-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 150224
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1024 PM EDT TUE MAY 14 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 WEDNESDAY MORNING/...

-- Changed Discussion --
1030 PM UPDATE...

CLOUDS LINGER ACROSS THE EASTERN HALF OF NEW ENGLAND UNDERNEATH A
STOUT DRY AIR INVERSION AT THE MID-LEVELS SEEN IN THE 0Z CHATHAM
SOUNDING. ANTICIPATING THESE CLOUDS TO LINGER WHICH SHOULD LEAD TO
MILDER LOW TEMPERATURES TOWARDS MORNING THANKS TO BLANKET
LIMITATIONS ON EFFECTIVE RADIATIONAL COOLING. LOWS DOWN TO THE
UPPER 30S ACROSS THE EASTERN INTERIOR TO MID 40S ALONG THE
COASTLINE.

ELSEWHERE...MAINLY WEST...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.

REMAINDER OF THE FORECAST REMAINS ON TRACK OTHER THAN A FEW
TWEAKS TO SURFACE FIELDS TO ACCOUNT FOR THE LATEST TRENDS.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...

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 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 /02Z WEDNESDAY THROUGH SUNDAY/...

FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH WEDNESDAY NIGHT/...

TONIGHT...HIGH CONFIDENCE. VFR WITH DIMINISHING WIND. DIMINISHING
SKY COVER BETWEEN 9 PM AND MIDNIGHT.

WEDNESDAY...MODERATE TO HIGH CONFIDENCE. VFR MOST OF THE DAY. MAY
SEE PATCHY MVFR CIGS/VSBYS MOVE INTO CT VALLEY LATE IN THE DAY.
SCT SHOWERS MOVE IN FROM W-E DURING THE DAY AS WARM FRONT
APPROACHES.

WEDNESDAY NIGHT...MODERATE CONFIDENCE. CIGS/VSBYS LOWERING TO MVFR
WITH POCKETS OF IFR CONDITIONS IN SCT-WIDESPREAD SHOWERS AND FOG.
S-SW WINDS MAY GUST TO 25 KT EARLY BEFORE WIND SHIFT. LOW
CONFIDENCE OF ISOLD THUNDER. CONDITIONS IMPROVE ACROSS WESTERN
AREAS AFTER MIDNIGHT ON W-NW WINDS.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THURSDAY... AREAS OF IFR IN MORNING FOG...OTHERWISE VFR. VFR
LEVEL CLOUDS DEVELOP MIDDAY/AFTERNOON ESPECIALLY SOUTHERN
NH/NORTHERN MASS. WEST-NORTHWEST WINDS INCREASE DURING THE
MORNING...WITH GUSTS TO 35 KNOTS EXPECTED IN THE AFTERNOON AND
DIMINISHING IN THE EVENING.

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

&&

.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...

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

&&

$$

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