Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 062334
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
634 PM EST FRI MAR 6 2015

.SYNOPSIS...
ARCTIC HIGH PRES WILL BUILD TO THE MID ATLANTIC COAST TONIGHT
BEFORE HEADING OFFSHORE THIS WEEKEND ALLOWING TEMPERATURES TO
MODERATE. TWO WEAK FRONTS MAY BRING A PERIOD OF SNOW SHOWERS OR
FLURRIES...FIRST SAT NIGHT INTO SUN AND AGAIN MONDAY. NEXT WEEK
MAINLY DRY WEATHER PREVAILS ALONG WITH TEMPS WARMING TO NEAR
NORMAL...BUT TURNING COLDER TOWARD THE END OF THE WEEK..

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...

634 PM UPDATE...

NO MAJOR CHANGES TO THE PREVIOUS FORECAST. DID TWEAK THE NEXT FEW
HOURS TO REFLECT OBSERVED TRENDS.

PREVIOUS DISCUSSION...

HIGH PRESSURE OVER THE MID ATLANTIC WILL KEEP SKIES CLEAR AND
WINDS CALM TONIGHT. THIS WILL RESULT IN A NIGHT OF EXCELLENT
RADIATIONAL COOLING. TEMPERATURES WILL PLUMMET INTO THE SINGLE
DIGITS AND TEENS. THERE IS SOME QUESTION AS TO WHETHER A DECK OF
HIGH CLOUDS MOVES IN OVERNIGHT. IF THIS OCCURS...IT MAY LIMIT THE
EXTENT TO WHICH TEMPERATURES DROP.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
HIGH PRESSURE MOVES OFFSHORE THE MID ATLANTIC AS LOW PRESSURE MOVES
THROUGH QUEBEC.  THE MODELS OFFER SOME VARIATION ON THE TRACK OF THE
LOW AND ITS ATTENDANT COLD FRONT...SOME KEEPING THE FRONT NORTH OF
SOUTHERN NEW ENGLAND AND OTHERS BRINGING IT THROUGH SOUTHERN NEW
ENGLAND.  THIS WILL PLAY A ROLE IN WHETHER WE SEE ANY SNOW SHOWERS
SATURDAY NIGHT AS A MID LEVEL SHORTWAVE CROSSES OVER OR NORTH OF
SOUTHERN NEW ENGLAND. HAVE OPTED TO KEEP SLIGHT CHANCE TO LOW END
CHANCE POPS IN THE FORECAST FOR THIS POSSIBILITY.  ANY SNOW SHOWERS
THAT DEVELOP SHOULD PRODUCE LESS THAN AN INCH OF SNOW IN ANY ONE
LOCATION.  TEMPERATURES WILL MODERATE SATURDAY BUT WILL REMAIN ABOUT
10 DEGREES BELOW NORMAL.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...

* TEMPERATURES...MODERATING TO NEAR NORMAL DURING THE FIRST HALF OF
  NEXT WEEK....THEN TURNING COLDER TOWARD THE END OF NEXT WEEK.

* PRECIPITATION...RELATIVELY DRY WITH ANY PRECIPITATION EVENTS
  REMAINING VERY MINOR.

OVERVIEW...

06/12Z MODELS REMAIN IN FAIRLY GOOD AGREEMENT ON THE OVERALL PATTERN
DURING THIS PORTION OF THE FORECAST. EASTERN PACIFIC RIDGE AND
DOWNSTREAM LONGWAVE TROF WILL PREVAIL OVER THE GREAT LAKES AND NEW
ENGLAND INTO EARLY NEXT WEEK...WITH A FEW WEAK SHORTWAVES ROTATING
THROUGH THIS FLOW PATTERN. TOWARD MIDWEEK...THE MID-LEVEL FLOW
DEAMPLIFIES...ALLOWING PACIFIC MODIFIED AIR TO MOVE INTO NEW
ENGLAND. THE RESULT SHOULD BE SEASONABLE TEMPERATURES. HOWEVER...MORE
UPSTREAM SHORTWAVES WILL REAMPLIFY THE NORTHERN STREAM WITH A
RETURN TO COLDER TEMPERATURES TOWARD THE END OF NEXT WEEK. WITH A
NEARLY ZONAL FLOW TO THE NORTHERN STREAM...TIMING THESE SHORTWAVES
IS PROBLEMATIC THIS FAR OUT IN TIME. BASED THIS FORECAST ON A
CONSENSUS BLEND FROM SUNDAY ONWARD TO SMOOTH OVER THE MINOR
DIFFERENCES.

