE MORNING WITH SHOWERS. BY AFTERNOON...CONDITIONS
IMPROVE TO VFR AND MAY STAY THAT WAY THEREAFTER.

OUTLOOK...SATURDAY THROUGH TUESDAY...

HIGH CONFIDENCE VFR. LOW PROBABILITY OF PATCHY MVFR/IFR FOG EACH
NIGHT.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT-TERM...THROUGH SATURDAY...HIGH CONFIDENCE.

E TO NE FLOW WILL CONTINUE INTO SAT AS HIGH PRES TO THE NE SLOWLY
REGAINS CONTROL. THROUGH THE DAY TODAY AND NIGHT TONIGHT...PERIODS
OF WIND GUSTS OF 15-20 KT ARE POSSIBLE AT TIMES WITH A SLOWLY
BUILDING SWELL. SEAS SHOULD REMAIN BELOW 4 FT EVEN ON THE SE AND S
WATERS. THEREFORE...NO SMALL CRAFT HEADLINES. SOME FOG AND SHOWERS
ARE POSSIBLE ON THE WATERS AT TIMES AS WELL...MAINLY THIS
MORNING...AND ONCE AGAIN OVERNIGHT.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

HIGH CONFIDENCE.

HIGH CONFIDENCE. QUIET BOATING WEATHER IS EXPECTED FOR MUCH OF THIS
PERIOD WITH HIGH PRESSURE ACROSS THE REGION. SEAS COULD APPROACH 5
FT ACROSS THE OUTERMOST SOUTHERN COASTAL WATERS THIS WEEKEND. NOT
ENOUGH CONFIDENCE TO ISSUE A SMALL CRAFT ADVISORY THOUGH. LOW
PROBABILITY OF PATCHY OVERNIGHT FOG LIMITING VISIBILITIES.

&&

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

&&

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



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