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000
FXUS61 KBOX 220500
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
100 AM EDT TUE MAY 22 2012
.SYNOPSIS...
LOW PRESSURE OFF THE CAROLINAS WILL TRACK UP THE COAST...BRINGING
SHOWERS THROUGH TUESDAY. HIGH PRESSURE WILL REMAIN STATIONARY OFF
THE COAST OF MAINE AND NOVA SCOTIA WEDNESDAY THROUGH FRIDAY WITH A
MOIST AIR FLOW CAUSING CLOUDS AND A FEW SHOWERS OR THUNDERSTORMS
MAINLY IN NORTHERN AND WESTERN AREAS. A COLD FRONT MAY PRODUCE
SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON SATURDAY.
COOLER HIGH PRESSURE FOR SUNDAY...THEN ANOTHER FRONT APPROACHES
LATE MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1 AM UPDATE...
AREAS OF SHOWERS AHEAD OF MID LEVEL CIRCULATION ARE LIFTING NWD
INTO SNE. BASED ON LATEST RADAR TRENDS WE WILL INCREASE POPS
ACROSS A PORTION OF THE REGION...ESPECIALLY FROM W MA TO THE S
COAST.
IN ADDITION...ABUNDANT LOW LEVEL MOISTURE WILL RESULT IN AREAS OF
DENSE FOG NEAR THE COAST ALONG WITH PATCHY DRIZZLE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
TUESDAY...
LOW PRESSURE PASSES OFFSHORE OF NANTUCKET AROUND MIDDAY AND MOVES
OFF. THIS WILL CONTINUE THE LOW LEVEL FEED OF MOIST AIR INTO NEW
ENGLAND DURING THE MORNING. THIS FLOW THEN SHIFTS INTO MAINE BY
AFTERNOON. WILL MAINTAIN CHANCE POPS ALTHOUGH WITH A DIMINISHING
TREND IN THE AFTERNOON AS THE LOW MOVES OFF. THE LOW REMAINS FAR
ENOUGH OFFSHORE TO KEEP ANY STRONG WINDS OFFSHORE AS WELL.
CLOUDS AND SHOWERS SHOULD HOLD TEMPS FROM THEIR FULL HEATING
POTENTIAL. BUT BREAKS IN THE CLOUDS IN THE AFTERNOON WILL ALLOW
SOME HEATING. MIXING POTENTIAL IS FORECAST AT 3500-4000 FEET.
TEMPS AT 900 MB WILL BE 12-13C...SIMILAR TO 7-8C FROM 850 MB. SO
MAX TEMPS SHOULD BE IN THE LOW TO MID 70S. WE AGAIN USED THE B-C
MAV VALUES.
TUESDAY NIGHT...
ALTHOUGH THE SURFACE LOW MOVES OFF PAST NOVA SCOTIA...THE UPPER
LOW REMAINS IN PLACE OVER THE NORTHEAST USA WITH LOTS OF MOISTURE
TRAPPED IN THE AIRMASS OVER NEW ENGLAND. NIGHTTIME COOLING WILL
WORK AGAINST BREAKING THE CLOUD COVER. THE ECMWF FORECASTS
LINGERING LIFT OVER OUR NORTHWEST AREAS. SO WE WILL GO WITH A
CLOUDY FORECAST WITH LINGERING CHANCE POPS MAINLY OVER OUR
NORTHWEST AREAS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
OVERVIEW...
UPPER LEVEL LOW PRESSURE WILL CONTINUE TO SLOWLY MOVE NORTHEAST
SOUTH OF THE CANADIAN MARITIME PROVINCES FROM MID TO LATE IN THE
WEEK. MODELS THEN DIFFER IN THE HANDLING OF UPPER LEVEL FEATURES.
THE CANADIAN MODEL KEEPS AN UPPER LOW PARKED OVER THE MID ATLANTIC
COAST WHICH PARTIALLY DISRUPTS THE BUILDING UPPER RIDGE. HAVE
DISREGARDED THIS SOLUTION BECAUSE THE GFS AND ECMWF ARE BOTH QUITE
EMPHATIC ABOUT VERY STRONG BUILDING HEIGHTS FROM THE TENNESSEE
VALLEY TO SOUTHERN NEW ENGLAND BY SATURDAY. ALSO IMPORTANT TO NOTE
THAT THE CANADIAN HAS ABANDONED THE IDEA OF A BIG STORM MOVING
BODILY NORTHWARD TOWARD NEW ENGLAND FOR FRIDAY. AM EXPECTING A
COLD FRONT TO TRAVERSE THE REGION SATURDAY AFTERNOON WITH A GOOD
CHANCE OF SHOWERS AND THUNDERSTORMS. LOOKS LIKE DRY COOLER HIGH
PRESSURE ON NORTHEAST WINDS FOR SUNDAY. MEMORIAL DAY RIGHT NOW
APPEARS DRY WITH WARM TEMPERATURES AND WINDS RETURNING TO A
SOUTHERLY DIRECTION AHEAD OF ANOTHER APPROACHING FRONT.
DAY TO DAY DETAILS...
WEDNESDAY THROUGH FRIDAY...
GENERALLY A MOSTLY CLOUDY PERIOD...BUT GRADUALLY INCREASING SUNSHINE
BY FRIDAY. AFTERNOON HIGHS SHOULD BE IN THE UPPER 70S TO LOWER 80S WITH
DEWPOINT TEMPERATURES HANGING AROUND THE UPPER 50S TO LOWER 60S.
INSTABILITY IS PRESENT BUT WEAK IN THE NORTHWEST THIRD OF THE
REGION...SO THERE COULD POSSIBLY BE A FEW SHOWERS OR THUNDERSTORMS
THERE EACH AFTERNOON AND EARLY EVENING. A TRIGGER MECHANISM IS
LACKING HOWEVER...THUS ANY ACTIVITY SHOULD QUICKLY DIMINISH AFTER SUNSET.
SATURDAY...
STRONG SHORT WAVE TROUGH PROGRESSING ACROSS SOUTHERN CANADA HAS AN
ASSOCIATED COLD FRONT THAT SWINGS THROUGH SOUTHERN NEW ENGLAND
DURING THE DAY ON SATURDAY. AT 12Z SATURDAY THE ECMWF HAS THE
FRONT STILL WAY OUT IN WESTERN NEW YORK STATE WHEREAS THE FASTER
GFS HAS IT MOVING INTO EASTERN NEW YORK STATE. THIS DISCREPANCY COULD
BE SIGNIFICANT. IF THE ECMWF IS RIGHT AND THERE IS A SLOWER
PROGRESSION...IT COULD START OUT WITH PARTIAL SUNSHINE AND WITH
+21C AT 925 MB...TEMPERATURES COULD SOAR WELL INTO THE 80S BY LATE
MORNING SETTING THE STAGE FOR STRONG THUNDERSTORMS IN THE
AFTERNOON. A QUICKER FRONT WOULD STILL PRODUCE SHOWERS AND
THUNDERSTORMS...BUT NOT AS STRONG. HAVE INCREASED POPS TO AROUND
50 PERCENT WHICH IS FAIRLY HIGH THAT FAR IN ADVANCE. GFS HAS
SURFACE DEWPOINTS CLIMBING INTO 70S AND CORRESPONDINGLY ITS LIFTED
INDICES DECREASE TO -8 TO -10 ACROSS THE REGION. THE ECMWF IS ALSO
UNSTABLE BUT LESS SO...WITH DEWPOINTS IN THE MID 60S AND LIFTED
INDICES OF -3 TO -4. HAVE RAISED DEWPOINT TEMPERATURES ABOVE
GUIDANCE...INTO THE MID AND UPPER 60S. WIND FIELDS ARE RATHER
UNIDIRECTIONAL AND NOT THAT STRONG WHICH POINTS MORE TO LOCALLY
HEAVY RAINS THAN SEVERE...BUT THIS IS STILL A LONG WAY OUT.
SUNDAY AND MONDAY...
SOME DISPARITY IN MODEL SOLUTIONS. BUT IN GENERAL AM EXPECTING
HIGH PRESSURE OVER NORTHERN NEW ENGLAND TO WORK ITS WAY EASTWARD
TO NOVA SCOTIA. IT SHOULD PROVIDE NORTHEAST WINDS SUNDAY BRINGING
COOLER TEMPERATURES ALONG THE IMMEDIATE EAST COAST...WITH HIGHS
ONLY NEAR 70 THERE...BUT MAINLY 75 TO 80 INLAND. WINDS WILL TURN
SOUTHEAST TO SOUTH BEHIND THE HIGH ON MEMORIAL DAY. SKIES SHOULD
BE MOSTLY SUNNY SUNDAY AND PARTLY SUNNY MONDAY. A FRONT WILL
APPROACH LATER MONDAY NIGHT WITH A SLIGHT CHANCE OF SHOWERS IN
WESTERN AREAS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
TONIGHT...HIGH CONFIDENCE CIGS WILL REMAIN IFR WITH AREAS OF LIFR
OVERNIGHT. LOW TO MODERATE CONFIDENCE WITH VSBYS...MAINLY IFR IN
FOG AND DRIZZLE BUT COULD BE MVFR AT TIMES AT THE SURFACE.
ISOLATED SHOWERS.
TUESDAY...LOW CONFIDENCE CIGS AND VSBYS WILL
IMPROVE BY MIDDAY...AND MAY REACH VFR IN THE INTERIOR. EAST
COASTAL AREAS WILL IMPROVE TO MVFR...BUT SOUTH COASTAL AREAS
INCLUDING CAPE COD SHOULD HOLD AT IFR. LOW PRESSURE OFFSHORE WILL
PASS US AROUND MIDDAY AND MOVE OUT TO SEA. THIS WILL BRING
CHANGEABLE WINDS OVER NEW ENGLAND DURING THE AFTERNOON.
TUESDAY NIGHT...
LIGHT WIND AND LOTS OF MOISTURE WILL MEAN POTENTIAL FOR FOG/LOW
CLOUDS BRINGING WIDESPREAD IFR/LIFR.
KBOS TAF...HIGH CONFIDENCE IN CEILINGS BELOW 500 FT OVERNIGHT.
VSBYS AT THE SURFACE MAY IMPROVE TO UNRESTRICTED BUT WILL BE 1-3
MILES IN FOG JUST ABOVE THE RUNWAYS. VSBYS LOWER TO 1 MILE TONIGHT
WITH POTENTIAL FOR PERIODS OF 1/2 MILE. IMPROVEMENT TO MVFR CIGS
AND VFR VSBYS ON TUESDAY.
KBDL TAF...MODERATE CONFIDENCE. MVFR CIGS WILL LOWER TO IFR
TONIGHT. SHOWERS AND AREAS OF LIGHT FOG MAY BRING MVFR VSBYS.
OUTLOOK...WEDNESDAY THOUGH SATURDAY...
WED THROUGH THU NIGHT...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR
CIGS/VSBYS IN VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS MAINLY
IN WESTERN MA AND SOUTHERN NH. PATCHY STRATUS AND FOG WITH IFR
CIGS/VSBYS MAY FORM AT NIGHT.
FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS. POSSIBLE PATCHY
FOG WITH MVFR LATE AT NIGHT.
SAT...MODERATE CONFIDENCE. VFR BECOMING MVFR CEILINGS IN SHOWERS
AND THUNDERSTORMS. ISOLATED IFR VISIBILITIES POSSIBLE IN HEAVIER
THUNDERSTORMS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY NIGHT.
SOUTH TO SOUTHEAST SWELL WILL BUILD TO 7 FEET BY TUESDAY ACROSS
THE OUTER WATERS. SWELL OF 5-6 FEET WILL ALSO REACH EXPOSED
WATERS SUCH AS RI SOUND AND BID SOUND. SWELL WILL SUBSIDE TUESDAY
NIGHT...BUT REMAIN A SOURCE OF CONCERN. THE WAVEWATCH AND SWAN
WAVE MODELS WERE CLOSE ENOUGH SO THAT WE USED A BLEND OF THE
TWO.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES TUESDAY.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS HAS BEEN EXTENDED THROUGH
TUESDAY NIGHT...AND EXPANDED TO INCLUDE RI SOUND AND BID SOUND.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SWELLS SUBSIDING TO BELOW 5 FT BY WED NIGHT.
SEAS MAY INCREASE AGAIN TO 5 FT BY SAT AS A FRONT APPROACHES.
SOUTHERLY WINDS MAY GUST TO 20 KT FROM TIME TO TIME WED THROUGH
FRI...WITH SOUTHWEST WINDS SAT APPROACHING 25 KT GUSTS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT
WEDNESDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 8 AM THIS MORNING
TO 6 AM EDT WEDNESDAY FOR ANZ235-237.
&&
$$
SYNOPSIS...WTB/GAF
NEAR TERM...KJC
SHORT TERM...WTB
LONG TERM...GAF
AVIATION...WTB/GAF
MARINE...WTB/GAF
000
FXUS61 KBOX 220155
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
955 PM EDT MON MAY 21 2012
.SYNOPSIS...
LOW PRESSURE OFF THE CAROLINAS WILL TRACK UP THE COAST...BRINGING
SHOWERS THROUGH TUESDAY. HIGH PRESSURE WILL REMAIN STATIONARY OFF
THE COAST OF MAINE AND NOVA SCOTIA WEDNESDAY THROUGH FRIDAY WITH A
MOIST AIR FLOW CAUSING CLOUDS AND A FEW SHOWERS OR THUNDERSTORMS
MAINLY IN NORTHERN AND WESTERN AREAS. A COLD FRONT MAY PRODUCE
SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON SATURDAY.
COOLER HIGH PRESSURE FOR SUNDAY...THEN ANOTHER FRONT APPROACHES
LATE MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
10 PM UPDATE...
SNE LARGELY PRECIP FREE THIS EVENING AS ONE AREA OF SHOWERS LIFTS
TO THE N. HOWEVER...WIDELY SCT SHOWERS DEVELOPING JUST S OF NEW
ENG WILL MOVE NWD ACROSS PORTIONS OF RI AND CT THIS EVENING...AND
MORE SHOWERS S OF LONG ISLAND EXPECTED TO LIFT NWD ACROSS SNE
OVERNIGHT. WV LOOP SHOWS MID LEVEL CIRCULATION OFF THE MID ATLC
COAST WITH WEAK SHORTWAVES LIFTING NWD.
NONE OF THE SHORT RANGE MODELS ARE HANDLING THE PRECIP
PARTICULARLY WELL AND IT APPEARS MAIN FOCUS WILL BE ACROSS SW NEW
ENG WHERE WE WILL HAVE LIKELY POPS...BUT HAVE LOWERED POPS TO CHC
ELSEWHERE.
IN ADDITION...ABUNDANT LOW LEVEL MOISTURE WILL RESULT IN AREAS OF
DENSE FOG NEAR THE COAST ALONG WITH PATCHY DRIZZLE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY...
LOW PRESSURE PASSES OFFSHORE OF NANTUCKET AROUND MIDDAY AND MOVES
OFF. THIS WILL CONTINUE THE LOW LEVEL FEED OF MOIST AIR INTO NEW
ENGLAND DURING THE MORNING. THIS FLOW THEN SHIFTS INTO MAINE BY
AFTERNOON. WILL MAINTAIN CHANCE POPS ALTHOUGH WITH A DIMINISHING
TREND IN THE AFTERNOON AS THE LOW MOVES OFF. THE LOW REMAINS FAR
ENOUGH OFFSHORE TO KEEP ANY STRONG WINDS OFFSHORE AS WELL.
CLOUDS AND SHOWERS SHOULD HOLD TEMPS FROM THEIR FULL HEATING
POTENTIAL. BUT BREAKS IN THE CLOUDS IN THE AFTERNOON WILL ALLOW
SOME HEATING. MIXING POTENTIAL IS FORECAST AT 3500-4000 FEET.
TEMPS AT 900 MB WILL BE 12-13C...SIMILAR TO 7-8C FROM 850 MB. SO
MAX TEMPS SHOULD BE IN THE LOW TO MID 70S. WE AGAIN USED THE B-C
MAV VALUES.
TUESDAY NIGHT...
ALTHOUGH THE SURFACE LOW MOVES OFF PAST NOVA SCOTIA...THE UPPER
LOW REMAINS IN PLACE OVER THE NORTHEAST USA WITH LOTS OF MOISTURE
TRAPPED IN THE AIRMASS OVER NEW ENGLAND. NIGHTTIME COOLING WILL
WORK AGAINST BREAKING THE CLOUD COVER. THE ECMWF FORECASTS
LINGERING LIFT OVER OUR NORTHWEST AREAS. SO WE WILL GO WITH A
CLOUDY FORECAST WITH LINGERING CHANCE POPS MAINLY OVER OUR
NORTHWEST AREAS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
OVERVIEW...
UPPER LEVEL LOW PRESSURE WILL CONTINUE TO SLOWLY MOVE NORTHEAST
SOUTH OF THE CANADIAN MARITIME PROVINCES FROM MID TO LATE IN THE
WEEK. MODELS THEN DIFFER IN THE HANDLING OF UPPER LEVEL FEATURES.
THE CANADIAN MODEL KEEPS AN UPPER LOW PARKED OVER THE MID ATLANTIC
COAST WHICH PARTIALLY DISRUPTS THE BUILDING UPPER RIDGE. HAVE
DISREGARDED THIS SOLUTION BECAUSE THE GFS AND ECMWF ARE BOTH QUITE
EMPHATIC ABOUT VERY STRONG BUILDING HEIGHTS FROM THE TENNESSEE
VALLEY TO SOUTHERN NEW ENGLAND BY SATURDAY. ALSO IMPORTANT TO NOTE
THAT THE CANADIAN HAS ABANDONED THE IDEA OF A BIG STORM MOVING
BODILY NORTHWARD TOWARD NEW ENGLAND FOR FRIDAY. AM EXPECTING A
COLD FRONT TO TRAVERSE THE REGION SATURDAY AFTERNOON WITH A GOOD
CHANCE OF SHOWERS AND THUNDERSTORMS. LOOKS LIKE DRY COOLER HIGH
PRESSURE ON NORTHEAST WINDS FOR SUNDAY. MEMORIAL DAY RIGHT NOW
APPEARS DRY WITH WARM TEMPERATURES AND WINDS RETURNING TO A
SOUTHERLY DIRECTION AHEAD OF ANOTHER APPROACHING FRONT.
DAY TO DAY DETAILS...
WEDNESDAY THROUGH FRIDAY...
GENERALLY A MOSTLY CLOUDY PERIOD...BUT GRADUALLY INCREASING SUNSHINE
BY FRIDAY. AFTERNOON HIGHS SHOULD BE IN THE UPPER 70S TO LOWER 80S WITH
DEWPOINT TEMPERATURES HANGING AROUND THE UPPER 50S TO LOWER 60S.
INSTABILITY IS PRESENT BUT WEAK IN THE NORTHWEST THIRD OF THE
REGION...SO THERE COULD POSSIBLY BE A FEW SHOWERS OR THUNDERSTORMS
THERE EACH AFTERNOON AND EARLY EVENING. A TRIGGER MECHANISM IS
LACKING HOWEVER...THUS ANY ACTIVITY SHOULD QUICKLY DIMINISH AFTER SUNSET.
SATURDAY...
STRONG SHORT WAVE TROUGH PROGRESSING ACROSS SOUTHERN CANADA HAS AN
ASSOCIATED COLD FRONT THAT SWINGS THROUGH SOUTHERN NEW ENGLAND
DURING THE DAY ON SATURDAY. AT 12Z SATURDAY THE ECMWF HAS THE
FRONT STILL WAY OUT IN WESTERN NEW YORK STATE WHEREAS THE FASTER
GFS HAS IT MOVING INTO EASTERN NEW YORK STATE. THIS DISCREPANCY COULD
BE SIGNIFICANT. IF THE ECMWF IS RIGHT AND THERE IS A SLOWER
PROGRESSION...IT COULD START OUT WITH PARTIAL SUNSHINE AND WITH
+21C AT 925 MB...TEMPERATURES COULD SOAR WELL INTO THE 80S BY LATE
MORNING SETTING THE STAGE FOR STRONG THUNDERSTORMS IN THE
AFTERNOON. A QUICKER FRONT WOULD STILL PRODUCE SHOWERS AND
THUNDERSTORMS...BUT NOT AS STRONG. HAVE INCREASED POPS TO AROUND
50 PERCENT WHICH IS FAIRLY HIGH THAT FAR IN ADVANCE. GFS HAS
SURFACE DEWPOINTS CLIMBING INTO 70S AND CORRESPONDINGLY ITS LIFTED
INDICES DECREASE TO -8 TO -10 ACROSS THE REGION. THE ECMWF IS ALSO
UNSTABLE BUT LESS SO...WITH DEWPOINTS IN THE MID 60S AND LIFTED
INDICES OF -3 TO -4. HAVE RAISED DEWPOINT TEMPERATURES ABOVE
GUIDANCE...INTO THE MID AND UPPER 60S. WIND FIELDS ARE RATHER
UNIDIRECTIONAL AND NOT THAT STRONG WHICH POINTS MORE TO LOCALLY
HEAVY RAINS THAN SEVERE...BUT THIS IS STILL A LONG WAY OUT.
SUNDAY AND MONDAY...
SOME DISPARITY IN MODEL SOLUTIONS. BUT IN GENERAL AM EXPECTING
HIGH PRESSURE OVER NORTHERN NEW ENGLAND TO WORK ITS WAY EASTWARD
TO NOVA SCOTIA. IT SHOULD PROVIDE NORTHEAST WINDS SUNDAY BRINGING
COOLER TEMPERATURES ALONG THE IMMEDIATE EAST COAST...WITH HIGHS
ONLY NEAR 70 THERE...BUT MAINLY 75 TO 80 INLAND. WINDS WILL TURN
SOUTHEAST TO SOUTH BEHIND THE HIGH ON MEMORIAL DAY. SKIES SHOULD
BE MOSTLY SUNNY SUNDAY AND PARTLY SUNNY MONDAY. A FRONT WILL
APPROACH LATER MONDAY NIGHT WITH A SLIGHT CHANCE OF SHOWERS IN
WESTERN AREAS.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
TONIGHT...HIGH CONFIDENCE CIGS WILL REMAIN IFR WITH AREAS OF LIFR
OVERNIGHT. LOW TO MODERATE CONFIDENCE WITH VSBYS...MAINLY IFR IN
FOG AND DRIZZLE BUT COULD BE MVFR AT TIMES AT THE SURFACE.
ISOLATED SHOWERS.
TUESDAY...LOW CONFIDENCE CIGS AND VSBYS WILL
IMPROVE BY MIDDAY...AND MAY REACH VFR IN THE INTERIOR. EAST
COASTAL AREAS WILL IMPROVE TO MVFR...BUT SOUTH COASTAL AREAS
INCLUDING CAPE COD SHOULD HOLD AT IFR. LOW PRESSURE OFFSHORE WILL
PASS US AROUND MIDDAY AND MOVE OUT TO SEA. THIS WILL BRING
CHANGEABLE WINDS OVER NEW ENGLAND DURING THE AFTERNOON.
TUESDAY NIGHT...
LIGHT WIND AND LOTS OF MOISTURE WILL MEAN POTENTIAL FOR FOG/LOW
CLOUDS BRINGING WIDESPREAD IFR/LIFR.
KBOS TAF...HIGH CONFIDENCE IN CEILINGS BELOW 500 FT OVERNIGHT.
VSBYS AT THE SURFACE MAY IMPROVE TO UNRESTRICTED BUT WILL BE 1-3
MILES IN FOG JUST ABOVE THE RUNWAYS. VSBYS LOWER TO 1 MILE TONIGHT
WITH POTENTIAL FOR PERIODS OF 1/2 MILE. IMPROVEMENT TO MVFR CIGS
AND VFR VSBYS ON TUESDAY.
KBDL TAF...MODERATE CONFIDENCE. MVFR CIGS WILL LOWER TO IFR
TONIGHT. SHOWERS AND AREAS OF LIGHT FOG MAY BRING MVFR VSBYS.
OUTLOOK...WEDNESDAY THOUGH SATURDAY...
WED THROUGH THU NIGHT...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR
CIGS/VSBYS IN VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS MAINLY
IN WESTERN MA AND SOUTHERN NH. PATCHY STRATUS AND FOG WITH IFR
CIGS/VSBYS MAY FORM AT NIGHT.
FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS. POSSIBLE PATCHY
FOG WITH MVFR LATE AT NIGHT.
SAT...MODERATE CONFIDENCE. VFR BECOMING MVFR CEILINGS IN SHOWERS
AND THUNDERSTORMS. ISOLATED IFR VISIBILITIES POSSIBLE IN HEAVIER
THUNDERSTORMS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY NIGHT.
SOUTH TO SOUTHEAST SWELL WILL BUILD TO 7 FEET BY TUESDAY ACROSS
THE OUTER WATERS. SWELL OF 5-6 FEET WILL ALSO REACH EXPOSED
WATERS SUCH AS RI SOUND AND BID SOUND. SWELL WILL SUBSIDE TUESDAY
NIGHT...BUT REMAIN A SOURCE OF CONCERN. THE WAVEWATCH AND SWAN
WAVE MODELS WERE CLOSE ENOUGH SO THAT WE USED A BLEND OF THE
TWO.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES TUESDAY.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS HAS BEEN EXTENDED THROUGH
TUESDAY NIGHT...AND EXPANDED TO INCLUDE RI SOUND AND BID SOUND.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SWELLS SUBSIDING TO BELOW 5 FT BY WED NIGHT.
SEAS MAY INCREASE AGAIN TO 5 FT BY SAT AS A FRONT APPROACHES.
SOUTHERLY WINDS MAY GUST TO 20 KT FROM TIME TO TIME WED THROUGH
FRI...WITH SOUTHWEST WINDS SAT APPROACHING 25 KT GUSTS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT
WEDNESDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 8 AM TUESDAY TO 6
AM EDT WEDNESDAY FOR ANZ235-237.
&&
$$
SYNOPSIS...WTB/GAF
NEAR TERM...KJC
SHORT TERM...WTB
LONG TERM...GAF
AVIATION...WTB/GAF
MARINE...WTB/GAF
000
FXUS61 KBOX 212320
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
720 PM EDT MON MAY 21 2012
.SYNOPSIS...
LOW PRESSURE OFF THE CAROLINAS WILL TRACK UP THE COAST...BRINGING
SHOWERS THROUGH TUESDAY. HIGH PRESSURE WILL REMAIN STATIONARY OFF
THE COAST OF MAINE AND NOVA SCOTIA WEDNESDAY THROUGH FRIDAY WITH A
MOIST AIR FLOW CAUSING CLOUDS AND A FEW SHOWERS OR THUNDERSTORMS
MAINLY IN NORTHERN AND WESTERN AREAS. A COLD FRONT MAY PRODUCE
SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON SATURDAY.
COOLER HIGH PRESSURE FOR SUNDAY...THEN ANOTHER FRONT APPROACHES
LATE MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
715 PM UPDATE...
LOWERED TEMPERATURES OVER NE MA AS ALREADY AROUND 57 IN ESSEX COUNTY.
RAISED DEWPOINTS TO NEAR 60 IN SOUTHERN HALF OF THE AREA PER
CURRENT OBSERVATIONS. LOWERED POPS FOR A FEW HOURS THIS EVENING IN
EASTERN MA AND RI AS SINGLE BAND OF SHOWERS HAS MOVED NORTHWARD
TO NEAR THE MA/NH BORDER. SATELLITE IMAGERY SHOWS THAT CLOUD TOPS
HAVE WARMED IN THE BAND OF ENHANCEMENT THAT HAD BEEN LIFTING
NORTHWARD ALONG 70W. THIS MAY TRANSLATE INTO LESS RAIN THAN
ANTICIPATED FOR EASTERN SECTIONS OVERNIGHT... WILL SEE IF THAT
TREND CONTINUES.
PREVIOUS DISCUSSION...
MAIN BAND OF SHOWERS HAS REMAINED IN NYC/EASTERN NY/WESTERN CT.
FARTHER EAST SCATTERED SHOWERS POPPED DURING THE AFTERNOON BUT
COVERAGE IS FAR LESS THAN WHAT WAS ANTICIPATED. MODELS CONTINUE TO
PAINT BROAD AREAS OF 1/4 TO 1/2 INCH RAIN ACROSS SOUTHERN NEW
ENGLAND WHICH SEEMS TO BE OUT OF PROPORTION TO WHAT SHOULD FALL BY
THIS EVENING. AT LEAST THE ECMWF SHOWS A GRADIENT WITH NEAR ZERO
PCPN ACROSS BOSTON AND THE NORTH SHORE.
SATELLITE SHOWS TWO AREAS OF COOLER CLOUD TOPS OVER THE OCEAN. ONE
IS OVER 70W AND THE OTHER IS WELL EAST OF 70W. THE ONE OVER 70W
SEEMS TO BE IN POSITION TO MOVE UP ACROSS SOUTHERN NEW
ENGLAND THIS EVENING...THAT SUGGESTS AT LEAST SOME SHOWERS.
THE BEST CHANCE OF SHOWERS SHOULD BE IN THE CT VALLEY/EAST SLOPE
AREAS THAT ARE CLOSEST TO THE EXISTING BAND OF RAIN.
PRECIPITABLE WATER VALUES OF 1.5 INCHES CONTINUE TO FEED IN FROM
THE OCEAN...SO POTENTIAL CONTINUES FOR LOCALIZED DOWNPOURS.
OBSERVED DEWPOINTS IN THE MID 50S TO AROUND 60...THIS SHOULD FORM
A BASE FOR MIN TEMPS TONIGHT. BIAS CORRECTED MAV VALUES WERE USED
FOR TEMPERATURES/DEWPOINTS.
CONFIDENCE IN THIS PERIOD IS LOW.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY...
LOW PRESSURE PASSES OFFSHORE OF NANTUCKET AROUND MIDDAY AND MOVES
OFF. THIS WILL CONTINUE THE LOW LEVEL FEED OF MOIST AIR INTO NEW
ENGLAND DURING THE MORNING. THIS FLOW THEN SHIFTS INTO MAINE BY
AFTERNOON. WILL MAINTAIN CHANCE POPS ALTHOUGH WITH A DIMINISHING
TREND IN THE AFTERNOON AS THE LOW MOVES OFF. THE LOW REMAINS FAR
ENOUGH OFFSHORE TO KEEP ANY STRONG WINDS OFFSHORE AS WELL.
CLOUDS AND SHOWERS SHOULD HOLD TEMPS FROM THEIR FULL HEATING
POTENTIAL. BUT BREAKS IN THE CLOUDS IN THE AFTERNOON WILL ALLOW
SOME HEATING. MIXING POTENTIAL IS FORECAST AT 3500-4000 FEET.
TEMPS AT 900 MB WILL BE 12-13C...SIMILAR TO 7-8C FROM 850 MB. SO
MAX TEMPS SHOULD BE IN THE LOW TO MID 70S. WE AGAIN USED THE B-C
MAV VALUES.
TUESDAY NIGHT...
ALTHOUGH THE SURFACE LOW MOVES OFF PAST NOVA SCOTIA...THE UPPER
LOW REMAINS IN PLACE OVER THE NORTHEAST USA WITH LOTS OF MOISTURE
TRAPPED IN THE AIRMASS OVER NEW ENGLAND. NIGHTTIME COOLING WILL
WORK AGAINST BREAKING THE CLOUD COVER. THE ECMWF FORECASTS
LINGERING LIFT OVER OUR NORTHWEST AREAS. SO WE WILL GO WITH A
CLOUDY FORECAST WITH LINGERING CHANCE POPS MAINLY OVER OUR
NORTHWEST AREAS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
OVERVIEW...
UPPER LEVEL LOW PRESSURE WILL CONTINUE TO SLOWLY MOVE NORTHEAST
SOUTH OF THE CANADIAN MARITIME PROVINCES FROM MID TO LATE IN THE
WEEK. MODELS THEN DIFFER IN THE HANDLING OF UPPER LEVEL FEATURES.
THE CANADIAN MODEL KEEPS AN UPPER LOW PARKED OVER THE MID ATLANTIC
COAST WHICH PARTIALLY DISRUPTS THE BUILDING UPPER RIDGE. HAVE
DISREGARDED THIS SOLUTION BECAUSE THE GFS AND ECMWF ARE BOTH QUITE
EMPHATIC ABOUT VERY STRONG BUILDING HEIGHTS FROM THE TENNESSEE
VALLEY TO SOUTHERN NEW ENGLAND BY SATURDAY. ALSO IMPORTANT TO NOTE
THAT THE CANADIAN HAS ABANDONED THE IDEA OF A BIG STORM MOVING
BODILY NORTHWARD TOWARD NEW ENGLAND FOR FRIDAY. AM EXPECTING A
COLD FRONT TO TRAVERSE THE REGION SATURDAY AFTERNOON WITH A GOOD
CHANCE OF SHOWERS AND THUNDERSTORMS. LOOKS LIKE DRY COOLER HIGH
PRESSURE ON NORTHEAST WINDS FOR SUNDAY. MEMORIAL DAY RIGHT NOW
APPEARS DRY WITH WARM TEMPERATURES AND WINDS RETURNING TO A
SOUTHERLY DIRECTION AHEAD OF ANOTHER APPROACHING FRONT.
DAY TO DAY DETAILS...
WEDNESDAY THROUGH FRIDAY...
GENERALLY A MOSTLY CLOUDY PERIOD...BUT GRADUALLY INCREASING SUNSHINE
BY FRIDAY. AFTERNOON HIGHS SHOULD BE IN THE UPPER 70S TO LOWER 80S WITH
DEWPOINT TEMPERATURES HANGING AROUND THE UPPER 50S TO LOWER 60S.
INSTABILITY IS PRESENT BUT WEAK IN THE NORTHWEST THIRD OF THE
REGION...SO THERE COULD POSSIBLY BE A FEW SHOWERS OR THUNDERSTORMS
THERE EACH AFTERNOON AND EARLY EVENING. A TRIGGER MECHANISM IS
LACKING HOWEVER...THUS ANY ACTIVITY SHOULD QUICKLY DIMINISH AFTER SUNSET.
SATURDAY...
