Area Forecast Discussion
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000
FXUS61 KBOX 180811
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
411 AM EDT SAT APR 18 2015

.SYNOPSIS...

MILDER WEATHER RETURNS TODAY AHEAD OF A DRY COLD FRONT WHICH MOVES
THROUGH DURING THE AFTERNOON. CANADIAN HIGH PRESSURE BRINGS MUCH
COOLER WEATHER TONIGHT AND SUNDAY. THEN A COASTAL LOW DELIVERS A
WIND SWEPT SOAKING RAIN TO THE REGION MON AFTERNOON AND NIGHT. MILD
WEATHER TUE ALONG WITH A DRYING TREND. THEN MID TO LATE WEEK THE
TREND WILL BE TOWARD MUCH COOLER WEATHER TEMPERATURES ALONG WITH THE
RISK OF MAINLY DIURNAL SCATTERED SHOWERS.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

YESTERDAYS CONVECTIVE FORECAST SURELY NOT PLAYING OUT ACROSS NE MA
AS THE CONSENSUS OF FORECAST GUIDANCE HAS NUDGED THE SE SWEEPING
POTENT MID-LEVEL IMPULSE FURTHER NE ACROSS NH/ME. THIS TAKES THE
BETTER INSTABILITY AND MOISTURE OUT OF THE EQUATION ALONG WITH THE
LIKELIHOOD OF WET WEATHER. WILL STILL KEEP WITH CHANCE POPS FOR N/NE
MA.

OTHERWISE FOCUS IS ALONG COLD FRONT PARENT TO SE SWEEPING IMPULSE
AND THE ELEVATED FIRE WEATHER POTENTIAL. THE FRONT ANTICIPATED TO
SWEEP S NEW ENGLAND DURING THE AFTERNOON HOURS WILL BE ACCOMPANIED
BY COOLER AND DRIER AIR USHERED BY BLUSTERY NW-WINDS. WITH THE
LOCAL ENVIRONMENT ALONG AND AHEAD WARMING INTO THE LOW-70S AT THE
SURFACE...EXPECT THE BOUNDARY-LAYER TO BECOME WELL-MIXED UP TO H7
ALLOWING FOR THE MIX-DOWN OF DRIER AIR AND FASTER MOMENTUM TO THE
SURFACE WITH AFTERNOON FRONTAL PASSAGE. SUBSEQUENTLY...EXPECTING
MINIMUM RELATIVE HUMIDITY TO DROP AS LOW AS 20 PERCENT AS
SUSTAINED WINDS APPROACH 20 MPH /ESPECIALLY ALONG THE HIGH
TERRAIN/ WITH GUSTS UP TO 30 MPH. SEA-BREEZES ALONG THE E-COAST
PRIOR TO COLD FRONTAL PASSAGE SHOULD BE EASILY SCOURED OUT BY THE
STRONG NW-FLOW...BUT THAT TAKING PLACE CLOSER TO EVENING.

SO BETTER CHANCES FOR ELEVATED FIRE WEATHER POTENTIAL IS ACROSS
THE REGION WHICH WAS IN THE FIRE WEATHER WATCH WHICH HAS NOW BEEN
CONVERTED TO A RED FLAG WARNING FOR THE STATE OF CT...WITH A
SPECIAL WX STATEMENT FOR ALL OTHER LOCALES PREVIOUSLY ADDRESSED IN
THE WATCH. PLEASE SEE THE FIRE WX DISCUSSION BELOW FOR MORE
DETAILS.

HIGHS ACROSS THE REGION AROUND THE LOW-70S WITH WARMEST CONDITIONS
OVER THE LOWER CT-VALLEY WITH HIGHS AROUND THE MID-70S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...

SATURDAY NIGHT...

N/NW-WINDS DIMINISHING DIMINISHING AS HIGH PRESSURE BUILDS ACROSS
THE REGION. EARLIER H925 +14C TEMPERATURES DROP TO NEAR THE FREEZING
MARK OVERNIGHT. BECOMING MOSTLY CLEAR...EXPECT A CHILLY NIGHT WITH
LOWS DROPPING DOWN TO AROUND THE UPPER-30S TO LOW-40S. EXPECT ACROSS
THE HIGH TERRAIN FOR LOWS TO DROP INTO THE LOW-30S.

