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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 252327
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
727 PM EDT SAT MAY 25 2013

.SYNOPSIS...
-- Changed Discussion --
LOW PRESSURE IN THE GULF OF MAINE WILL SLOWLY MOVE NORTHEASTWARD
TONIGHT. SOME IMPROVEMENT IS LIKELY SUNDAY AS THIS LOW DEPARTS
INTO NORTHERN NEW ENGLAND. MAINLY DRY WEATHER IS ANTICIPATED WITH
MODERATING TEMPS MONDAY INTO TUESDAY. A WARM FRONT WILL MOVE
THROUGH WEDNESDAY BRINGING SOME SHOWERS AND THUNDER. EXPECT WARM
AND MUGGY CONDITIONS BY THE END OF THE WORK WEEK.
-- End Changed Discussion --

&&

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

-- Changed Discussion --
730 PM UPDATE...SHOWERS AND DRIZZLE CONTINUE. THE SURFACE LOW WAS OFF
PORTLAND AND THE UPPER LOW OVERHEAD. AS THESE SHIFT
NORTHEAST...THE COLDEST AIR ALOFT WILL MOVE OVER SOUTHERN NEW
ENGLAND. MODEL SOUNDINGS SUGGEST THAT RAIN IN THE HIGHER TERRAIN
MAY MIX WITH OR CHANGE OVER TO SNOW IN THE HEAVIER SHOWERS. THE
BEST CHANCE FOR THIS TO OCCUR EXISTS AT ELEVATIONS GREATER THAN
1000 FT. GIVEN THAT ITS LATE MAY...TEMPERATURES AT THE SURFACE AND
ON THE GROUND ARE TOO WARM FOR ANY APPRECIABLE ACCUMULATIONS.
ELEVATED SURFACES SUCH AS TREES AND POWER LINES MAY SEE A DUSTING
OF SNOW. LOW TEMPERATURES ARE EXPECTED TO BE 10 TO 15 DEGS BELOW
SEASONAL NORMALS.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SUNDAY...LEFTOVER SHOWERS WILL END FROM SOUTH TO NORTH DURING THE
DAY AS LOW PRESSURE MOVES INTO THE MARITIMES. CLOUDS WILL REMAIN
FOR MOST OF THE DAY AS NORTHWEST WINDS PICK UP. EXPECTING GUSTS UP
TO 30-35 MPH...ESPECIALLY ACROSS CENTRAL AND WESTERN AREAS. WILL
REMAIN COOL WITH HIGHS AGAIN 10-15 DEGREES BELOW NORMAL.

SUNDAY NIGHT...SHOULD SEE CLEARING SKIES AS HIGH PRESSURE STARTS
TO BUILD INTO SOUTHERN NEW ENGLAND. WINDS WILL STAY UP ENOUGH TO
PREVENT OPTIMAL RADIATIONAL COOLING SO TEMPS WON/T BE AS COOL AS
TONIGHT BUT WILL STILL BE 5 TO 10 DEGREES BELOW NORMAL.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
BIG PICTURE... UPPER LOW OVER THE NORTHEAST USA MIGRATES NORTHEAST
THROUGH THE MARITIMES.  UPPER HIGH PRESSURE OVER THE PLAINS SHIFTS
EAST FOR THE LATTER HALF OF THE WEEK.  PACIFIC UPPER LOW DIGS OVER
THE ROCKIES MIDWEEK...THEN EJECTS THROUGH THE NORTHERN PLAINS BY
NEXT WEEKEND.

MODEL PREFERENCES... UPPER CONTOUR FIELDS ARE SIMILAR FOR MUCH OF
THE WEEK.  MINOR DIFFERENCES IN HANDLING THE EJECTING PACIFIC LOW
UPSTREAM LATE WEEK.  WE USED BLENDS OF HPC/GMOS AND GFS/ECMWF DATA
AS AVAILABLE.

THE DAILIES...

MONDAY-TUESDAY... UPPER TROUGH SHIFTS EAST MONDAY BUT STILL CYCLONIC
FLOW ALOFT AS THE SURFACE HIGH BUILDS IN.  LIMITED MOISTURE AROUND
850 MB SHOULD SUPPORT SOME DIURNAL CLOUD DEVELOPMENT...BUT NOT DEEP
ENOUGH FOR ANY SHOWERS.  MONDAY SHOULD BE A DRY DAY WITH AT WORST
PARTLY CLOUDY SKIES.  OF MORE CONCERN ARE THE TEMPERATURES.  BOTH
MAV AND MET GUIDANCE SHOW HIGHS IN THE MID 70S PVD-BDL AND LOW
70S BOS...WHILE MODEL TEMPS AT THE TOP OF THE MIXED LAYER SUPPORT
VALUES OF 65-70. EITHER THE MODEL TEMPS ALOFT ARE WRONG...THE
PROJECTED MIXING DEPTH IS WRONG...OR MOS IS WRONG. WE FAVORED A
BLEND THAT EDGES TOWARD THE COOLER VALUES WITH A RANGE IN THE
UPPER 60S TO LOW 70S.