STRONG SHORT WAVE TROUGH PROGRESSING ACROSS SOUTHERN CANADA HAS AN
ASSOCIATED COLD FRONT THAT SWINGS THROUGH SOUTHERN NEW ENGLAND
DURING THE DAY ON SATURDAY. AT 12Z SATURDAY THE ECMWF HAS THE
FRONT STILL WAY OUT IN WESTERN NEW YORK STATE WHEREAS THE FASTER
GFS HAS IT MOVING INTO EASTERN NEW YORK STATE. THIS DISCREPANCY COULD
BE SIGNIFICANT. IF THE ECMWF IS RIGHT AND THERE IS A SLOWER
PROGRESSION...IT COULD START OUT WITH PARTIAL SUNSHINE AND WITH
+21C AT 925 MB...TEMPERATURES COULD SOAR WELL INTO THE 80S BY LATE
MORNING SETTING THE STAGE FOR STRONG THUNDERSTORMS IN THE
AFTERNOON. A QUICKER FRONT WOULD STILL PRODUCE SHOWERS AND
THUNDERSTORMS...BUT NOT AS STRONG. HAVE INCREASED POPS TO AROUND
50 PERCENT WHICH IS FAIRLY HIGH THAT FAR IN ADVANCE. GFS HAS
SURFACE DEWPOINTS CLIMBING INTO 70S AND CORRESPONDINGLY ITS LIFTED
INDICES DECREASE TO -8 TO -10 ACROSS THE REGION. THE ECMWF IS ALSO
UNSTABLE BUT LESS SO...WITH DEWPOINTS IN THE MID 60S AND LIFTED
INDICES OF -3 TO -4. HAVE RAISED DEWPOINT TEMPERATURES ABOVE
GUIDANCE...INTO THE MID AND UPPER 60S. WIND FIELDS ARE RATHER
UNIDIRECTIONAL AND NOT THAT STRONG WHICH POINTS MORE TO LOCALLY
HEAVY RAINS THAN SEVERE...BUT THIS IS STILL A LONG WAY OUT.
SUNDAY AND MONDAY...
SOME DISPARITY IN MODEL SOLUTIONS. BUT IN GENERAL AM EXPECTING
HIGH PRESSURE OVER NORTHERN NEW ENGLAND TO WORK ITS WAY EASTWARD
TO NOVA SCOTIA. IT SHOULD PROVIDE NORTHEAST WINDS SUNDAY BRINGING
COOLER TEMPERATURES ALONG THE IMMEDIATE EAST COAST...WITH HIGHS
ONLY NEAR 70 THERE...BUT MAINLY 75 TO 80 INLAND. WINDS WILL TURN
SOUTHEAST TO SOUTH BEHIND THE HIGH ON MEMORIAL DAY. SKIES SHOULD
BE MOSTLY SUNNY SUNDAY AND PARTLY SUNNY MONDAY. A FRONT WILL
APPROACH LATER MONDAY NIGHT WITH A SLIGHT CHANCE OF SHOWERS IN
WESTERN AREAS.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
TONIGHT...HIGH CONFIDENCE CIGS WILL REMAIN IFR WITH AREAS OF LIFR
OVERNIGHT. LOW TO MODERATE CONFIDENCE WITH VSBYS...MAINLY IFR IN
FOG AND DRIZZLE BUT COULD BE MVFR AT TIMES AT THE SURFACE.
ISOLATED SHOWERS.
TUESDAY...LOW CONFIDENCE CIGS AND VSBYS WILL
IMPROVE BY MIDDAY...AND MAY REACH VFR IN THE INTERIOR. EAST
COASTAL AREAS WILL IMPROVE TO MVFR...BUT SOUTH COASTAL AREAS
INCLUDING CAPE COD SHOULD HOLD AT IFR. LOW PRESSURE OFFSHORE WILL
PASS US AROUND MIDDAY AND MOVE OUT TO SEA. THIS WILL BRING
CHANGEABLE WINDS OVER NEW ENGLAND DURING THE AFTERNOON.
TUESDAY NIGHT...
LIGHT WIND AND LOTS OF MOISTURE WILL MEAN POTENTIAL FOR FOG/LOW
CLOUDS BRINGING WIDESPREAD IFR/LIFR.
KBOS TAF...HIGH CONFIDENCE IN CEILINGS BELOW 500 FT OVERNIGHT.
VSBYS AT THE SURFACE MAY IMPROVE TO UNRESTRICTED BUT WILL BE 1-3
MILES IN FOG JUST ABOVE THE RUNWAYS. VSBYS LOWER TO 1 MILE TONIGHT
WITH POTENTIAL FOR PERIODS OF 1/2 MILE. IMPROVEMENT TO MVFR CIGS
AND VFR VSBYS ON TUESDAY.
KBDL TAF...MODERATE CONFIDENCE. MVFR CIGS WILL LOWER TO IFR
TONIGHT. SHOWERS AND AREAS OF LIGHT FOG MAY BRING MVFR VSBYS.
OUTLOOK...WEDNESDAY THOUGH SATURDAY...
WED THROUGH THU NIGHT...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR
CIGS/VSBYS IN VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS MAINLY
IN WESTERN MA AND SOUTHERN NH. PATCHY STRATUS AND FOG WITH IFR
CIGS/VSBYS MAY FORM AT NIGHT.
FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS. POSSIBLE PATCHY
FOG WITH MVFR LATE AT NIGHT.
SAT...MODERATE CONFIDENCE. VFR BECOMING MVFR CEILINGS IN SHOWERS
AND THUNDERSTORMS. ISOLATED IFR VISIBILITIES POSSIBLE IN HEAVIER
THUNDERSTORMS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY NIGHT.
SOUTH TO SOUTHEAST SWELL WILL BUILD TO 7 FEET BY TUESDAY ACROSS
THE OUTER WATERS. SWELL OF 5-6 FEET WILL ALSO REACH EXPOSED
WATERS SUCH AS RI SOUND AND BID SOUND. SWELL WILL SUBSIDE TUESDAY
NIGHT...BUT REMAIN A SOURCE OF CONCERN. THE WAVEWATCH AND SWAN
WAVE MODELS WERE CLOSE ENOUGH SO THAT WE USED A BLEND OF THE
TWO.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES TUESDAY.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS HAS BEEN EXTENDED THROUGH
TUESDAY NIGHT...AND EXPANDED TO INCLUDE RI SOUND AND BID SOUND.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SWELLS SUBSIDING TO BELOW 5 FT BY WED NIGHT.
SEAS MAY INCREASE AGAIN TO 5 FT BY SAT AS A FRONT APPROACHES.
SOUTHERLY WINDS MAY GUST TO 20 KT FROM TIME TO TIME WED THROUGH
FRI...WITH SOUTHWEST WINDS SAT APPROACHING 25 KT GUSTS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT
WEDNESDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS
EVENING TO 6 AM EDT WEDNESDAY FOR ANZ235-237.
&&
$$
SYNOPSIS...WTB/GAF
NEAR TERM...WTB/GAF
SHORT TERM...WTB
LONG TERM...GAF
AVIATION...WTB/GAF
MARINE...WTB/GAF
000
FXUS61 KBOX 212054
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
454 PM EDT MON MAY 21 2012
.SYNOPSIS...
LOW PRESSURE OFF THE CAROLINAS WILL TRACK UP THE COAST...BRINGING
SHOWERS THROUGH TUESDAY. HIGH PRESSURE WILL REMAIN STATIONARY OFF
THE COAST OF MAINE AND NOVA SCOTIA WEDNESDAY THROUGH FRIDAY WITH A
MOIST AIR FLOW CAUSING CLOUDS AND A FEW SHOWERS OR THUNDERSTORMS
MAINLY IN NORTHERN AND WESTERN AREAS. A COLD FRONT MAY PRODUCE
SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON SATURDAY.
COOLER HIGH PRESSURE FOR SUNDAY...THEN ANOTHER FRONT APPROACHES
LATE MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
MAIN BAND OF SHOWERS HAS REMAINED IN NYC/EASTERN NY/WESTERN CT.
FARTHER EAST SCATTERED SHOWERS POPPED DURING THE AFTERNOON BUT
COVERAGE IS FAR LESS THAN WHAT WAS ANTICIPATED. MODELS CONTINUE TO
PAINT BROAD AREAS OF 1/4 TO 1/2 INCH RAIN ACROSS SOUTHERN NEW
ENGLAND WHICH SEEMS TO BE OUT OF PROPORTION TO WHAT SHOULD FALL BY
THIS EVENING. AT LEAST THE ECMWF SHOWS A GRADIENT WITH NEAR ZERO
PCPN ACROSS BOSTON AND THE NORTH SHORE.
SATELLITE SHOWS TWO AREAS OF COOLER CLOUD TOPS OVER THE OCEAN. ONE
IS OVER 70W AND THE OTHER IS WELL EAST OF 70W. THE ONE OVER 70W
SEEMS TO BE IN POSITION TO MOVE UP ACROSS SOUTHERN NEW
ENGLAND THIS EVENING...THAT SUGGESTS AT LEAST SOME SHOWERS.
THE BEST CHANCE OF SHOWERS SHOULD BE IN THE CT VALLEY/EAST SLOPE
AREAS THAT ARE CLOSEST TO THE EXISTING BAND OF RAIN.
PRECIPITABLE WATER VALUES OF 1.5 INCHES CONTINUE TO FEED IN FROM
THE OCEAN...SO POTENTIAL CONTINUES FOR LOCALIZED DOWNPOURS.
OBSERVED DEWPOINTS IN THE MID 50S TO AROUND 60...THIS SHOULD FORM
A BASE FOR MIN TEMPS TONIGHT. BIAS CORRECTED MAV VALUES WERE USED
FOR TEMPERATURES/DEWPOINTS.
CONFIDENCE IN THIS PERIOD IS LOW.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY...
LOW PRESSURE PASSES OFFSHORE OF NANTUCKET AROUND MIDDAY AND MOVES
OFF. THIS WILL CONTINUE THE LOW LEVEL FEED OF MOIST AIR INTO NEW
ENGLAND DURING THE MORNING. THIS FLOW THEN SHIFTS INTO MAINE BY
AFTERNOON. WILL MAINTAIN CHANCE POPS ALTHOUGH WITH A DIMINISHING
TREND IN THE AFTERNOON AS THE LOW MOVES OFF. THE LOW REMAINS FAR
ENOUGH OFFSHORE TO KEEP ANY STRONG WINDS OFFSHORE AS WELL.
CLOUDS AND SHOWERS SHOULD HOLD TEMPS FROM THEIR FULL HEATING
POTENTIAL. BUT BREAKS IN THE CLOUDS IN THE AFTERNOON WILL ALLOW
SOME HEATING. MIXING POTENTIAL IS FORECAST AT 3500-4000 FEET.
TEMPS AT 900 MB WILL BE 12-13C...SIMILAR TO 7-8C FROM 850 MB. SO
MAX TEMPS SHOULD BE IN THE LOW TO MID 70S. WE AGAIN USED THE B-C
MAV VALUES.
TUESDAY NIGHT...
ALTHOUGH THE SURFACE LOW MOVES OFF PAST NOVA SCOTIA...THE UPPER
LOW REMAINS IN PLACE OVER THE NORTHEAST USA WITH LOTS OF MOISTURE
TRAPPED IN THE AIRMASS OVER NEW ENGLAND. NIGHTTIME COOLING WILL
WORK AGAINST BREAKING THE CLOUD COVER. THE ECMWF FORECASTS
LINGERING LIFT OVER OUR NORTHWEST AREAS. SO WE WILL GO WITH A
CLOUDY FORECAST WITH LINGERING CHANCE POPS MAINLY OVER OUR
NORTHWEST AREAS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
OVERVIEW...
UPPER LEVEL LOW PRESSURE WILL CONTINUE TO SLOWLY MOVE NORTHEAST
SOUTH OF THE CANADIAN MARITIME PROVINCES FROM MID TO LATE IN THE
WEEK. MODELS THEN DIFFER IN THE HANDLING OF UPPER LEVEL FEATURES.
THE CANADIAN MODEL KEEPS AN UPPER LOW PARKED OVER THE MID ATLANTIC
COAST WHICH PARTIALLY DISRUPTS THE BUILDING UPPER RIDGE. HAVE
DISREGARDED THIS SOLUTION BECAUSE THE GFS AND ECMWF ARE BOTH QUITE
EMPHATIC ABOUT VERY STRONG BUILDING HEIGHTS FROM THE TENNESSEE
VALLEY TO SOUTHERN NEW ENGLAND BY SATURDAY. ALSO IMPORTANT TO NOTE
THAT THE CANADIAN HAS ABANDONED THE IDEA OF A BIG STORM MOVING
BODILY NORTHWARD TOWARD NEW ENGLAND FOR FRIDAY. AM EXPECTING A
COLD FRONT TO TRAVERSE THE REGION SATURDAY AFTERNOON WITH A GOOD
CHANCE OF SHOWERS AND THUNDERSTORMS. LOOKS LIKE DRY COOLER HIGH
PRESSURE ON NORTHEAST WINDS FOR SUNDAY. MEMORIAL DAY RIGHT NOW
APPEARS DRY WITH WARM TEMPERATURES AND WINDS RETURNING TO A
SOUTHERLY DIRECTION AHEAD OF ANOTHER APPROACHING FRONT.
DAY TO DAY DETAILS...
WEDNESDAY THROUGH FRIDAY...
GENERALLY A MOSTLY CLOUDY PERIOD...BUT GRADUALLY INCREASING SUNSHINE
BY FRIDAY. AFTERNOON HIGHS SHOULD BE IN THE UPPER 70S TO LOWER 80S WITH
DEWPOINT TEMPERATURES HANGING AROUND THE UPPER 50S TO LOWER 60S.
INSTABILITY IS PRESENT BUT WEAK IN THE NORTHWEST THIRD OF THE
REGION...SO THERE COULD POSSIBLY BE A FEW SHOWERS OR THUNDERSTORMS
THERE EACH AFTERNOON AND EARLY EVENING. A TRIGGER MECHANISM IS
LACKING HOWEVER...THUS ANY ACTIVITY SHOULD QUICKLY DIMINISH AFTER SUNSET.
SATURDAY...
STRONG SHORT WAVE TROUGH PROGRESSING ACROSS SOUTHERN CANADA HAS AN
ASSOCIATED COLD FRONT THAT SWINGS THROUGH SOUTHERN NEW ENGLAND
DURING THE DAY ON SATURDAY. AT 12Z SATURDAY THE ECMWF HAS THE
FRONT STILL WAY OUT IN WESTERN NEW YORK STATE WHEREAS THE FASTER
GFS HAS IT MOVING INTO EASTERN NEW YORK STATE. THIS DISCREPANCY COULD
BE SIGNIFICANT. IF THE ECMWF IS RIGHT AND THERE IS A SLOWER
PROGRESSION...IT COULD START OUT WITH PARTIAL SUNSHINE AND WITH
+21C AT 925 MB...TEMPERATURES COULD SOAR WELL INTO THE 80S BY LATE
MORNING SETTING THE STAGE FOR STRONG THUNDERSTORMS IN THE
AFTERNOON. A QUICKER FRONT WOULD STILL PRODUCE SHOWERS AND
THUNDERSTORMS...BUT NOT AS STRONG. HAVE INCREASED POPS TO AROUND
50 PERCENT WHICH IS FAIRLY HIGH THAT FAR IN ADVANCE. GFS HAS
SURFACE DEWPOINTS CLIMBING INTO 70S AND CORRESPONDINGLY ITS LIFTED
INDICES DECREASE TO -8 TO -10 ACROSS THE REGION. THE ECMWF IS ALSO
UNSTABLE BUT LESS SO...WITH DEWPOINTS IN THE MID 60S AND LIFTED
INDICES OF -3 TO -4. HAVE RAISED DEWPOINT TEMPERATURES ABOVE
GUIDANCE...INTO THE MID AND UPPER 60S. WIND FIELDS ARE RATHER
UNIDIRECTIONAL AND NOT THAT STRONG WHICH POINTS MORE TO LOCALLY
HEAVY RAINS THAN SEVERE...BUT THIS IS STILL A LONG WAY OUT.
SUNDAY AND MONDAY...
SOME DISPARITY IN MODEL SOLUTIONS. BUT IN GENERAL AM EXPECTING
HIGH PRESSURE OVER NORTHERN NEW ENGLAND TO WORK ITS WAY EASTWARD
TO NOVA SCOTIA. IT SHOULD PROVIDE NORTHEAST WINDS SUNDAY BRINGING
COOLER TEMPERATURES ALONG THE IMMEDIATE EAST COAST...WITH HIGHS
ONLY NEAR 70 THERE...BUT MAINLY 75 TO 80 INLAND. WINDS WILL TURN
SOUTHEAST TO SOUTH BEHIND THE HIGH ON MEMORIAL DAY. SKIES SHOULD
BE MOSTLY SUNNY SUNDAY AND PARTLY SUNNY MONDAY. A FRONT WILL
APPROACH LATER MONDAY NIGHT WITH A SLIGHT CHANCE OF SHOWERS IN
WESTERN AREAS.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 00Z...HIGH CONFIDENCE CIGS/LOW CONFIDENCE VSBYS
LIGHT EAST FLOW SHOULD MAINTAIN CIGS AROUND 500 FEET OR A LITTLE
LOWER THROUGH THE EVENING. FARTHER INLAND...CEILINGS WILL BE
1000-2000 FEET. VSBYS WILL BE VARIABLE...WITH LIFR/IFR OVER THE
CAPE AND ISLANDS AND MVFR OVER PARTS OF RI/SE MASS. BRIEF SHOWERS
WILL ALSO PRESENT A VARIABLE WITH CIGS/VSBYS BRIEFLY LOWERING AS
THE SHOWERS MOVE THROUGH.
TONIGHT...LOW-MODERATE CONFIDENCE
CIGS WILL REMAIN AROUND 500 FEET ALONG THE COAST AND LOWER TO 1000
FEET OR BELOW IN THE INTERIOR. VSBYS WILL LOWER AFTER
SUNSET...MOSTLY FROM FOG AND DRIZZLE BUT ALSO FROM SCATTERED
SHOWERS.
TUESDAY...LOW CONFIDENCE
CIGS AND VSBYS WILL IMPROVE BY MIDDAY...AND MAY REACH VFR IN THE
INTERIOR. EAST COASTAL AREAS WILL IMPROVE TO MVFR...BUT SOUTH
COASTAL AREAS INCLUDING CAPE COD SHOULD HOLD AT IFR. LOW PRESSURE
OFFSHORE WILL PASS US AROUND MIDDAY AND MOVE OUT TO SEA. THIS WILL
BRING CHANGEABLE WINDS OVER NEW ENGLAND DURING THE AFTERNOON.
TUESDAY NIGHT...
LIGHT WIND AND LOTS OF MOISTURE WILL MEAN POTENTIAL FOR FOG/LOW
CLOUDS BRINGING WIDESPREAD IFR/LIFR.
KBOS TAF...MODERATE CONFIDENCE. CEILINGS BELOW 1000 FEET THIS
EVENING AND BELOW 500 FEET AT NIGHT. VSBYS AT THE SURFACE MAY
IMPROVE TO UNRESTRICTED BUT WILL BE 1-3 MILES IN FOG JUST ABOVE
THE RUNWAYS. VSBYS LOWER TO 1 MILE TONIGHT WITH POTENTIAL FOR
PERIODS OF 1/2 MILE. IMPROVEMENT TO MVFR CIGS AND VFR VSBYS ON
TUESDAY.
KBDL TAF...MODERATE CONFIDENCE. MVFR CIGS WILL LOWER TO IFR
TONIGHT. SHOWERS AND AREAS OF LIGHT FOG MAY BRING MVFR VSBYS.
OUTLOOK...WEDNESDAY THOUGH SATURDAY...
WED THROUGH THU NIGHT...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR
CIGS/VSBYS IN VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS MAINLY
IN WESTERN MA AND SOUTHERN NH. PATCHY STRATUS AND FOG WITH IFR
CIGS/VSBYS MAY FORM AT NIGHT.
FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS. POSSIBLE PATCHY
FOG WITH MVFR LATE AT NIGHT.
SAT...MODERATE CONFIDENCE. VFR BECOMING MVFR CEILINGS IN SHOWERS
AND THUNDERSTORMS. ISOLATED IFR VISIBILITIES POSSIBLE IN HEAVIER
THUNDERSTORMS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY NIGHT.
SOUTH TO SOUTHEAST SWELL WILL BUILD TO 7 FEET BY TUESDAY ACROSS
THE OUTER WATERS. SWELL OF 5-6 FEET WILL ALSO REACH EXPOSED
WATERS SUCH AS RI SOUND AND BID SOUND. SWELL WILL SUBSIDE TUESDAY
NIGHT...BUT REMAIN A SOURCE OF CONCERN. THE WAVEWATCH AND SWAN
WAVE MODELS WERE CLOSE ENOUGH SO THAT WE USED A BLEND OF THE
TWO.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES TUESDAY.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS HAS BEEN EXTENDED THROUGH
TUESDAY NIGHT...AND EXPANDED TO INCLUDE RI SOUND AND BID SOUND.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SWELLS SUBSIDING TO BELOW 5 FT BY WED NIGHT.
SEAS MAY INCREASE AGAIN TO 5 FT BY SAT AS A FRONT APPROACHES.
SOUTHERLY WINDS MAY GUST TO 20 KT FROM TIME TO TIME WED THROUGH
FRI...WITH SOUTHWEST WINDS SAT APPROACHING 25 KT GUSTS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT
WEDNESDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS
EVENING TO 6 AM EDT WEDNESDAY FOR ANZ235-237.
&&
$$
SYNOPSIS...WTB/GAF
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...GAF
AVIATION...WTB/GAF
MARINE...WTB/GAF
000
FXUS61 KBOX 212021
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
421 PM EDT MON MAY 21 2012
.SYNOPSIS...
LOW PRESSURE OFF THE CAROLINAS WILL TRACK UP THE COAST...BRINGING
SHOWERS THROUGH TUESDAY. SCATTERED MAINLY AFTERNOON SHOWERS OR
THUNDERSTORMS ARE EXPECTED WEDNESDAY AFTERNOON. A COLD FRONT MAY
PRODUCE SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON
SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
MAIN BAND OF SHOWERS HAS REMAINED IN NYC/EASTERN NY/WESTERN CT.
FARTHER EAST SCATTERED SHOWERS POPPED DURING THE AFTERNOON BUT
COVERAGE IS FAR LESS THAN WHAT WAS ANTICIPATED. MODELS CONTINUE TO
PAINT BROAD AREAS OF 1/4 TO 1/2 INCH RAIN ACROSS SOUTHERN NEW
ENGLAND WHICH SEEMS TO BE OUT OF PROPORTION TO WHAT SHOULD FALL BY
THIS EVENING. AT LEAST THE ECMWF SHOWS A GRADIENT WITH NEAR ZERO
PCPN ACROSS BOSTON AND THE NORTH SHORE.
SATELLITE SHOWS TWO AREAS OF COOLER CLOUD TOPS OVER THE OCEAN. ONE
IS OVER 70W AND THE OTHER IS WELL EAST OF 70W. THE ONE OVER 70W
SEEMS TO BE IN POSITION TO MOVE UP ACROSS SOUTHERN NEW
ENGLAND THIS EVENING...THAT SUGGESTS AT LEAST SOME SHOWERS.
THE BEST CHANCE OF SHOWERS SHOULD BE IN THE CT VALLEY/EAST SLOPE
AREAS THAT ARE CLOSEST TO THE EXISTING BAND OF RAIN.
PRECIPITABLE WATER VALUES OF 1.5 INCHES CONTINUE TO FEED IN FROM
THE OCEAN...SO POTENTIAL CONTINUES FOR LOCALIZED DOWNPOURS.
OBSERVED DEWPOINTS IN THE MID 50S TO AROUND 60...THIS SHOULD FORM
A BASE FOR MIN TEMPS TONIGHT. BIAS CORRECTED MAV VALUES WERE USED
FOR TEMPERATURES/DEWPOINTS.
CONFIDENCE IN THIS PERIOD IS LOW.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY...
LOW PRESSURE PASSES OFFSHORE OF NANTUCKET AROUND MIDDAY AND MOVES
OFF. THIS WILL CONTINUE THE LOW LEVEL FEED OF MOIST AIR INTO NEW
ENGLAND DURING THE MORNING. THIS FLOW THEN SHIFTS INTO MAINE BY
AFTERNOON. WILL MAINTAIN CHANCE POPS ALTHOUGH WITH A DIMINISHING
TREND IN THE AFTERNOON AS THE LOW MOVES OFF. THE LOW REMAINS FAR
ENOUGH OFFSHORE TO KEEP ANY STRONG WINDS OFFSHORE AS WELL.
CLOUDS AND SHOWERS SHOULD HOLD TEMPS FROM THEIR FULL HEATING
POTENTIAL. BUT BREAKS IN THE CLOUDS IN THE AFTERNOON WILL ALLOW
SOME HEATING. MIXING POTENTIAL IS FORECAST AT 3500-4000 FEET.
TEMPS AT 900 MB WILL BE 12-13C...SIMILAR TO 7-8C FROM 850 MB. SO
MAX TEMPS SHOULD BE IN THE LOW TO MID 70S. WE AGAIN USED THE B-C
MAV VALUES.
TUESDAY NIGHT...
ALTHOUGH THE SURFACE LOW MOVES OFF PAST NOVA SCOTIA...THE UPPER
LOW REMAINS IN PLACE OVER THE NORTHEAST USA WITH LOTS OF MOISTURE
TRAPPED IN THE AIRMASS OVER NEW ENGLAND. NIGHTTIME COOLING WILL
WORK AGAINST BREAKING THE CLOUD COVER. THE ECMWF FORECASTS
LINGERING LIFT OVER OUR NORTHWEST AREAS. SO WE WILL GO WITH A
CLOUDY FORECAST WITH LINGERING CHANCE POPS MAINLY OVER OUR
NORTHWEST AREAS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
OVERVIEW...
VARIOUS LARGE SCALE PATTERN CHANGES ADVERTISED BY MEDIUM RANGE
MODELS DURING THIS FORECAST TIME PERIOD. BROAD DIFFUSE UPPER TROF
LOOKS TO PERSIST THROUGH MID WEEK ALONG THE EASTERN SEABOARD
FOLLOWED BY SIGNIFICANT LONG WAVE AMPLIFICATION ACROSS NORTH AMERICA
TOWARD END OF THE WEEK INTO THE WEEKEND WITH VERY ANOMALOUS MID
TROPOSPHERIC HEIGHT FALLS IN THE WEST AND RISES IN THE EAST. THEN
THERE LOOKS TO BE A TRANSITION TO A MORE ZONAL PATTERN FOR THE
FOLLOWING WEEK. FOR SOUTHERN NEW ENGLAND...WE START TO EXPERIENCE
BUILDING HEIGHTS TOWARD THE END OF THE WEEK ONLY TO HAVE A STRONG
ENOUGH SHORT WAVE TROF PROGRESSING ACROSS CANADA TO ARREST THIS
DEVELOPMENT AND BRING NW FLOW ALOFT TO THE REGION BY AT LEAST THE
SECOND HALF OF THE HOLIDAY WEEKEND. JUST HOW THIS UNFOLDS WILL
DETERMINE THE SENSIBLE WEATHER. THE 00Z GFS IS A LITTLE FASTER IN
ITS CFROPA COMPARED WITH THE 00Z ECMWF.
DAY TO DAY DETAILS...
TUE NIGHT THROUGH THU NIGHT... LARGE SCALE PATTERN
INFLUENCED BY BROAD UPPER LOW OVER MID ATLANTIC STATES THAT LIFTS
OUT AND DIMINISHES AS HEIGHTS ACROSS NEW ENGLAND AND SE CANADA
BUILD. CONDITIONS LOOK MARGINALLY UNSTABLE WED AND TO A LESSER
EXTENT THU AFTERNOON WITH RELATIVELY HIGH PWATS 1.25 TO 1.5
INCHES. AM FORECASTING SCT DIURNAL CONVECTION WED AFTERNOON INTO
THE EARLY EVENING AND TO A LESSER EXTENT THU AFTERNOON. NOTE BY
THU THAT A LOW/MID LEVEL RIDGE BUILDS FROM THE NW ATLANTIC INTO SE
CANADA AND NORTHERN NEW ENGLAND. NO SIGNIFICANT FORCING EITHER DAY
SO ANY SHOWERS/TSTMS MAY DEVELOP ON FAIRLY WEAK DIFFUSE BOUNDARIES
INCLUDING ANY OUTFLOW BOUNDARIES. JUST WENT SLIGHT CHANCE SE
COASTAL AREAS WHERE SURFACE BASED INSTABILITY IS LESS.
FRI...
HAVE GONE WITH A DRY SOLUTION AS BOTH GFS AND ECMWF SHOW RIDGING
OVER THE AREA. GEM BRINGS SIGNIFICANT LOW UP COAST ON FRI BUT THIS
APPEARS TO BE AN OUTLIER WITHOUT ANY SUPPORT FROM OTHER MEDIUM RANGE
MODELS.
SAT...
STRONG SHORT WAVE TROF PROGRESSING ACROSS SOUTHERN CANADA HAS
ASSOCIATED COLD FRONT THAT APPROACHES SAT AND THEN PROBABLY WASHES
OUT AS IT MOVES S OF THE AREA SAT NIGHT AND SUN. ECMWF SLOWER WITH
TIMING THAN GFS WHICH COULD PROVE CORRECT CONSIDERING THE STRENGTH
OF THE EASTERN RIDGE. NOT MUCH VERTICAL WIND SHEAR SHOWN AT THIS
TIME BUT UNSTABLE WITH MOISTURE POOLING TO SUPPORT CHANCE TSTMS SAT
AFTERNOON AND EVENING. ACTIVITY MIGHT LINGER FOR A WHILE SAT NIGHT
ALONG THE S COAST. HAVE MODERATE CONFIDENCE IN THIS SOLUTION DUE TO
REASONABLY GOOD MODEL CONTINUITY OF THIS FEATURE...ALTHOUGH A
STRONGER EXTENSION OF THE MAJOR EASTERN USA UPPER RIDGE COULD CAUSE
FRONT TO BECOME DELAYED OR STALL PRIOR TO MAKING IT THROUGH THE
AREA.
SUN...
EXPECT LOWER DEWPOINTS BUT SOME DISPARITY AS TO EXTENT OF COOLING
BETWEEN GFS AND ECMWF. ECMWF DOES NOT FLATTEN UPPER RIDGE AS MUCH AS
GFS...AND IN FACT KEEPS 850 MB TEMPS OF 16C OVER THE AREA. FOR NOW
HEDGED A LITTLE WARMER FROM GFS BASED SOLUTION TO REFLECT THIS
UNCERTAINTY.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 00Z...HIGH CONFIDENCE CIGS/LOW CONFIDENCE VSBYS
LIGHT EAST FLOW SHOULD MAINTAIN CIGS AROUND 500 FEET OR A LITTLE
LOWER THROUGH THE EVENING. FARTHER INLAND...CEILINGS WILL BE
1000-2000 FEET. VSBYS WILL BE VARIABLE...WITH LIFR/IFR OVER THE
CAPE AND ISLANDS AND MVFR OVER PARTS OF RI/SE MASS. BRIEF SHOWERS
WILL ALSO PRESENT A VARIABLE WITH CIGS/VSBYS BRIEFLY LOWERING AS
THE SHOWERS MOVE THROUGH.
TONIGHT...LOW-MODERATE CONFIDENCE
CIGS WILL REMAIN AROUND 500 FEET ALONG THE COAST AND LOWER TO 1000
FEET OR BELOW IN THE INTERIOR. VSBYS WILL LOWER AFTER
SUNSET...MOSTLY FROM FOG AND DRIZZLE BUT ALSO FROM SCATTERED
SHOWERS.
TUESDAY...LOW CONFIDENCE
CIGS AND VSBYS WILL IMPROVE BY MIDDAY...AND MAY REACH VFR IN THE
INTERIOR. EAST COASTAL AREAS WILL IMPROVE TO MVFR...BUT SOUTH
COASTAL AREAS INCLUDING CAPE COD SHOULD HOLD AT IFR. LOW PRESSURE
OFFSHORE WILL PASS US AROUND MIDDAY AND MOVE OUT TO SEA. THIS WILL
BRING CHANGEABLE WINDS OVER NEW ENGLAND DURING THE AFTERNOON.
TUESDAY NIGHT...
LIGHT WIND AND LOTS OF MOISTURE WILL MEAN POTENTIAL FOR FOG/LOW
CLOUDS BRINGING WIDESPREAD IFR/LIFR.
KBOS TAF...MODERATE CONFIDENCE. CEILINGS BELOW 1000 FEET THIS
EVENING AND BELOW 500 FEET AT NIGHT. VSBYS AT THE SURFACE MAY
IMPROVE TO UNRESTRICTED BUT WILL BE 1-3 MILES IN FOG JUST ABOVE
THE RUNWAYS. VSBYS LOWER TO 1 MILE TONIGHT WITH POTENTIAL FOR
PERIODS OF 1/2 MILE. IMPROVEMENT TO MVFR CIGS AND VFR VSBYS ON
TUESDAY.
KBDL TAF...MODERATE CONFIDENCE. MVFR CIGS WILL LOWER TO IFR
TONIGHT. SHOWERS AND AREAS OF LIGHT FOG MAY BRING MVFR VSBYS.
OUTLOOK...WEDNESDAY THOUGH FRIDAY...
WED...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR CIGS/VSBYS IN
VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS.
WED NIGHT...LOW TO MODERATE CONFIDENCE. PATCHY STRATUS AND FOG WITH
IFR CIGS/VSBYS.
THU THROUGH FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY NIGHT.
SOUTH TO SOUTHEAST SWELL WILL BUILD TO 7 FEET BY TUESDAY ACROSS
THE OUTER WATERS. SWELL OF 5-6 FEET WILL ALSO REACH EXPOSED
WATERS SUCH AS RI SOUND AND BID SOUND. SWELL WILL SUBSIDE TUESDAY
NIGHT...BUT REMAIN A SOURCE OF CONCERN. THE WAVEWATCH AND SWAN
WAVE MODELS WERE CLOSE ENOUGH SO THAT WE USED A BLEND OF THE
TWO.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES TUESDAY.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS HAS BEEN EXTENDED THROUGH
TUESDAY NIGHT...AND EXPANDED TO INCLUDE RI SOUND AND BID SOUND.