SUNDAY...

HIGH PRESSURE PUSHES THROUGH THE REGION AND OFFSHORE. COOLER AIRMASS
STILL IN PLACE WITH H925 TEMPERATURES +4-6C. DESPITE THIN HIGH CLOUD
INCREASING TOWARDS THE LATER HALF OF THE DAY AHEAD OF MONDAYS WET WX
EXPECT HIGHS ACROSS THE INTERIOR INTO THE LOW-60S...COOLER ALONG THE
SHORES WITH ANTICIPATED VEERING E/SE ONSHORE FLOW OFF THE CHILLY
WATERS. HIGHS AROUND THE MID-50S.

&&

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

HIGHLIGHTS...

* MON/MON NGT...WIND SWEPT SOAKING RAIN
* TUE...DRYING TREND AND MILD
* WED-FRI...COOLER WITH PERIODS OF SHOWERS MID TO LATE NEXT WEEK

SYNOPTIC OVERVIEW...

BOTH GEFS AND EPS ENSEMBLE TELECONNECTIONS SUPPORT A TYPICAL SPRING-
LIKE BLOCKY UPPER AIR PATTERN NEXT WEEK WITH NAO AND AO BECOMING
FAIRLY NEGATIVE ESPECIALLY THE NAO. IN ADDITION THE PNA REMAINS
POSITIVE BUT MORE IMPORTANTLY THE EPO BECOMES VERY NEGATIVE. THUS A
VERY STRONG SIGNAL FOR A TREND TOWARD COOLER AND UNSETTLED WEATHER
HERE IN NEW ENGLAND MID TO LATE NEXT WEEK. THIS PATTERN CHANGE WILL
KICK-OFF WITH STREAMS MERGING LATE SUN/SUN NGT...SENDING SOUTHERN
STREAM MOISTURE UP THE EASTERN SEABOARD MON/MON NGT INTO NEW
ENGLAND. ANOMALOUS PWAT AND WIND ANOMALIES WITHIN THIS MOIST/WARM
CONVEYOR BELT WILL RESULT IN A PERIOD OF HEAVY WIND SWEPT RAIN AS
TRIPLE POINT LOW RIDES THE COASTLINE.

DAILY DETAILS...

* SUNDAY NIGHT...RIDGING OVER THE AREA SLOWLY RETREATS OFFSHORE. DRY
  WEATHER PREVAILS BUT INCREASING CLOUDS.

* MONDAY...NAM...GFS AND GEFS HAVE SPED UP ONSET OF PRECIP WITH RAIN
  OVERSPREADING THE AREA DURING THE MORNING. HOWEVER NON NCEP MODELS
  SUCH AS ECENS ENSEMBLES ALONG WITH EC AND UKMET ARE SLOWER WITH
  PRECIP ARRIVING LATE MORNING/EARLY AFTERNOON FROM WEST TO EAST.
  GIVEN AMPLIFYING UPPER AIR PATTERN A SLOWER ONSET SEEMS
  REASONABLE. GIVEN TIME RANGE A MODEL BLEND OF POPS APPEARS
  PRUDENT. THUS THINKING MARATHON BEGINS DRY BUT INCREASING CHANCES
  OF RAIN FROM MIDDAY ONWARD. A SOAKING WIND SWEPT RAIN REMAINS
  LIKELY AS TRIPLE POINT LOW MOVES UP THE COASTLINE ACTING ON PWATS
  +2 STANDARD DEVIATIONS /SD/ ABOVE CLIMO ALONG WITH STRONG ATLC
  INFLOW WITH WIND ANOMALIES +3 SD FROM CLIMO. THIS WILL YIELD A
  HIGH PROBABILITY FOR A WIDESPREAD RAINFALL APPROACHING 1" WITH A
  LOW TO MODERATE PROBABILITY OF RAINFALL UP TO 1.5". AS FOR
  WINDS...SOUNDINGS BECOME INVERTED WITH STRONG LOW LEVEL WARM AIR
  ADVECTION. HOWEVER BEFORE THIS OCCURS BLYR IS INITIALLY COOL
  DURING THE MORNING AND MODEL SOUNDINGS SUGGEST SE WINDS IN THE
  MORNING COULD GUSTS UP TO 40 MPH.