SUNDAY THROUGH MONDAY...A SERIES OF WEAK SHORTWAVES ROTATING
THROUGH THE FLOW WILL BRING A CHANCE OF A FEW SNOW SHOWERS OR
FLURRIES EARLY SUNDAY...AND AGAIN ON MONDAY. MOST OF THIS TIME
PERIOD WILL BE DRY. TEMPERATURES MODERATING...BUT REMAINING BELOW
NORMAL.

TUESDAY INTO WEDNESDAY...MODERATING TEMPERATURES...BUT EXTENT OF
WARMING TUESDAY WILL LIKELY BE LIMITED BY A POTENTIAL LOW LEVEL
INVERSION. WILL ALSO HAVE TO WATCH AN OFFSHORE LOW PRESSURE
TUESDAY...AS THE NORTHERN EDGE OF THE PRECIPITATION SHIELD COULD
COME CLOSE TO THE IMMEDIATE SOUTH COAST. LOW CONFIDENCE
TEMPERATURE FORECAST WEDNESDAY...AS THERE ARE MORE TIMING
DIFFERENCES WITH THE PASSAGE OF A COLD FRONT.

THURSDAY AND FRIDAY...COLDER...WITH BELOW NORMAL TEMPERATURES
BEHIND A COLD FRONT AS A STRONG HIGH PRESSURE ARRIVES FROM THE
NORTHWEST.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE THROUGH SAT NIGHT.

VFR. LOW PROBABILITY OF SCT-BKN020-030 CAPE AND ISLANDS EARLY
THIS EVENING. INCREASING MID/HIGH CLOUDS SAT...WITH CIGS AOA 080.

KBOS TAF...HIGH CONFIDENCE.

KBDL TAF...HIGH CONFIDENCE.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE CONFIDENCE.

MAINLY VFR. BRIEF MVFR CIGS/VSBYS POSSIBLE SUNDAY...AND AGAIN
MONDAY IN WIDELY SCATTERED SNOW SHOWERS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

HIGH CONFIDENCE THROUGH SATURDAY NIGHT.  HIGH PRESSURE OVER THE MID-
ATLANTIC WILL PROVIDE FOR CALM WINDS AND SEAS THROUGH MIDDAY
SATURDAY.  AS HIGH PRESSURE MOVES AWAY FROM THE REGION...SEAS AND
WINDS WILL BUILD JUST BARELY TO SMALL CRAFT LEVELS.  SMALL CRAFT
CONDITIONS LAST LONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY FOR
SATURDAY AFTERNOON AND EVENING BUT IT IS MARGINAL.

OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE CONFIDENCE.

SUNDAY INTO MONDAY...LINGERING ROUGH SEAS ACROSS THE OUTER COASTAL
WATERS GRADUAL SUBSIDE SUNDAY INTO SUNDAY NIGHT. THERE IS A LOW
PROBABILITY FOR WESTERLY 25 KT GUSTS MONDAY AFTERNOON AND EVENING.

TUESDAY AND WEDNESDAY...CONDITIONS MAINLY BELOW SMALL CRAFT
ADVISORY LEVELS. LOW PROBABILITY FOR 5 FOOT SEAS TO DEVELOP ACROSS
THE OUTER COASTAL WATERS AS A STORM PASSES BY TO OUR SOUTH
TUESDAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM EST SATURDAY TO 4 AM EDT SUNDAY
     FOR ANZ250-254>256.

&&

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


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