OUTLOOK...WEDNESDAY THROUGH FRIDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SUBSIDING SWELLS DURING THIS PERIOD. ONLY
UNCERTAINTY IS IF ALBERTO RETAINS A LITTLE MORE LIFE THAN EXPECTED
AND KEEPS SWELL HIGHER THAN CURRENTLY EXPECTED FOR THE MID WEEK TIME
PERIOD. NO SIGNIFICANT WINDS EXPECTED ACROSS THE COASTAL WATERS
DURING THIS TIME PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ254>256.
&&
$$
SYNOPSIS...WTB/THOMPSON
NEAR TERM...WTB/THOMPSON
SHORT TERM...WTB
LONG TERM...THOMPSON
AVIATION...WTB/THOMPSON
MARINE...WTB/THOMPSON
000
FXUS61 KBOX 211804
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
204 PM EDT MON MAY 21 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK UP THE COAST...BRINGING SHOWERS THROUGH
TONIGHT. SCATTERED MAINLY AFTERNOON SHOWERS OR THUNDERSTORMS ARE
EXPECTED BOTH TUESDAY AND WEDNESDAY AFTERNOON. A COLD FRONT MAY
PRODUCE SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...LOW CLOUDS/FOG/DRIZZLE HAVE MOVED UP THE COASTAL
PLAIN AND BY LATE MORNING EXTENDED FROM BOSTON TO WESTERLY. LOWEST
CONDITIONS ARE ALONG THE IMMEDIATE COAST WITH VSBYS 1 MILE OR
LESS. SOME SUN LINGERED IN SOUTHERN NH LATE MORNING BUT THE
MOVEMENT OF CLOUDS SHOULD COVER THE SKY THERE FOR THE AFTERNOON.
EXPECT THE FOG TO LINGER IN THE COASTAL PLAIN THROUGH THE
AFTERNOON. VSBYS SHOULD IMPROVE THIS AFTERNOON AS TEMPS CLIMB A
FEW MORE DEGREES. LOW CONFIDENCE ON THIS IMPROVEMENT HAPPENING
ALONG THE IMMEDIATE COAST...WHERE ONSHORE WINDS MAY KEEP TEMPS
COOLER AND DEWPOINTS HIGHER.
MOST OF THE OBSERVED SHOWERS HAVE BEEN MOVING NORTHWEST THROUGH
NYC AND SOUTHERN NY...ALSO NW INTO SOUTHERN NEW JERSEY. OKX RADAR
SHOWS SIGNS OF SHOWERS AT EXTREME RANGE VOER THE OFFSHORE WATERS
SOUTH OF NEW ENGLAND. EXTRAPOLATION OF THESE SHOWERS WOULD BRING
THEM TO THE SOUTH NEW ENGLAND COAST AROUND 18Z. THIS IS IN LINE
WITH OUR FORECAST OF LIKELY POPS TO THE COAST. WE HAVE SLOWED POPS
A LITTLE AND TIGHTENED THE GRADIENT FROM NIL POP TO LIKELY. BUT
OVERALL FORECAST REMAINS INTACT.
PREVIOUS DISCUSSION...
MOST OF THE LONG RANGE MODELS APPEARED IN FAIRLY GOOD AGREEMENT
FOR THIS PERIOD. ONLY OUTLIER NOTED WAS THE 00Z OP NAM RUN...WHICH
APPEARED TO DEVELOP A DEEPER LOW AND BRING IT UP THE COAST QUICKER
THAN THE GGEM/GFS OR ECWMF. EXPECT FIRST LOW TO PUSH INTO THE MID
ATLC COAST TODAY...THEN ANOTHER LOW WILL WORK UP THE COAST LATER
TODAY WHICH WILL BRING FIRST SLUG OF MOISTURE INTO THE REGION.
ALONG WITH INCREASING LOW LEVEL MOISTURE WORKING UP WITH THIS LOW
IS ALSO INCREASING PW/S...ON THE ORDER OF AROUND 1.5 INCHES BY
THIS EVENING. WILL ALSO SEE FAIRLY GOOD INSTABILITY WORKING
NORTHWARD AHEAD OF DEFORMATION ZONE/WARM FRONT. NOTING TQ VALUES
FOR ELEVATED INSTABILITY AT AROUND 20...WITH LIFTED INDICES AS LOW
AS -1 MOVING ACROSS FROM S-N THROUGH THE DAY. HAVE KEPT MENTION OF
ISOLD THUNDER IN THE GRIDS AND ZONES.
AS SHOWERS MOVE INTO THE REGION...SOME COULD BRING BRIEF HEAVY
DOWNPOURS MAINLY THIS AFTERNOON BUT NOT EXPECTING WIDESPREAD HEAVY
RAINFALL AT THIS POINT. WILL ALSO SEE PATCHY FOG ESPECIALLY ALONG
THE COAST WITH LIGHT ONSHORE WINDS. EVEN WITH LIGHT E-SE
WINDS...EXPECT HIGHS ONLY IN THE 60S...MAYBE PUSHING TO AROUND 70
WELL INLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...LOOKS LIKE BAND OF HEAVIER PRECIP WILL MOVE ACROSS AS WARM
FRONT MOVES ACROSS. IF ANY INSTABILITY MANAGES TO MAKE IT IN...
SHOULD OCCUR PRIOR TO OR AROUND MIDNIGHT. PW/S INCREASE JUST A BIT
MORE AS LOW LEVEL MOISTURE CONTINUES TO FEED UP TO COAST...UPWARDS
TO 1.6 TO 1.7 INCHES...SO COULD SEE SOME LOCALIZED DOWNPOURS AGAIN
MAINLY ALONG THE COAST. BAND OF PRECIP SHIFTS N-NW WITH A BREAK IN
THE BEST ACTION AFTER MIDNIGHT...BUT COULD STILL SEE SCATTERED
SHOWERS WITH SHORT WAVE MOVING ACROSS. OVERNIGHT LOWS WILL ONLY FALL
BACK TO THE MID 50S TO AROUND 60.
TUESDAY...MODELS CONTINUE TO SIGNAL ANOTHER LOW TO PASS E OF
NANTUCKET AND CAPE COD DURING THE DAY. LOOKS LIKE MOST OF THE PRECIP
WILL REMAIN OFFSHORE...THOUGH SOME MAY CLIP THE CAPE AND ISLANDS.
SHORT WAVE WILL ALSO PUSH NE...SO COULD SEE SOME IMPROVING
CONDITIONS THOUGH CLOUDS WILL LINGER. MAY SEE SOME BRIEF GUSTY E-NE
WINDS ACROSS THE CAPE AS THE LOW PASSES DURING THE MORNING UNTIL
AROUND MIDDAY. HAVE KEPT CHANCE POPS GOING MAINLY IN THE
MORNING...THEN MAY BREAK UP BRIEFLY DURING THE AFTERNOON. HIGHS WILL
BE IN LOWER-MID 70S EXCEPT IN THE 60S ALONG THE COAST WITH CONTINUED
ONSHORE WINDS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW...
VARIOUS LARGE SCALE PATTERN CHANGES ADVERTISED BY MEDIUM RANGE
MODELS DURING THIS FORECAST TIME PERIOD. BROAD DIFFUSE UPPER TROF
LOOKS TO PERSIST THROUGH MID WEEK ALONG THE EASTERN SEABOARD
FOLLOWED BY SIGNIFICANT LONG WAVE AMPLIFICATION ACROSS NORTH AMERICA
TOWARD END OF THE WEEK INTO THE WEEKEND WITH VERY ANOMALOUS MID
TROPOSPHERIC HEIGHT FALLS IN THE WEST AND RISES IN THE EAST. THEN
THERE LOOKS TO BE A TRANSITION TO A MORE ZONAL PATTERN FOR THE
FOLLOWING WEEK. FOR SOUTHERN NEW ENGLAND...WE START TO EXPERIENCE
BUILDING HEIGHTS TOWARD THE END OF THE WEEK ONLY TO HAVE A STRONG
ENOUGH SHORT WAVE TROF PROGRESSING ACROSS CANADA TO ARREST THIS
DEVELOPMENT AND BRING NW FLOW ALOFT TO THE REGION BY AT LEAST THE
SECOND HALF OF THE HOLIDAY WEEKEND. JUST HOW THIS UNFOLDS WILL
DETERMINE THE SENSIBLE WEATHER. THE 00Z GFS IS A LITTLE FASTER IN
ITS CFROPA COMPARED WITH THE 00Z ECMWF.
DAY TO DAY DETAILS...
TUE NIGHT THROUGH THU NIGHT... LARGE SCALE PATTERN
INFLUENCED BY BROAD UPPER LOW OVER MID ATLANTIC STATES THAT LIFTS
OUT AND DIMINISHES AS HEIGHTS ACROSS NEW ENGLAND AND SE CANADA
BUILD. CONDITIONS LOOK MARGINALLY UNSTABLE WED AND TO A LESSER
EXTENT THU AFTERNOON WITH RELATIVELY HIGH PWATS 1.25 TO 1.5
INCHES. AM FORECASTING SCT DIURNAL CONVECTION WED AFTERNOON INTO
THE EARLY EVENING AND TO A LESSER EXTENT THU AFTERNOON. NOTE BY
THU THAT A LOW/MID LEVEL RIDGE BUILDS FROM THE NW ATLANTIC INTO SE
CANADA AND NORTHERN NEW ENGLAND. NO SIGNIFICANT FORCING EITHER DAY
SO ANY SHOWERS/TSTMS MAY DEVELOP ON FAIRLY WEAK DIFFUSE BOUNDARIES
INCLUDING ANY OUTFLOW BOUNDARIES. JUST WENT SLIGHT CHANCE SE
COASTAL AREAS WHERE SURFACE BASED INSTABILITY IS LESS.
FRI...
HAVE GONE WITH A DRY SOLUTION AS BOTH GFS AND ECMWF SHOW RIDGING
OVER THE AREA. GEM BRINGS SIGNIFICANT LOW UP COAST ON FRI BUT THIS
APPEARS TO BE AN OUTLIER WITHOUT ANY SUPPORT FROM OTHER MEDIUM RANGE
MODELS.
SAT...
STRONG SHORT WAVE TROF PROGRESSING ACROSS SOUTHERN CANADA HAS
ASSOCIATED COLD FRONT THAT APPROACHES SAT AND THEN PROBABLY WASHES
OUT AS IT MOVES S OF THE AREA SAT NIGHT AND SUN. ECMWF SLOWER WITH
TIMING THAN GFS WHICH COULD PROVE CORRECT CONSIDERING THE STRENGTH
OF THE EASTERN RIDGE. NOT MUCH VERTICAL WIND SHEAR SHOWN AT THIS
TIME BUT UNSTABLE WITH MOISTURE POOLING TO SUPPORT CHANCE TSTMS SAT
AFTERNOON AND EVENING. ACTIVITY MIGHT LINGER FOR A WHILE SAT NIGHT
ALONG THE S COAST. HAVE MODERATE CONFIDENCE IN THIS SOLUTION DUE TO
REASONABLY GOOD MODEL CONTINUITY OF THIS FEATURE...ALTHOUGH A
STRONGER EXTENSION OF THE MAJOR EASTERN USA UPPER RIDGE COULD CAUSE
FRONT TO BECOME DELAYED OR STALL PRIOR TO MAKING IT THROUGH THE
AREA.
SUN...
EXPECT LOWER DEWPOINTS BUT SOME DISPARITY AS TO EXTENT OF COOLING
BETWEEN GFS AND ECMWF. ECMWF DOES NOT FLATTEN UPPER RIDGE AS MUCH AS
GFS...AND IN FACT KEEPS 850 MB TEMPS OF 16C OVER THE AREA. FOR NOW
HEDGED A LITTLE WARMER FROM GFS BASED SOLUTION TO REFLECT THIS
UNCERTAINTY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THIS AFTERNOON...HIGH CONFIDENCE CIGS/LOW CONFIDENCE VSBYS
MODEL DATA SHOW PCPN DEVELOPING AS THIS IS BEING TYPED. BUT RADAR
SHOWS MOST OF THE ACTION IN NYC/WESTERN CT. HINTS OF
SPRINKLES...BUT NOTHING UPSTREAM OVER THE OCEAN. THE CONSTANT IS
A MOIST LOW LEVEL EAST FLOW WHICH SHOULD KEEP CIGS AROUND 500 FEET
ALONG THE COAST AND AROUND 15 HUNDRED FEET INLAND. WE HAVE CUT
BACK ON PCPN TO SCATTERED/WIDELY SCATTERED LEVELS AND MAINTAINED
FOG/DRIZZLE WITH MINOR VSBY RESTRICTIONS.
TONIGHT...LOW-MODERATE CONFIDENCE
CIGS WILL REMAIN AROUND 500 FEET ALONG THE COAST AND LOWER TO 1000
FEET OR BELOW IN THE INTERIOR. VSBYS WILL LOWER AFTER SUNSET...BUT
THE QUESTION IS WHETHER IT WILL BE FROM SHOWERS OR FROM FOG AND
DRIZZLE. WE HAVE MAINTAINED A PERIOD OF SHOWERS MOVING ACROSS
SOUTHERN NEW ENGLAND...BUT WITH LOW CONFIDENCE DUE TO THE LACK OF
GROUND TRUTH UPWIND.
TUESDAY...LOW CONFIDENCE
CIGS AND VSBYS WILL IMPROVE BY MIDDAY...AND MAY REACH VFR IN THE
INTERIOR. EAST COASTAL AREAS WILL IMPROVE TO MVFR...BUT SOUTH
COASTAL AREAS INCLUDING CAPE COD SHOULD HOLD AT IFR. LOW PRESSURE
OFFSHORE WILL PASS US AROUND MIDDAY AND MOVE OUT TO SEA. THIS WILL
BRING CHANGEABLE WINDS OVER NEW ENGLAND DURING THE AFTERNOON.
TUESDAY NIGHT...
LIGHT WIND AND LOTS OF MOISTURE WILL MEAN POTENTIAL FOR FOG/LOW
CLOUDS BRINGING WIDESPREAD IFR/LIFR.
KBOS TAF...MODERATE CONFIDENCE. CEILINGS BELOW 1000 FEET THIS
AFTERNOON AND BELOW 500 FEET AT NIGHT. VSBYS AT THE SURFACE MAY
IMPROVE TO UNRESTRICTED BUT WILL BE 1-3 MILES IN FOG JUST ABOVE
THE RUNWAYS. VSBYS LOWER TO 1 MILE TONIGHT WITH POTENTIAL FOR
PERIODS OF 1/2 MILE. IMPROVEMENT TO MVFR CIGS AND VFR VSBYS ON
TUESDAY.
KBDL TAF...MODERATE CONFIDENCE. MVFR CIGS WILL LOWER TO IFR
TONIGHT. SHOWERS AND AREAS OF LIGHT FOG MAY BRING MVFR VSBYS.
OUTLOOK...WEDNESDAY THOUGH FRIDAY...
WED...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR CIGS/VSBYS IN
VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS.
WED NIGHT...LOW TO MODERATE CONFIDENCE. PATCHY STRATUS AND FOG WITH
IFR CIGS/VSBYS.
THU THROUGH FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY.
EXPECT S-SE SWELLS UP TO 7 FT TO CONTINUE MOVING ACROSS THE OUTER
WATERS INTO THE OPEN SOUTH SOUNDS THROUGH THIS PERIOD. HAVE EXTENDED
SMALL CRAFT FOR HAZARDOUS SEAS FOR THE WATERS E OF CAPE COD
SOUTHWARD THROUGH TUESDAY...AND WILL LIKELY NEED TO EXTEND UP THE
COAST ON TUESDAY AS LOW PRES PASSES.
EXPECT WINDS TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH
TUESDAY...THOUGH LOW PROBABILITY OF BRIEF 25 KT GUSTS EARLY TUESDAY
ON THE EASTERN OUTER WATERS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SUBSIDING SWELLS DURING THIS PERIOD. ONLY
UNCERTAINTY IS IF ALBERTO RETAINS A LITTLE MORE LIFE THAN EXPECTED
AND KEEPS SWELL HIGHER THAN CURRENTLY EXPECTED FOR THE MID WEEK TIME
PERIOD. NO SIGNIFICANT WINDS EXPECTED ACROSS THE COASTAL WATERS
DURING THIS TIME PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ254>256.
&&
$$
SYNOPSIS...EVT/THOMPSON
NEAR TERM...WTB/EVT/THOMPSON
SHORT TERM...EVT
LONG TERM...THOMPSON
AVIATION...WTB/THOMPSON
MARINE...EVT/THOMPSON
000
FXUS61 KBOX 211425
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1025 AM EDT MON MAY 21 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK UP THE COAST...BRINGING SHOWERS THROUGH
TONIGHT. SCATTERED MAINLY AFTERNOON SHOWERS OR THUNDERSTORMS ARE
EXPECTED BOTH TUESDAY AND WEDNESDAY AFTERNOON. A COLD FRONT MAY
PRODUCE SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...LOW CLOUDS/FOG/DRIZZLE HAVE MOVED UP THE COASTAL
PLAIN AND BY LATE MORNING EXTENDED FROM BOSTON TO WESTERLY. LOWEST
CONDITIONS ARE ALONG THE IMMEDIATE COAST WITH VSBYS 1 MILE OR
LESS. SOME SUN LINGERED IN SOUTHERN NH LATE MORNING BUT THE
MOVEMENT OF CLOUDS SHOULD COVER THE SKY THERE FOR THE AFTERNOON.
EXPECT THE FOG TO LINGER IN THE COASTAL PLAIN THROUGH THE
AFTERNOON. VSBYS SHOULD IMPROVE THIS AFTERNOON AS TEMPS CLIMB A
FEW MORE DEGREES. LOW CONFIDENCE ON THIS IMPROVEMENT HAPPENING
ALONG THE IMMEDIATE COAST...WHERE ONSHORE WINDS MAY KEEP TEMPS
COOLER AND DEWPOINTS HIGHER.
MOST OF THE OBSERVED SHOWERS HAVE BEEN MOVING NORTHWEST THROUGH
NYC AND SOUTHERN NY...ALSO NW INTO SOUTHERN NEW JERSEY. OKX RADAR
SHOWS SIGNS OF SHOWERS AT EXTREME RANGE VOER THE OFFSHORE WATERS
SOUTH OF NEW ENGLAND. EXTRAPOLATION OF THESE SHOWERS WOULD BRING
THEM TO THE SOUTH NEW ENGLAND COAST AROUND 18Z. THIS IS IN LINE
WITH OUR FORECAST OF LIKELY POPS TO THE COAST. WE HAVE SLOWED POPS
A LITTLE AND TIGHTENED THE GRADIENT FROM NIL POP TO LIKELY. BUT
OVERALL FORECAST REMAINS INTACT.
PREVIOUS DISCUSSION...
MOST OF THE LONG RANGE MODELS APPEARED IN FAIRLY GOOD AGREEMENT
FOR THIS PERIOD. ONLY OUTLIER NOTED WAS THE 00Z OP NAM RUN...WHICH
APPEARED TO DEVELOP A DEEPER LOW AND BRING IT UP THE COAST QUICKER
THAN THE GGEM/GFS OR ECWMF. EXPECT FIRST LOW TO PUSH INTO THE MID
ATLC COAST TODAY...THEN ANOTHER LOW WILL WORK UP THE COAST LATER
TODAY WHICH WILL BRING FIRST SLUG OF MOISTURE INTO THE REGION.
ALONG WITH INCREASING LOW LEVEL MOISTURE WORKING UP WITH THIS LOW
IS ALSO INCREASING PW/S...ON THE ORDER OF AROUND 1.5 INCHES BY
THIS EVENING. WILL ALSO SEE FAIRLY GOOD INSTABILITY WORKING
NORTHWARD AHEAD OF DEFORMATION ZONE/WARM FRONT. NOTING TQ VALUES
FOR ELEVATED INSTABILITY AT AROUND 20...WITH LIFTED INDICES AS LOW
AS -1 MOVING ACROSS FROM S-N THROUGH THE DAY. HAVE KEPT MENTION OF
ISOLD THUNDER IN THE GRIDS AND ZONES.
AS SHOWERS MOVE INTO THE REGION...SOME COULD BRING BRIEF HEAVY
DOWNPOURS MAINLY THIS AFTERNOON BUT NOT EXPECTING WIDESPREAD HEAVY
RAINFALL AT THIS POINT. WILL ALSO SEE PATCHY FOG ESPECIALLY ALONG
THE COAST WITH LIGHT ONSHORE WINDS. EVEN WITH LIGHT E-SE
WINDS...EXPECT HIGHS ONLY IN THE 60S...MAYBE PUSHING TO AROUND 70
WELL INLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...LOOKS LIKE BAND OF HEAVIER PRECIP WILL MOVE ACROSS AS WARM
FRONT MOVES ACROSS. IF ANY INSTABILITY MANAGES TO MAKE IT IN...
SHOULD OCCUR PRIOR TO OR AROUND MIDNIGHT. PW/S INCREASE JUST A BIT
MORE AS LOW LEVEL MOISTURE CONTINUES TO FEED UP TO COAST...UPWARDS
TO 1.6 TO 1.7 INCHES...SO COULD SEE SOME LOCALIZED DOWNPOURS AGAIN
MAINLY ALONG THE COAST. BAND OF PRECIP SHIFTS N-NW WITH A BREAK IN
THE BEST ACTION AFTER MIDNIGHT...BUT COULD STILL SEE SCATTERED
SHOWERS WITH SHORT WAVE MOVING ACROSS. OVERNIGHT LOWS WILL ONLY FALL
BACK TO THE MID 50S TO AROUND 60.
TUESDAY...MODELS CONTINUE TO SIGNAL ANOTHER LOW TO PASS E OF
NANTUCKET AND CAPE COD DURING THE DAY. LOOKS LIKE MOST OF THE PRECIP
WILL REMAIN OFFSHORE...THOUGH SOME MAY CLIP THE CAPE AND ISLANDS.
SHORT WAVE WILL ALSO PUSH NE...SO COULD SEE SOME IMPROVING
CONDITIONS THOUGH CLOUDS WILL LINGER. MAY SEE SOME BRIEF GUSTY E-NE
WINDS ACROSS THE CAPE AS THE LOW PASSES DURING THE MORNING UNTIL
AROUND MIDDAY. HAVE KEPT CHANCE POPS GOING MAINLY IN THE
MORNING...THEN MAY BREAK UP BRIEFLY DURING THE AFTERNOON. HIGHS WILL
BE IN LOWER-MID 70S EXCEPT IN THE 60S ALONG THE COAST WITH CONTINUED
ONSHORE WINDS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW...
VARIOUS LARGE SCALE PATTERN CHANGES ADVERTISED BY MEDIUM RANGE
MODELS DURING THIS FORECAST TIME PERIOD. BROAD DIFFUSE UPPER TROF
LOOKS TO PERSIST THROUGH MID WEEK ALONG THE EASTERN SEABOARD
FOLLOWED BY SIGNIFICANT LONG WAVE AMPLIFICATION ACROSS NORTH AMERICA
TOWARD END OF THE WEEK INTO THE WEEKEND WITH VERY ANOMALOUS MID
TROPOSPHERIC HEIGHT FALLS IN THE WEST AND RISES IN THE EAST. THEN
THERE LOOKS TO BE A TRANSITION TO A MORE ZONAL PATTERN FOR THE
FOLLOWING WEEK. FOR SOUTHERN NEW ENGLAND...WE START TO EXPERIENCE
BUILDING HEIGHTS TOWARD THE END OF THE WEEK ONLY TO HAVE A STRONG
ENOUGH SHORT WAVE TROF PROGRESSING ACROSS CANADA TO ARREST THIS
DEVELOPMENT AND BRING NW FLOW ALOFT TO THE REGION BY AT LEAST THE
SECOND HALF OF THE HOLIDAY WEEKEND. JUST HOW THIS UNFOLDS WILL
DETERMINE THE SENSIBLE WEATHER. THE 00Z GFS IS A LITTLE FASTER IN
ITS CFROPA COMPARED WITH THE 00Z ECMWF.
DAY TO DAY DETAILS...
TUE NIGHT THROUGH THU NIGHT... LARGE SCALE PATTERN
INFLUENCED BY BROAD UPPER LOW OVER MID ATLANTIC STATES THAT LIFTS
OUT AND DIMINISHES AS HEIGHTS ACROSS NEW ENGLAND AND SE CANADA
BUILD. CONDITIONS LOOK MARGINALLY UNSTABLE WED AND TO A LESSER
EXTENT THU AFTERNOON WITH RELATIVELY HIGH PWATS 1.25 TO 1.5
INCHES. AM FORECASTING SCT DIURNAL CONVECTION WED AFTERNOON INTO
THE EARLY EVENING AND TO A LESSER EXTENT THU AFTERNOON. NOTE BY
THU THAT A LOW/MID LEVEL RIDGE BUILDS FROM THE NW ATLANTIC INTO SE
CANADA AND NORTHERN NEW ENGLAND. NO SIGNIFICANT FORCING EITHER DAY
SO ANY SHOWERS/TSTMS MAY DEVELOP ON FAIRLY WEAK DIFFUSE BOUNDARIES
INCLUDING ANY OUTFLOW BOUNDARIES. JUST WENT SLIGHT CHANCE SE
COASTAL AREAS WHERE SURFACE BASED INSTABILITY IS LESS.
FRI...
HAVE GONE WITH A DRY SOLUTION AS BOTH GFS AND ECMWF SHOW RIDGING
OVER THE AREA. GEM BRINGS SIGNIFICANT LOW UP COAST ON FRI BUT THIS
APPEARS TO BE AN OUTLIER WITHOUT ANY SUPPORT FROM OTHER MEDIUM RANGE
MODELS.
SAT...
STRONG SHORT WAVE TROF PROGRESSING ACROSS SOUTHERN CANADA HAS
ASSOCIATED COLD FRONT THAT APPROACHES SAT AND THEN PROBABLY WASHES
OUT AS IT MOVES S OF THE AREA SAT NIGHT AND SUN. ECMWF SLOWER WITH
TIMING THAN GFS WHICH COULD PROVE CORRECT CONSIDERING THE STRENGTH
OF THE EASTERN RIDGE. NOT MUCH VERTICAL WIND SHEAR SHOWN AT THIS
TIME BUT UNSTABLE WITH MOISTURE POOLING TO SUPPORT CHANCE TSTMS SAT
AFTERNOON AND EVENING. ACTIVITY MIGHT LINGER FOR A WHILE SAT NIGHT
ALONG THE S COAST. HAVE MODERATE CONFIDENCE IN THIS SOLUTION DUE TO
REASONABLY GOOD MODEL CONTINUITY OF THIS FEATURE...ALTHOUGH A
STRONGER EXTENSION OF THE MAJOR EASTERN USA UPPER RIDGE COULD CAUSE
FRONT TO BECOME DELAYED OR STALL PRIOR TO MAKING IT THROUGH THE
AREA.
SUN...
EXPECT LOWER DEWPOINTS BUT SOME DISPARITY AS TO EXTENT OF COOLING
BETWEEN GFS AND ECMWF. ECMWF DOES NOT FLATTEN UPPER RIDGE AS MUCH AS
GFS...AND IN FACT KEEPS 850 MB TEMPS OF 16C OVER THE AREA. FOR NOW
HEDGED A LITTLE WARMER FROM GFS BASED SOLUTION TO REFLECT THIS
UNCERTAINTY.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THIS AFTERNOON...MODERATE CONFIDENCE
CIGS REMAINING AT IFR/LIFR IN FOG/DRIZZLE OVER THE COASTAL PLAIN
WITH MVFR CIGS IN INTERIOR SOUTHERN NEW ENGLAND. SCT SHOWERS
MOVING ONTO THE S COAST EARLY AFTERNOON AND SPREADING TO SW NH BY
EVENING. LOW PROB OF +SHRA AND ISOLD TSTMS.
TONIGHT...MODERATE CONFIDENCE.
MAINLY IFR CIGS AND VSBYS WITH LIFR CONDITIONS LIKELY SE OF A BOS-
PVD LINE.
TUESDAY...LOW CONFIDENCE.
MVFR-IFR CIGS/VSBYS TO START...THEN MAY IMPROVE TO VFR FROM W-E. LOW
CONFIDENCE ON TIMING.
KBOS TAF...MODERATE CONFIDENCE. VSBYS BELOW 1 MILE MOVED ACROSS
THE FIELD MID TO LATE MORNING. EXPECT SMALL IMPROVEMENT THIS
AFTERNOON BUT CONDITIONS SHOULD REMAIN NO BETTER THAN IFR DUE TO
LIGHT ONSHORE FLOW.
KBDL TAF...MODERATE CONFIDENCE. EXPECTING MVFR CIGS EARLY
AFTERNOON. SHOWERS...FOG AND DRIZZLE EXPECTED MID TO LATE
AFTERNOON AND TONIGHT. CONDITIONS MAY LOWER TO IFR FOR A TIME
TONIGHT AND EARLY TUE MORNING. ISOLD TSTMS MAY REACH THE VICINITY
THIS AFTERNOON.
OUTLOOK...TUESDAY NIGHT THOUGH FRIDAY...
TUE NIGHT...MODERATE CONFIDENCE. BECOMING MOSTLY VFR EXCEPT PATCHY
IFR CIGS/FOG SOME VALLEYS AND ALONG S COAST.
WED...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR CIGS/VSBYS IN
VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS.
WED NIGHT...LOW TO MODERATE CONFIDENCE. PATCHY STRATUS AND FOG WITH
IFR CIGS/VSBYS.
THU THROUGH FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY.
EXPECT S-SE SWELLS UP TO 7 FT TO CONTINUE MOVING ACROSS THE OUTER
WATERS INTO THE OPEN SOUTH SOUNDS THROUGH THIS PERIOD. HAVE EXTENDED
SMALL CRAFT FOR HAZARDOUS SEAS FOR THE WATERS E OF CAPE COD
SOUTHWARD THROUGH TUESDAY...AND WILL LIKELY NEED TO EXTEND UP THE
COAST ON TUESDAY AS LOW PRES PASSES.
EXPECT WINDS TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH
TUESDAY...THOUGH LOW PROBABILITY OF BRIEF 25 KT GUSTS EARLY TUESDAY
ON THE EASTERN OUTER WATERS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SUBSIDING SWELLS DURING THIS PERIOD. ONLY
UNCERTAINTY IS IF ALBERTO RETAINS A LITTLE MORE LIFE THAN EXPECTED
AND KEEPS SWELL HIGHER THAN CURRENTLY EXPECTED FOR THE MID WEEK TIME
PERIOD. NO SIGNIFICANT WINDS EXPECTED ACROSS THE COASTAL WATERS
DURING THIS TIME PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ254>256.
&&
$$
SYNOPSIS...EVT/THOMPSON
NEAR TERM...WTB/EVT/THOMPSON
SHORT TERM...EVT
LONG TERM...THOMPSON
AVIATION...EVT/THOMPSON
MARINE...EVT/THOMPSON
000
FXUS61 KBOX 211157
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
757 AM EDT MON MAY 21 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK UP THE COAST...BRINGING SHOWERS THROUGH
TONIGHT. SCATTERED MAINLY AFTERNOON SHOWERS OR THUNDERSTORMS ARE
EXPECTED BOTH TUESDAY AND WEDNESDAY AFTERNOON. A COLD FRONT MAY
PRODUCE SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
730 AM UPDATE...CONTINUE TO SEE LOW CLOUDS AND AREAS OF FOG AND
PATCHY DRIZZLE WORKING ITS WAY NORTH. AT 11Z THE NORTHERN EDGE OF
THE STRATUS SHIELD WAS ROUGHLY ALONG A BVY-CEF-JUST S BAF LINE.
THE TIMING OF MEASURABLE SHOWER ACTIVITY LOOKS GOOD FROM THE PRIOR
FORECAST...JUST TIGHTENED UP THE POP GRADIENT SOME AS GETTING INTO
THE NEAR TERM.
PREVIOUS DISCUSSION...
LOW CLOUDS AND PATCHY FOG HAS PUSHED NORTH THROUGH THE EARLY
MORNING HOURS. ALSO NOTING RISING DEWPTS ESPECIALLY ALONG THE
COAST. ALSO NOTING SOME AREAS WITH LOWERING TEMPS/DEWPTS MAINLY IN
THE NORMALLY COLDER VALLEYS WELL INLAND WITH MAINLY CLEAR SKIES
AND LIGHT OR CALM WINDS.
AREA OF SHOWERS/TSTMS SEEN ON NE 88D RADAR MOSAIC OFF THE DELMARVA/S
NJ COAST AT 08Z WHICH WAS MOVING N-NW TOWARD THE NJ COAST. THIS IS
ASSOCIATED WITH ONE OF A SERIES OF WEAK LOWS OFF THE EASTERN
SEABOARD AS WELL AS TROPICAL STORM ALBERTO E OF THE SC/FL COAST.
AREAS OF MID LAYER MOISTURE ALSO SEEN ON WATER VAPOR SATELLITE LOOP.
MOST OF THE LONG RANGE MODELS APPEARED IN FAIRLY GOOD AGREEMENT FOR
THIS PERIOD. ONLY OUTLIER NOTED WAS THE 00Z OP NAM RUN...WHICH
APPEARED TO DEVELOP A DEEPER LOW AND BRING IT UP THE COAST QUICKER
THAN THE GGEM/GFS OR ECWMF. EXPECT FIRST LOW TO PUSH INTO THE MID
ATLC COAST TODAY...THEN ANOTHER LOW WILL WORK UP THE COAST LATER
TODAY WHICH WILL BRING FIRST SLUG OF MOISTURE INTO THE REGION. ALONG
WITH INCREASING LOW LEVEL MOISTURE WORKING UP WITH THIS LOW IS ALSO
INCREASING PW/S...ON THE ORDER OF AROUND 1.5 INCHES BY THIS EVENING.
WILL ALSO SEE FAIRLY GOOD INSTABILITY WORKING NORTHWARD AHEAD OF
DEFORMATION ZONE/WARM FRONT. NOTING TQ VALUES FOR ELEVATED
INSTABILITY AT AROUND 20...WITH LIFTED INDICES AS LOW AS -1 MOVING
ACROSS FROM S-N THROUGH THE DAY. HAVE KEPT MENTION OF ISOLD THUNDER
IN THE GRIDS AND ZONES.
