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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 150552
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
152 AM EDT WED MAY 15 2013

.SYNOPSIS...

COOL CONDITIONS WILL PERSIST TONIGHT AS A HIGH PRESSURE RIDGE
BUILDS ACROSS NEW ENGLAND. A WARM FRONT WILL APPROACH...BRINGING
SHOWERS INTO THE REGION WEDNESDAY AFTERNOON AND NIGHT. HIGH
PRESSURE BUILDS SOUTH FROM CANADA WITH DRY WEATHER AND SEASONABLE
TEMPERATURES FOR MOST OF THURSDAY THROUGH NEXT TUESDAY.

&&

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

-- Changed Discussion --
2 AM UPDATE...

MINOR TWEAKS TO ACCOUNT TO THE LATEST TRENDS. OTHERWISE THE
FORECAST REMAINS ON TRACK.

PREVIOUS DISCUSSION...

MOSTLY CLEAR CONDITIONS AND CALM WINDS ARE ALLOWING SURFACE
TEMPERATURES TO DROP QUICKLY. AM ANTICIPATING LOWS AROUND THE LOW
TO MID 30S ACROSS THE CONNECTICUT RIVER VALLEY. AREAS OF NORTHERN
AND WESTERN MASSACHUSETTS INTO SOUTHERN NEW HAMPSHIRE ARE NOT
WITHIN THEIR GROWING SEASON...THOUGH THERE IS THE POSSIBILITY FOR
FROST TO EXTEND SOUTHWARD ACROSS THE HIGHER ELEVATIONS OF THE
NORTHERN CONNECTICUT. DEWPOINTS HAVE BEEN NOTABLY RISING THE PAST
FEW HOURS...AND THIS MAY LIMIT FROST DEVELOPMENT. WILL HOLD OF ON
THE ISSUANCE OF ANY FROST HEADLINES AND MONITOR CLOSELY AS
CONFIDENCE IS NOT HIGH.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...

WEDNESDAY...
UPPER LEVEL PATTERN REMAINS PROGRESSIVE ACROSS THE LOWER 48...SO
EXPECT NEXT DISTURBANCE TO WORK OUT OF THE GREAT LAKES DURING WED.
WILL SEE CLOUDS INCREASE STEADILY DURING THE DAY WITH THE APPROACH
OF A WARM FRONT. SHOWERS WILL MOVE INTO THE CT VALLEY IN THE
AFTERNOON AND MOVE STEADILY E. MAY HAVE MARGINAL INSTABILITY...
WITH TOTAL TOTALS FROM 48 TO 50 MOVING ACROSS SOUTHERN AREAS.
HAVE MENTIONED ISOLD THUNDER THERE...BUT LOW CONFIDENCE ON THIS
ASPECT. TOTAL QFP WILL BE AROUND 0.25 INCHES...BUT CAN NOT RULE
OUT LOCALIZED SPOTTY DOWNPOURS.

AS WARM FRONT PASSES...S-SW WINDS WILL PICK UP WITH GUSTS UP TO
20-25 KT FROM AROUND 18Z INTO THE EVENING...HIGHEST ALONG THE S
COAST.

EXPECT HIGHS IN THE 60S...EXCEPT THE MID-UPPER 50S ALONG THE S
COAST.

WEDNESDAY NIGHT...
TRAILING COLD FRONT WILL STEADILY MOVE ACROSS THE REGION EARLY.
SHOWERS SHOULD PUSH E AFTER MIDNIGHT...EXITING THE CAPE AND
ISLANDS BY 10Z OR SO. WINDS WILL SHIFT TO W AND DIMINISH. WITH
CLOUDS LINGERING...EXPECT TEMPS TO ONLY FALL BACK TO THE MID 40S
TO LOWER 50S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...

BIG PICTURE...
UPPER TROUGH OVER NEW ENGLAND AND THE MARITIMES LATE WEEK AND
OVER THE WEEKEND. UPPER RIDGE BUILDS ON MONDAY-TUESDAY.

MODEL PREFERENCES...
MODEL MASS FIELDS THIS SIDE OF THE GREAT LAKES LOOK RATHER
SIMILAR THROUGH THE PERIOD. WE USED A BLEND OF THE LONG RANGE
HPC/GMOS TEMPS AND GFS/ECMWF SKY COVER. POP CONTOURS WERE HAND
DRAWN BASED ON OVERLAID QPF FIELDS.