* TUESDAY...COULD TURN OUT TO BE A DECENT AFTERNOON PENDING EXACT
  TIMING ON DEPARTURE OF MID LEVEL TROUGH AND ASSOCIATED DEEP LAYER
  MOISTURE. APPEARS RISK OF MORNING SHOWERS WITH COLUMN DRYING
  DURING THE AFTERNOON FROM SOUTH TO NORTH. COLD AIR ADVECTION HOLDS
  OFF TIL LATE IN THE DAY OR AT NIGHT. THUS IF SUNSHINE BREAKS OUT
  IN THE AFTN COULD SEE TEMPS JUMP WELL INTO THE 60S TO NEAR 70.

* WEDNESDAY THRU FRIDAY...MUCH COOLER AS GREAT LAKES MID LEVEL LOW
  TRAVERSES EASTWARD INTO NORTHERN NEW ENGLAND. COLD POOL COMBINED
  WITH CYCLONIC FLOW ALOFT WILL YIELD A RISK OF SHOWERS AT TIMES
  ESPECIALLY DIURNALLY DRIVEN. NOT EXPECTING RAIN ALL THE TIME.
  THUS WILL BE PERIODS OF DRY WEATHER AS WELL.

&&

.AVIATION /08Z 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/...

* INTO MORNING...PATCHY IFR-LIFR CIGS / VSBYS FOR SE MA ERODE
  TOWARDS MORNING. VFR ALL OTHER LOCALES.

* TODAY...VFR. SEA-BREEZE ACROSS THE E. INCREASING W/NW-WINDS
  OVER THE INTERIOR IN WAKE OF A COLD FRONT. SUSTAINED 10-15 KTS
  WITH GUSTS UP TO 30 KTS. BEST CHANCE OF LOW-END VFR CIGS AND
  -SHRA ACROSS NE MA.

* TONIGHT...VFR. WINDS DIMINISHING.

* SUNDAY...VFR. WINDS VEERING TURING E/SE AND ONSHORE. INCREASING
  LATE ALONG WITH HIGH CLOUDS.

* KBOS TAF...HIGH CONFIDENCE. SEABREEZE DEVELOPING TOWARDS
  MIDDAY...ERODING AS IT IS PUSHED OFFSHORE BY STRONG W/NW-WINDS
  BY EVENING.

* KBDL TAF...MODERATE CONFIDENCE. COLD FRONTAL PASSAGE FOLLOWED
  BY STRONGER NW-WINDS EXPECTED BY AFTERNOON.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

* SUN NIGHT...VFR AND LIGHT WINDS. HIGH CONFIDENCE.

* MON...MVFR/IFR DEVELOPING IN RAIN/FOG BY AFTERNOON. LIFR
  POSSIBLE TOWARD 00Z. E/SE WIND GUSTING TO 25-30KT NEAR COAST.
  MODERATE CONFIDENCE.

* TUE...LIFR/IFR TRENDING TOWARD MVFR/VFR IN THE AFTERNOON.
  SHOWERS MOST NUMEROUS IN THE MORNING. MODERATE CONFIDENCE.

* WED...MAINLY VFR WITH SCT MVFR IN DIURNAL CU/SHOWERS. MODERATE
  CONFIDENCE.

&&

.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.

ONSHORE FLOW AROUND 10 KTS THROUGH THE DAY AS SEAS REMAIN BELOW
5-FEET. LOW CLOUDS AND PERHAPS PATCHY FOG MAY LINGER. COLD FRONT
APPROACHING THE WATERS TOWARDS EVENING BEHIND WHICH W/NW-FLOW
INCREASES WITH THE POTENTIAL FOR SUSTAINED WINDS UP TO 15 KTS AND
GUSTS AROUND 25 KTS. SUBSEQUENT WIND STRESS COULD RESULT IN SEAS
BUILDING IN EXCESS OF 5-FEET FOR THE OVERNIGHT PERIOD INTO THE
EARLY HALF OF SUNDAY BY WHICH POINT HIGH PRESSURE WILL SETTLE
ACROSS THE REGION ALLOWING WINDS AND WAVES TO RELAX. WILL ALLOW
THE DAY-SHIFT TO EVALUATE AND MAKE THE CALL AS TO WHETHER SMALL-
CRAFTS SHOULD BE ISSUED.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

SUNDAY NIGHT...HIGH CONFIDENCE.

