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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 151944
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
344 PM EDT WED MAY 15 2013

.SYNOPSIS...
-- Changed Discussion --
A WARM FRONT WILL BE THE FOCUS FOR SCATTERED SHOWERS INTO
TONIGHT. BEHIND THE FRONT...DRIER AND MILDER WEATHER FOLLOWS
THURSDAY. A DRY COLD FRONT SWEEPS ACROSS THE REGION THU NIGHT
USHERING COOLER BUT SEASONABLE WEATHER INTO THE AREA BEGINNING
FRIDAY AND CONTINUING INTO THE WEEKEND. A WARMING TREND IS LIKELY
EARLY NEXT WEEK AS MARITIME HIGH PRESSURE MOVES OFFSHORE.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
145 PM UPDATE...
AREA OF SHOWERS MOVING ACROSS CENTRAL AND WESTERN AREAS AT 17Z.
HOWEVER...WITH WIDE TEMP/DEWPT SPREADS...LITTLE IF ANY IS REACHING
THE GROUND. DO NOTE A TRACE AT 17Z AT KPSF...WITH BAND OF HEAVIER
SHOWERS APPROACHING WESTERN AREAS OUT OF THE CAPITAL DISTRICT OF
NY STATE. ALSO NOTE SOME C/G LTNG IN THIS AREA ALONG WITH S-SW
WIND GUSTS UP TO 25-30 KT.

LOOKS LIKE THE MAIN ACTION WILL MOVE ACROSS THE REGION THIS EVENING
WITH QUICK MOVING FRONTAL SYSTEM AND LOW PRES OUT OF WESTERN NY
STATE. NOTING PRONOUNCED DRY SLOT NEAR TRIPLE POINT OF OCCLUSION
MOVING QUICKLY E ON IR SATELLITE...WHILE PRECIP RIDES WELL AHEAD.
WITH WIDE DEWPT DEPRESSIONS AND QUICKLY MOVING PRECIP...WILL SEE
LITTLE IF ANY RAINFALL...ONLY SPOTTY LIGHT AMOUNTS. DID KEEP LOW
LIKELY POPS GOING FOR CENTRAL AND NORTHERN AREAS FOR NOW...BUT
WILL PROBABLY CUT THIS BACK TO CHANCE BEFORE 4 PM ISSUANCE
DEPENDING UPON OBS AND RADAR TRENDS.

NOTING S-SW WIND GUSTS OF 25 KT AT 17Z...BUT COULD SEE THEM UP TO
30 KT PRIOR TO FRONTAL PASSAGE THIS EVENING.

HAVE UPDATED GRIDS TO BRING CONDITIONS CURRENT.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
TONIGHT...
SHOWERS AND DRIZZLE LINGER NORTH AND EAST...CLEARING OUT BY
MIDNIGHT. MID-HIGH LEVEL CLOUDS WILL LINGER ACROSS THE REGION IN
ASSOCIATION THE BROADER MID-LEVEL LOW OVER THE SAINT LAWRENCE
RIVER VALLEY. WHILE A COLD FRONT WILL SLIDE ACROSS THE REGION
OVERNIGHT THERE IS LITTLE CHANGE IN AIRMASS /AND LITTLE AVAILABLE
MOISTURE...NOT THINKING ANY SHOWERS/. SHOULD SEE SOUTHERLY WINDS
DIMINISH ACROSS THE INTERIOR WITH BOUNDARY LAYER DECOUPLING...BUT
REMAINING BRISK ALONG THE WATERS. LOWS REMAINING MILD AROUND THE
UPPER 40S.

THURSDAY...
DRY CONDITIONS. CONTINUED CYCLONIC FLOW WITH THE DEPARTURE OF THE
MID-LEVEL LOW WILL RESULT IN MID-HIGH LEVEL CLOUDS FILTERING
ACROSS THE REGION. BOUNDARY LAYER MIX-DOWN OF AN ELEVATED MIXED
LATER +8- 10C AT H85 WILL RESULT HIGH TEMPERATURES AROUND THE MID-
UPPER 70S WITH A FEW LOCALES REPORTING LOW 80S. WILL SEE WESTERLY
WINDS WITH GUSTS OF 30 TO 35 MPH. RELATIVE HUMIDITIES WILL RANGE
AROUND 25 TO 30 PERCENT PRESENTING THE POTENTIAL FOR FIRE WEATHER
CONCERNS /SEE THE FIRE-WEATHER DISCUSSION BELOW/.