AS SHOWERS MOVE INTO THE REGION...SOME COULD BRING BRIEF HEAVY
DOWNPOURS MAINLY THIS AFTERNOON BUT NOT EXPECTING WIDESPREAD HEAVY
RAINFALL AT THIS POINT. WILL ALSO SEE PATCHY FOG ESPECIALLY ALONG
THE COAST WITH LIGHT ONSHORE WINDS. EVEN WITH LIGHT E-SE
WINDS...EXPECT HIGHS ONLY IN THE 60S...MAYBE PUSHING TO AROUND 70
WELL INLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...LOOKS LIKE BAND OF HEAVIER PRECIP WILL MOVE ACROSS AS WARM
FRONT MOVES ACROSS. IF ANY INSTABILITY MANAGES TO MAKE IT IN...
SHOULD OCCUR PRIOR TO OR AROUND MIDNIGHT. PW/S INCREASE JUST A BIT
MORE AS LOW LEVEL MOISTURE CONTINUES TO FEED UP TO COAST...UPWARDS
TO 1.6 TO 1.7 INCHES...SO COULD SEE SOME LOCALIZED DOWNPOURS AGAIN
MAINLY ALONG THE COAST. BAND OF PRECIP SHIFTS N-NW WITH A BREAK IN
THE BEST ACTION AFTER MIDNIGHT...BUT COULD STILL SEE SCATTERED
SHOWERS WITH SHORT WAVE MOVING ACROSS. OVERNIGHT LOWS WILL ONLY FALL
BACK TO THE MID 50S TO AROUND 60.
TUESDAY...MODELS CONTINUE TO SIGNAL ANOTHER LOW TO PASS E OF
NANTUCKET AND CAPE COD DURING THE DAY. LOOKS LIKE MOST OF THE PRECIP
WILL REMAIN OFFSHORE...THOUGH SOME MAY CLIP THE CAPE AND ISLANDS.
SHORT WAVE WILL ALSO PUSH NE...SO COULD SEE SOME IMPROVING
CONDITIONS THOUGH CLOUDS WILL LINGER. MAY SEE SOME BRIEF GUSTY E-NE
WINDS ACROSS THE CAPE AS THE LOW PASSES DURING THE MORNING UNTIL
AROUND MIDDAY. HAVE KEPT CHANCE POPS GOING MAINLY IN THE
MORNING...THEN MAY BREAK UP BRIEFLY DURING THE AFTERNOON. HIGHS WILL
BE IN LOWER-MID 70S EXCEPT IN THE 60S ALONG THE COAST WITH CONTINUED
ONSHORE WINDS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW...
VARIOUS LARGE SCALE PATTERN CHANGES ADVERTISED BY MEDIUM RANGE
MODELS DURING THIS FORECAST TIME PERIOD. BROAD DIFFUSE UPPER TROF
LOOKS TO PERSIST THROUGH MID WEEK ALONG THE EASTERN SEABOARD
FOLLOWED BY SIGNIFICANT LONG WAVE AMPLIFICATION ACROSS NORTH AMERICA
TOWARD END OF THE WEEK INTO THE WEEKEND WITH VERY ANOMALOUS MID
TROPOSPHERIC HEIGHT FALLS IN THE WEST AND RISES IN THE EAST. THEN
THERE LOOKS TO BE A TRANSITION TO A MORE ZONAL PATTERN FOR THE
FOLLOWING WEEK. FOR SOUTHERN NEW ENGLAND...WE START TO EXPERIENCE
BUILDING HEIGHTS TOWARD THE END OF THE WEEK ONLY TO HAVE A STRONG
ENOUGH SHORT WAVE TROF PROGRESSING ACROSS CANADA TO ARREST THIS
DEVELOPMENT AND BRING NW FLOW ALOFT TO THE REGION BY AT LEAST THE
SECOND HALF OF THE HOLIDAY WEEKEND. JUST HOW THIS UNFOLDS WILL
DETERMINE THE SENSIBLE WEATHER. THE 00Z GFS IS A LITTLE FASTER IN
ITS CFROPA COMPARED WITH THE 00Z ECMWF.
DAY TO DAY DETAILS...
TUE NIGHT THROUGH THU NIGHT... LARGE SCALE PATTERN
INFLUENCED BY BROAD UPPER LOW OVER MID ATLANTIC STATES THAT LIFTS
OUT AND DIMINISHES AS HEIGHTS ACROSS NEW ENGLAND AND SE CANADA
BUILD. CONDITIONS LOOK MARGINALLY UNSTABLE WED AND TO A LESSER
EXTENT THU AFTERNOON WITH RELATIVELY HIGH PWATS 1.25 TO 1.5
INCHES. AM FORECASTING SCT DIURNAL CONVECTION WED AFTERNOON INTO
THE EARLY EVENING AND TO A LESSER EXTENT THU AFTERNOON. NOTE BY
THU THAT A LOW/MID LEVEL RIDGE BUILDS FROM THE NW ATLANTIC INTO SE
CANADA AND NORTHERN NEW ENGLAND. NO SIGNIFICANT FORCING EITHER DAY
SO ANY SHOWERS/TSTMS MAY DEVELOP ON FAIRLY WEAK DIFFUSE BOUNDARIES
INCLUDING ANY OUTFLOW BOUNDARIES. JUST WENT SLIGHT CHANCE SE
COASTAL AREAS WHERE SURFACE BASED INSTABILITY IS LESS.
FRI...
HAVE GONE WITH A DRY SOLUTION AS BOTH GFS AND ECMWF SHOW RIDGING
OVER THE AREA. GEM BRINGS SIGNIFICANT LOW UP COAST ON FRI BUT THIS
APPEARS TO BE AN OUTLIER WITHOUT ANY SUPPORT FROM OTHER MEDIUM RANGE
MODELS.
SAT...
STRONG SHORT WAVE TROF PROGRESSING ACROSS SOUTHERN CANADA HAS
ASSOCIATED COLD FRONT THAT APPROACHES SAT AND THEN PROBABLY WASHES
OUT AS IT MOVES S OF THE AREA SAT NIGHT AND SUN. ECMWF SLOWER WITH
TIMING THAN GFS WHICH COULD PROVE CORRECT CONSIDERING THE STRENGTH
OF THE EASTERN RIDGE. NOT MUCH VERTICAL WIND SHEAR SHOWN AT THIS
TIME BUT UNSTABLE WITH MOISTURE POOLING TO SUPPORT CHANCE TSTMS SAT
AFTERNOON AND EVENING. ACTIVITY MIGHT LINGER FOR A WHILE SAT NIGHT
ALONG THE S COAST. HAVE MODERATE CONFIDENCE IN THIS SOLUTION DUE TO
REASONABLY GOOD MODEL CONTINUITY OF THIS FEATURE...ALTHOUGH A
STRONGER EXTENSION OF THE MAJOR EASTERN USA UPPER RIDGE COULD CAUSE
FRONT TO BECOME DELAYED OR STALL PRIOR TO MAKING IT THROUGH THE
AREA.
SUN...
EXPECT LOWER DEWPOINTS BUT SOME DISPARITY AS TO EXTENT OF COOLING
BETWEEN GFS AND ECMWF. ECMWF DOES NOT FLATTEN UPPER RIDGE AS MUCH AS
GFS...AND IN FACT KEEPS 850 MB TEMPS OF 16C OVER THE AREA. FOR NOW
HEDGED A LITTLE WARMER FROM GFS BASED SOLUTION TO REFLECT THIS
UNCERTAINTY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
SHORT TERM FORECAST PERIOD WILL CONSTITUTE A FAIRLY HIGH AVIATION IMPACT
DUE TO EXTENSIVE AND WHAT IS EXPECTED TO BE PERSISTENT STRATUS AND
AREAS OF FOG. HIGH CONFIDENCE IN CONDITIONS REMAINING OR LOWERING
TO IFR OR LOW END MVFR CIGS FOR MOST OF THE AREA TODAY. MODERATE
CONFIDENCE IN LOCATION AND TIMING OF LOWERED VSBY FROM FOG AS WELL
AS TIMING OF LIFR CONDITIONS ACROSS ALONG THE S COAST.
TODAY...MODERATE CONFIDENCE.
CIGS REMAINING OR LOWERING FROM S TO N IN GENERAL MVFR-IFR RANGE
WITH AREAS OF MVFR VSBY FROM FOG INLAND AND IFR OR EVEN LIFR VSBY
FROM FOG OR FOG AND DRIZZLE ALONG THE COAST. SCT -SHRA MOVING ONTO
THE S COAST BY AFTERNOON AND SPREADING TO SW NH BY EVENING. LOW
PROB OF +SHRA AND ISOLD TSTMS.
TONIGHT...MODERATE CONFIDENCE.
MAINLY IFR CIGS AND VSBYS WITH LIFR CONDITIONS LIKELY SE OF A BOS-
PVD LINE.
TUESDAY...LOW CONFIDENCE.
MVFR-IFR CIGS/VSBYS TO START...THEN MAY IMPROVE TO VFR FROM W-E. LOW
CONFIDENCE ON TIMING.
KBOS TAF...MODERATE CONFIDENCE. NEAR TERM ISSUE IS TO EXTENT THAT
FOG WILL ENVELOPE THE FIELD. AM PESSIMISTIC DUE TO THE ONSHORE
FLOW AND LOW VSBYS IN FOG AT GHG AND MQE VIA PHONE REPORT. TOWER
COULD ALSO SEE AT 11Z FOG BANK THAT HAD REACHED LONG ISLAND IN BOS
HARBOR. MAY SEE A LITTLE IMPROVEMENT THIS AFTERNOON GIVEN THE TIME
OF YEAR BUT LIKELY LOWERING BACK TO IFR AFTER DARK WITH CONTINUED
LIGHT ONSHORE FLOW.
KBDL TAF...MODERATE CONFIDENCE. EXPECTING MVFR CIGS AND OCCASIONAL
VSBYS IN SHOWERS...FOG AND DRIZZLE LATE THIS AFTERNOON AND
TONIGHT. CONDITIONS MAY LOWER TO IFR FOR A TIME TONIGHT AND EARLY
TUE MORNING. ISOLD TSTMS MAY REACH THE VICINITY THIS AFTERNOON.
OUTLOOK...TUESDAY NIGHT THOUGH FRIDAY...
TUE NIGHT...MODERATE CONFIDENCE. BECOMING MOSTLY VFR EXCEPT PATCHY
IFR CIGS/FOG SOME VALLEYS AND ALONG S COAST.
WED...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR CIGS/VSBYS IN
VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS.
WED NIGHT...LOW TO MODERATE CONFIDENCE. PATCHY STRATUS AND FOG WITH
IFR CIGS/VSBYS.
THU THROUGH FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY.
EXPECT S-SE SWELLS UP TO 7 FT TO CONTINUE MOVING ACROSS THE OUTER
WATERS INTO THE OPEN SOUTH SOUNDS THROUGH THIS PERIOD. HAVE EXTENDED
SMALL CRAFT FOR HAZARDOUS SEAS FOR THE WATERS E OF CAPE COD
SOUTHWARD THROUGH TUESDAY...AND WILL LIKELY NEED TO EXTEND UP THE
COAST ON TUESDAY AS LOW PRES PASSES.
EXPECT WINDS TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH
TUESDAY...THOUGH LOW PROBABILITY OF BRIEF 25 KT GUSTS EARLY TUESDAY
ON THE EASTERN OUTER WATERS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SUBSIDING SWELLS DURING THIS PERIOD. ONLY
UNCERTAINTY IS IF ALBERTO RETAINS A LITTLE MORE LIFE THAN EXPECTED
AND KEEPS SWELL HIGHER THAN CURRENTLY EXPECTED FOR THE MID WEEK TIME
PERIOD. NO SIGNIFICANT WINDS EXPECTED ACROSS THE COASTAL WATERS
DURING THIS TIME PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ254>256.
&&
$$
SYNOPSIS...EVT/THOMPSON
NEAR TERM...EVT/THOMPSON
SHORT TERM...EVT
LONG TERM...THOMPSON
AVIATION...EVT/THOMPSON
MARINE...EVT/THOMPSON
000
FXUS61 KBOX 210900
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
455 AM EDT MON MAY 21 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK UP THE COAST...BRINGING SHOWERS THROUGH
TONIGHT. SCATTERED MAINLY AFTERNOON SHOWERS OR THUNDERSTORMS ARE
EXPECTED BOTH TUESDAY AND WEDNESDAY AFTERNOON. A COLD FRONT MAY
PRODUCE SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA ON
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW CLOUDS AND PATCHY FOG HAS PUSHED NORTH THROUGH THE EARLY MORNING
HOURS. ALSO NOTING RISING DEWPTS ESPECIALLY ALONG THE COAST. ALSO
NOTING SOME AREAS WITH LOWERING TEMPS/DEWPTS MAINLY IN THE NORMALLY
COLDER VALLEYS WELL INLAND WITH MAINLY CLEAR SKIES AND LIGHT OR CALM
WINDS.
AREA OF SHOWERS/TSTMS SEEN ON NE 88D RADAR MOSAIC OFF THE DELMARVA/S
NJ COAST AT 08Z WHICH WAS MOVING N-NW TOWARD THE NJ COAST. THIS IS
ASSOCIATED WITH ONE OF A SERIES OF WEAK LOWS OFF THE EASTERN
SEABOARD AS WELL AS TROPICAL STORM ALBERTO E OF THE SC/FL COAST.
AREAS OF MID LAYER MOISTURE ALSO SEEN ON WATER VAPOR SATELLITE LOOP.
MOST OF THE LONG RANGE MODELS APPEARED IN FAIRLY GOOD AGREEMENT FOR
THIS PERIOD. ONLY OUTLIER NOTED WAS THE 00Z OP NAM RUN...WHICH
APPEARED TO DEVELOP A DEEPER LOW AND BRING IT UP THE COAST QUICKER
THAN THE GGEM/GFS OR ECWMF. EXPECT FIRST LOW TO PUSH INTO THE MID
ATLC COAST TODAY...THEN ANOTHER LOW WILL WORK UP THE COAST LATER
TODAY WHICH WILL BRING FIRST SLUG OF MOISTURE INTO THE REGION. ALONG
WITH INCREASING LOW LEVEL MOISTURE WORKING UP WITH THIS LOW IS ALSO
INCREASING PW/S...ON THE ORDER OF AROUND 1.5 INCHES BY THIS EVENING.
WILL ALSO SEE FAIRLY GOOD INSTABILITY WORKING NORTHWARD AHEAD OF
DEFORMATION ZONE/WARM FRONT. NOTING TQ VALUES FOR ELEVATED
INSTABILITY AT AROUND 20...WITH LIFTED INDICES AS LOW AS -1 MOVING
ACROSS FROM S-N THROUGH THE DAY. HAVE KEPT MENTION OF ISOLD THUNDER
IN THE GRIDS AND ZONES.
AS SHOWERS MOVE INTO THE REGION...SOME COULD BRING BRIEF HEAVY
DOWNPOURS MAINLY THIS AFTERNOON BUT NOT EXPECTING WIDESPREAD HEAVY
RAINFALL AT THIS POINT. WILL ALSO SEE PATCHY FOG ESPECIALLY ALONG
THE COAST WITH LIGHT ONSHORE WINDS. EVEN WITH LIGHT E-SE
WINDS...EXPECT HIGHS ONLY IN THE 60S...MAYBE PUSHING TO AROUND 70
WELL INLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...LOOKS LIKE BAND OF HEAVIER PRECIP WILL MOVE ACROSS AS WARM
FRONT MOVES ACROSS. IF ANY INSTABILITY MANAGES TO MAKE IT IN...
SHOULD OCCUR PRIOR TO OR AROUND MIDNIGHT. PW/S INCREASE JUST A BIT
MORE AS LOW LEVEL MOISTURE CONTINUES TO FEED UP TO COAST...UPWARDS
TO 1.6 TO 1.7 INCHES...SO COULD SEE SOME LOCALIZED DOWNPOURS AGAIN
MAINLY ALONG THE COAST. BAND OF PRECIP SHIFTS N-NW WITH A BREAK IN
THE BEST ACTION AFTER MIDNIGHT...BUT COULD STILL SEE SCATTERED
SHOWERS WITH SHORT WAVE MOVING ACROSS. OVERNIGHT LOWS WILL ONLY FALL
BACK TO THE MID 50S TO AROUND 60.
TUESDAY...MODELS CONTINUE TO SIGNAL ANOTHER LOW TO PASS E OF
NANTUCKET AND CAPE COD DURING THE DAY. LOOKS LIKE MOST OF THE PRECIP
WILL REMAIN OFFSHORE...THOUGH SOME MAY CLIP THE CAPE AND ISLANDS.
SHORT WAVE WILL ALSO PUSH NE...SO COULD SEE SOME IMPROVING
CONDITIONS THOUGH CLOUDS WILL LINGER. MAY SEE SOME BRIEF GUSTY E-NE
WINDS ACROSS THE CAPE AS THE LOW PASSES DURING THE MORNING UNTIL
AROUND MIDDAY. HAVE KEPT CHANCE POPS GOING MAINLY IN THE
MORNING...THEN MAY BREAK UP BRIEFLY DURING THE AFTERNOON. HIGHS WILL
BE IN LOWER-MID 70S EXCEPT IN THE 60S ALONG THE COAST WITH CONTINUED
ONSHORE WINDS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW...
VARIOUS LARGE SCALE PATTERN CHANGES ADVERTISED BY MEDIUM RANGE
MODELS DURING THIS FORECAST TIME PERIOD. BROAD DIFFUSE UPPER TROF
LOOKS TO PERSIST THROUGH MID WEEK ALONG THE EASTERN SEABOARD
FOLLOWED BY SIGNIFICANT LONG WAVE AMPLIFICATION ACROSS NORTH AMERICA
TOWARD END OF THE WEEK INTO THE WEEKEND WITH VERY ANOMALOUS MID
TROPOSPHERIC HEIGHT FALLS IN THE WEST AND RISES IN THE EAST. THEN
THERE LOOKS TO BE A TRANSITION TO A MORE ZONAL PATTERN FOR THE
FOLLOWING WEEK. FOR SOUTHERN NEW ENGLAND...WE START TO EXPERIENCE
BUILDING HEIGHTS TOWARD THE END OF THE WEEK ONLY TO HAVE A STRONG
ENOUGH SHORT WAVE TROF PROGRESSING ACROSS CANADA TO ARREST THIS
DEVELOPMENT AND BRING NW FLOW ALOFT TO THE REGION BY AT LEAST THE
SECOND HALF OF THE HOLIDAY WEEKEND. JUST HOW THIS UNFOLDS WILL
DETERMINE THE SENSIBLE WEATHER. THE 00Z GFS IS A LITTLE FASTER IN
ITS CFROPA COMPARED WITH THE 00Z ECMWF.
DAY TO DAY DETAILS...
TUE NIGHT THROUGH THU NIGHT... LARGE SCALE PATTERN
INFLUENCED BY BROAD UPPER LOW OVER MID ATLANTIC STATES THAT LIFTS
OUT AND DIMINISHES AS HEIGHTS ACROSS NEW ENGLAND AND SE CANADA
BUILD. CONDITIONS LOOK MARGINALLY UNSTABLE WED AND TO A LESSER
EXTENT THU AFTERNOON WITH RELATIVELY HIGH PWATS 1.25 TO 1.5
INCHES. AM FORECASTING SCT DIURNAL CONVECTION WED AFTERNOON INTO
THE EARLY EVENING AND TO A LESSER EXTENT THU AFTERNOON. NOTE BY
THU THAT A LOW/MID LEVEL RIDGE BUILDS FROM THE NW ATLANTIC INTO SE
CANADA AND NORTHERN NEW ENGLAND. NO SIGNIFICANT FORCING EITHER DAY
SO ANY SHOWERS/TSTMS MAY DEVELOP ON FAIRLY WEAK DIFFUSE BOUNDARIES
INCLUDING ANY OUTFLOW BOUNDARIES. JUST WENT SLIGHT CHANCE SE
COASTAL AREAS WHERE SURFACE BASED INSTABILITY IS LESS.
FRI...
HAVE GONE WITH A DRY SOLUTION AS BOTH GFS AND ECMWF SHOW RIDGING
OVER THE AREA. GEM BRINGS SIGNIFICANT LOW UP COAST ON FRI BUT THIS
APPEARS TO BE AN OUTLIER WITHOUT ANY SUPPORT FROM OTHER MEDIUM RANGE
MODELS.
SAT...
STRONG SHORT WAVE TROF PROGRESSING ACROSS SOUTHERN CANADA HAS
ASSOCIATED COLD FRONT THAT APPROACHES SAT AND THEN PROBABLY WASHES
OUT AS IT MOVES S OF THE AREA SAT NIGHT AND SUN. ECMWF SLOWER WITH
TIMING THAN GFS WHICH COULD PROVE CORRECT CONSIDERING THE STRENGTH
OF THE EASTERN RIDGE. NOT MUCH VERTICAL WIND SHEAR SHOWN AT THIS
TIME BUT UNSTABLE WITH MOISTURE POOLING TO SUPPORT CHANCE TSTMS SAT
AFTERNOON AND EVENING. ACTIVITY MIGHT LINGER FOR A WHILE SAT NIGHT
ALONG THE S COAST. HAVE MODERATE CONFIDENCE IN THIS SOLUTION DUE TO
REASONABLY GOOD MODEL CONTINUITY OF THIS FEATURE...ALTHOUGH A
STRONGER EXTENSION OF THE MAJOR EASTERN USA UPPER RIDGE COULD CAUSE
FRONT TO BECOME DELAYED OR STALL PRIOR TO MAKING IT THROUGH THE
AREA.
SUN...
EXPECT LOWER DEWPOINTS BUT SOME DISPARITY AS TO EXTENT OF COOLING
BETWEEN GFS AND ECMWF. ECMWF DOES NOT FLATTEN UPPER RIDGE AS MUCH AS
GFS...AND IN FACT KEEPS 850 MB TEMPS OF 16C OVER THE AREA. FOR NOW
HEDGED A LITTLE WARMER FROM GFS BASED SOLUTION TO REFLECT THIS
UNCERTAINTY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 12Z...MODERATE CONFIDENCE.
MAINLY VFR FOR MOST AREAS. S COAST...LOW CLOUDS/FOG LOWERING
CONDITIONS TO MVFR-IFR. LOW PROB OF LIFR MAINLY CAPE COD AND THE
ISLANDS.
TODAY...MODERATE CONFIDENCE.
CONDITIONS LOWERING TO GENERAL MVFR-IFR ACROSS E MA/RI/N CT WITH
MAINLY MVFR CIGS ACROSS INLAND AREAS AFTER 16Z. LOW PROB OF +SHRA
AND ISOLD TSTMS.
TONIGHT...MODERATE CONFIDENCE.
MAINLY MVFR-IFR WITH LOWER CONDITIONS MOVING INLAND AROUND OR AFTER
MIDNIGHT.
TUESDAY...LOW CONFIDENCE.
MVFR-IFR CIGS/VSBYS TO START...THEN MAY IMPROVE TO VFR FROM W-E. LOW
CONFIDENCE ON TIMING.
KBOS TAF...MODERATE CONFIDENCE IN TIMING ARRIVAL OF LOWER CLOUDS
THROUGH 12Z-14Z...THEN START OF PRECIP THIS AFTERNOON.
KBDL TAF...MODERATE CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP
INTO TERMINAL.
OUTLOOK...TUESDAY NIGHT THOUGH FRIDAY...
TUE NIGHT...MODERATE CONFIDENCE. BECOMING MOSTLY VFR EXCEPT PATCHY
IFR CIGS/FOG SOME VALLEYS AND ALONG S COAST.
WED...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR CIGS/VSBYS IN
VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS.
WED NIGHT...LOW TO MODERATE CONFIDENCE. PATCHY STRATUS AND FOG WITH
IFR CIGS/VSBYS.
THU THROUGH FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH TUESDAY.
EXPECT S-SE SWELLS UP TO 7 FT TO CONTINUE MOVING ACROSS THE OUTER
WATERS INTO THE OPEN SOUTH SOUNDS THROUGH THIS PERIOD. HAVE EXTENDED
SMALL CRAFT FOR HAZARDOUS SEAS FOR THE WATERS E OF CAPE COD
SOUTHWARD THROUGH TUESDAY...AND WILL LIKELY NEED TO EXTEND UP THE
COAST ON TUESDAY AS LOW PRES PASSES.
EXPECT WINDS TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH
TUESDAY...THOUGH LOW PROBABILITY OF BRIEF 25 KT GUSTS EARLY TUESDAY
ON THE EASTERN OUTER WATERS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS
PERIOD. ANTICIPATE SUBSIDING SWELLS DURING THIS PERIOD. ONLY
UNCERTAINTY IS IF ALBERTO RETAINS A LITTLE MORE LIFE THAN EXPECTED
AND KEEPS SWELL HIGHER THAN CURRENTLY EXPECTED FOR THE MID WEEK TIME
PERIOD. NO SIGNIFICANT WINDS EXPECTED ACROSS THE COASTAL WATERS
DURING THIS TIME PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
TUESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...EVT/THOMPSON
NEAR TERM...EVT
SHORT TERM...EVT
LONG TERM...THOMPSON
AVIATION...EVT/THOMPSON
MARINE...EVT/THOMPSON
000
FXUS61 KBOX 210834
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
434 AM EDT MON MAY 21 2012
.SYNOPSIS...
A LOW PRESSURE WILL TRACK UP THE COAST...BRINGING AREAS OF SHOWERS
TO THE REGION TODAY AND TONIGHT. SCATTERED MAINLY AFTERNOON
SHOWERS OR THUNDERSTORMS ARE EXPECTED WEDNESDAY AFTERNOON. A COLD
FRONT MAY PRODUCE SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE
AREA ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 PM UPDATE...
MOSTLY CLEAR SKIES WITH ONLY SOME HIGH THIN CIRRUS CONTINUE ACROSS
THE REGION. NOTING AN AREA OF MUCH LOWER DEWPTS ACROSS CENTRAL AND
WESTERN CT INTO SE NY STATE OVER THE LAST SEVERAL HOURS WHILE DEWPTS
RISING THOUGH SLOWER THAN FORECAST ACROSS E MA/RI. HIGHEST DEWPTS
AT 02Z WERE ACROSS SW NH/W MA INTO UPSTATE NY...ALSO RISING ACROSS
LONG ISLAND.
BIG QUESTION FOR THE NIGHT WILL BE WHEN THE DEWPTS FINALLY START TO
RISE AS LOW LEVEL MOISTURE PLUME WORKS UP THE COAST. FEEL THIS WILL
FINALLY HAPPEN AFTER MIDNIGHT FROM S-N...BUT WILL CONTINUE TO
MONITOR CLOSELY.
THIS WILL DELAY ANY PROBLEMS WITH PATCHY FOG DEVELOPING ALONG THE S
COAST UNTIL WELL AFTER MIDNIGHT...AS WAS THE TREND FROM THE PREVIOUS
FORECAST. ALSO NOTED MENTION OF INCREASING CLOUDS...WHICH ARE
STARTING TO WORK N FROM THE DELMARVA REGION AT 02Z. KEPT SIMILAR
TREND FROM PREVIOUS FORECAST.
HAVE UPDATED GRIDS TO BRING CONDITIONS CURRENT AND INCORPORATED INTO
THE NEAR TERM TREND OVERNIGHT.
PREVIOUS DISCUSSION...
CONFIDENCE WANES. SUCH DRY CONDITIONS ALONG THE S COAST WOULD LEND
TO REASON THAT FOG HAS A LOW PROBABILITY OF DEVELOPING. CROSSOVER
TEMP...THAT IS THE DWPT AT TIME OF MAX HEATING...IS LOW...AND MIN
TEMPS ARE EXPECTED IN FALL INTO THE MID 50S...WELL ABOVE THE
CROSSOVER TEMP /THE THRESHOLD THAT IF CROSSED BY THE SFC TEMP WOULD
LEND GREATER PROBABILITY OF FOG FORMATION/.
BUT SHOULD WE SEE A STRONG NWD ADVECTION OF SUBTROPICAL MOISTURE
WITH INCREASING DWPTS EXCEEDING SEA-SFC TEMPS...THEN IT IS QUITE
PLAUSIBLE. DOWNSTREAM AND OFFSHORE FROM BUOY REPORTS...DEWPOINTS
AROUND THE MID 50S ARE BEING REPORTED...WITH LOW 60S ACROSS THE
DELMARVA PENINSULA CLOSER TO THE SFC LOW.
WILL LEAN CONSERVATIVELY. BY MORNING WITH INCREASED ADVECTIVE FLOW
AND APPROACH OF THE BROAD AREA OF LOW PRES AND SUBTROPICAL
MOISTURE...FEEL THERE IS A DISTINCT POSSIBILITY OF VSBYS FALLING
TO 1-2 MILES WITH MIST.
CLOUDS TO INCREASE FROM THE S THRU THE EVNG...THICKENING AND
LOWERING INTO MORNING. AM NOT CONFIDENT SHOWERS WILL GET TO THE S
COAST UNTIL THE MID-MORNING INTO MIDDAY HRS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
LOTS OF MOISTURE EXPECTED TO BE MOVED NORTH INTO OUR REGION.
HOWEVER...NO STRONG DYNAMICS ARE EXPECTED TO BE IN PLACE MONDAY OR
MONDAY NIGHT. PRECIPITABLE WATERS AROUND 1.5 INCHES INDICATE
POTENTIAL FOR HEAVIER RAINFALL...IF CONVECTION OF STRONGER
VERTICAL FORCING DEVELOPS. TIMING OF ONSET FOR ANY PARTICULAR
LOCATION IS TRICKY. AT THIS POINT OPTED TO BRING AT LEAST A CHANCE
OF RAIN DURING THE MORNING FROM SOUTH TO NORTH. THE BRUNT OF THE
RAINFALL SHOULD OCCUR DURING MONDAY AFTERNOON INTO MONDAY NIGHT.
AREAS NORTH OF ROUTE 2 IN MA AND SOUTHERN NH MAY EVEN SEE THE
STEADIER RAINFALL HOLD OFF UNTIL EVENING.
MOST OF THE 20/12Z GUIDANCE HINTING AT THE POTENTIAL FOR SOME
ELEVATED INSTABILITY. MOST OF THESE INDICES ARE MARGINAL...BUT
THINK THERE IS ENOUGH OF A CONSISTENT SIGNAL TO MAINTAIN ISOLATED
THUNDERSTORMS IN THE FORECAST. TIMING AGAIN IS IFFY.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES ONCE AGAIN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW...
VARIOUS LARGE SCALE PATTERN CHANGES ADVERTISED BY MEDIUM RANGE
MODELS DURING THIS FORECAST TIME PERIOD. BROAD DIFFUSE UPPER TROF
LOOKS TO PERSIST THROUGH MID WEEK ALONG THE EASTERN SEABOARD
FOLLOWED BY SIGNIFICANT LONG WAVE AMPLIFICATION ACROSS NORTH AMERICA
TOWARD END OF THE WEEK INTO THE WEEKEND WITH VERY ANOMALOUS MID
TROPOSPHERIC HEIGHT FALLS IN THE WEST AND RISES IN THE EAST. THEN
THERE LOOKS TO BE A TRANSITION TO A MORE ZONAL PATTERN FOR THE
FOLLOWING WEEK. FOR SOUTHERN NEW ENGLAND...WE START TO EXPERIENCE
BUILDING HEIGHTS TOWARD THE END OF THE WEEK ONLY TO HAVE A STRONG
ENOUGH SHORT WAVE TROF PROGRESSING ACROSS CANADA TO ARREST THIS
DEVELOPMENT AND BRING NW FLOW ALOFT TO THE REGION BY AT LEAST THE
SECOND HALF OF THE HOLIDAY WEEKEND. JUST HOW THIS UNFOLDS WILL
DETERMINE THE SENSIBLE WEATHER. THE 00Z GFS IS A LITTLE FASTER IN
ITS CFROPA COMPARED WITH THE 00Z ECMWF.
DAY TO DAY DETAILS...
TUE NIGHT THROUGH THU NIGHT... LARGE SCALE PATTERN
INFLUENCED BY BROAD UPPER LOW OVER MID ATLANTIC STATES THAT LIFTS
OUT AND DIMINISHES AS HEIGHTS ACROSS NEW ENGLAND AND SE CANADA
BUILD. CONDITIONS LOOK MARGINALLY UNSTABLE WED AND TO A LESSER
EXTENT THU AFTERNOON WITH RELATIVELY HIGH PWATS 1.25 TO 1.5
INCHES. AM FORECASTING SCT DIURNAL CONVECTION WED AFTERNOON INTO
THE EARLY EVENING AND TO A LESSER EXTENT THU AFTERNOON. NOTE BY
THU THAT A LOW/MID LEVEL RIDGE BUILDS FROM THE NW ATLANTIC INTO SE
CANADA AND NORTHERN NEW ENGLAND. NO SIGNIFICANT FORCING EITHER DAY
SO ANY SHOWERS/TSTMS MAY DEVELOP ON FAIRLY WEAK DIFFUSE BOUNDARIES
INCLUDING ANY OUTFLOW BOUNDARIES. JUST WENT SLIGHT CHANCE SE
COASTAL AREAS WHERE SURFACE BASED INSTABILITY IS LESS.
FRI...
HAVE GONE WITH A DRY SOLUTION AS BOTH GFS AND ECMWF SHOW RIDGING
OVER THE AREA. GEM BRINGS SIGNIFICANT LOW UP COAST ON FRI BUT THIS
APPEARS TO BE AN OUTLIER WITHOUT ANY SUPPORT FROM OTHER MEDIUM RANGE
MODELS.
SAT...
STRONG SHORT WAVE TROF PROGRESSING ACROSS SOUTHERN CANADA HAS
ASSOCIATED COLD FRONT THAT APPROACHES SAT AND THEN PROBABLY WASHES
OUT AS IT MOVES S OF THE AREA SAT NIGHT AND SUN. ECMWF SLOWER WITH
TIMING THAN GFS WHICH COULD PROVE CORRECT CONSIDERING THE STRENGTH
OF THE EASTERN RIDGE. NOT MUCH VERTICAL WIND SHEAR SHOWN AT THIS
TIME BUT UNSTABLE WITH MOISTURE POOLING TO SUPPORT CHANCE TSTMS SAT
AFTERNOON AND EVENING. ACTIVITY MIGHT LINGER FOR A WHILE SAT NIGHT
ALONG THE S COAST. HAVE MODERATE CONFIDENCE IN THIS SOLUTION DUE TO
REASONABLY GOOD MODEL CONTINUITY OF THIS FEATURE...ALTHOUGH A
STRONGER EXTENSION OF THE MAJOR EASTERN USA UPPER RIDGE COULD CAUSE
FRONT TO BECOME DELAYED OR STALL PRIOR TO MAKING IT THROUGH THE
AREA.