THE DAILIES...

THURSDAY... COLD FRONT MOVES OFFSHORE EARLY.  UPPER TROUGH AND COLD
POOL MOVE ACROSS DURING THE DAY.  SOME DESTABILIZATION/CAA ALOFT/
OVER OUR AREA...BUT THE FOCUS OF THIS WILL TAKE PLACE OVER
VT/NH/MAINE. EXPECT DIURNAL CUMULUS BUT AIRMASS LOOKS TOO DRY FOR
SHOWERS. MIXING WILL BE DEEP...REACHING ABOVE 800 MB. WINDS IN
THIS LAYER ARE EXPECTED TO REACH 35 KNOTS...EVEN A FEW INDICATIONS
OF NEAR 40 KNOTS HIGH IN THE LAYER. SO WIND GUSTS ABOVE 30 KNOTS
ARE ALSO EXPECTED DURING THE AFTERNOON. CLOUDS AND WIND DIMINISH
IN THE EVENING. TEMPS ARE A BLEND OF MOS.

FRIDAY THROUGH SUNDAY... DRY THROUGH THE PERIOD AS HIGH PRESSURE
BUILDS SOUTH FROM NORTHERN QUEBEC. THE HIGH SHIFTS OFFSHORE DURING
SUNDAY. THERE MAY BE ADDITIONAL DIURNAL CUMULUS ESPECIALLY ON FRIDAY-
SATURDAY AND IN THIS RESPECT THE FORECAST MAY BE TOO OPTIMISTIC WITH
SUNSHINE.  BUT THE AIRMASS LOOKS SUFFICIENTLY DRY TO LIMIT CLOUD
DEVELOPMENT.  TEMPS ARE A BLEND OF LONG-RANGE MOS.

SUNDAY NIGHT-MONDAY-TUESDAY... BUILDING RIDGE ALOFT WILL WORK TO
KEEP THE WEATHER DRY. WARM ADVECTION WEST OF THE SURFACE HIGH WILL
BRING ISENTROPIC LIFT AND WORK TO INCREASE SKY COVER. CLOUDS OVER
THE MID ATLANTIC/OHIO VALLEY WILL GET CAUGHT UP IN THE RETURN FLOW
AND GET DRAWN NORTH. NOT A LOT OF CONFIDENCE IN THIS PART OF THE
FORECAST...BUT MOST OF THE FAVORABLE PARAMETERS FOR SHOWERS WILL
REMAIN TO OUR WEST OVER NY/PA THIS PERIOD. SOME SEMBLANCE OF A
WARM FRONT MOVES THROUGH LATER SUNDAY NIGHT/MONDAY...AND WE HAVE
INCLUDED CHANCE POPS DURING THIS PERIOD IN OUR WESTERN AND
NORTHERN ZONES. MORE SHOWERS APPROACH FROM THE WEST LATE
TUESDAY...AND SO WE HAVE CHANCE POPS ENTER FROM THE WEST TUESDAY
NIGHT. STAY TUNED FOR LATER FORECAST CYCLES AS THIS SETUP BECOMES
CLEARER.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...

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

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

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

VFR WITH SOUTHERLY WINDS WILL PREVAIL INTO THE MORNING HOURS.
THEREAFTER...WILL SEE INCREASING CLOUDS WITH -SHRA INTO THE
AFTERNOON AND EVENING PERIOD. LOW CONFIDENCE -TSRA. WILL KEEP
CIGS AT OR ABOVE LOW-END VFR. UNCERTAIN WITH MVFR-IFR IMPACTS...
BEST CHANCES WOULD BE ALONG THE IMMEDIATE SOUTHCOAST INCLUDING THE
CAPE AND ISLANDS WITH POTENTIAL COASTAL FOG. SOUTHERLY FLOW WITH
GUSTS 25 TO 30 KTS WILL BE POSSIBLE DURING THE DAY. COULD SEE LLWS
IMPACTS DURING THE EVENING AS A WARM FRONT LIFTS NORTH ACROSS THE
TERMINALS /SW SUSTAINED 50 KTS AT 2 KFT/.