THURSDAY NIGHT...

WINDS WILL DIMINISH ACROSS THE INTERIOR BUT REMAIN BRISK ALONG THE
COAST. ANOTHER COLD FRONT WILL SWEEP THROUGH THE REGION WITH LITTLE
FAN-FARE. WESTERLY WINDS WILL BACK OUT OF THE NORTH WITH COLD
FRONTAL PASSAGE. COOLER AIRMASS WILL BUILD ACROSS THE REGION
ALOFT.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
BIG PICTURE...
UPPER TROUGH OVER NEW ENGLAND MOVES OFF THROUGH THE MARITIMES BY SATURDAY.
UPPER RIDGE THEN BUILDS OVER THE EASTERN USA FOR THE FIRST HALF OF NEXT WEEK.
TREND TO A SLOWER MOVING PATTERN DURING NEXT WEEK.

MODEL PREFERENCES... GENERAL AGREEMENT BETWEEN THE GFS AND ECMWF ON
ON LARGE SCALE MASS FIELDS.  DURING NEXT WEEK THE GFS IS MORE
AGGRESSIVE IN BRINGING NORTHERN CANADA UPPER LOW SOUTH TO NEW
ENGLAND...THE ECMWF GETS AROUND TO IT 24 HOURS LATER.  WE USED A
BLEND OF HPC AND GMOS GRIDS EXCEPT POPS WERE HAND DRAWN BASED ON
ENSEMBLE COMPARISON OF THE VARIOUS MODEL QPF.

THE DAILIES...

FRIDAY... CYCLONIC FLOW ALOFT WITH COLD POOL PRESENT ALOFT.  HOWEVER
DESTABILIZING SHARP LAPSE RATES REMAIN ACROSS MAINE AND NORTHERN
VT/NH.  LIMITED MOISTURE 800-850 MB BUT MUCH DRIER ABOVE.  SO WE
EXPECT LIMITED DIURNAL CUMULUS BUT OTHERWISE A DRY DAY.  MIXING
DEPTHS REACH ABOVE 850 MB...POSSIBLY CLOSE TO 800 MB.  WINDS THROUGH
THIS LAYER WILL BE 15 KTS OR LESS.  TEMPS IN THE LAYER WILL SUPPORT
LOWER 70S...WITH A LITTLE DEEPER MIXING A FEW SPOTS COULD REACH MID
70S.  SURFACE PRESSURE PATTERN IS SUFFICIENTLY LIGHT TO ALLOW
MIDDAY/AFTERNOON SEABREEZES.

SATURDAY-SUNDAY... HIGH PRESSURE BUILDS OVER THE REGION SATURDAY AND
SHIFTS OFFSHORE SUNDAY.  FAIR SKIES SATURDAY.  FLOW TURNS SOUTHEAST
SUNDAY WITH MODELS SHOWING MOISTURE INCREASING FROM THE SOUTH...SO
MORE IN THE WAY OF CLOUDS ON SUNDAY BUT WITH DRY WEATHER.

MONDAY THROUGH WEDNESDAY...UPPER RIDGE BREAKS DOWN DURING THIS
PERIOD. HIGH PRESSURE OFFSHORE SHOULD KEEP US DRY MONDAY. THE GFS
SWINGS A COLD FRONT THROUGH LATE TUESDAY FOLLOWED BY CANADIAN HIGH
PRESSURE BUILDING SOUTH WITH DRY WEATHER WEDNESDAY.  THE ECMWF
BRINGS THE FRONT THROUGH ON WEDNESDAY.  WE HAVE BROUGHT CHANCE POPS
TO MOST OF THE REGION TUESDAY NIGHT AND WEDNESDAY.  WHETHER THE
SLOWER OR FASTER SCENARIO OCCURS...WE EXPECT A WARMING TREND THROUGH
THE FIRST HALF OF THE WEEK WITH COOLING TEMPS AFTER THE COLD FRONT
MOVES THROUGH.
-- End Changed Discussion --

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS...

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

145 PM UPDATE...

SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE TO HIGH
CONFIDENCE.

THROUGH 00Z...MAINLY VFR. MAY SEE POCKETS OF MVFR CIGS/BRIEF
MVFR-IFR VSBYS IN ANY SHOWERS AROUND OR AFTER 21Z. S-SW WINDS
GUSTING TO 25 TO 30 KTS. LOW PROB OF ISOLD THUNDER.