SUN...
EXPECT LOWER DEWPOINTS BUT SOME DISPARITY AS TO EXTENT OF COOLING
BETWEEN GFS AND ECMWF. ECMWF DOES NOT FLATTEN UPPER RIDGE AS MUCH AS
GFS...AND IN FACT KEEPS 850 MB TEMPS OF 16C OVER THE AREA. FOR NOW
HEDGED A LITTLE WARMER FROM GFS BASED SOLUTION TO REFLECT THIS
UNCERTAINTY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 12Z...MODERATE CONFIDENCE.
MAINLY VFR FOR MOST AREAS. S COAST...LOW CLOUDS/FOG LOWERING
CONDITIONS TO MVFR-IFR. LOW PROB OF LIFR MAINLY CAPE COD AND THE
ISLANDS.
TODAY...MODERATE CONFIDENCE.
CONDITIONS LOWERING TO GENERAL MVFR-IFR ACROSS E MA/RI/N CT WITH
MAINLY MVFR CIGS ACROSS INLAND AREAS AFTER 16Z. LOW PROB OF +SHRA
AND ISOLD TSTMS.
TONIGHT...MODERATE CONFIDENCE.
MAINLY MVFR-IFR WITH LOWER CONDITIONS MOVING INLAND AROUND OR AFTER
MIDNIGHT.
TUESDAY...LOW CONFIDENCE.
MVFR-IFR CIGS/VSBYS TO START...THEN MAY IMPROVE TO VFR FROM W-E. LOW
CONFIDENCE ON TIMING.
KBOS TAF...MODERATE CONFIDENCE IN TIMING ARRIVAL OF LOWER CLOUDS
THROUGH 12Z-14Z...THEN START OF PRECIP THIS AFTERNOON.
KBDL TAF...MODERATE CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP
INTO TERMINAL.
OUTLOOK...TUESDAY NIGHT THOUGH FRIDAY...
TUE NIGHT...MODERATE CONFIDENCE. BECOMING MOSTLY VFR EXCEPT PATCHY
IFR CIGS/FOG SOME VALLEYS AND ALONG S COAST.
WED...MODERATE CONFIDENCE. MOSTLY VFR EXCEPT MVFR CIGS/VSBYS IN
VICINITY OF SCT AFTERNOON/EARLY EVENING TSTMS.
WED NIGHT...LOW TO MODERATE CONFIDENCE. PATCHY STRATUS AND FOG WITH
IFR CIGS/VSBYS.
THU THROUGH FRI...MODERATE CONFIDENCE. MOSTLY VFR CONDITIONS.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH MONDAY.
SOUTH-SOUTHEAST SWELLS OF 3-6 FT WILL CONTINUE TO IMPACT THE
SOUTHERN COASTAL WATERS. WITH LITTLE MOVEMENT IN THE WEATHER PATTERN
EXPECTED FOR THE NEXT 24 HOURS OR SO...DO NOT THINK THIS SWELL WILL
CHANGE MUCH DURING THAT TIME. AS SUCH WILL CONTINUE THE SMALL CRAFT
ADVISORY DUE TO HAZARDOUS SEAS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY THROUGH FRIDAY...
MODERATE CONFIDENCE. WAVE WATCH MODEL LOOKS REASONABLE FOR THIS PERIOD. ANTICIPATE
SUBSIDING SWELLS DURING THIS PERIOD. ONLY UNCERTAINTY IS IF ALBERTO
RETAINS A LITTLE MORE LIFE THAN EXPECTED AND KEEPS SWELL HIGHER THAN
CURRENTLY EXPECTED FOR THE MID WEEK TIME PERIOD. NO SIGNIFICANT
WINDS EXPECTED ACROSS THE COASTAL WATERS DURING THIS TIME PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ254>256.
&&
$$
SYNOPSIS...EVT/THOMPSON
NEAR TERM...EVT
SHORT TERM...EVT
LONG TERM...THOMPSON
AVIATION...EVT/THOMPSON
MARINE...EVT/THOMPSON
000
FXUS61 KBOX 210651
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
250 AM EDT MON MAY 21 2012
.SYNOPSIS...
A LOW PRESSURE WILL TRACK UP THE COAST...BRINGING AREAS OF SHOWERS
MONDAY AND MONDAY NIGHT. SCATTERED SHOWERS CONTINUE TUESDAY AND
WEDNESDAY WITH PERIODS OF FOG ALONG THE SOUTH COAST. IMPROVING
WEATHER IS EXPECTED THURSDAY INTO SATURDAY AHEAD OF A COLD FRONT
EXPECTED SATURDAY AFTERNOON WITH SHOWERS AND POSSIBLE THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1030 PM UPDATE...
MOSTLY CLEAR SKIES WITH ONLY SOME HIGH THIN CIRRUS CONTINUE ACROSS
THE REGION. NOTING AN AREA OF MUCH LOWER DEWPTS ACROSS CENTRAL AND
WESTERN CT INTO SE NY STATE OVER THE LAST SEVERAL HOURS WHILE DEWPTS
RISING THOUGH SLOWER THAN FORECAST ACROSS E MA/RI. HIGHEST DEWPTS
AT 02Z WERE ACROSS SW NH/W MA INTO UPSTATE NY...ALSO RISING ACROSS
LONG ISLAND.
BIG QUESTION FOR THE NIGHT WILL BE WHEN THE DEWPTS FINALLY START TO
RISE AS LOW LEVEL MOISTURE PLUME WORKS UP THE COAST. FEEL THIS WILL
FINALLY HAPPEN AFTER MIDNIGHT FROM S-N...BUT WILL CONTINUE TO
MONITOR CLOSELY.
THIS WILL DELAY ANY PROBLEMS WITH PATCHY FOG DEVELOPING ALONG THE S
COAST UNTIL WELL AFTER MIDNIGHT...AS WAS THE TREND FROM THE PREVIOUS
FORECAST. ALSO NOTED MENTION OF INCREASING CLOUDS...WHICH ARE
STARTING TO WORK N FROM THE DELMARVA REGION AT 02Z. KEPT SIMILAR
TREND FROM PREVIOUS FORECAST.
HAVE UPDATED GRIDS TO BRING CONDITIONS CURRENT AND INCORPORATED INTO
THE NEAR TERM TREND OVERNIGHT.
PREVIOUS DISCUSSION...
CONFIDENCE WANES. SUCH DRY CONDITIONS ALONG THE S COAST WOULD LEND
TO REASON THAT FOG HAS A LOW PROBABILITY OF DEVELOPING. CROSSOVER
TEMP...THAT IS THE DWPT AT TIME OF MAX HEATING...IS LOW...AND MIN
TEMPS ARE EXPECTED IN FALL INTO THE MID 50S...WELL ABOVE THE
CROSSOVER TEMP /THE THRESHOLD THAT IF CROSSED BY THE SFC TEMP WOULD
LEND GREATER PROBABILITY OF FOG FORMATION/.
BUT SHOULD WE SEE A STRONG NWD ADVECTION OF SUBTROPICAL MOISTURE
WITH INCREASING DWPTS EXCEEDING SEA-SFC TEMPS...THEN IT IS QUITE
PLAUSIBLE. DOWNSTREAM AND OFFSHORE FROM BUOY REPORTS...DEWPOINTS
AROUND THE MID 50S ARE BEING REPORTED...WITH LOW 60S ACROSS THE
DELMARVA PENINSULA CLOSER TO THE SFC LOW.
WILL LEAN CONSERVATIVELY. BY MORNING WITH INCREASED ADVECTIVE FLOW
AND APPROACH OF THE BROAD AREA OF LOW PRES AND SUBTROPICAL
MOISTURE...FEEL THERE IS A DISTINCT POSSIBILITY OF VSBYS FALLING
TO 1-2 MILES WITH MIST.
CLOUDS TO INCREASE FROM THE S THRU THE EVNG...THICKENING AND
LOWERING INTO MORNING. AM NOT CONFIDENT SHOWERS WILL GET TO THE S
COAST UNTIL THE MID-MORNING INTO MIDDAY HRS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
LOTS OF MOISTURE EXPECTED TO BE MOVED NORTH INTO OUR REGION.
HOWEVER...NO STRONG DYNAMICS ARE EXPECTED TO BE IN PLACE MONDAY OR
MONDAY NIGHT. PRECIPITABLE WATERS AROUND 1.5 INCHES INDICATE
POTENTIAL FOR HEAVIER RAINFALL...IF CONVECTION OF STRONGER
VERTICAL FORCING DEVELOPS. TIMING OF ONSET FOR ANY PARTICULAR
LOCATION IS TRICKY. AT THIS POINT OPTED TO BRING AT LEAST A CHANCE
OF RAIN DURING THE MORNING FROM SOUTH TO NORTH. THE BRUNT OF THE
RAINFALL SHOULD OCCUR DURING MONDAY AFTERNOON INTO MONDAY NIGHT.
AREAS NORTH OF ROUTE 2 IN MA AND SOUTHERN NH MAY EVEN SEE THE
STEADIER RAINFALL HOLD OFF UNTIL EVENING.
MOST OF THE 20/12Z GUIDANCE HINTING AT THE POTENTIAL FOR SOME
ELEVATED INSTABILITY. MOST OF THESE INDICES ARE MARGINAL...BUT
THINK THERE IS ENOUGH OF A CONSISTENT SIGNAL TO MAINTAIN ISOLATED
THUNDERSTORMS IN THE FORECAST. TIMING AGAIN IS IFFY.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES ONCE AGAIN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
TUESDAY INTO WEDNESDAY...
BROAD AREA OF LOW PRES AND ABUNDANCE OF LOW-LVL MOISTURE REMNANT
FROM TS ALBERTO AND NEIGHBORING AREA OF LOW PRES OVER THE ERN
ATLANTIC MAKES FOR A CHAOTIC FCST. CONFIDENCE LIES THAT AN ELONGATED
SHRTWV TROF AXIS ACROSS THE ERN CONUS WILL GRADUALLY SWEEP OFFSHORE
ACTING AS A FOCUS FOR DIURNALLY DRIVEN STORMS WHILE PUSHING THE
BROAD AREA OF LOW PRES NEWD AND OUT OF THE RGN. WHILE IT/S FELT THE
AXIS WILL PROVIDE ENHANCED ASCENT LENDING TO SFC CONVERGENCE AND
FRONTOGENESIS...INSTABILITY AND SHEAR APPEARS VERY WEAK DUE TO THE
WEAK NATURE OF THE TROF AXIS AND ATTENDANT BAROCLINIC ZONE. FEEL TUE
MAYBE FAIRLY CLOUDY WITH ISOLATED TO SCTD SHOWERS /BETTER CHCS TO
THE WEST/...WHEREAS WED WILL BE THE BETTER CHC FOR WET WX AS THE
TROF AXIS SWEEPS THRU THE RGN. ANTICIPATING AREAS OF FOG AND DRIZZLE
FOR THE TUE EVNG PD /ESPECIALLY ACROSS THE COASTLINES AND OVER THE
WATERS/.
THURSDAY...
ENERGY ALONG THE SRN TIER OF AFOREMENTIONED SHRTWV TROF AXIS WILL
CYCLONICALLY DEEPEN AS IT INTERACTS WITH THE SUBTROPICAL JET
ORIENTED SW-NE ACROSS FLORIDA INTO THE CENTRAL ATLANTIC. ANTICIPATE
A SECONDARY BROAD AREA OF LOW PRES TO GRADUALLY LIFT WITH THE MEAN
FLOW THRU THE MID-ATLANTIC AND OFFSHORE. BROAD LIFT ACROSS THE RGN
COUPLED WITH A FAIRLY MOIST COLUMN LENDS TO THE POSSIBILITY OF SOME
SCTD POP-UP SHOWERS. FEEL SOME ORTHOGRAPHICAL AID IS GIVEN ALONG THE
EWD SLOPES OF HIGHER TERRAIN AS E/SELY ONSHORE FLOW WILL ENHANCE IN
RESPONSE TO AN APPROACHING DEEPER SYS ACROSS THE CNTRL CONUS. FLOW
WILL LIKELY BE ENHANCED OUT OF THE SW ALOFT ADVECTING WARMER AIR
ACROSS THE RGN AND ACTING TO CAP THE LOW-LVLS AROUND H85. SO
UNCERTAINTY PREVAILS AS TO WHETHER LOW-LVL FORCING WILL OVERCOME THE
MID-LYR CAP. ANTICIPATE SHOWERS TO BE LIGHT WITH LOW CONFIDENCE ON
THUNDER.
FRIDAY INTO SATURDAY...
AS THE BROAD AREA OF LOW PRES MOVES OFFSHORE...WAA AND SUBSEQUENT
RIDGING AHEAD OF A DEEP SYS THRU THE NRN CONUS WILL LIKELY KEEP THE
FCST DRY INTO SATURDAY. INHERENT UNCERTAINTIES ON THE STRENGTH AND
TIMING OF THE RIDGE ULTIMATELY IMPACTS THE EXPECTATION OF A SFC COLD
FRNT ACROSS THE RGN WITH SHOWERS AND PSBL THUNDERSTORMS. CONFIDENCE
LIES THAT SHOULD THE SFC COLD FRNT TRAVERSE THE RGN DURING THE SAT
AFTN PD...THEN LIKELY SFC-BASED INSTABILITY COUPLED WITH FRONTO-
GENETIC FORCING WILL LIKELY YIELD THUNDERSTORMS /ESPECIALLY ACROSS
THE INTERIOR AND AWAY FROM THE MARINE ZONES/. WILL HINT AS THE
POSSIBILITY IN THE FCST FOR SAT AFTN. WHETHER THE SFC COLD FRNT
PUSHES OFFSHORE REMAINS IN QUESTION...BUT MUCH OF THE FCST GUIDANCE
SUGGESTS THAT STRONGER HIGH PRES WILL BUILD S OUT OF CANADA AND PUSH
ENERGY OUT TO SEA.
SUNDAY AND BEYOND...
AT FIRST GUESS IT APPEARS THAT HIGH PRES RIDGING SEWD OUT OF CANADA
WILL KEEP THE FCST PD COOL AND DRY UNDER NLY FLOW. LOW-LVL PROFILES
WILL LIKELY BE WELL-MIXED LENDING TO DIURNAL CU AND MIX-DOWN OF BOTH
DRIER AIR AND FASTER MOMENTUM.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 12Z...MODERATE CONFIDENCE.
MAINLY VFR FOR MOST AREAS. S COAST...LOW CLOUDS/FOG LOWERING
CONDITIONS TO MVFR-IFR. LOW PROB OF LIFR MAINLY CAPE COD AND THE
ISLANDS.
TODAY...MODERATE CONFIDENCE.
CONDITIONS LOWERING TO GENERAL MVFR-IFR ACROSS E MA/RI/N CT WITH
MAINLY MVFR CIGS ACROSS INLAND AREAS AFTER 16Z. LOW PROB OF +SHRA
AND ISOLD TSTMS.
TONIGHT...MODERATE CONFIDENCE.
MAINLY MVFR-IFR WITH LOWER CONDITIONS MOVING INLAND AROUND OR AFTER
MIDNIGHT.
TUESDAY...LOW CONFIDENCE.
MVFR-IFR CIGS/VSBYS TO START...THEN MAY IMPROVE TO VFR FROM W-E. LOW
CONFIDENCE ON TIMING.
KBOS TAF...MODERATE CONFIDENCE IN TIMING ARRIVAL OF LOWER CLOUDS
THROUGH 12Z-14Z...THEN START OF PRECIP THIS AFTERNOON.
KBDL TAF...MODERATE CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP
INTO TERMINAL.
OUTLOOK...TUESDAY NIGHT THOUGH FRIDAY...
TUESDAY NIGHT AND WEDNESDAY...
MODERATE CONFIDENCE. MIXED MVFR-IFR CONDITIONS. AREAS OF DRIZZLE
AND FOG FOR TUES NGT. SHOWERS MORE LIKELY DURING THE DAY WED. LGT
SLY WINDS.
THURSDAY AND FRIDAY...
MODERATE CONFIDENCE. MVFR-IFR TO LINGER THRU THURS...IMPROVING VFR
INTO FRI. COLD FRNT APPROACHING...INCREASING SLY FLOW.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH MONDAY.
SOUTH-SOUTHEAST SWELLS OF 3-6 FT WILL CONTINUE TO IMPACT THE
SOUTHERN COASTAL WATERS. WITH LITTLE MOVEMENT IN THE WEATHER PATTERN
EXPECTED FOR THE NEXT 24 HOURS OR SO...DO NOT THINK THIS SWELL WILL
CHANGE MUCH DURING THAT TIME. AS SUCH WILL CONTINUE THE SMALL CRAFT
ADVISORY DUE TO HAZARDOUS SEAS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY THROUGH FRIDAY...
MODERATE CONFIDENCE. INITIALLY MONDAY NIGHT INTO TUESDAY...A WEAK
AND DIFFUSE COLD FRNTL DISTURBANCE WILL APPROACH FROM THE W AS TS
ALBERTO LIFTS NEWD JUST S AND E OF THE 40N 70W BENCHMARK. LIKELY
SWELL FROM THE STORM WILL RESULT IN SIGNIFICANT WAVE HEIGHTS OVER
THE WATERS...BUT THE PROXIMITY AND THE DISTINCT NATURE OF TS
ALBERTO SHOULD KEEP THE WIND IMPACTS MINIMAL ALONG THE S/E OUTER
WATERS. WILL MONITOR CLOSELY. SCA FOR HAZ SEAS CONTINUING.
OTHERWISE...A SERIES OF BROAD AREAS OF LOW PRES ACROSS THE WATERS
FOR THE PERIOD SHALL INVOKE LIFT OF A VERY MOIST SUB-TROPICAL
AIRMASS. ANTICIPATE INTERMITTENT SHOWERS OVER THE WATERS WITH EVNG
PERIODS COMPRISED OF AREAS OF FOG AND DRIZZLE /TUE EVNG LOOKING LIKE
A SURE BET/. LIKELY VSBY IMPACTS WHILE THE PREVAILING FLOW WILL BE
S/SELY FOR THE WEEK...EXPECT LIGHT WINDS ENHANCING BY FRI AHEAD OF A
COLD FNTL DISTURBANCE OUT OF THE GRT LKS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT
TUESDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT EARLY
THIS MORNING FOR ANZ235-237.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...SIPPRELL/EVT
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL/EVT
MARINE...BELK/SIPPRELL
000
FXUS61 KBOX 210239
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1040 PM EDT SUN MAY 20 2012
.SYNOPSIS...
A LOW PRESSURE WILL TRACK UP THE COAST...BRINGING AREAS OF SHOWERS
MONDAY AND MONDAY NIGHT. SCATTERED SHOWERS CONTINUE TUESDAY AND
WEDNESDAY WITH PERIODS OF FOG ALONG THE SOUTH COAST. IMPROVING
WEATHER IS EXPECTED THURSDAY INTO SATURDAY AHEAD OF A COLD FRONT
EXPECTED SATURDAY AFTERNOON WITH SHOWERS AND POSSIBLE THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1030 PM UPDATE...
MOSTLY CLEAR SKIES WITH ONLY SOME HIGH THIN CIRRUS CONTINUE ACROSS
THE REGION. NOTING AN AREA OF MUCH LOWER DEWPTS ACROSS CENTRAL AND
WESTERN CT INTO SE NY STATE OVER THE LAST SEVERAL HOURS WHILE DEWPTS
RISING THOUGH SLOWER THAN FORECAST ACFROSS E MA/RI. HIGHEST DEWPTS
AT 02Z WERE ACROSS SW NH/W MA INTO UPSTATE NY...ALSO RISING ACROSS
LONG ISLAND.
BIG QUESTION FOR THE NIGHT WILL BE WHEN THE DEWPTS FINALLY START TO
RISE AS LOW LEVEL MOISTURE PLUME WORKS UP THE COAST. FEEL THIS WILL
FINALLY HAPPEN AFTER MIDNIGHT FROM S-N...BUT WILL CONTINUE TO
MONITOR CLOSELY.
THIS WILL DELAY ANY PROBLEMS WITH PATCHY FOG DEVELOPING ALONG THE S
COAST UNTIL WELL AFTER MIDNIGHT...AS WAS THE TREND FROM THE PREVIOUS
FORECAST. ALSO NOTED MENTION OF INCREASING CLOUDS...WHICH ARE
STARTING TO WORK N FROM THE DELMARVA REGION AT 02Z. KEPT SIMILAR
TREND FROM PREVIOUS FORECAST.
HAVE UPDATED GRIDS TO BRING CONDITIONS CURRENT AND INCORPORATED INTO
THE NEAR TERM TREND OVERNIGHT.
PREVIOUS DISCUSSION...
CONFIDENCE WANES. SUCH DRY CONDITIONS ALONG THE S COAST WOULD LEND
TO REASON THAT FOG HAS A LOW PROBABILITY OF DEVELOPING. CROSSOVER
TEMP...THAT IS THE DWPT AT TIME OF MAX HEATING...IS LOW...AND MIN
TEMPS ARE EXPECTED IN FALL INTO THE MID 50S...WELL ABOVE THE
CROSSOVER TEMP /THE THRESHOLD THAT IF CROSSED BY THE SFC TEMP WOULD
LEND GREATER PROBABILITY OF FOG FORMATION/.
BUT SHOULD WE SEE A STRONG NWD ADVECTION OF SUBTROPICAL MOISTURE
WITH INCREASING DWPTS EXCEEDING SEA-SFC TEMPS...THEN IT IS QUITE
PLAUSIBLE. DOWNSTREAM AND OFFSHORE FROM BUOY REPORTS...DEWPOINTS
AROUND THE MID 50S ARE BEING REPORTED...WITH LOW 60S ACROSS THE
DELMARVA PENINSULA CLOSER TO THE SFC LOW.
WILL LEAN CONSERVATIVELY. BY MORNING WITH INCREASED ADVECTIVE FLOW
AND APPROACH OF THE BROAD AREA OF LOW PRES AND SUBTROPICAL
MOISTURE...FEEL THERE IS A DISTINCT POSSIBILITY OF VSBYS FALLING
TO 1-2 MILES WITH MIST.
CLOUDS TO INCREASE FROM THE S THRU THE EVNG...THICKENING AND
LOWERING INTO MORNING. AM NOT CONFIDENT SHOWERS WILL GET TO THE S
COAST UNTIL THE MID-MORNING INTO MIDDAY HRS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
LOTS OF MOISTURE EXPECTED TO BE MOVED NORTH INTO OUR REGION.
HOWEVER...NO STRONG DYNAMICS ARE EXPECTED TO BE IN PLACE MONDAY OR
MONDAY NIGHT. PRECIPITABLE WATERS AROUND 1.5 INCHES INDICATE
POTENTIAL FOR HEAVIER RAINFALL...IF CONVECTION OF STRONGER
VERTICAL FORCING DEVELOPS. TIMING OF ONSET FOR ANY PARTICULAR
LOCATION IS TRICKY. AT THIS POINT OPTED TO BRING AT LEAST A CHANCE
OF RAIN DURING THE MORNING FROM SOUTH TO NORTH. THE BRUNT OF THE
RAINFALL SHOULD OCCUR DURING MONDAY AFTERNOON INTO MONDAY NIGHT.
AREAS NORTH OF ROUTE 2 IN MA AND SOUTHERN NH MAY EVEN SEE THE
STEADIER RAINFALL HOLD OFF UNTIL EVENING.
MOST OF THE 20/12Z GUIDANCE HINTING AT THE POTENTIAL FOR SOME
ELEVATED INSTABILITY. MOST OF THESE INDICES ARE MARGINAL...BUT
THINK THERE IS ENOUGH OF A CONSISTENT SIGNAL TO MAINTAIN ISOLATED
THUNDERSTORMS IN THE FORECAST. TIMING AGAIN IS IFFY.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES ONCE AGAIN.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
TUESDAY INTO WEDNESDAY...
BROAD AREA OF LOW PRES AND ABUNDANCE OF LOW-LVL MOISTURE REMNANT
FROM TS ALBERTO AND NEIGHBORING AREA OF LOW PRES OVER THE ERN
ATLANTIC MAKES FOR A CHAOTIC FCST. CONFIDENCE LIES THAT AN ELONGATED
SHRTWV TROF AXIS ACROSS THE ERN CONUS WILL GRADUALLY SWEEP OFFSHORE
ACTING AS A FOCUS FOR DIURNALLY DRIVEN STORMS WHILE PUSHING THE
BROAD AREA OF LOW PRES NEWD AND OUT OF THE RGN. WHILE IT/S FELT THE
AXIS WILL PROVIDE ENHANCED ASCENT LENDING TO SFC CONVERGENCE AND
FRONTO- GENESIS...INSTABILITY AND SHEAR APPEARS VERY WEAK DUE TO THE
WEAK NATURE OF THE TROF AXIS AND ATTENDANT BAROCLINIC ZONE. FEEL TUE
MAYBE FAIRLY CLOUDY WITH ISOLATED TO SCTD SHOWERS /BETTER CHCS TO
THE WEST/...WHEREAS WED WILL BE THE BETTER CHC FOR WET WX AS THE
TROF AXIS SWEEPS THRU THE RGN. ANTICIPATING AREAS OF FOG AND DRIZZLE
FOR THE TUE EVNG PD /ESPECIALLY ACROSS THE COASTLINES AND OVER THE
WATERS/.
THURSDAY...
ENERGY ALONG THE SRN TIER OF AFOREMENTIONED SHRTWV TROF AXIS WILL
CYCLONICALLY DEEPEN AS IT INTERACTS WITH THE SUBTROPICAL JET
ORIENTED SW-NE ACROSS FLORIDA INTO THE CENTRAL ATLANTIC. ANTICIPATE
A SECONDARY BROAD AREA OF LOW PRES TO GRADUALLY LIFT WITH THE MEAN
FLOW THRU THE MID-ATLANTIC AND OFFSHORE. BROAD LIFT ACROSS THE RGN
COUPLED WITH A FAIRLY MOIST COLUMN LENDS TO THE POSSIBILITY OF SOME
SCTD POP-UP SHOWERS. FEEL SOME OROGRAPHICAL AID IS GIVEN ALONG THE
EWD SLOPES OF HIGHER TERRAIN AS E/SELY ONSHORE FLOW WILL ENHANCE IN
RESPONSE TO AN APPROACHING DEEPER SYS ACROSS THE CNTRL CONUS. FLOW
WILL LIKELY BE ENHANCED OUT OF THE SW ALOFT ADVECTING WARMER AIR
ACROSS THE RGN AND ACTING TO CAP THE LOW-LVLS AROUND H85. SO
UNCERTAINTY PREVAILS AS TO WHETHER LOW-LVL FORCING WILL OVERCOME THE
MID-LYR CAP. ANTICIPATE SHOWERS TO BE LIGHT WITH LOW CONFIDENCE ON
THUNDER.
FRIDAY INTO SATURDAY...
AS THE BROAD AREA OF LOW PRES MOVES OFFSHORE...WAA AND SUBSEQUENT
RIDGING AHEAD OF A DEEP SYS THRU THE NRN CONUS WILL LIKELY KEEP THE
FCST DRY INTO SATURDAY. INHERENT UNCERTAINTIES ON THE STRENGTH AND
TIMING OF THE RIDGE ULTIMATELY IMPACTS THE EXPECTATION OF A SFC COLD
FRNT ACROSS THE RGN WITH SHOWERS AND PSBL THUNDERSTORMS. CONFIDENCE
LIES THAT SHOULD THE SFC COLD FRNT TRAVERSE THE RGN DURING THE SAT
AFTN PD...THEN LIKELY SFC-BASED INSTABILITY COUPLED WITH FRONTO-
GENETICAL FORCING WILL LIKELY YIELD THUNDERSTORMS /ESPECIALLY ACROSS
THE INTERIOR AND AWAY FROM THE MARINE ZONES/. WILL HINT AS THE
POSSIBILITY IN THE FCST FOR SAT AFTN. WHETHER THE SFC COLD FRNT
PUSHES OFFSHORE REMAINS IN QUESTION...BUT MUCH OF THE FCST GUIDANCE
SUGGESTS THAT STRONGER HIGH PRES WILL BUILD S OUT OF CANADA AND PUSH
ENERGY OUT TO SEA.
SUNDAY AND BEYOND...
AT FIRST GUESS IT APPEARS THAT HIGH PRES RIDGING SEWD OUT OF CANADA
WILL KEEP THE FCST PD COOL AND DRY UNDER NLY FLOW. LOW-LVL PROFILES
WILL LIKELY BE WELL-MIXED LENDING TO DIURNAL CU AND MIX-DOWN OF BOTH
DRIER AIR AND FASTER MOMENTUM.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...
INCREASING LOW-LVL MOISTURE AND STRATUS FROM THE S...THICKENING AND
LOWERING WITH TIME. INTO MON MORN...INCREASING CONFIDENCE OF MVFR-
IFR VSBY/CIGS /LIFR WILL BE PSBL AS FOG ALONG THE S SHORE IS
EXPECTED/. BANDS OF SHRA /WITH +SHRA AND PSBL ISOLATED TSRA/
SWEEPING N-S THRU THE TERMINALS...INCREASING IN AERIAL EXTENT
INTO LATE MON AND MON NGT. E/SE FLOW PREVAILS.
KBOS TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP INTO MONDAY.
KBDL TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP INTO MONDAY.
OUTLOOK...TUESDAY THOUGH FRIDAY...
TUESDAY AND WEDNESDAY...
MODERATE CONFIDENCE. DURING THE DAY MIXED MVFR-IFR CONDITIONS WITH
INTERMITTENT VFR PSBL. AREAS OF DRIZZLE AND FOG FOR TUES NGT.
SHOWERS MORE LIKELY DURING THE DAY WED. LGT SLY WINDS.
THURSDAY AND FRIDAY...
MODERATE CONFIDENCE. MVFR-IFR TO LINGER THRU THURS...IMPROVING VFR
INTO FRI. COLD FRNT APPROACHING...INCREASING SLY FLOW.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH MONDAY.
SOUTH-SOUTHEAST SWELLS OF 3-6 FT WILL CONTINUE TO IMPACT THE
SOUTHERN COASTAL WATERS. WITH LITTLE MOVEMENT IN THE WEATHER PATTERN
EXPECTED FOR THE NEXT 24 HOURS OR SO...DO NOT THINK THIS SWELL WILL
CHANGE MUCH DURING THAT TIME. AS SUCH WILL CONTINUE THE SMALL CRAFT
ADVISORY DUE TO HAZARDOUS SEAS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY THROUGH FRIDAY...
MODERATE CONFIDENCE. INITIALLY MONDAY NIGHT INTO TUESDAY...A WEAK
AND DIFFUSE COLD FRNTL DISTURBANCE WILL APPROACH FROM THE W AS TS
ALBERTO LIFTS NEWD JUST S AND E OF THE 40N 70W BENCHMARK. LIKELY
SWELL FROM THE STORM WILL RESULT IN SIGNIFICANT WAVE HEIGHTS OVER
THE WATERS...BUT THE PROXIMITY AND THE DISTINCT NATURE OF TS
ALBERTO SHOULD KEEP THE WIND IMPACTS MINIMAL ALONG THE S/E OUTER
WATERS. WILL MONITOR CLOSELY. SCA FOR HAZ SEAS CONTINUING.
OTHERWISE...A SERIES OF BROAD AREAS OF LOW PRES ACROSS THE WATERS
FOR THE PERIOD SHALL INVOKE LIFT OF A VERY MOIST SUB-TROPICAL
AIRMASS. ANTICIPATE INTERMITTENT SHOWERS OVER THE WATERS WITH EVNG
PERIODS COMPRISED OF AREAS OF FOG AND DRIZZLE /TUE EVNG LOOKING LIKE
A SURE BET/. LIKELY VSBY IMPACTS WHILE THE PREVAILING FLOW WILL BE
S/SELY FOR THE WEEK...EXPECT LIGHT WINDS ENHANCING BY FRI AHEAD OF A
COLD FNTL DISTURBANCE OUT OF THE GRT LKS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT
TUESDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...SIPPRELL/EVT
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
000
FXUS61 KBOX 202325
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
725 PM EDT SUN MAY 20 2012
.SYNOPSIS...
A LOW PRESSURE WILL TRACK UP THE COAST...BRINGING PERIODS OF
SHOWERS MONDAY AND MONDAY NIGHT. SCATTERED SHOWERS CONTINUE
TUESDAY AND WEDNESDAY WITH PERIODS OF FOG ALONG THE SOUTH COAST.
IMPROVING WEATHER IS EXPECTED THURSDAY INTO SATURDAY AHEAD OF A
COLD FRONT EXPECTED SATURDAY AFTERNOON WITH SHOWERS AND POSSIBLE
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
7 PM UPDATE...
UPDATING THE NEAR-TERM TO INCORPORATE THE LATEST TRENDS. NOTABLY
CONDITIONS ALONG THE S SHORE HAVE BEEN DRY...WITH DWPTS OVER
NANTUCKET GETTING AS LOW AS 35 DEGREES. WITH THAT BEING SAID...
THE EXPECTATION FOR THIS EVNG IS FOR E/SELY FLOW TO ADVECT
SUBTROPICAL MOISTURE N AND W ACROSS S NEW ENGLAND INTO THE
MORNING HRS...AND CONSEQUENTIALLY IMPACTS UPON VSYBS DUE TO FOG.
CONFIDENCE WANES. SUCH DRY CONDITIONS ALONG THE S WOULD LEND TO
REASON THAT FOG HAS A LOW PROBABILITY OF DEVELOPING. CROSSOVER
TEMP...THAT IS THE DWPT AT TIME OF MAX HEATING...IS LOW...AND MIN
TEMPS ARE EXPECTED IN FALL INTO THE MID 50S...WELL ABOVE THE
CROSSOVER TEMP /THE THRESHOLD THAT IF CROSSED BY THE SFC TEMP
WOULD LEND GREATER PROBABILITY OF FOG FORMATION/.