DRIER WEATHER PREVAILS BEGINNING AROUND MIDNIGHT THURSDAY INTO
THURSDAY NIGHT. MAY HAVE TO CONTENT WITH MORNING COASTAL FOG ALONG
THE SOUTH-SOUTHEAST COAST. WINDS WILL BACK MORE SOUTHWESTERLY...
GUSTY DURING THE DAY THURSDAY WITH SPEEDS OF AROUND 30 KTS...
DIMINISHING OVERNIGHT. VFR.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...THURSDAY THROUGH SUNDAY...

FRIDAY THROUGH SUNDAY... VFR THROUGH THE PERIOD. LIGHTER WINDS
WITH POTENTIAL FOR MIDDAY/AFTERNOON SEABREEZES EACH DAY.
-- End Changed Discussion --

&&

.MARINE...

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 THROUGH PERIOD.

EXPECT WINDS AND SEAS TO REMAIN BELOW SMALL CRAFT THROUGH
WEDNESDAY MORNING. S-SW WINDS WILL PICK UP...GUSTING TO 25 KT OVER
THE OPEN WATERS. SEAS WILL ALSO BUILD...UP TO 8 FT ON THE OUTER
WATERS. WINDS WILL SHIFT TO W AND GRADUALLY DIMINISH LATE WED AS
COLD FRONT PASSES. SEAS WILL REMAIN AOA 5 FT THROUGH WED NIGHT.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY...SEAS 5 TO 7 FEET ON THE OUTER WATERS AND RI/BID
SOUNDS...SO A SMALL CRAFT ADVISORY FOR SEAS WILL CONTINUE TO BE
NEEDED. WINDS OVER LAND WILL INCREASE TO 25-35 KNOTS MIDDAY AND
AFTERNOON. SOME OF THIS WIND MAY AFFECT THE NEARSHORE WATERS AND
REQUIRE A SMALL CRAFT HEADLINE AS WELL.

FRIDAY THROUGH SUNDAY... WINDS AND SEAS EXPECTED TO REMAIN BELOW
SMALL CRAFT CRITERIA MOST OF THE PERIOD.  SEAS ON THE OUTER WATERS
MAY APPROACH 5 FEET ON SUNDAY.

&&

.FIRE WEATHER...

WEDNESDAY...EXPECT MINIMUM RH VALUES TO RANGE FROM THE MID 30S
ACROSS E MA TO 50-60 PERCENT ACROSS S COAST...CAPE COD AND THE
ISLANDS EARLY WED...THEN WILL INCREASE AS CLOUDS AND SHOWERS MOVE
IN. GREEN-UP ALSO CONTINUES...AS MUCH OF THE REGION REMAINS BELOW
NORMAL FOR TOTAL RAINFALL OVER THE LAST TWO MONTHS. S-SW WINDS
WILL BECOME GUSTY...UP TO 20-25 KT WED AFTERNOON AND NIGHT BUT
SHOULD SEE WIDESPREAD SHOWERS MOVING IN. NOT EXPECTING A LOT OF
RAINFALL LATE WED AND WED NIGHT...MAINLY AROUND 0.25 INCHES.

THE FORECASTED RAINFALL WILL BE OF SOME HELP TOWARDS THE BELOW
NORMAL RAINFALL CONDITIONS. HOWEVER...THE REGION REMAINS DRY
POSSIBLY CONDUCIVE TOWARDS FUTURE FIRE WEATHER POTENTIAL.

OUTLOOK...
MINIMUM RELATIVE HUMIDITY FOR THURSDAY AND FRIDAY IS EXPECTED AT
20 TO 30 PERCENT EACH DAY. WEST-NORTHWEST WINDS ON THURSDAY WILL
INCREASE BY MIDDAY WITH AFTERNOON GUSTS TO 30 KNOTS AND POSSIBLY
35 KNOTS. THESE CONDITIONS ON THURSDAY WILL NEED TO BE WATCHED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

-- Changed Discussion --
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM EDT
     THURSDAY FOR ANZ232.
     SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT
     THURSDAY FOR ANZ235-237-250-254>256.
     SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 AM EDT
     THURSDAY FOR ANZ251.
-- End Changed Discussion --

&&

$$

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