TONIGHT...MAY SEE POCKETS OF MVFR-IFR CIGS/VSBYS WITH ANY SHOWERS
THROUGH MIDNIGHT...THEN SHOULD IMPROVE. MAY SEE LINGERING MVFR-IFR
VSBYS IN PATCHY FOG BEFORE WIND SHIFT TO W AFTER MIDNIGHT MAINLY
FROM THE MASS PIKE SOUTH. SHOULD IMPROVE TO VFR BY AROUND SUNRISE
EXCEPT OVER THE CAPE AND ISLANDS. MAY ALSO SEE BRIEF LLWS ON
INCREASING NW FLOW TOWARD DAYBREAK.

THURSDAY-THURSDAY NIGHT...VFR CONDITIONS. MAY SEE MVFR-IFR
THROUGH 14Z- 15Z ACROSS CAPE COD AND THE ISLANDS. MAY SEE GUSTY
W-SW WINDS UP TO 30 KT DURING THU...DIMINISHING THU NIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...FRIDAY THROUGH MONDAY...

GENERALLY VFR DURING THE PERIOD. LOCAL IFR IN AREAS OF LATE
NIGHT/MORNING FOG.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS...

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

1040 AM UPDATE...
NO MAJOR CHANGES TO PREVIOUS FORECAST.

PREVIOUS DISCUSSION...
INCREASING WINDS THIS AFTERNOON ACROSS THE NEAR SHORE WATERS OF
MA AND RI. SCA IN EFFECT FOR ALL WATERS. S WINDS WILL GUSTS TO
25-30 KT FROM 2 PM TO 8 PM. STRONGEST WINDS NEAR SHORE.

SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE CONFIDENCE.

WITH WINDS INCREASING OUT OF THE S/SW TODAY WITH GUSTS UP TO
AROUND 30 KTS...ANTICIPATE SEAS TO BUILD ACROSS THE OUTER WATERS.
SMALL CRAFT ADVISORIES ARE IN EFFECT ACCORDINGLY. ADVISORIES MAY
NEED TO BE EXTENDED TO THE INNER HARBORS AND BAYS. WILL MONITOR
CLOSELY.

WINDS TO REMAIN BRISK TONIGHT...BACKING OUT OF THE WEST AS A COLD
FRONT SWEEPS THROUGH THE REGION. THURSDAY WILL BE A REPEAT WITH
WESTERLY WINDS GUSTING AROUND 30 KTS. MAY NEED TO BE CONCERNED
ABOUT GALE HEADLINES /ESPECIALLY CLOSER TO SHORE/. ANOTHER COLD
FRONT WILL SWEEP THE WATERS THURSDAY NIGHT RESULTING IN WINDS TO
DIMINISH AS THEY BACK OUT OF THE NORTH.

THROUGHOUT ALL OF THE FORECAST PERIOD...SEAS WILL CONTINUE TO
REMAIN ABOVE 5 FEET ACROSS THE OUTER WATERS.

OUTLOOK...FRIDAY THROUGH MONDAY...

FRIDAY THROUGH MONDAY...WINDS BELOW 25 KNOTS THROUGH THE PERIOD.
SEAS BELOW 5 FEET FRIDAY THROUGH SUNDAY...THEN 5 FOOT SEAS RETURN
TO THE EXPOSED SOUTHERN WATERS ON MONDAY.
-- End Changed Discussion --

&&

.FIRE WEATHER...
-- Changed Discussion --
MINIMUM RELATIVE HUMIDITY THURSDAY IS EXPECTED AT 20 TO 30
PERCENT. WEST-NORTHWEST WINDS ON THURSDAY WILL INCREASE BY MIDDAY
WITH AFTERNOON GUSTS TO 30 KNOTS AND POSSIBLY 35 KNOTS. THESE
CONDITIONS WILL NEED TO BE WATCHED.

MINIMUM RELATIVE HUMIDITY FRIDAY AND SATURDAY WILL BE 25 TO 40
PERCENT...BUT WITH WINDS BELOW 20 KNOTS.
-- End Changed Discussion --

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR ANZ232.
     SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ230-
     233-234-236.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ231-251.
     SMALL CRAFT ADVISORY UNTIL 5 AM EDT FRIDAY FOR ANZ235-237.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ250-254>256.

&&

$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...EVT/THOMPSON
SHORT TERM...SIPPRELL/EVT
LONG TERM...WTB
AVIATION...WTB/EVT/THOMPSON
MARINE...WTB/SIPPRELL/EVT
FIRE WEATHER...