BUT SHOULD WE SEE A STRONG NWD ADVECTION OF SUBTROPICAL MOISTURE
WITH INCREASING DWPTS EXCEEDING SEA-SFC TEMPS...THEN IT IS QUITE
PLAUSIBLE. DOWNSTREAM AND OFFSHORE FROM BUOY REPORTS...DEWPOINTS
AROUND THE MID 50S ARE BEING REPORTED...WITH LOW 60S ACROSS THE
DELMARVA PENINSULA CLOSER TO THE SFC LOW.
WILL LEAN CONSERVATIVELY. BY MORNING WITH INCREASED ADVECTIVE FLOW
AND APPROACH OF THE BROAD AREA OF LOW PRES AND SUBTROPICAL
MOISTURE...FEEL THERE IS A DISTINCT POSSIBILITY OF VSBYS FALLING
TO 1-2 MILES WITH MIST.
CLOUDS TO INCREASE FROM THE S THRU THE EVNG...THICKENING AND
LOWERING INTO MORNING. AM NOT CONFIDENT SHOWERS WILL GET TO THE S
COAST UNTIL THE MID-MORNING INTO MIDDAY HRS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
LOTS OF MOISTURE EXPECTED TO BE MOVED NORTH INTO OUR REGION.
HOWEVER...NO STRONG DYNAMICS ARE EXPECTED TO BE IN PLACE MONDAY OR
MONDAY NIGHT. PRECIPITABLE WATERS AROUND 1.5 INCHES INDICATE
POTENTIAL FOR HEAVIER RAINFALL...IF CONVECTION OF STRONGER
VERTICAL FORCING DEVELOPS. TIMING OF ONSET FOR ANY PARTICULAR
LOCATION IS TRICKY. AT THIS POINT OPTED TO BRING AT LEAST A CHANCE
OF RAIN DURING THE MORNING FROM SOUTH TO NORTH. THE BRUNT OF THE
RAINFALL SHOULD OCCUR DURING MONDAY AFTERNOON INTO MONDAY NIGHT.
AREAS NORTH OF ROUTE 2 IN MA AND SOUTHERN NH MAY EVEN SEE THE
STEADIER RAINFALL HOLD OFF UNTIL EVENING.
MOST OF THE 20/12Z GUIDANCE HINTING AT THE POTENTIAL FOR SOME
ELEVATED INSTABILITY. MOST OF THESE INDICES ARE MARGINAL...BUT
THINK THERE IS ENOUGH OF A CONSISTENT SIGNAL TO MAINTAIN ISOLATED
THUNDERSTORMS IN THE FORECAST. TIMING AGAIN IS IFFY.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES ONCE AGAIN.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
TUESDAY INTO WEDNESDAY...
BROAD AREA OF LOW PRES AND ABUNDANCE OF LOW-LVL MOISTURE REMNANT
FROM TS ALBERTO AND NEIGHBORING AREA OF LOW PRES OVER THE ERN ATLANTIC
MAKES FOR A CHAOTIC FCST. CONFIDENCE LIES THAT AN ELONGATED SHRTWV
TROF AXIS ACROSS THE ERN CONUS WILL GRADUALLY SWEEP OFFSHORE ACTING
AS A FOCUS FOR DIURNALLY DRIVEN STORMS WHILE PUSHING THE BROAD AREA
OF LOW PRES NEWD AND OUT OF THE RGN. WHILE IT/S FELT THE AXIS WILL
PROVIDE ENHANCED ASCENT LENDING TO SFC CONVERGENCE AND FRONTO-
GENESIS...INSTABILITY AND SHEAR APPEARS VERY WEAK DUE TO THE WEAK
NATURE OF THE TROF AXIS AND ATTENDANT BAROCLINIC ZONE. FEEL TUE
MAYBE FAIRLY CLOUDY WITH ISOLATED TO SCTD SHOWERS /BETTER CHCS TO
THE WEST/...WHEREAS WED WILL BE THE BETTER CHC FOR WET WX AS THE
TROF AXIS SWEEPS THRU THE RGN. ANTICIPATING AREAS OF FOG AND DRIZZLE
FOR THE TUE EVNG PD /ESPECIALLY ACROSS THE COASTLINES AND OVER THE
WATERS/.
THURSDAY...
ENERGY ALONG THE SRN TIER OF AFOREMENTIONED SHRTWV TROF AXIS WILL
CYCLONICALLY DEEPEN AS IT INTERACTS WITH THE SUBTROPICAL JET
ORIENTED SW-NE ACROSS FLORIDA INTO THE CENTRAL ATLANTIC. ANTICIPATE
A SECONDARY BROAD AREA OF LOW PRES TO GRADUALLY LIFT WITH THE MEAN
FLOW THRU THE MID-ATLANTIC AND OFFSHORE. BROAD LIFT ACROSS THE RGN
COUPLED WITH A FAIRLY MOIST COLUMN LENDS TO THE POSSIBILITY OF SOME
SCTD POP-UP SHOWERS. FEEL SOME OROGRAPHICAL AID IS GIVEN ALONG THE
EWD SLOPES OF HIGHER TERRAIN AS E/SELY ONSHORE FLOW WILL ENHANCE IN
RESPONSE TO AN APPROACHING DEEPER SYS ACROSS THE CNTRL CONUS. FLOW
WILL LIKELY BE ENHANCED OUT OF THE SW ALOFT ADVECTING WARMER AIR
ACROSS THE RGN AND ACTING TO CAP THE LOW-LVLS AROUND H85. SO
UNCERTAINTY PREVAILS AS TO WHETHER LOW-LVL FORCING WILL OVERCOME THE
MID-LYR CAP. ANTICIPATE SHOWERS TO BE LIGHT WITH LOW CONFIDENCE ON
THUNDER.
FRIDAY INTO SATURDAY...
AS THE BROAD AREA OF LOW PRES MOVES OFFSHORE...WAA AND SUBSEQUENT
RIDGING AHEAD OF A DEEP SYS THRU THE NRN CONUS WILL LIKELY KEEP THE
FCST DRY INTO SATURDAY. INHERENT UNCERTAINTIES ON THE STRENGTH AND
TIMING OF THE RIDGE ULTIMATELY IMPACTS THE EXPECTATION OF A SFC COLD
FRNT ACROSS THE RGN WITH SHOWERS AND PSBL THUNDERSTORMS. CONFIDENCE
LIES THAT SHOULD THE SFC COLD FRNT TRAVERSE THE RGN DURING THE SAT
AFTN PD...THEN LIKELY SFC-BASED INSTABILITY COUPLED WITH FRONTO-
GENETICAL FORCING WILL LIKELY YIELD THUNDERSTORMS /ESPECIALLY ACROSS
THE INTERIOR AND AWAY FROM THE MARINE ZONES/. WILL HINT AS THE
POSSIBILITY IN THE FCST FOR SAT AFTN. WHETHER THE SFC COLD FRNT
PUSHES OFFSHORE REMAINS IN QUESTION...BUT MUCH OF THE FCST GUIDANCE
SUGGESTS THAT STRONGER HIGH PRES WILL BUILD S OUT OF CANADA AND PUSH
ENERGY OUT TO SEA.
SUNDAY AND BEYOND...
AT FIRST GUESS IT APPEARS THAT HIGH PRES RIDGING SEWD OUT OF CANADA
WILL KEEP THE FCST PD COOL AND DRY UNDER NLY FLOW. LOW-LVL PROFILES
WILL LIKELY BE WELL-MIXED LENDING TO DIURNAL CU AND MIX-DOWN OF BOTH
DRIER AIR AND FASTER MOMENTUM.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...
INCREASING LOW-LVL MOISTURE AND STRATUS FROM THE S...THICKENING AND
LOWERING WITH TIME. INTO MON MORN...INCREASING CONFIDENCE OF MVFR-
IFR VSBY/CIGS /LIFR WILL BE PSBL AS FOG ALONG THE S SHORE IS
EXPECTED/. BANDS OF SHRA /WITH +SHRA AND PSBL ISOLATED TSRA/
SWEEPING N-S THRU THE TERMINALS...INCREASING IN AERIAL EXTENT
INTO LATE MON AND MON NGT. E/SE FLOW PREVAILS.
KBOS TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP INTO MONDAY.
KBDL TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP INTO MONDAY.
OUTLOOK...TUESDAY THOUGH FRIDAY...
TUESDAY AND WEDNESDAY...
MODERATE CONFIDENCE. DURING THE DAY MIXED MVFR-IFR CONDITIONS WITH
INTERMITTENT VFR PSBL. AREAS OF DRIZZLE AND FOG FOR TUES NGT.
SHOWERS MORE LIKELY DURING THE DAY WED. LGT SLY WINDS.
THURSDAY AND FRIDAY...
MODERATE CONFIDENCE. MVFR-IFR TO LINGER THRU THURS...IMPROVING VFR
INTO FRI. COLD FRNT APPROACHING...INCREASING SLY FLOW.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH MONDAY.
3-5 FT SOUTH-SOUTHEAST SWELLS CONTINUE TO IMPACT THE SOUTHERN
COASTAL WATERS. WITH LITTLE MOVEMENT IN THE WEATHER PATTERN
EXPECTED FOR THE NEXT 24 HOURS OR SO...DO NOT THINK THIS SWELL
WILL CHANGE MUCH DURING THAT TIME. AS SUCH WILL CONTINUE THE SMALL
CRAFT ADVISORY DUE TO HAZARDOUS SEAS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY THROUGH FRIDAY...
MODERATE CONFIDENCE. INITIALLY MONDAY NIGHT INTO TUESDAY...A WEAK
AND DIFFUSE COLD FRNTL DISTURBANCE WILL APPROACH FROM THE W AS TS
ALBERTO LIFTS NEWD JUST S AND E OF THE 40N 70W BENCHMARK. LIKELY
SWELL FROM THE STORM WILL RESULT IN SIGNIFICANT WAVE HEIGHTS OVER
THE WATERS...BUT THE PROXIMITY AND THE DISTINCT NATURE OF TS
ALBERTO SHOULD KEEP THE WIND IMPACTS MINIMAL ALONG THE S/E OUTER
WATERS. WILL MONITOR CLOSELY. SCA FOR HAZ SEAS CONTINUING.
OTHERWISE...A SERIES OF BROAD AREAS OF LOW PRES ACROSS THE WATERS
FOR THE PERIOD SHALL INVOKE LIFT OF A VERY MOIST SUB-TROPICAL
AIRMASS. ANTICIPATE INTERMITTENT SHOWERS OVER THE WATERS WITH EVNG
PERIODS COMPRISED OF AREAS OF FOG AND DRIZZLE /TUE EVNG LOOKING LIKE
A SURE BET/. LIKELY VSBY IMPACTS WHILE THE PREVAILING FLOW WILL BE
S/SELY FOR THE WEEK...EXPECT LIGHT WINDS ENHANCING BY FRI AHEAD OF A
COLD FNTL DISTURBANCE OUT OF THE GRT LKS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT TUESDAY
FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK/SIPPRELL
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
000
FXUS61 KBOX 201931
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
331 PM EDT SUN MAY 20 2012
.SYNOPSIS...
A LOW PRESSURE WILL TRACK UP THE COAST...BRINGING PERIODS OF
SHOWERS MONDAY AND MONDAY NIGHT. SCATTERED SHOWERS CONTINUE
TUESDAY AND WEDNESDAY WITH PERIODS OF FOG ALONG THE SOUTH COAST.
IMPROVING WEATHER IS EXPECTED THURSDAY INTO SATURDAY AHEAD OF A
COLD FRONT EXPECTED SATURDAY AFTERNOON WITH SHOWERS AND POSSIBLE
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
2 PM UPDATE...ONLY MINOR TWEAKS TO REFLECT LATEST OBSERVED
TEMPERATURE AND DEW POINT TRENDS. MOS GUIDANCE DEW POINTS ARE TOO
LOW...FOUND VALUES MUCH CLOSER TO REALITY IN THE RAW MODEL OUTPUT.
TONIGHT...SURFACE RIDGE ACROSS NEW ENGLAND IS EXPECTED TO SLOWLY
MOVE OUT TO SEA OVERNIGHT. THIS WILL OPEN THE DOOR FOR A BROAD
MID-LEVEL CUTOFF LOW TO STEER A SERIES OF WEAK MID-LEVEL
SHORTWAVES OUR WAY LATE TONIGHT.
MAIN IMPACT TONIGHT WILL BE A INCREASE IN CLOUDS FROM THE SOUTH
LATE TONIGHT. CANNOT COMPLETELY RULE OUT THE IDEA OF STRATUS AND
FOG ACROSS THE SOUTH COAST TONIGHT. AM THINKING THESE LOWER CLOUDS
AND FOG...AS WELL AS MOST OF THE PRECIPITATION...WILL HOLD OFF
UNTIL MONDAY ACROSS MOST OF SOUTHERN NEW ENGLAND. CUTOFF LOW ALONG
THE SOUTHEAST COAST DOES NOT ARGUE FOR A FASTER TIMING.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
LOTS OF MOISTURE EXPECTED TO BE MOVED NORTH INTO OUR REGION.
HOWEVER...NO STRONG DYNAMICS ARE EXPECTED TO BE IN PLACE MONDAY OR
MONDAY NIGHT. PRECIPITABLE WATERS AROUND 1.5 INCHES INDICATE
POTENTIAL FOR HEAVIER RAINFALL...IF CONVECTION OF STRONGER
VERTICAL FORCING DEVELOPS. TIMING OF ONSET FOR ANY PARTICULAR
LOCATION IS TRICKY. AT THIS POINT OPTED TO BRING AT LEAST A CHANCE
OF RAIN DURING THE MORNING FROM SOUTH TO NORTH. THE BRUNT OF THE
RAINFALL SHOULD OCCUR DURING MONDAY AFTERNOON INTO MONDAY NIGHT.
AREAS NORTH OF ROUTE 2 IN MA AND SOUTHERN NH MAY EVEN SEE THE
STEADIER RAINFALL HOLD OFF UNTIL EVENING.
MOST OF THE 20/12Z GUIDANCE HINTING AT THE POTENTIAL FOR SOME
ELEVATED INSTABILITY. MOST OF THESE INDICES ARE MARGINAL...BUT
THINK THERE IS ENOUGH OF A CONSISTENT SIGNAL TO MAINTAIN ISOLATED
THUNDERSTORMS IN THE FORECAST. TIMING AGAIN IS IFFY.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES ONCE AGAIN.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
TUESDAY INTO WEDNESDAY...
BROAD AREA OF LOW PRES AND ABUNDANCE OF LOW-LVL MOISTURE REMNANT
FROM TS ALBERTO AND NEIGHBORING AREA OF LOW PRES OVER THE ERN ATLANTIC
MAKES FOR A CHAOTIC FCST. CONFIDENCE LIES THAT AN ELONGATED SHRTWV
TROF AXIS ACROSS THE ERN CONUS WILL GRADUALLY SWEEP OFFSHORE ACTING
AS A FOCUS FOR DIURNALLY DRIVEN STORMS WHILE PUSHING THE BROAD AREA
OF LOW PRES NEWD AND OUT OF THE RGN. WHILE IT/S FELT THE AXIS WILL
PROVIDE ENHANCED ASCENT LENDING TO SFC CONVERGENCE AND FRONTO-
GENESIS...INSTABILITY AND SHEAR APPEARS VERY WEAK DUE TO THE WEAK
NATURE OF THE TROF AXIS AND ATTENDANT BAROCLINIC ZONE. FEEL TUE
MAYBE FAIRLY CLOUDY WITH ISOLATED TO SCTD SHOWERS /BETTER CHCS TO
THE WEST/...WHEREAS WED WILL BE THE BETTER CHC FOR WET WX AS THE
TROF AXIS SWEEPS THRU THE RGN. ANTICIPATING AREAS OF FOG AND DRIZZLE
FOR THE TUE EVNG PD /ESPECIALLY ACROSS THE COASTLINES AND OVER THE
WATERS/.
THURSDAY...
ENERGY ALONG THE SRN TIER OF AFOREMENTIONED SHRTWV TROF AXIS WILL
CYCLONICALLY DEEPEN AS IT INTERACTS WITH THE SUBTROPICAL JET
ORIENTED SW-NE ACROSS FLORIDA INTO THE CENTRAL ATLANTIC. ANTICIPATE
A SECONDARY BROAD AREA OF LOW PRES TO GRADUALLY LIFT WITH THE MEAN
FLOW THRU THE MID-ATLANTIC AND OFFSHORE. BROAD LIFT ACROSS THE RGN
COUPLED WITH A FAIRLY MOIST COLUMN LENDS TO THE POSSIBILITY OF SOME
SCTD POP-UP SHOWERS. FEEL SOME OROGRAPHICAL AID IS GIVEN ALONG THE
EWD SLOPES OF HIGHER TERRAIN AS E/SELY ONSHORE FLOW WILL ENHANCE IN
RESPONSE TO AN APPROACHING DEEPER SYS ACROSS THE CNTRL CONUS. FLOW
WILL LIKELY BE ENHANCED OUT OF THE SW ALOFT ADVECTING WARMER AIR
ACROSS THE RGN AND ACTING TO CAP THE LOW-LVLS AROUND H85. SO
UNCERTAINTY PREVAILS AS TO WHETHER LOW-LVL FORCING WILL OVERCOME THE
MID-LYR CAP. ANTICIPATE SHOWERS TO BE LIGHT WITH LOW CONFIDENCE ON
THUNDER.
FRIDAY INTO SATURDAY...
AS THE BROAD AREA OF LOW PRES MOVES OFFSHORE...WAA AND SUBSEQUENT
RIDGING AHEAD OF A DEEP SYS THRU THE NRN CONUS WILL LIKELY KEEP THE
FCST DRY INTO SATURDAY. INHERENT UNCERTAINTIES ON THE STRENGTH AND
TIMING OF THE RIDGE ULTIMATELY IMPACTS THE EXPECTATION OF A SFC COLD
FRNT ACROSS THE RGN WITH SHOWERS AND PSBL THUNDERSTORMS. CONFIDENCE
LIES THAT SHOULD THE SFC COLD FRNT TRAVERSE THE RGN DURING THE SAT
AFTN PD...THEN LIKELY SFC-BASED INSTABILITY COUPLED WITH FRONTO-
GENETICAL FORCING WILL LIKELY YIELD THUNDERSTORMS /ESPECIALLY ACROSS
THE INTERIOR AND AWAY FROM THE MARINE ZONES/. WILL HINT AS THE
POSSIBILITY IN THE FCST FOR SAT AFTN. WHETHER THE SFC COLD FRNT
PUSHES OFFSHORE REMAINS IN QUESTION...BUT MUCH OF THE FCST GUIDANCE
SUGGESTS THAT STRONGER HIGH PRES WILL BUILD S OUT OF CANADA AND PUSH
ENERGY OUT TO SEA.
SUNDAY AND BEYOND...
AT FIRST GUESS IT APPEARS THAT HIGH PRES RIDGING SEWD OUT OF CANADA
WILL KEEP THE FCST PD COOL AND DRY UNDER NLY FLOW. LOW-LVL PROFILES
WILL LIKELY BE WELL-MIXED LENDING TO DIURNAL CU AND MIX-DOWN OF BOTH
DRIER AIR AND FASTER MOMENTUM.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 00Z...HIGH CONFIDENCE VFR.
TONIGHT...HIGH CONFIDENCE VFR MOST OF SOUTHERN NEW ENGLAND.
MODERATE CONFIDENCE MVFR-IFR CIGS AND VSBYS IN STRATUS AND FOG
IMPACT THE ISLANDS OVERNIGHT. LOW CONFIDENCE ON TIMING THIS AREAS
OF MVFR/IFR AS IT MOVES NORTH. COULD ALSO SEE SCATTERED SHOWERS BRING
MVFR CONDITIONS SOUTH OF I-90 LATE TONIGHT.
MONDAY...MODERATE CONFIDENCE. CONDITIONS LOWER TO MVFR-IFR ACROSS
THE REGION AS SHOWERS AND AREAS OF FOG CONTINUE TO MOVE N. LOWEST
CONDITIONS ALONG THE COAST WITH LOCAL LIFR CONDITIONS. CONDITIONS
MAINLY VFR-MVFR ACROSS SW NH/NW MA. ISOLD TSTMS POSSIBLE.
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN
LOW CLOUDS/PATCHY FOG AND SHOWERS.
KBOS TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP MONDAY.
KBDL TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP LATE TONIGHT AND
MONDAY.
OUTLOOK...TUESDAY THOUGH FRIDAY...
TUESDAY AND WEDNESDAY...
MODERATE CONFIDENCE. DURING THE DAY MIXED MVFR-IFR CONDITIONS WITH
INTERMITTENT VFR PSBL. AREAS OF DRIZZLE AND FOG FOR TUES NGT.
SHOWERS MORE LIKELY DURING THE DAY WED. LGT SLY WINDS.
THURSDAY AND FRIDAY...
MODERATE CONFIDENCE. MVFR-IFR TO LINGER THRU THURS...IMPROVING VFR
INTO FRI. COLD FRNT APPROACHING...INCREASING SLY FLOW.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH MONDAY.
3-5 FT SOUTH-SOUTHEAST SWELLS CONTINUE TO IMPACT THE SOUTHERN
COASTAL WATERS. WITH LITTLE MOVEMENT IN THE WEATHER PATTERN
EXPECTED FOR THE NEXT 24 HOURS OR SO...DO NOT THINK THIS SWELL
WILL CHANGE MUCH DURING THAT TIME. AS SUCH WILL CONTINUE THE SMALL
CRAFT ADVISORY DUE TO HAZARDOUS SEAS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY THROUGH FRIDAY...
MODERATE CONFIDENCE. INITIALLY MONDAY NIGHT INTO TUESDAY...A WEAK
AND DIFFUSE COLD FRNTL DISTURBANCE WILL APPROACH FROM THE W AS TS
ALBERTO LIFTS NEWD JUST S AND E OF THE 40N 70W BENCHMARK. LIKELY
SWELL FROM THE STORM WILL RESULT IN SIGNIFICANT WAVE HEIGHTS OVER
THE WATERS...BUT THE PROXIMITY AND THE DISTINCT NATURE OF TS
ALBERTO SHOULD KEEP THE WIND IMPACTS MINIMAL ALONG THE S/E OUTER
WATERS. WILL MONITOR CLOSELY. SCA FOR HAZ SEAS CONTINUING.
OTHERWISE...A SERIES OF BROAD AREAS OF LOW PRES ACROSS THE WATERS
FOR THE PERIOD SHALL INVOKE LIFT OF A VERY MOIST SUB-TROPICAL
AIRMASS. ANTICIPATE INTERMITTENT SHOWERS OVER THE WATERS WITH EVNG
PERIODS COMPRISED OF AREAS OF FOG AND DRIZZLE /TUE EVNG LOOKING LIKE
A SURE BET/. LIKELY VSBY IMPACTS WHILE THE PREVAILING FLOW WILL BE
S/SELY FOR THE WEEK...EXPECT LIGHT WINDS ENHANCING BY FRI AHEAD OF A
COLD FNTL DISTURBANCE OUT OF THE GRT LKS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT TUESDAY
FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
000
FXUS61 KBOX 201901
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
301 PM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING US ONE MORE BEAUTIFUL DAY TO CLOSE OUT THE
WEEKEND. LOW PRESSURE WILL TRACK UP THE COAST...BRINGING PERIODS
OF SHOWERS MONDAY AND MONDAY NIGHT. SCATTERED SHOWERS CONTINUE
TUESDAY AND WEDNESDAY WITH PERIODS OF FOG ALONG THE SOUTH COAST.
IMPROVING WEATHER IS EXPECTED THURSDAY INTO SATURDAY AHEAD OF A COLD
FRONT EXPECTED SATURDAY AFTERNOON WITH SHOWERS AND POSSIBLE
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
2 PM UPDATE...ONLY MINOR TWEAKS TO REFLECT LATEST OBSERVED
TEMPERATURE AND DEW POINT TRENDS. MOS GUIDANCE DEW POINTS ARE TOO
LOW...FOUND VALUES MUCH CLOSER TO REALITY IN THE RAW MODEL OUTPUT.
TONIGHT...SURFACE RIDGE ACROSS NEW ENGLAND IS EXPECTED TO SLOWLY
MOVE OUT TO SEA OVERNIGHT. THIS WILL OPEN THE DOOR FOR A BROAD
MID-LEVEL CUTOFF LOW TO STEER A SERIES OF WEAK MID-LEVEL
SHORTWAVES OUR WAY LATE TONIGHT.
MAIN IMPACT TONIGHT WILL BE A INCREASE IN CLOUDS FROM THE SOUTH
LATE TONIGHT. CANNOT COMPLETELY RULE OUT THE IDEA OF STRATUS AND
FOG ACROSS THE SOUTH COAST TONIGHT. AM THINKING THESE LOWER CLOUDS
AND FOG...AS WELL AS MOST OF THE PRECIPITATION...WILL HOLD OFF
UNTIL MONDAY ACROSS MOST OF SOUTHERN NEW ENGLAND. CUTOFF LOW ALONG
THE SOUTHEAST COAST DOES NOT ARGUE FOR A FASTER TIMING.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
LOTS OF MOISTURE EXPECTED TO BE MOVED NORTH INTO OUR REGION.
HOWEVER...NO STRONG DYNAMICS ARE EXPECTED TO BE IN PLACE MONDAY OR
MONDAY NIGHT. PRECIPITABLE WATERS AROUND 1.5 INCHES INDICATE
POTENTIAL FOR HEAVIER RAINFALL...IF CONVECTION OF STRONGER
VERTICAL FORCING DEVELOPS. TIMING OF ONSET FOR ANY PARTICULAR
LOCATION IS TRICKY. AT THIS POINT OPTED TO BRING AT LEAST A CHANCE
OF RAIN DURING THE MORNING FROM SOUTH TO NORTH. THE BRUNT OF THE
RAINFALL SHOULD OCCUR DURING MONDAY AFTERNOON INTO MONDAY NIGHT.
AREAS NORTH OF ROUTE 2 IN MA AND SOUTHERN NH MAY EVEN SEE THE
STEADIER RAINFALL HOLD OFF UNTIL EVENING.
MOST OF THE 20/12Z GUIDANCE HINTING AT THE POTENTIAL FOR SOME
ELEVATED INSTABILITY. MOST OF THESE INDICES ARE MARGINAL...BUT
THINK THERE IS ENOUGH OF A CONSISTENT SIGNAL TO MAINTAIN ISOLATED
THUNDERSTORMS IN THE FORECAST. TIMING AGAIN IS IFFY.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES ONCE AGAIN.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
TUESDAY INTO WEDNESDAY...
BROAD AREA OF LOW PRES AND ABUNDANCE OF LOW-LVL MOISTURE REMNANT
FROM TS ALBERTO AND NEIGHBORING AREA OF LOW PRES OVER THE ERN ATLANTIC
MAKES FOR A CHAOTIC FCST. CONFIDENCE LIES THAT AN ELONGATED SHRTWV
TROF AXIS ACROSS THE ERN CONUS WILL GRADUALLY SWEEP OFFSHORE ACTING
AS A FOCUS FOR DIURNALLY DRIVEN STORMS WHILE PUSHING THE BROAD AREA
OF LOW PRES NEWD AND OUT OF THE RGN. WHILE IT/S FELT THE AXIS WILL
PROVIDE ENHANCED ASCENT LENDING TO SFC CONVERGENCE AND FRONTO-
GENESIS...INSTABILITY AND SHEAR APPEARS VERY WEAK DUE TO THE WEAK
NATURE OF THE TROF AXIS AND ATTENDANT BAROCLINIC ZONE. FEEL TUE
MAYBE FAIRLY CLOUDY WITH ISOLATED TO SCTD SHOWERS /BETTER CHCS TO
THE WEST/...WHEREAS WED WILL BE THE BETTER CHC FOR WET WX AS THE
TROF AXIS SWEEPS THRU THE RGN. ANTICIPATING AREAS OF FOG AND DRIZZLE
FOR THE TUE EVNG PD /ESPECIALLY ACROSS THE COASTLINES AND OVER THE
WATERS/.
THURSDAY...
ENERGY ALONG THE SRN TIER OF AFOREMENTIONED SHRTWV TROF AXIS WILL
CYCLONICALLY DEEPEN AS IT INTERACTS WITH THE SUBTROPICAL JET
ORIENTED SW-NE ACROSS FLORIDA INTO THE CENTRAL ATLANTIC. ANTICIPATE
A SECONDARY BROAD AREA OF LOW PRES TO GRADUALLY LIFT WITH THE MEAN
FLOW THRU THE MID-ATLANTIC AND OFFSHORE. BROAD LIFT ACROSS THE RGN
COUPLED WITH A FAIRLY MOIST COLUMN LENDS TO THE POSSIBILITY OF SOME
SCTD POP-UP SHOWERS. FEEL SOME OROGRAPHICAL AID IS GIVEN ALONG THE
EWD SLOPES OF HIGHER TERRAIN AS E/SELY ONSHORE FLOW WILL ENHANCE IN
RESPONSE TO AN APPROACHING DEEPER SYS ACROSS THE CNTRL CONUS. FLOW
WILL LIKELY BE ENHANCED OUT OF THE SW ALOFT ADVECTING WARMER AIR
ACROSS THE RGN AND ACTING TO CAP THE LOW-LVLS AROUND H85. SO
UNCERTAINTY PREVAILS AS TO WHETHER LOW-LVL FORCING WILL OVERCOME THE
MID-LYR CAP. ANTICIPATE SHOWERS TO BE LIGHT WITH LOW CONFIDENCE ON
THUNDER.
FRIDAY INTO SATURDAY...
AS THE BROAD AREA OF LOW PRES MOVES OFFSHORE...WAA AND SUBSEQUENT
RIDGING AHEAD OF A DEEP SYS THRU THE NRN CONUS WILL LIKELY KEEP THE
FCST DRY INTO SATURDAY. INHERENT UNCERTAINTIES ON THE STRENGTH AND
TIMING OF THE RIDGE ULTIMATELY IMPACTS THE EXPECTATION OF A SFC COLD
FRNT ACROSS THE RGN WITH SHOWERS AND PSBL THUNDERSTORMS. CONFIDENCE
LIES THAT SHOULD THE SFC COLD FRNT TRAVERSE THE RGN DURING THE SAT
AFTN PD...THEN LIKELY SFC-BASED INSTABILITY COUPLED WITH FRONTO-
GENETICAL FORCING WILL LIKELY YIELD THUNDERSTORMS /ESPECIALLY ACROSS
THE INTERIOR AND AWAY FROM THE MARINE ZONES/. WILL HINT AS THE
POSSIBILITY IN THE FCST FOR SAT AFTN. WHETHER THE SFC COLD FRNT
PUSHES OFFSHORE REMAINS IN QUESTION...BUT MUCH OF THE FCST GUIDANCE
SUGGESTS THAT STRONGER HIGH PRES WILL BUILD S OUT OF CANADA AND PUSH
ENERGY OUT TO SEA.
SUNDAY AND BEYOND...
AT FIRST GUESS IT APPEARS THAT HIGH PRES RIDGING SEWD OUT OF CANADA
WILL KEEP THE FCST PD COOL AND DRY UNDER NLY FLOW. LOW-LVL PROFILES
WILL LIKELY BE WELL-MIXED LENDING TO DIURNAL CU AND MIX-DOWN OF BOTH
DRIER AIR AND FASTER MOMENTUM.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 00Z...HIGH CONFIDENCE VFR.
TONIGHT...HIGH CONFIDENCE VFR MOST OF SOUTHERN NEW ENGLAND.
MODERATE CONFIDENCE MVFR-IFR CIGS AND VSBYS IN STRATUS AND FOG
IMPACT THE ISLANDS OVERNIGHT. LOW CONFIDENCE ON TIMING THIS AREAS
OF MVFR/IFR AS IT MOVES NORTH. COULD ALSO SEE SCATTERED SHOWERS BRING
MVFR CONDITIONS SOUTH OF I-90 LATE TONIGHT.
MONDAY...MODERATE CONFIDENCE. CONDITIONS LOWER TO MVFR-IFR ACROSS
THE REGION AS SHOWERS AND AREAS OF FOG CONTINUE TO MOVE N. LOWEST
CONDITIONS ALONG THE COAST WITH LOCAL LIFR CONDITIONS. CONDITIONS
MAINLY VFR-MVFR ACROSS SW NH/NW MA. ISOLD TSTMS POSSIBLE.
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN
LOW CLOUDS/PATCHY FOG AND SHOWERS.
KBOS TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP MONDAY.
KBDL TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP LATE TONIGHT AND
MONDAY.
OUTLOOK...TUESDAY THOUGH FRIDAY...
TUESDAY AND WEDNESDAY...
MODERATE CONFIDENCE. DURING THE DAY MIXED MVFR-IFR CONDITIONS WITH
INTERMITTENT VFR PSBL. AREAS OF DRIZZLE AND FOG FOR TUES NGT.
SHOWERS MORE LIKELY DURING THE DAY WED. LGT SLY WINDS.
THURSDAY AND FRIDAY...
MODERATE CONFIDENCE. MVFR-IFR TO LINGER THRU THURS...IMPROVING VFR
INTO FRI. COLD FRNT APPROACHING...INCREASING SLY FLOW.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH MONDAY.
3-5 FT SOUTH-SOUTHEAST SWELLS CONTINUE TO IMPACT THE SOUTHERN
COASTAL WATERS. WITH LITTLE MOVEMENT IN THE WEATHER PATTERN
EXPECTED FOR THE NEXT 24 HOURS OR SO...DO NOT THINK THIS SWELL
WILL CHANGE MUCH DURING THAT TIME. AS SUCH WILL CONTINUE THE SMALL
CRAFT ADVISORY DUE TO HAZARDOUS SEAS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY THROUGH FRIDAY...
MODERATE CONFIDENCE. INITIALLY MONDAY NIGHT INTO TUESDAY...A WEAK
AND DIFFUSE COLD FRNTL DISTURBANCE WILL APPROACH FROM THE W AS TS
ALBERTO LIFTS NEWD JUST S AND E OF THE 40N 70W BENCHMARK. LIKELY
SWELL FROM THE STORM WILL RESULT IN SIGNIFICANT WAVE HEIGHTS OVER
THE WATERS...BUT THE PROXIMITY AND THE DISTINCT NATURE OF TS
ALBERTO SHOULD KEEP THE WIND IMPACTS MINIMAL ALONG THE S/E OUTER
WATERS. WILL MONITOR CLOSELY. SCA FOR HAZ SEAS CONTINUING.