CLEAR SKIES AND LIGHT WINDS MONDAY NIGHT...DEWPOINTS 35-40.  COULD
BE SOME FROST IN THE BERKSHIRES AND MONADNOCKS BUT ELSEWHERE TEMPS
SHOULD BOTTOM OUT IN THE UPPER 30S TO MID 40S.

HIGH PRESSURE OVERHEAD TUESDAY WITH TEMPS ALOFT WARMING...VALUES
AROUND 9-10C SUPPORT MAX TEMPS 75-80. COOLER AT THE COAST AS THE
LIGHT FLOW WILL ALLOW FOR DEVELOPING SEA BREEZES.

WEDNESDAY... UPPER RIDGE WILL PUSH WARMING TEMPS INTO THE REGION.
WARM FRONT REPRESENTING THE LEADING EDGE OF THIS WARMER AIR MOVES
ACROSS NEW ENGLAND LATE WEDNESDAY/WEDNESDAY NIGHT.  THIS WILL
GENERATE SOME SHOWERS...AND STABILITY PARAMETERS SUPPORT POTENTIAL
FOR THUNDER AS WELL.

THURSDAY THROUGH SATURDAY... VERY WARM AIR ALOFT WITH 850 MB TEMPS
AROUND 16C.  DEWPOINTS ARE EXPECTED IN THE LOW TO MID 60S.  MIXING
SHOULD SUPPORT MAX TEMPS IN THE MID AND UPPER 80S...DEWPOINTS POINT
TO HUMID AIR WITH NIGHT MINS IN THE 60S.  SHOWER POTENTIAL LOOKS LOW
THURSDAY AND FRIDAY.  AN APPROACHING COLD FRONT MAY BRING A CHANCE
OF SHOWERS SATURDAY ESPECIALLY NORTH OF THE MASS PIKE.  BUT THE
STRENGTH OF THE UPPER RIDGE MAY KEEP THIS FRONT TO OUR NORTH AND
PRECLUDE SHOWERS.  SO THE PCPN FORECAST IS LOW CONFIDENCE BY NEXT
SATURDAY.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS...

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

OVERVIEW...

TONIGHT...MODERATE CONFIDENCE. SNOW MAY MIX IN WITH THE RAIN
ACROSS THE HIGHER TERRAIN IN WESTERN MA AND SOUTHWEST NH. SHOWERS
WILL KEEP CONDITIONS VARIABLE ACROSS THE REGION. MVFR CIGS OVER
THE COASTAL PLAIN AND NORTH OF MASS ROUTE 2...MVFR/IFR VSBYS ALONG
THE EAST COAST. VFR CONDITIONS POSSIBLE ELSEWHERE.

SUNDAY...MODERATE CONFIDENCE. PRECIPITATION TAPERS OFF FROM S-N
WITH VFR CONDITIONS MOST EVERYWHERE BY LATE SUNDAY AFTERNOON.

SUNDAY NIGHT...HIGH CONFIDENCE.  VFR.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. LOW CONFIDENCE IN
OVERALL TIMING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LOW CONFIDENCE IN
OVERALL TIMING.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY THROUGH THURSDAY... GENERALLY VFR. EARLY MORNING IFR POSSIBLE
IN FOG AND LOW CLOUDS.  LOCAL MVFR CIGS/VSBYS IN SHOWERS/TSTMS
WEDNESDAY AND WEDNESDAY NIGHT. SEA BREEZES AT THE COAST TUESDAY.
-- End Changed Discussion --

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

NORTHWESTERLY WINDS AND SEAS INCREASE TONIGHT INTO SUNDAY AS LOW
PRESSURE ROTATES IN THE GULF OF MAINE AND THEN MOVES INTO THE
MARITIMES SUNDAY. SMALL CRAFT ADVISORIES ARE UP FOR ALL MARINE
ZONES AT SOME POINT THROUGH SUNDAY NIGHT. WEST-NORTHWESTERLY WINDS
TAKE AWHILE TO KICK UP ON THE EASTERN WATERS SO ADVISORIES BEGIN
LATER OVER THOSE INTERIOR ZONES WHERE SEAS REMAIN BELOW 5 FEET.
WINDS WILL BE STRONGER ON THE SOUTHERN OUTER WATERS SO HAVE OPTED
FOR GALE WARNINGS ACROSS THOSE WATERS...ESPECIALLY GIVEN THE
BUSIER HOLIDAY WEEKEND. SHOWERS AND FOG MAY LIMIT VISIBILITIES
THROUGH SUNDAY MORNING WITH SHOWERS TAPERING OFF SUNDAY AFTERNOON.