LIGHT WINDS AND NEAR CALM SEAS.

MONDAY...MODERATE CONFIDENCE.

INCREASING E/SE WINDS EXPECTED MON WITH BUILDING SEAS...PROBABLY
REQUIRING SCA WITH GUSTS REACHING 25-30KT. OUTSIDE CHANCE OF
REACHING MARGINAL GALES /35KT/. SEAS COULD REACH AS HIGH AS 8-11 FT
ON OUTER WATERS MON NIGHT. RAIN AND FOG WILL LIMIT VSBY MON
AFTERNOON AND AND MON NIGHT.

TUESDAY...MODERATE CONFIDENCE.

LEFT OVER HIGH SEAS IN THE FORM OF SE SWELLS. WINDS DIMINISH AS LOW
PRES MOVES OVERHEAD. LOW VSBY IN MORNING FOG AND SHOWERS IMPROVES
DURING THE AFTERNOON.

WEDNESDAY...MODERATE CONFIDENCE.

SEAS AND WIND WILL SLOWLY SUBSIDE.

&&

.FIRE WEATHER...

THERE IS THE POTENTIAL FOR ELEVATED FIRE WEATHER CONDITIONS TODAY
MAINLY ACROSS THE INTERIOR AND AWAY FROM THE SHORES WHICH ARE LIKELY
TO SEA-BREEZE WITH AN ONSHORE MOIST FLOW /OUTLINED BY THE PRIOR FIRE
WEATHER WATCH/.

FOCUS IS ALONG A COLD FRONT WHICH SWEEPS ACROSS THE REGION DURING
THE AFTERNOON HOURS. CONDITIONS WARM AHEAD OF THE FRONT AROUND THE
LOW-70S ALLOWING FOR DEEP-LAYER MIXING AND MIX-DOWN OF DRIER AIR AND
FASTER MOMENTUM TO THE SURFACE. EXPECTING NW-WINDS SUSTAINED AROUND
15 MPH WITH GUSTS AROUND 30 MPH /STRONGER ACROSS THE HIGH TERRAIN/
IMMEDIATELY BEHIND THE COLD FRONT AS THE RELATIVE HUMIDITY DROPS
CLOSE TO 20 PERCENT. THIS IS NOT HELPFUL TO AN ENVIRONMENT IN WHERE
FRIDAYS WET WEATHER WAS NOTHING OF A WASHOUT. ONLY A TENTH OR TWO OF
RAINFALL WAS OBSERVED. SO EXPECT IT TO BE CONSIDERABLY DRY.

BUT WITH THE BULK OF CONDITIONS THAT MEET FIRE WEATHER PARAMETERS
OCCURRING DURING THE AFTERNOON INTO EVENING HOURS...THE SHORT-LIVED
EVENT WITH SUSTAINED WINDS BELOW 20 MPH MAKE THIS A MARGINAL EVENT.
PER COLLABORATION WITH SURROUNDING WFOS AND FIRE WEATHER OFFICIALS
FROM THE STATE OF MA...WILL REVERT THE FIRE WEATHER WATCH TO A RED
FLAG WARNING FOR THE STATE OF CT...WHILE ISSUING A SPECIAL WEATHER
STATEMENT FOR THE REMAINDER OF THE WATCH ENCOMPASSING CENTRAL AND
INTERIOR E MA...AS WELL AS NW RI.

HIGH PRESSURE MOVES IN ON SUNDAY KEEPING THE WINDS GUSTS AT BAY...
BUT ALLOWING FOR RH/S TO DROP NEAR 25 PERCENT AGAIN.

CONDITIONS WILL TURN MORE WET BY NEXT WEEK WITH SEVERAL CHANCES OF
SHOWERS AND COOLER WEATHER THROUGHOUT THE WORK WEEK.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...RED FLAG WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
     CTZ002>004.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...NOCERA/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...NOCERA
AVIATION...NOCERA/SIPPRELL
MARINE...NOCERA/SIPPRELL
FIRE WEATHER...WFO BOX STAFF



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