OTHERWISE...A SERIES OF BROAD AREAS OF LOW PRES ACROSS THE WATERS
FOR THE PERIOD SHALL INVOKE LIFT OF A VERY MOIST SUB-TROPICAL
AIRMASS. ANTICIPATE INTERMITTENT SHOWERS OVER THE WATERS WITH EVNG
PERIODS COMPRISED OF AREAS OF FOG AND DRIZZLE /TUE EVNG LOOKING LIKE
A SURE BET/. LIKELY VSBY IMPACTS WHILE THE PREVAILING FLOW WILL BE
S/SELY FOR THE WEEK...EXPECT LIGHT WINDS ENHANCING BY FRI AHEAD OF A
COLD FNTL DISTURBANCE OUT OF THE GRT LKS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT MONDAY
FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
000
FXUS61 KBOX 201852
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
252 PM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING US ONE MORE BEAUTIFUL DAY TO CLOSE OUT THE
WEEKEND. LOW PRESSURE WILL TRACK UP THE COAST...BRINGING PERIODS OF
SHOWERS MONDAY AND MONDAY NIGHT. A FEW SHOWERS MAY LINGER TUESDAY
INTO WEDNESDAY...BUT A WASHOUT IS NOT EXPECTED. MAINLY DRY WEATHER
IS EXPECTED FOR THE END OF THE WORK WEEK WITH PLEASANT TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
2 PM UPDATE...ONLY MINOR TWEAKS TO REFLECT LATEST OBSERVED
TEMPERATURE AND DEW POINT TRENDS. MOS GUIDANCE DEW POINTS ARE TOO
LOW...FOUND VALUES MUCH CLOSER TO REALITY IN THE RAW MODEL OUTPUT.
TONIGHT...SURFACE RIDGE ACROSS NEW ENGLAND IS EXPECTED TO SLOWLY
MOVE OUT TO SEA OVERNIGHT. THIS WILL OPEN THE DOOR FOR A BROAD
MID-LEVEL CUTOFF LOW TO STEER A SERIES OF WEAK MID-LEVEL
SHORTWAVES OUR WAY LATE TONIGHT.
MAIN IMPACT TONIGHT WILL BE A INCREASE IN CLOUDS FROM THE SOUTH
LATE TONIGHT. CANNOT COMPLETELY RULE OUT THE IDEA OF STRATUS AND
FOG ACROSS THE SOUTH COAST TONIGHT. AM THINKING THESE LOWER CLOUDS
AND FOG...AS WELL AS MOST OF THE PRECIPITATION...WILL HOLD OFF
UNTIL MONDAY ACROSS MOST OF SOUTHERN NEW ENGLAND. CUTOFF LOW ALONG
THE SOUTHEAST COAST DOES NOT ARGUE FOR A FASTER TIMING.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
LOTS OF MOISTURE EXPECTED TO BE MOVED NORTH INTO OUR REGION.
HOWEVER...NO STRONG DYNAMICS ARE EXPECTED TO BE IN PLACE MONDAY OR
MONDAY NIGHT. PRECIPITABLE WATERS AROUND 1.5 INCHES INDICATE
POTENTIAL FOR HEAVIER RAINFALL...IF CONVECTION OF STRONGER
VERTICAL FORCING DEVELOPS. TIMING OF ONSET FOR ANY PARTICULAR
LOCATION IS TRICKY. AT THIS POINT OPTED TO BRING AT LEAST A CHANCE
OF RAIN DURING THE MORNING FROM SOUTH TO NORTH. THE BRUNT OF THE
RAINFALL SHOULD OCCUR DURING MONDAY AFTERNOON INTO MONDAY NIGHT.
AREAS NORTH OF ROUTE 2 IN MA AND SOUTHERN NH MAY EVEN SEE THE
STEADIER RAINFALL HOLD OFF UNTIL EVENING.
MOST OF THE 20/12Z GUIDANCE HINTING AT THE POTENTIAL FOR SOME
ELEVATED INSTABILITY. MOST OF THESE INDICES ARE MARGINAL...BUT
THINK THERE IS ENOUGH OF A CONSISTENT SIGNAL TO MAINTAIN ISOLATED
THUNDERSTORMS IN THE FORECAST. TIMING AGAIN IS IFFY.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES ONCE AGAIN.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* PERIODS OF SHOWERS LIKELY MON NIGHT
* SCATTERED SHOWERS MAY LINGER TUE-WED BUT WASHOUT IS NOT EXPECTED
* MAINLY DRY WEATHER THU AND FRI WITH PLEASANT TEMPS
DETAILS...
TUESDAY AND WEDNESDAY...MODERATE CONFIDENCE.
THIS SYSTEM WILL LIFT OFF TO THE NORTHEAST INTO THE CANADIAN
MARITIMES. HOWEVER...AN ABUNDANCE OF LOW LEVEL MOISTURE WILL REMAIN
ACROSS SOUTHERN NEW ENGLAND. WHILE A WASHOUT IS NOT
EXPECTED...DIURNALLY DRIVEN SCATTERED SHOWERS WILL BE POSSIBLE.
DID NOT INSERT ANY THUNDER AT THIS TIME SINCE INSTABILITY IS
UNCERTAIN...BUT LATER SHIFTS MAY HAVE TO CONSIDER IT. BEST CHANCE
FOR THAT APPEARS TO BE ON WED. HIGHS WILL MAINLY BE IN THE
70S...BUT SOME MIDDLE TO UPPER 60S ARE LIKELY ALONG PORTIONS OF THE
IMMEDIATE COAST WITH ONSHORE FLOW.
THURSDAY AND FRIDAY...MODERATE CONFIDENCE.
THE MODELS APPEAR TO HAVE ENOUGH UPPER LEVEL RIDGING TO SUPPORT
MAINLY DRY WEATHER OVER THIS PERIOD...ALTHOUGH A FEW BRIEF SPOT
SHOWERS WILL REMAIN POSSIBLE. TEMPERATURES WILL LIKELY AVERAGE AT
LEAST A FEW DEGREES ABOVE NORMAL GIVEN HIGH HEIGHT FIELDS.
SATURDAY...LOW CONFIDENCE.
A COLD FRONT MAY BRING THE CHANCE FOR A PERIOD OF SCATTERED SHOWER
SOMETIME SAT AND/OR SAT NIGHT. WILL CARRY CHANCE POPS AT THIS
TIME. NO THUNDER IN THE FORECAST THIS FAR OUT...BUT IF TIMING IS
RIGHT LATER SHIFTS WILL CERTAINLY HAVE TO CONSIDER.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 00Z...HIGH CONFIDENCE VFR.
TONIGHT...HIGH CONFIDENCE VFR MOST OF SOUTHERN NEW ENGLAND.
MODERATE CONFIDENCE MVFR-IFR CIGS AND VSBYS IN STRATUS AND FOG
IMPACT THE ISLANDS OVERNIGHT. LOW CONFIDENCE ON TIMING THIS AREAS
OF MVFR/IFR AS IT MOVES NORTH. COULD ALSO SEE SCATTERED SHOWERS BRING
MVFR CONDITIONS SOUTH OF I-90 LATE TONIGHT.
MONDAY...MODERATE CONFIDENCE. CONDITIONS LOWER TO MVFR-IFR ACROSS
THE REGION AS SHOWERS AND AREAS OF FOG CONTINUE TO MOVE N. LOWEST
CONDITIONS ALONG THE COAST WITH LOCAL LIFR CONDITIONS. CONDITIONS
MAINLY VFR-MVFR ACROSS SW NH/NW MA. ISOLD TSTMS POSSIBLE.
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN
LOW CLOUDS/PATCHY FOG AND SHOWERS.
KBOS TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP MONDAY.
KBDL TAF...HIGH CONFIDENCE IN TAF THROUGH MIDNIGHT. MODERATE
CONFIDENCE IN TIMING OF LOWER CLOUDS AND PRECIP LATE TONIGHT AND
MONDAY.
OUTLOOK...TUESDAY THROUGH THURSDAY...
TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS
MAY BE MIXED WITH TIMES OF MVFR-IFR CONDITIONS ESPECIALLY DURING THE
OVERNIGHT AND EARLY MORNING HOURS.
THURSDAY...MODERATE CONFIDENCE. ANY LOWER CONDITIONS SHOULD IMPROVE
TO VFR BY AFTERNOON.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE IN FORECAST THROUGH MONDAY.
3-5 FT SOUTH-SOUTHEAST SWELLS CONTINUE TO IMPACT THE SOUTHERN
COASTAL WATERS. WITH LITTLE MOVEMENT IN THE WEATHER PATTERN
EXPECTED FOR THE NEXT 24 HOURS OR SO...DO NOT THINK THIS SWELL
WILL CHANGE MUCH DURING THAT TIME. AS SUCH WILL CONTINUE THE SMALL
CRAFT ADVISORY DUE TO HAZARDOUS SEAS.
EXPECT THESE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED SOUTH COAST BEACHES.
OUTLOOK...TUESDAY THROUGH THURSDAY...
MODERATE CONFIDENCE. THE MAIN CONCERN WILL BE FOR SOME OF THE
REMNANTS OF TROPICAL STORM ALBERTO BEING ABSORBED INTO A LOW
PRESSURE SYSTEM. SWELL FROM THIS SYSTEM WILL RESULT IN SCA SEAS
ACROSS OUR SOUTHERN AND EASTERN WATERS MON NIGHT INTO AT LEAST
PART OF WED. A PERIOD OF MARGINAL 25 KNOT WIND GUSTS ARE POSSIBLE
EARLY TUE ACROSS OUR SOUTHEAST WATERS. HOWEVER...THE STRONGEST
WINDS WILL BE CONFINED TO THE EAST OF THE CENTER OVER THE OFFSHORE
WATERS. MARINERS PLANNING TO TRAVEL OFFSHORE SHOULD KEEP ALERT OF
THE LATEST WEATHER FORECASTS. WILL CONTINUE TO HIGHLIGHT THIS
CONCERN IN OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT MONDAY
FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...BELK/FRANK
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...FRANK
AVIATION...BELK/FRANK
MARINE...BELK/FRANK
000
FXUS61 KBOX 201440
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1040 AM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING US ONE MORE BEAUTIFUL DAY TO CLOSE OUT THE
WEEKEND. LOW PRESSURE WILL TRACK UP THE COAST...BRINGING PERIODS OF
SHOWERS MONDAY AND MONDAY NIGHT. A FEW SHOWERS MAY LINGER TUESDAY
INTO WEDNESDAY...BUT A WASHOUT IS NOT EXPECTED. MAINLY DRY WEATHER
IS EXPECTED FOR THE END OF THE WORK WEEK WITH PLEASANT TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
ONLY MADE MINOR TWEAKS TO TEMPERATURE TRENDS THIS MORNING. MADE
MORE SIGNIFICANT CHANGES TO DEW POINT TRENDS THIS AFTERNOON INTO
TONIGHT. LATEST OBSERVED DEW POINTS WERE HIGHER THAN PREVIOUSLY
EXPECTED. DESPITE THE HIGHER DEW POINTS...DO NOT EXPECT ANY
INCREASE IN CLOUD COVER OR RAINFALL CHANCES.
PREVIOUS DISCUSSION...
HIGH PRESSURE WILL CREST ACROSS THE REGION TODAY. LIGHT E-SE WINDS
WILL BE IN PLACE AS WELL WITH THE CENTER OF THE HIGH WELL OFFSHORE.
SHORT RANGE MODELS KEEP LOW LEVEL MOISTURE AT BAY THROUGH TODAY.
WITH NEARLY FULL SUNSHINE AND A LITTLE HIGHER LAUNCHING POINT...
EXPECT TEMPS TO REBOUND NICELY...AND A BIT MILDER AWAY FROM THE
COAST AS H85 TEMPS OF +12C TO +14C MOVE IN. HIGHS WILL RANGE FROM
THE 60S TO AROUND 70 NEAR THE COAST...UP TO THE LOWER-MID 80S WELL
INLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
TONIGHT...BROAD CUTOFF LOW PRES WILL SPIN SEVERAL WEAK SURFACE
SYSTEMS...AS WELL AS T.S. ALBERTO ACROSS THE MID ATLC AND SE COAST.
ONE OF THESE LOWS WILL START TO PUSH UP THE COAST...BRINGING CLOUDS
FROM THE S DURING TONIGHT. E-SE WINDS WILL ALSO ALLOW LOW LEVEL
MOISTURE TO START TO PUSH IN. SOME MODELS STARTING TO SHOW AN
INVERTED TROUGH TRYING TO SET UP NEAR OR OFF THE S COAST...WHICH
WILL HELP FOCUS MOISTURE AS IT WORKS TOWARD THE COAST. HOWEVER...
WITH DRY AIRMASS ACROSS THE REGION AS THE HIGH CONTINUES TO NOSE
ACROSS THE REGION...LOOKS LIKE PRECIP WILL HOLD OFF UNTIL MONDAY.
HOWEVER...LOW OCEAN CLOUDS WILL WORK INTO S COASTAL AREAS PROBABLY
WELL AFTER MIDNIGHT ALONG WITH PATCHY FOG. WITH INCREASING MOISTURE
AND LIGHT E-SE WINDS...EXPECT LOWS TO BE A BIT MILDER...MAINLY IN
THE LOWER-MID 50S.
MONDAY...APPEARS THAT THE INVERTED TROUGH/DEFORMATION ZONE WILL PUSH
INTO THE REGION. CONTINUED TO CARRY LIKELY POPS...AND SOME AREAS
COULD SEE SOME HEAVIER RAINFALL AS PW/S INCREASE TO 1.5 TO 1.7
INCHES AS TROPICAL AIR STARTS TO MOVE IN FROM DOWN THE COAST. MAY
SEE SOME DOWNPOURS WITH THIS...BUT HARD TO PINPOINT WHERE THE
DEFORMATION ZONE WILL SET UP. BEST SHOT RIGHT NOW WILL BE ALONG THE
S COAST...BUT MIGHT PUSH FURTHER INLAND. ALSO NOTING GOOD
INSTABILITY WORKING IN WITH THE MOISTURE WITH LIFTED INDICES BELOW
ZERO AND TQ VALUES APPROACHING 20 /GOOD FOR ELEVATED INSTABILITY/.
HAVE MENTIONED ISOLD THUNDER DURING THE DAY...BUT AGAIN HARD TO
PINPOINT WHERE THIS MAY HAPPEN. EXPECT DAYTIME HIGHS IN THE MID 60S
TO AROUND 70 DEGREES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* PERIODS OF SHOWERS LIKELY MON NIGHT
* SCATTERED SHOWERS MAY LINGER TUE-WED BUT WASHOUT IS NOT EXPECTED
* MAINLY DRY WEATHER THU AND FRI WITH PLEASANT TEMPS
DETAILS...
MONDAY NIGHT...MODERATE CONFIDENCE.
THE REMNANTS OF AT LEAST PART OF TROPICAL STORM ALBERTO LOOK TO GET
ABSORBED INTO A LOW PRESSURE SYSTEM. THIS SYSTEM IS EXPECTED TO
PASS NEAR OR JUST SOUTHEAST OF THE BENCHMARK MON NIGHT. SINCE THIS
SYSTEM WILL STILL HAVE SOME TROPICAL CHARACTERISTICS...HIGH PWATS
WILL SUPPORT A SWATH OF HEAVY RAIN. AT THIS POINT...IT APPEARS THAT
THE HEAVIEST RAIN WILL LIKELY REMAIN OFFSHORE. STILL EXPECT PERIODS
OF SHOWERS OVER MUCH OF THE REGION AND WITH HIGH PWATS...BRIEF HEAVY
RAIN IS POSSIBLE WITH ANY SHOWERS. NOT TOO CONCERNED FOR STRONG
WINDS...AS WE WILL BE ON THE WEST SIDE OF THIS SYSTEM.
TUESDAY AND WEDNESDAY...MODERATE CONFIDENCE.
THIS SYSTEM WILL LIFT OFF TO THE NORTHEAST INTO THE CANADIAN
MARITIMES. HOWEVER...AN ABUNDANCE OF LOW LEVEL MOISTURE WILL REMAIN
ACROSS SOUTHERN NEW ENGLAND. WHILE A WASHOUT IS NOT
EXPECTED...DIURNALLY DRIVEN SCATTERED SHOWERS WILL BE POSSIBLE.
DID NOT INSERT ANY THUNDER AT THIS TIME SINCE INSTABILITY IS
UNCERTAIN...BUT LATER SHIFTS MAY HAVE TO CONSIDER IT. BEST CHANCE
FOR THAT APPEARS TO BE ON WED. HIGHS WILL MAINLY BE IN THE
70S...BUT SOME MIDDLE TO UPPER 60S ARE LIKELY ALONG PORTIONS OF THE
IMMEDIATE COAST WITH ONSHORE FLOW.
THURSDAY AND FRIDAY...MODERATE CONFIDENCE.
THE MODELS APPEAR TO HAVE ENOUGH UPPER LEVEL RIDGING TO SUPPORT
MAINLY DRY WEATHER OVER THIS PERIOD...ALTHOUGH A FEW BRIEF SPOT
SHOWERS WILL REMAIN POSSIBLE. TEMPERATURES WILL LIKELY AVERAGE AT
LEAST A FEW DEGREES ABOVE NORMAL GIVEN HIGH HEIGHT FIELDS.
SATURDAY...LOW CONFIDENCE.
A COLD FRONT MAY BRING THE CHANCE FOR A PERIOD OF SCATTERED SHOWER
SOMETIME SAT AND/OR SAT NIGHT. WILL CARRY CHANCE POPS AT THIS
TIME. NO THUNDER IN THE FORECAST THIS FAR OUT...BUT IF TIMING IS
RIGHT LATER SHIFTS WILL CERTAINLY HAVE TO CONSIDER.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
TODAY...HIGH CONFIDENCE IN VFR CONDITIONS.
TONIGHT...MODERATE CONFIDENCE.
VFR TO START FOR ALL AREAS. MVFR-IFR CIGS/VSBYS MOVE IN ACROSS S
RI/S COASTAL MA IN STRATUS AND AREAS OF FOG AROUND MIDNIGHT...THEN
MOVES N THROUGH THE NIGHT. SCT SHOWERS ALSO MOVE IN FROM S-N.
MONDAY...MODERATE CONFIDENCE.
CONDITIONS LOWER TO MVFR-IFR ACROSS THE REGION AS SHOWERS AND AREAS
OF FOG CONTINUE TO MOVE N...LOWEST ALONG THE COAST WITH LOCAL LIFR
CONDITIONS. CONDITIONS MAINLY VFR-MVFR ACROSS SW NH/NW MA. GENERAL
E-SE WINDS 10 KT OR LESS. ISOLD TSTMS POSSIBLE.
KBOS TAF...HIGH CONFIDENCE IN VFR CONDITIONS TODAY AND TONIGHT.
HIGH CONFIDENCE IN EASTERLY WINDS DEVELOPING BY MID TO LATE MORNING
AT SPEEDS OF AROUND 10 KNOTS.
KBDL TAF...HIGH CONFIDENCE IN VFR CONDITIONS TODAY AND TONIGHT.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN
LOW CLOUDS/FOG PATCHES AND SHOWERS.
TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS
MAY BE MIXED WITH TIMES OF MVFR-IFR CONDITIONS ESPECIALLY DURING THE
OVERNIGHT AND EARLY MORNING HOURS.
THURSDAY...MODERATE CONFIDENCE. ANY LOWER CONDITIONS SHOULD IMPROVE
TO VFR BY AFTERNOON.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE CONTINUES THROUGH MONDAY.
TODAY...S SWELLS OF 5 FEET CONTINUE TO PROPAGATE ACROSS THE OUTER
WATERS FROM CAPE COD SOUTHWARD...SO HAVE CONTINUED SMALL CRAFT FOR
HAZARDOUS SEAS. OTHERWISE...E-SE WINDS WILL REMAIN LIGHT AS HIGH
PRES RIDGE BUILDS ACROSS THE WATERS.
TONIGHT-MONDAY...HAVE EXTENDED THE SMALL CRAFT FOR HAZARDOUS SEAS
THROUGH MONDAY AS WILL SEE CONTINUE S-SE WIND FETCH OFF THE OCEAN AS
WELL AS SWELLS PROPAGATING UP THE COAST FROM SYSTEMS S OF THE REGION
INCLUDING TROPICAL STORM ALBERTO. SEAS WILL LIKELY INCREASE TO 7 FT
ON THE SOUTHERN OUTER WATERS MONDAY.
EXPECT THE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED S COAST BEACHES.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MODERATE CONFIDENCE. THE MAIN CONCERN WILL BE FOR SOME OF THE
REMNANTS OF TROPICAL STORM ALBERTO BEING ABSORBED INTO A LOW
PRESSURE SYSTEM. THIS SYSTEM IS THEN EXPECTED TO PASS NEAR OR
SOUTHEAST OF THE BENCHMARK MON NIGHT. SWELL FROM THIS SYSTEM WILL
RESULT IN SCA SEAS ACROSS OUR SOUTHERN AND EASTERN WATERS MON NIGHT
INTO AT LEAST PART OF WED. A PERIOD OF MARGINAL 20 TO 25 KNOT WIND
GUSTS ARE POSSIBLE LATE MON AND EARLY TUE ACROSS OUR SOUTHEAST
WATERS. HOWEVER...THE STRONGEST WINDS WILL BE CONFINED TO THE EAST
OF THE CENTER OVER THE OFFSHORE WATERS. MARINERS PLANNING TO TRAVEL
OFFSHORE SHOULD KEEP ALERT OF THE LATEST WEATHER FORECASTS. WILL
CONTINUE TO HIGHLIGHT THIS CONCERN IN OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT MONDAY
FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...EVT/FRANK
NEAR TERM...BELK/EVT/FRANK
SHORT TERM...EVT
LONG TERM...FRANK
AVIATION...EVT/FRANK
MARINE...EVT/FRANK
000
FXUS61 KBOX 201124
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
724 AM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING US ONE MORE BEAUTIFUL DAY TO CLOSE OUT THE
WEEKEND. LOW PRESSURE WILL TRACK UP THE COAST...BRINGING PERIODS OF
SHOWERS MONDAY AND MONDAY NIGHT. A FEW SHOWERS MAY LINGER TUESDAY
INTO WEDNESDAY...BUT A WASHOUT IS NOT EXPECTED. MAINLY DRY WEATHER
IS EXPECTED FOR THE END OF THE WORK WEEK WITH PLEASANT TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
715 AM UPDATE...
OTHER THAN SOME HIGH THIN CLOUDINESS EARLY THIS MORNING...MOSTLY
SUNNY SKIES WILL ALLOW FOR A RAPID CLIMB IN TEMPERATURES OVER THE
NEXT FEW HOURS.
HIGH PRESSURE WILL CREST ACROSS THE REGION TODAY. LIGHT E-SE WINDS
WILL BE IN PLACE AS WELL WITH THE CENTER OF THE HIGH WELL OFFSHORE.
SHORT RANGE MODELS KEEP LOW LEVEL MOISTURE AT BAY THROUGH TODAY.
WITH NEARLY FULL SUNSHINE AND A LITTLE HIGHER LAUNCHING POINT...
EXPECT TEMPS TO REBOUND NICELY...AND A BIT MILDER AWAY FROM THE
COAST AS H85 TEMPS OF +12C TO +14C MOVE IN. HIGHS WILL RANGE FROM
THE 60S TO AROUND 70 NEAR THE COAST...UP TO THE LOWER-MID 80S WELL
INLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
TONIGHT...BROAD CUTOFF LOW PRES WILL SPIN SEVERAL WEAK SURFACE
SYSTEMS...AS WELL AS T.S. ALBERTO ACROSS THE MID ATLC AND SE COAST.
ONE OF THESE LOWS WILL START TO PUSH UP THE COAST...BRINGING CLOUDS
FROM THE S DURING TONIGHT. E-SE WINDS WILL ALSO ALLOW LOW LEVEL
MOISTURE TO START TO PUSH IN. SOME MODELS STARTING TO SHOW AN
INVERTED TROUGH TRYING TO SET UP NEAR OR OFF THE S COAST...WHICH
WILL HELP FOCUS MOISTURE AS IT WORKS TOWARD THE COAST. HOWEVER...
WITH DRY AIRMASS ACROSS THE REGION AS THE HIGH CONTINUES TO NOSE
ACROSS THE REGION...LOOKS LIKE PRECIP WILL HOLD OFF UNTIL MONDAY.
HOWEVER...LOW OCEAN CLOUDS WILL WORK INTO S COASTAL AREAS PROBABLY
WELL AFTER MIDNIGHT ALONG WITH PATCHY FOG. WITH INCREASING MOISTURE
AND LIGHT E-SE WINDS...EXPECT LOWS TO BE A BIT MILDER... MAINLY IN
THE LOWER-MID 50S.
MONDAY...APPEARS THAT THE INVERTED TROUGH/DEFORMATION ZONE WILL PUSH
INTO THE REGION. CONTINUED TO CARRY LIKELY POPS...AND SOME AREAS
COULD SEE SOME HEAVIER RAINFALL AS PW/S INCREASE TO 1.5 TO 1.7
INCHES AS TROPICAL AIR STARTS TO MOVE IN FROM DOWN THE COAST. MAY
SEE SOME DOWNPOURS WITH THIS...BUT HARD TO PINPOINT WHERE THE
DEFORMATION ZONE WILL SET UP. BEST SHOT RIGHT NOW WILL BE ALONG THE
S COAST...BUT MIGHT PUSH FURTHER INLAND. ALSO NOTING GOOD
INSTABILITY WORKING IN WITH THE MOISTURE WITH LIFTED INDICES BELOW
ZERO AND TQ VALUES APPROACHING 20 /GOOD FOR ELEVATED INSTABILITY/.
HAVE MENTIONED ISOLD THUNDER DURING THE DAY...BUT AGAIN HARD TO
PINPOINT WHERE THIS MAY HAPPEN. EXPECT DAYTIME HIGHS IN THE MID 60S
TO AROUND 70 DEGREES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* PERIODS OF SHOWERS LIKELY MON NIGHT
* SCATTERED SHOWERS MAY LINGER TUE-WED BUT WASHOUT IS NOT EXPECTED
* MAINLY DRY WEATHER THU AND FRI WITH PLEASANT TEMPS
DETAILS...
MONDAY NIGHT...MODERATE CONFIDENCE.
THE REMNANTS OF AT LEAST PART OF TROPICAL STORM ALBERTO LOOK TO GET
ABSORBED INTO A LOW PRESSURE SYSTEM. THIS SYSTEM IS EXPECTED TO
PASS NEAR OR JUST SOUTHEAST OF THE BENCHMARK MON NIGHT. SINCE THIS
SYSTEM WILL STILL HAVE SOME TROPICAL CHARACTERISTICS...HIGH PWATS
WILL SUPPORT A SWATH OF HEAVY RAIN. AT THIS POINT...IT APPEARS THAT
THE HEAVIEST RAIN WILL LIKELY REMAIN OFFSHORE. STILL EXPECT PERIODS
OF SHOWERS OVER MUCH OF THE REGION AND WITH HIGH PWATS...BRIEF HEAVY
RAIN IS POSSIBLE WITH ANY SHOWERS. NOT TOO CONCERNED FOR STRONG
WINDS...AS WE WILL BE ON THE WEST SIDE OF THIS SYSTEM.
TUESDAY AND WEDNESDAY...MODERATE CONFIDENCE.
THIS SYSTEM WILL LIFT OFF TO THE NORTHEAST INTO THE CANADIAN
MARITIMES. HOWEVER...AN ABUNDANCE OF LOW LEVEL MOISTURE WILL REMAIN
ACROSS SOUTHERN NEW ENGLAND. WHILE A WASHOUT IS NOT
EXPECTED...DIURNALLY DRIVEN SCATTERED SHOWERS WILL BE POSSIBLE.
DID NOT INSERT ANY THUNDER AT THIS TIME SINCE INSTABILITY IS
UNCERTAIN...BUT LATER SHIFTS MAY HAVE TO CONSIDER IT. BEST CHANCE
FOR THAT APPEARS TO BE ON WED. HIGHS WILL MAINLY BE IN THE
70S...BUT SOME MIDDLE TO UPPER 60S ARE LIKELY ALONG PORTIONS OF THE
IMMEDIATE COAST WITH ONSHORE FLOW.
THURSDAY AND FRIDAY...MODERATE CONFIDENCE.
THE MODELS APPEAR TO HAVE ENOUGH UPPER LEVEL RIDGING TO SUPPORT
MAINLY DRY WEATHER OVER THIS PERIOD...ALTHOUGH A FEW BRIEF SPOT
SHOWERS WILL REMAIN POSSIBLE. TEMPERATURES WILL LIKELY AVERAGE AT
LEAST A FEW DEGREES ABOVE NORMAL GIVEN HIGH HEIGHT FIELDS.
SATURDAY...LOW CONFIDENCE.
A COLD FRONT MAY BRING THE CHANCE FOR A PERIOD OF SCATTERED SHOWER
SOMETIME SAT AND/OR SAT NIGHT. WILL CARRY CHANCE POPS AT THIS
TIME. NO THUNDER IN THE FORECAST THIS FAR OUT...BUT IF TIMING IS
RIGHT LATER SHIFTS WILL CERTAINLY HAVE TO CONSIDER.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
TODAY...HIGH CONFIDENCE IN VFR CONDITIONS.
TONIGHT...MODERATE CONFIDENCE.
VFR TO START FOR ALL AREAS. MVFR-IFR CIGS/VSBYS MOVE IN ACROSS S
RI/S COASTAL MA IN STRATUS AND AREAS OF FOG AROUND MIDNIGHT...THEN
MOVES N THROUGH THE NIGHT. SCT SHOWERS ALSO MOVE IN FROM S-N.
MONDAY...MODERATE CONFIDENCE.
CONDITIONS LOWER TO MVFR-IFR ACROSS THE REGION AS SHOWERS AND AREAS
OF FOG CONTINUE TO MOVE N...LOWEST ALONG THE COAST WITH LOCAL LIFR
CONDITIONS. CONDITIONS MAINLY VFR-MVFR ACROSS SW NH/NW MA. GENERAL
E-SE WINDS 10 KT OR LESS. ISOLD TSTMS POSSIBLE.
KBOS TAF...HIGH CONFIDENCE IN VFR CONDITIONS TODAY AND TONIGHT.
HIGH CONFIDENCE IN EASTERLY WINDS DEVELOPING BY MID TO LATE MORNING
AT SPEEDS OF AROUND 10 KNOTS.
KBDL TAF...HIGH CONFIDENCE IN VFR CONDITIONS TODAY AND TONIGHT.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN
LOW CLOUDS/FOG PATCHES AND SHOWERS.
TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS
MAY BE MIXED WITH TIMES OF MVFR-IFR CONDITIONS ESPECIALLY DURING THE
OVERNIGHT AND EARLY MORNING HOURS.
THURSDAY...MODERATE CONFIDENCE. ANY LOWER CONDITIONS SHOULD IMPROVE
TO VFR BY AFTERNOON.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE CONTINUES THROUGH MONDAY.
TODAY...S SWELLS OF 5 FEET CONTINUE TO PROPAGATE ACROSS THE OUTER
WATERS FROM CAPE COD SOUTHWARD...SO HAVE CONTINUED SMALL CRAFT FOR
HAZARDOUS SEAS. OTHERWISE...E-SE WINDS WILL REMAIN LIGHT AS HIGH
PRES RIDGE BUILDS ACROSS THE WATERS.
TONIGHT-MONDAY...HAVE EXTENDED THE SMALL CRAFT FOR HAZARDOUS SEAS
THROUGH MONDAY AS WILL SEE CONTINUE S-SE WIND FETCH OFF THE OCEAN AS
WELL AS SWELLS PROPAGATING UP THE COAST FROM SYSTEMS S OF THE REGION
INCLUDING TROPICAL STORM ALBERTO. SEAS WILL LIKELY INCREASE TO 7 FT
ON THE SOUTHERN OUTER WATERS MONDAY.
EXPECT THE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED S COAST BEACHES.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MODERATE CONFIDENCE. THE MAIN CONCERN WILL BE FOR SOME OF THE
REMNANTS OF TROPICAL STORM ALBERTO BEING ABSORBED INTO A LOW
PRESSURE SYSTEM. THIS SYSTEM IS THEN EXPECTED TO PASS NEAR OR
SOUTHEAST OF THE BENCHMARK MON NIGHT. SWELL FROM THIS SYSTEM WILL
RESULT IN SCA SEAS ACROSS OUR SOUTHERN AND EASTERN WATERS MON NIGHT
INTO AT LEAST PART OF WED. A PERIOD OF MARGINAL 20 TO 25 KNOT WIND
GUSTS ARE POSSIBLE LATE MON AND EARLY TUE ACROSS OUR SOUTHEAST
WATERS. HOWEVER...THE STRONGEST WINDS WILL BE CONFINED TO THE EAST
OF THE CENTER OVER THE OFFSHORE WATERS. MARINERS PLANNING TO TRAVEL
OFFSHORE SHOULD KEEP ALERT OF THE LATEST WEATHER FORECASTS. WILL
CONTINUE TO HIGHLIGHT THIS CONCERN IN OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
MONDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...EVT/FRANK
NEAR TERM...FRANK/EVT
SHORT TERM...EVT
LONG TERM...FRANK
AVIATION...EVT/FRANK
MARINE...EVT/FRANK
000
FXUS61 KBOX 200913
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
505 AM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING US ONE MORE BEAUTIFUL DAY TO CLOSE OUT THE
WEEKEND. LOW PRESSURE WILL TRACK UP THE COAST...BRINGING PERIODS OF
SHOWERS MONDAY AND MONDAY NIGHT. A FEW SHOWERS MAY LINGER TUESDAY
INTO WEDNESDAY...BUT A WASHOUT IS NOT EXPECTED. MAINLY DRY WEATHER
IS EXPECTED FOR THE END OF THE WORK WEEK WITH PLEASANT TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OTHER THAN AN AREA OF HIGH THIN CIRRUS CLOUDS...DRY CONDITIONS
CONTINUE EARLY THIS MORNING.
HIGH PRESSURE WILL CREST ACROSS THE REGION TODAY. LIGHT E-SE WINDS
WILL BE IN PLACE AS WELL WITH THE CENTER OF THE HIGH WELL OFFSHORE.