OUTLOOK...MONDAY THROUGH THURSDAY...

MONDAY THROUGH WEDNESDAY...WINDS AND SEAS BELOW SMALL CRAFT
THRESHOLDS.  SOUTH WINDS MAY GUST NEAR 25 KNOTS NEARSHORE OF THE
CAPE AND ISLANDS WEDNESDAY AFTERNOON.

THURSDAY...SOUTHWEST WINDS GUSTING NEAR 25 KNOTS NEARSHORE OF THE
CAPE AND ISLANDS.  THE SOUTHWEST WIND WILL BUILD SEAS WITH 5-6 FOOT
VALUES ON THE OUTER WATERS...POSSIBLY ON RI AND BLOCK ISLAND SOUNDS
AS WELL.

&&

.HYDROLOGY...
WHILE THERE MAY BE PERIODIC HEAVIER RAIN SHOWERS ACROSS SOUTHERN
NEW ENGLAND THROUGH EARLY SUNDAY...NOT THINKING IT WILL BE
PERSISTENT ENOUGH TO RESULT IN FLOODING. WILL HAVE TO MONITOR THE
POSSIBILITY OF TRAINING CELLS THOUGH. NO HEADLINES PLANNED AT THIS
TIME.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES ARE EXPECTED ALONG THE EAST COAST OF
MASSACHUSETTS THIS WEEKEND. AT BOSTON...A HIGH TIDE OF 12.2 FT
WILL OCCUR EARLY SUNDAY MORNING AT 12:12 AM. AFTER HIGH TIDE THIS
AFTERNOON...THERE WAS ABOUT A HALF FOOT OF SURGE LINGERING AT
BOSTON. WITH ESTOFS INDICATING UP TO 0.7 FT SURGE...SEEMS
REASONABLE THAT IT COULD REACH 13 FEET EVEN WITH MINIMAL WAVE
ACTION OFFSHORE. CONFIDENCE NOT HIGH ENOUGH TO ISSUE A COASTAL
FLOOD ADVISORY ESPECIALLY BEING A MARGINAL EVENT BUT OPTED TO
ISSUE A COASTAL FLOOD STATEMENT FOR THE EASTERN MASSACHUSETTS
ZONES FOR THE POTENTIAL OF SOME SPLASHOVER.

&&

.CLIMATE...
SEVERAL CLIMATE RECORDS COULD BE REACHED OVER THE WEEKEND. WHILE
BOSTON...PROVIDENCE...AND WORCESTER WERE SEVERAL DEGREES OVER
THEIR RECORD LOW MAX TEMPERATURE THIS AFTERNOON...HARTFORD HAS
TIED ITS RECORD LOW MAX OF 48 SO FAR. IF THEIR TEMPERATURE GOES UP
EVEN A DEGREE THE RECORD SET IN 1967 WILL HOLD. HOWEVER...THINK
THERES A GOOD CHANCE THAT WE WILL TIE THAT RECORD IN HARTFORD.

TONIGHT...THE FORECAST LOW AT WORCESTER...34 DEGREES...WOULD BREAK
THE CURRENT RECORD LOW OF 35 DEGREES SET IN 1992. THE FORECAST
LOWS AT PROVIDENCE...HARTFORD...AND BOSTON ARE WITHIN 2-3 DEGREES
OF THE PREVIOUS RECORDS /SEE BELOW/.

HARTFORD -    FORECAST LOW - 39  RECORD LOW - 36 (1992)
PROVIDENCE -  FORECAST LOW - 38  RECORD LOW - 35 (1972)
BOSTON -      FORECAST LOW - 41  RECORD LOW - 39 (1882)

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR ANZ232>234.
     SMALL CRAFT ADVISORY FROM 2 PM SUNDAY TO 4 AM EDT MONDAY FOR
     ANZ230-231-251.
     SMALL CRAFT ADVISORY UNTIL 9 PM EDT SUNDAY FOR ANZ236.
     SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR ANZ235-237-250-
     254.
     GALE WARNING UNTIL 7 AM EDT SUNDAY FOR ANZ255-256.
-- End Changed Discussion --

&&

$$
SYNOPSIS...DUNTEN/RLG
NEAR TERM...WTB/RLG
SHORT TERM...RLG
LONG TERM...DUNTEN
AVIATION...WTB/DUNTEN/RLG
MARINE...DUNTEN/RLG
HYDROLOGY...
TIDES/COASTAL FLOODING...
CLIMATE...