SHORT RANGE MODELS KEEP LOW LEVEL MOISTURE AT BAY THROUGH TODAY.
WITH NEARLY FULL SUNSHINE AND A LITTLE HIGHER LAUNCHING POINT...
EXPECT TEMPS TO REBOUND NICELY...AND A BIT MILDER AWAY FROM THE
COAST AS H85 TEMPS OF +12C TO +14C MOVE IN. HIGHS WILL RANGE FROM
THE 60S TO AROUND 70 NEAR THE COAST...UP TO THE LOWER-MID 80S WELL
INLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
TONIGHT...BROAD CUTOFF LOW PRES WILL SPIN SEVERAL WEAK SURFACE
SYSTEMS...AS WELL AS T.S. ALBERTO ACROSS THE MID ATLC AND SE COAST.
ONE OF THESE LOWS WILL START TO PUSH UP THE COAST...BRINGING CLOUDS
FROM THE S DURING TONIGHT. E-SE WINDS WILL ALSO ALLOW LOW LEVEL
MOISTURE TO START TO PUSH IN. SOME MODELS STARTING TO SHOW AN
INVERTED TROUGH TRYING TO SET UP NEAR OR OFF THE S COAST...WHICH
WILL HELP FOCUS MOISTURE AS IT WORKS TOWARD THE COAST. HOWEVER...
WITH DRY AIRMASS ACROSS THE REGION AS THE HIGH CONTINUES TO NOSE
ACROSS THE REGION...LOOKS LIKE PRECIP WILL HOLD OFF UNTIL MONDAY.
HOWEVER...LOW OCEAN CLOUDS WILL WORK INTO S COASTAL AREAS PROBABLY
WELL AFTER MIDNIGHT ALONG WITH PATCHY FOG. WITH INCREASING MOISTURE
AND LIGHT E-SE WINDS...EXPECT LOWS TO BE A BIT MILDER... MAINLY IN
THE LOWER-MID 50S.
MONDAY...APPEARS THAT THE INVERTED TROUGH/DEFORMATION ZONE WILL PUSH
INTO THE REGION. CONTINUED TO CARRY LIKELY POPS...AND SOME AREAS
COULD SEE SOME HEAVIER RAINFALL AS PW/S INCREASE TO 1.5 TO 1.7
INCHES AS TROPICAL AIR STARTS TO MOVE IN FROM DOWN THE COAST. MAY
SEE SOME DOWNPOURS WITH THIS...BUT HARD TO PINPOINT WHERE THE
DEFORMATION ZONE WILL SET UP. BEST SHOT RIGHT NOW WILL BE ALONG THE
S COAST...BUT MIGHT PUSH FURTHER INLAND. ALSO NOTING GOOD
INSTABILITY WORKING IN WITH THE MOISTURE WITH LIFTED INDICES BELOW
ZERO AND TQ VALUES APPROACHING 20 /GOOD FOR ELEVATED INSTABILITY/.
HAVE MENTIONED ISOLD THUNDER DURING THE DAY...BUT AGAIN HARD TO
PINPOINT WHERE THIS MAY HAPPEN. EXPECT DAYTIME HIGHS IN THE MID 60S
TO AROUND 70 DEGREES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* PERIODS OF SHOWERS LIKELY MON NIGHT
* SCATTERED SHOWERS MAY LINGER TUE-WED BUT WASHOUT IS NOT EXPECTED
* MAINLY DRY WEATHER THU AND FRI WITH PLEASANT TEMPS
DETAILS...
MONDAY NIGHT...MODERATE CONFIDENCE.
THE REMNANTS OF AT LEAST PART OF TROPICAL STORM ALBERTO LOOK TO GET
ABSORBED INTO A LOW PRESSURE SYSTEM. THIS SYSTEM IS EXPECTED TO
PASS NEAR OR JUST SOUTHEAST OF THE BENCHMARK MON NIGHT. SINCE THIS
SYSTEM WILL STILL HAVE SOME TROPICAL CHARACTERISTICS...HIGH PWATS
WILL SUPPORT A SWATH OF HEAVY RAIN. AT THIS POINT...IT APPEARS THAT
THE HEAVIEST RAIN WILL LIKELY REMAIN OFFSHORE. STILL EXPECT PERIODS
OF SHOWERS OVER MUCH OF THE REGION AND WITH HIGH PWATS...BRIEF HEAVY
RAIN IS POSSIBLE WITH ANY SHOWERS. NOT TOO CONCERNED FOR STRONG
WINDS...AS WE WILL BE ON THE WEST SIDE OF THIS SYSTEM.
TUESDAY AND WEDNESDAY...MODERATE CONFIDENCE.
THIS SYSTEM WILL LIFT OFF TO THE NORTHEAST INTO THE CANADIAN
MARITIMES. HOWEVER...AN ABUNDANCE OF LOW LEVEL MOISTURE WILL REMAIN
ACROSS SOUTHERN NEW ENGLAND. WHILE A WASHOUT IS NOT
EXPECTED...DIURNALLY DRIVEN SCATTERED SHOWERS WILL BE POSSIBLE.
DID NOT INSERT ANY THUNDER AT THIS TIME SINCE INSTABILITY IS
UNCERTAIN...BUT LATER SHIFTS MAY HAVE TO CONSIDER IT. BEST CHANCE
FOR THAT APPEARS TO BE ON WED. HIGHS WILL MAINLY BE IN THE
70S...BUT SOME MIDDLE TO UPPER 60S ARE LIKELY ALONG PORTIONS OF THE
IMMEDIATE COAST WITH ONSHORE FLOW.
THURSDAY AND FRIDAY...MODERATE CONFIDENCE.
THE MODELS APPEAR TO HAVE ENOUGH UPPER LEVEL RIDGING TO SUPPORT
MAINLY DRY WEATHER OVER THIS PERIOD...ALTHOUGH A FEW BRIEF SPOT
SHOWERS WILL REMAIN POSSIBLE. TEMPERATURES WILL LIKELY AVERAGE AT
LEAST A FEW DEGREES ABOVE NORMAL GIVEN HIGH HEIGHT FIELDS.
SATURDAY...LOW CONFIDENCE.
A COLD FRONT MAY BRING THE CHANCE FOR A PERIOD OF SCATTERED SHOWER
SOMETIME SAT AND/OR SAT NIGHT. WILL CARRY CHANCE POPS AT THIS
TIME. NO THUNDER IN THE FORECAST THIS FAR OUT...BUT IF TIMING IS
RIGHT LATER SHIFTS WILL CERTAINLY HAVE TO CONSIDER.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 12Z...HIGH CONFIDENCE.
EXPECT VFR CONDITIONS. MAY SEE LOCAL MVFR-IFR VSBYS IN PATCHY FOG
AT A FEW OF THE NORMALLY SUSCEPTIBLE AIRPORT LOCATIONS LIKE KORE OR
KEEN.
TODAY...HIGH CONFIDENCE.
VFR CONDITIONS. ANY LOCAL MVFR-IFR VSBYS THAT MAY DEVELOP WILL
IMPROVE BY 14Z. SEA BREEZES DEVELOPING DURING THE AFTERNOON ALONG
THE COAST WITH LIGHT PRESSURE GRADIENT DUE TO HIGH PRESSURE.
TONIGHT...MODERATE CONFIDENCE.
VFR TO START FOR ALL AREAS. MVFR-IFR CIGS/VSBYS MOVE IN ACROSS S
RI/S COASTAL MA IN STRATUS AND AREAS OF FOG AROUND MIDNIGHT...THEN
MOVES N THROUGH THE NIGHT. SCT SHOWERS ALSO MOVE IN FROM S-N.
MONDAY...MODERATE CONFIDENCE.
CONDITIONS LOWER TO MVFR-IFR ACROSS THE REGION AS SHOWERS AND AREAS
OF FOG CONTINUE TO MOVE N...LOWEST ALONG THE COAST WITH LOCAL LIFR
CONDITIONS. CONDITIONS MAINLY VFR-MVFR ACROSS SW NH/NW MA. GENERAL
E-SE WINDS 10 KT OR LESS. ISOLD TSTMS POSSIBLE.
KBOS TAF...MODERATE TO HIGH CONFIDENCE IN VFR CONDITIONS THROUGH
12Z MONDAY. MODERATE CONFIDENCE OF CONDITIONS LOWERING TO MAINLY IN
CIGS BUT PATCHY FOG AS WELL. EXPECT SEA BREEZE DURING THIS
AFTERNOON...THEN GENERAL E-SE WINDS FOR TONIGHT AND SUNDAY AROUND
APPROACHING LOW PRES. ISOLD TSTM POSSIBLE MONDAY AFTERNOON.
KBDL TAF...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND MIDNIGHT
SUNDAY. MODERATE CONFIDENCE OF MVFR CIGS WORKING N TO THE AIRPORT
BY DAYBREAK MON. ISOLD TSTM POSSIBLE DURING MONDAY.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN
LOW CLOUDS/FOG PATCHES AND SHOWERS.
TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS
MAY BE MIXED WITH TIMES OF MVFR-IFR CONDITIONS ESPECIALLY DURING THE
OVERNIGHT AND EARLY MORNING HOURS.
THURSDAY...MODERATE CONFIDENCE. ANY LOWER CONDITIONS SHOULD IMPROVE
TO VFR BY AFTERNOON.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE CONTINUES THROUGH MONDAY.
TODAY...S SWELLS OF 5 FEET CONTINUE TO PROPAGATE ACROSS THE OUTER
WATERS FROM CAPE COD SOUTHWARD...SO HAVE CONTINUED SMALL CRAFT FOR
HAZARDOUS SEAS. OTHERWISE...E-SE WINDS WILL REMAIN LIGHT AS HIGH
PRES RIDGE BUILDS ACROSS THE WATERS.
TONIGHT-MONDAY...HAVE EXTENDED THE SMALL CRAFT FOR HAZARDOUS SEAS
THROUGH MONDAY AS WILL SEE CONTINUE S-SE WIND FETCH OFF THE OCEAN AS
WELL AS SWELLS PROPAGATING UP THE COAST FROM SYSTEMS S OF THE REGION
INCLUDING TROPICAL STORM ALBERTO. SEAS WILL LIKELY INCREASE TO 7 FT
ON THE SOUTHERN OUTER WATERS MONDAY.
EXPECT THE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED S COAST BEACHES.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MODERATE CONFIDENCE. THE MAIN CONCERN WILL BE FOR SOME OF THE
REMNANTS OF TROPICAL STORM ALBERTO BEING ABSORBED INTO A LOW
PRESSURE SYSTEM. THIS SYSTEM IS THEN EXPECTED TO PASS NEAR OR
SOUTHEAST OF THE BENCHMARK MON NIGHT. SWELL FROM THIS SYSTEM WILL
RESULT IN SCA SEAS ACROSS OUR SOUTHERN AND EASTERN WATERS MON NIGHT
INTO AT LEAST PART OF WED. A PERIOD OF MARGINAL 20 TO 25 KNOT WIND
GUSTS ARE POSSIBLE LATE MON AND EARLY TUE ACROSS OUR SOUTHEAST
WATERS. HOWEVER...THE STRONGEST WINDS WILL BE CONFINED TO THE EAST
OF THE CENTER OVER THE OFFSHORE WATERS. MARINERS PLANNING TO TRAVEL
OFFSHORE SHOULD KEEP ALERT OF THE LATEST WEATHER FORECASTS. WILL
CONTINUE TO HIGHLIGHT THIS CONCERN IN OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
MONDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...FRANK
NEAR TERM...EVT
SHORT TERM...EVT
LONG TERM...FRANK
AVIATION...FRANK/EVT
MARINE...FRANK/EVT
000
FXUS61 KBOX 200908
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
505 AM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING US ONE MORE BEAUTIFUL DAY TO CLOSE OUT THE
WEEKEND. LOW PRESSURE WILL TRACK UP THE COAST...BRINGING PERIODS OF
SHOWERS MONDAY AND MONDAY NIGHT. A FEW SHOWERS MAY LINGER TUESDAY
INTO WEDNESDAY...BUT A WASHOUT IS NOT EXPECTED. MAINLY DRY WEATHER
IS EXPECTED FOR THE END OF THE WORK WEEK WITH PLEASANT TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OTHER THAN AN AREA OF HIGH THIN CIRRUS CLOUDS...DRY CONDITIONS
CONTINUE EARLY THIS MORNING.
HIGH PRESSURE WILL CREST ACROSS THE REGION TODAY. LIGHT E-SE WINDS
WILL BE IN PLACE AS WELL WITH THE CENTER OF THE HIGH WELL OFFSHORE.
SHORT RANGE MODELS KEEP LOW LEVEL MOISTURE AT BAY THROUGH TODAY.
WITH NEARLY FULL SUNSHINE AND A LITTLE HIGHER LAUNCHING POINT...
EXPECT TEMPS TO REBOUND NICELY...AND A BIT MILDER AWAY FROM THE
COAST AS H85 TEMPS OF +12C TO +14C MOVE IN. HIGHS WILL RANGE FROM
THE 60S TO AROUND 70 NEAR THE COAST...UP TO THE LOWER-MID 80S WELL
INLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
TONIGHT...WITH BROAD CUTOFF LOW PRES WILL SPIN SEVERAL WEAK SURFACE
SYSTEMS...AS WELL AS T.S. ALBERTO ACROSS THE MID ATLC AND SE COAST.
ONE OF THESE LOWS WILL START TO PUSH UP THE COAST...BRINGING CLOUDS
FROM THE S DURING TONIGHT. E-SE WINDS WILL ALSO ALLOW LOW LEVEL
MOISTURE TO START TO PUSH IN. SOME MODELS STARTING TO SHOW AN
INVERTED TROUGH TRYING TO SET UP NEAR OR OFF THE S COAST...WHICH
WILL HELP FOCUS MOISTURE AS IT WORKS IN ESPECIALLY ALONG THE COAST.
HOWEVER...WITH DRY AIRMASS ACROSS THE REGION AS THE HIGH CONTINUES
TO NOSE ACROSS THE REGION...LOOKS LIKE PRECIP WILL HOLD OFF UNTIL
MONDAY. HOWEVER...LOW OCEAN CLOUDS WILL WORK INTO S COASTAL AREAS
PROBABLY WELL AFTER MIDNIGHT ALONG WITH PATCHY FOG. WITH INCREASING
MOISTURE AND LIGHT E-SE WINDS...EXPECT LOWS TO BE A BIT
MILDER..MAINLY IN THE LOWER-MID 50S.
MONDAY...APPEARS THAT THE INVERTED TROUGH/DEFORMATION ZONE WILL PUSH
INTO THE REGION. CONTINUED TO CARRY LIKELY POPS...AND SOME AREAS
COULD SEE SOME HEAVIER RAINFALL AS PW/S INCREASE TO 1.5 TO 1.7
INCHES AS TROPICAL AIR STARTS TO MOVE IN FROM DOWN THE COAST. MAY
SEE SOME DOWNPOURS WITH THIS...BUT HARD TO PINPOINT WHERE THE
DEFORMATION ZONE WILL SET UP. BEST SHOT RIGHT NOW WILL BE ALONG THE
S COAST...BUT MIGHT PUSH FURTHER INLAND. ALSO NOTING GOOD
INSTABILITY WORKING IN WITH THE MOISTURE WITH LIFTED INDICES BELOW
ZERO AND TQ VALUES APPROACHING 20 /GOOD FOR ELEVATED INSTABILITY/.
HAVE MENTIONED ISOLD THUNDER DURING THE DAY...BUT AGAIN HARD TO
PINPOINT WHERE THIS MAY HAPPEN. EXPECT DAYTIME HIGHS IN THE MID 60S
TO AROUND 70 DEGREES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* PERIODS OF SHOWERS LIKELY MON NIGHT
* SCATTERED SHOWERS MAY LINGER TUE-WED BUT WASHOUT IS NOT EXPECTED
* MAINLY DRY WEATHER THU AND FRI WITH PLEASANT TEMPS
DETAILS...
MONDAY NIGHT...MODERATE CONFIDENCE.
THE REMNANTS OF AT LEAST PART OF TROPICAL STORM ALBERTO LOOK TO GET
ABSORBED INTO A LOW PRESSURE SYSTEM. THIS SYSTEM IS EXPECTED TO
PASS NEAR OR JUST SOUTHEAST OF THE BENCHMARK MON NIGHT. SINCE THIS
SYSTEM WILL STILL HAVE SOME TROPICAL CHARACTERISTICS...HIGH PWATS
WILL SUPPORT A SWATH OF HEAVY RAIN. AT THIS POINT...IT APPEARS THAT
THE HEAVIEST RAIN WILL LIKELY REMAIN OFFSHORE. STILL EXPECT PERIODS
OF SHOWERS OVER MUCH OF THE REGION AND WITH HIGH PWATS...BRIEF HEAVY
RAIN IS POSSIBLE WITH ANY SHOWERS. NOT TOO CONCERNED FOR STRONG
WINDS...AS WE WILL BE ON THE WEST SIDE OF THIS SYSTEM.
TUESDAY AND WEDNESDAY...MODERATE CONFIDENCE.
THIS SYSTEM WILL LIFT OFF TO THE NORTHEAST INTO THE CANADIAN
MARITIMES. HOWEVER...AN ABUNDANCE OF LOW LEVEL MOISTURE WILL REMAIN
ACROSS SOUTHERN NEW ENGLAND. WHILE A WASHOUT IS NOT
EXPECTED...DIURNALLY DRIVEN SCATTERED SHOWERS WILL BE POSSIBLE.
DID NOT INSERT ANY THUNDER AT THIS TIME SINCE INSTABILITY IS
UNCERTAIN...BUT LATER SHIFTS MAY HAVE TO CONSIDER IT. BEST CHANCE
FOR THAT APPEARS TO BE ON WED. HIGHS WILL MAINLY BE IN THE
70S...BUT SOME MIDDLE TO UPPER 60S ARE LIKELY ALONG PORTIONS OF THE
IMMEDIATE COAST WITH ONSHORE FLOW.
THURSDAY AND FRIDAY...MODERATE CONFIDENCE.
THE MODELS APPEAR TO HAVE ENOUGH UPPER LEVEL RIDGING TO SUPPORT
MAINLY DRY WEATHER OVER THIS PERIOD...ALTHOUGH A FEW BRIEF SPOT
SHOWERS WILL REMAIN POSSIBLE. TEMPERATURES WILL LIKELY AVERAGE AT
LEAST A FEW DEGREES ABOVE NORMAL GIVEN HIGH HEIGHT FIELDS.
SATURDAY...LOW CONFIDENCE.
A COLD FRONT MAY BRING THE CHANCE FOR A PERIOD OF SCATTERED SHOWER
SOMETIME SAT AND/OR SAT NIGHT. WILL CARRY CHANCE POPS AT THIS
TIME. NO THUNDER IN THE FORECAST THIS FAR OUT...BUT IF TIMING IS
RIGHT LATER SHIFTS WILL CERTAINLY HAVE TO CONSIDER.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 12Z...HIGH CONFIDENCE.
EXPECT VFR CONDITIONS. MAY SEE LOCAL MVFR-IFR VSBYS IN PATCHY FOG
AT A FEW OF THE NORMALLY SUSCEPTIBLE AIRPORT LOCATIONS LIKE KORE OR
KEEN.
TODAY...HIGH CONFIDENCE.
VFR CONDITIONS. ANY LOCAL MVFR-IFR VSBYS THAT MAY DEVELOP WILL
IMPROVE BY 14Z. SEA BREEZES DEVELOPING DURING THE AFTERNOON ALONG
THE COAST WITH LIGHT PRESSURE GRADIENT DUE TO HIGH PRESSURE.
TONIGHT...MODERATE CONFIDENCE.
VFR TO START FOR ALL AREAS. MVFR-IFR CIGS/VSBYS MOVE IN ACROSS S
RI/S COASTAL MA IN STRATUS AND AREAS OF FOG AROUND MIDNIGHT...THEN
MOVES N THROUGH THE NIGHT. SCT SHOWERS ALSO MOVE IN FROM S-N.
MONDAY...MODERATE CONFIDENCE.
CONDITIONS LOWER TO MVFR-IFR ACROSS THE REGION AS SHOWERS AND AREAS
OF FOG CONTINUE TO MOVE N...LOWEST ALONG THE COAST WITH LOCAL LIFR
CONDITIONS. CONDITIONS MAINLY VFR-MVFR ACROSS SW NH/NW MA. GENERAL
E-SE WINDS 10 KT OR LESS. ISOLD TSTMS POSSIBLE.
KBOS TAF...MODERATE TO HIGH CONFIDENCE IN VFR CONDITIONS THROUGH
12Z MONDAY. MODERATE CONFIDENCE OF CONDITIONS LOWERING TO MAINLY IN
CIGS BUT PATCHY FOG AS WELL. EXPECT SEA BREEZE DURING THIS
AFTERNOON...THEN GENERAL E-SE WINDS FOR TONIGHT AND SUNDAY AROUND
APPROACHING LOW PRES. ISOLD TSTM POSSIBLE MONDAY AFTERNOON.
KBDL TAF...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND MIDNIGHT
SUNDAY. MODERATE CONFIDENCE OF MVFR CIGS WORKING N TO THE AIRPORT
BY DAYBREAK MON. ISOLD TSTM POSSIBLE DURING MONDAY.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN
LOW CLOUDS/FOG PATCHES AND SHOWERS.
TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS
MAY BE MIXED WITH TIMES OF MVFR-IFR CONDITIONS ESPECIALLY DURING THE
OVERNIGHT AND EARLY MORNING HOURS.
THURSDAY...MODERATE CONFIDENCE. ANY LOWER CONDITIONS SHOULD IMPROVE
TO VFR BY AFTERNOON.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE CONTINUES THROUGH MONDAY.
TODAY...S SWELLS OF 5 FEET CONTINUE TO PROPAGATE ACROSS THE OUTER
WATERS FROM CAPE COD SOUTHWARD...SO HAVE CONTINUED SMALL CRAFT FOR
HAZARDOUS SEAS. OTHERWISE...E-SE WINDS WILL REMAIN LIGHT AS HIGH
PRES RIDGE BUILDS ACROSS THE WATERS.
TONIGHT-MONDAY...HAVE EXTENDED THE SMALL CRAFT FOR HAZARDOUS SEAS
THROUGH MONDAY AS WILL SEE CONTINUE S-SE WIND FETCH OFF THE OCEAN AS
WELL AS SWELLS PROPAGATING UP THE COAST FROM SYSTEMS S OF THE REGION
INCLUDING TROPICAL STORM ALBERTO. SEAS WILL LIKELY INCREASE TO 7 FT
ON THE SOUTHERN OUTER WATERS MONDAY.
EXPECT THE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP
CURRENTS ALONG EXPOSED S COAST BEACHES.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MODERATE CONFIDENCE. THE MAIN CONCERN WILL BE FOR SOME OF THE
REMNANTS OF TROPICAL STORM ALBERTO BEING ABSORBED INTO A LOW
PRESSURE SYSTEM. THIS SYSTEM IS THEN EXPECTED TO PASS NEAR OR
SOUTHEAST OF THE BENCHMARK MON NIGHT. SWELL FROM THIS SYSTEM WILL
RESULT IN SCA SEAS ACROSS OUR SOUTHERN AND EASTERN WATERS MON NIGHT
INTO AT LEAST PART OF WED. A PERIOD OF MARGINAL 20 TO 25 KNOT WIND
GUSTS ARE POSSIBLE LATE MON AND EARLY TUE ACROSS OUR SOUTHEAST
WATERS. HOWEVER...THE STRONGEST WINDS WILL BE CONFINED TO THE EAST
OF THE CENTER OVER THE OFFSHORE WATERS. MARINERS PLANNING TO TRAVEL
OFFSHORE SHOULD KEEP ALERT OF THE LATEST WEATHER FORECASTS. WILL
CONTINUE TO HIGHLIGHT THIS CONCERN IN OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
MONDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...FRANK
NEAR TERM...EVT
SHORT TERM...THOMPSON
LONG TERM...FRANK
AVIATION...FRANK/EVT
MARINE...FRANK/EVT
000
FXUS61 KBOX 200824
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
423 AM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING US ONE MORE BEAUTIFUL DAY TO CLOSE OUT THE
WEEKEND. LOW PRESSURE WILL TRACK UP THE COAST AND BRING PERIODS OF
SHOWERS MON AND MON NIGHT. A FEW SHOWERS MAY LINGER TUE INTO
WED...BUT A WASHOUT IS NOT EXPECTED. MAINLY DRY WEATHER IS EXPECTED
FOR THE END OF THE WORK WEEK WITH PLEASANT TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
245 AM UPDATE...
BAND OF CIRRUS CLOUDS HAS SLOWLY MOVED ACROSS E CT/RI/SE MA SINCE
02Z AS SEEN ON IR SATELLITE. OTHERWISE...MAINLY CLEAR SKIES AND
LIGHT OR CALM WINDS ACROSS THE REGION AS HIGH PRES RIDGE AXIS SITS
ACROSS NORTHERN NEW ENGLAND AT 06Z.
HAVE UPDATED GRIDS TO BRING CONDITIONS CURRENT...THOUGH DEWPTS ARE
STILL PROBLEMATIC. READINGS ARE ALL OVER THE PLACE...THOUGH MAINLY
IN THE 40S EXCEPT FOR A FEW LOW 50S. WITH THE HIGHER THAN FORECAST
DEWPTS AND TEMPS FALLING THANKS TO RADIATIONAL COOLING...WOULD NOT
BE SURPRISED TO SEE SOME PATCHY FOG DEVELOP IN SOME OF THE NORMALLY
SUSCEPTIBLE LOCATIONS THROUGH SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SUNDAY...THE AIR MASS WILL HAVE WARMED SLIGHTLY FROM TODAY
ALTHOUGH NOT QUITE AS MUCH AS ORIGINALLY MODELED. ANTICIPATE HIGH
TEMPERATURES GENERALLY IN THE LOW 80S INLAND WITH A FEW SPOTS
POSSIBLY MAKING IT TO 85 DEGREES. IN CONTRAST THE LIGHT PRES
GRADIENT WILL SET THE STAGE FOR SEA BREEZES ALONG ALL COASTS WHERE
HIGH TEMPERATURES WILL GENERALLY BE 65 TO 75 DEGREES. EXPECT SKIES
TO REMAIN CLEAR OR MOSTLY CLEAR WITH PERHAPS JUST SOME HIGH CLOUDS
SHOWING UP ALONG THE SOUTH COAST LATE IN THE DAY.
SUNDAY NIGHT...A SOMEWHAT COMPLICATED PATTERN OF ONE OR MORE LOW
PRES CENTERS OFF THE MID ATLANTIC COAST WILL BEGIN TO BE A PLAYER
IN OUR WEATHER. EXPECT THE NORTHERN EDGE OF CLOUDS TO WORK ITS WAY
INTO SOUTHERN NEW ENGLAND SUNDAY NIGHT AND BELIEVE THERE IS A
CHANCE OF SHOWERS OR POSSIBLY DRIZZLE REACHING THE SOUTH COAST
LATE AT NIGHT. THE CLOUDS WILL KEEP TEMPERATURES MORE ELEVATED
SUNDAY NIGHT AND GENERALLY IN THE LOW TO MID 50S EXCEPT ACROSS FAR
NW MA AND SW NH WHERE MOSTLY CLEAR SKIES FOR A LONG ENOUGH PERIOD
AT NIGHT MAY ALLOW TEMPERATURES TO DROP INTO THE MID TO UPPER 40S.
DEWPOINTS WILL BEGIN RISING ALONG THE SOUTH COAST OVER THE COOLER
WATER TEMPERATURES SETTING THE STAGE FOR AREAS OF STRATUS AND FOG
TOWARD MONDAY MORNING. BOTH THE MET AND MAV GUIDANCE ARE BULLISH
ON BRINGING STRATUS AND FOG ONTO THE S COAST LATE SUN NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* PERIODS OF SHOWERS LIKELY MON NIGHT
* SCATTERED SHOWERS MAY LINGER TUE-WED BUT A WASHOUT IS NOT EXPECTED
* MAINLY DRY WEATHER THU AND FRI WITH PLEASANT TEMPS
DETAILS...
MONDAY NIGHT...MODERATE CONFIDENCE.
THE REMNANTS OF AT LEAST PART OF TROPICAL STORM ALBERTO LOOK TO GET
ABSORBED INTO A LOW PRESSURE SYSTEM. THIS SYSTEM IS EXPECTED TO
PASS NEAR OR JUST SOUTHEAST OF THE BENCHMARK MON NIGHT. SINCE THIS
SYSTEM WILL STILL HAVE SOME TROPICAL CHARACTERISTICS...HIGH PWATS
WILL SUPPORT A SWATH OF HEAVY RAIN. AT THIS POINT...IT APPEARS THAT
THE HEAVIEST RAIN WILL LIKELY REMAIN OFFSHORE. STILL EXPECT PERIODS
OF SHOWERS OVER MUCH OF THE REGION AND WITH HIGH PWATS...BRIEF HEAVY
RAIN IS POSSIBLE WITH ANY SHOWERS. NOT TOO CONCERNED FOR STRONG
WINDS...AS WE WILL BE ON THE WEST SIDE OF THIS SYSTEM.
TUESDAY AND WEDNESDAY...MODERATE CONFIDENCE.
THIS SYSTEM WILL LIFT OFF TO THE NORTHEAST INTO THE CANADIAN
MARITIMES. HOWEVER...AN ABUNDANCE OF LOW LEVEL MOISTURE WILL REMAIN
ACROSS SOUTHERN NEW ENGLAND. WHILE A WASHOUT IS NOT
EXPECTED...DIURNALLY DRIVEN SCATTERED SHOWERS WILL BE POSSIBLE.
DID NOT INSERT ANY THUNDER AT THIS TIME SINCE INSTABILITY IS
UNCERTAIN...BUT LATER SHIFTS MAY HAVE TO CONSIDER IT. BEST CHANCE
FOR THAT APPEARS TO BE ON WED. HIGHS WILL MAINLY BE IN THE
70S...BUT SOME MIDDLE TO UPPER 60S ARE LIKELY ALONG PORTIONS OF THE
IMMEDIATE COAST WITH ONSHORE FLOW.
THURSDAY AND FRIDAY...MODERATE CONFIDENCE.
THE MODELS APPEAR TO HAVE ENOUGH UPPER LEVEL RIDGING TO SUPPORT
MAINLY DRY WEATHER OVER THIS PERIOD...ALTHOUGH A FEW BRIEF SPOT
SHOWERS WILL REMAIN POSSIBLE. TEMPERATURES WILL LIKELY AVERAGE AT
LEAST A FEW DEGREES ABOVE NORMAL GIVEN HIGH HEIGHT FIELDS.
SATURDAY...LOW CONFIDENCE.
A COLD FRONT MAY BRING THE CHANCE FOR A PERIOD OF SCATTERED SHOWER
SOMETIME SAT AND/OR SAT NIGHT. WILL CARRY CHANCE POPS AT THIS
TIME. NO THUNDER IN THE FORECAST THIS FAR OUT...BUT IF TIMING IS
RIGHT LATER SHIFTS WILL CERTAINLY HAVE TO CONSIDER.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 12Z...HIGH CONFIDENCE.
EXPECT VFR CONDITIONS. MAY SEE LOCAL MVFR-IFR VSBYS IN PATCHY FOG
AT A FEW OF THE NORMALLY SUSCEPTIBLE AIRPORT LOCATIONS LIKE KORE OR
KEEN.
TODAY...HIGH CONFIDENCE.
VFR CONDITIONS. ANY LOCAL MVFR-IFR VSBYS THAT MAY DEVELOP WILL
IMPROVE BY 14Z. SEA BREEZES DEVELOPING DURING THE AFTERNOON ALONG
THE COAST WITH LIGHT PRESSURE GRADIENT DUE TO HIGH PRESSURE.
TONIGHT...MODERATE CONFIDENCE.
VFR TO START FOR ALL AREAS. MVFR-IFR CIGS/VSBYS MOVE IN ACROSS S
RI/S COASTAL MA IN STRATUS AND AREAS OF FOG AROUND MIDNIGHT...THEN
MOVES N THROUGH THE NIGHT. SCT SHOWERS ALSO MOVE IN FROM S-N.
MONDAY...MODERATE CONFIDENCE.
CONDITIONS LOWER TO MVFR-IFR ACROSS THE REGION AS SHOWERS AND AREAS
OF FOG CONTINUE TO MOVE N...LOWEST ALONG THE COAST WITH LOCAL LIFR
CONDITIONS. CONDITIONS MAINLY VFR-MVFR ACROSS SW NH/NW MA. GENERAL
E-SE WINDS 10 KT OR LESS. ISOLD TSTMS POSSIBLE.
KBOS TAF...MODERATE TO HIGH CONFIDENCE IN VFR CONDITIONS THROUGH
12Z MONDAY. MODERATE CONFIDENCE OF CONDITIONS LOWERING TO MAINLY IN
CIGS BUT PATCHY FOG AS WELL. EXPECT SEA BREEZE DURING THIS
AFTERNOON...THEN GENERAL E-SE WINDS FOR TONIGHT AND SUNDAY AROUND
APPROACHING LOW PRES. ISOLD TSTM POSSIBLE MONDAY AFTERNOON.
KBDL TAF...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND MIDNIGHT
SUNDAY. MODERATE CONFIDENCE OF MVFR CIGS WORKING N TO THE AIRPORT
BY DAYBREAK MON. ISOLD TSTM POSSIBLE DURING MONDAY.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN
LOW CLOUDS/FOG PATCHES AND SHOWERS.
TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS
MAY BE MIXED WITH TIMES OF MVFR-IFR CONDITIONS ESPECIALLY DURING THE
OVERNIGHT AND EARLY MORNING HOURS.
THURSDAY...MODERATE CONFIDENCE. ANY LOWER CONDITIONS SHOULD IMPROVE
TO VFR BY AFTERNOON.
&&
.MARINE...
1025 PM UPDATE...
NOTED HIGH SOUTH SWELLS STILL PROPAGATING ACROSS THE OUTER WATERS...
UP TO 7 FEET AT BUOYS 44097 AND 44008 AT 02Z. ADJUSTED SEAS JUST A
TAD...OTHERWISE REMAINDER OF PREVIOUS FORECAST LOOKS GOOD.
PREVIOUS DISCUSSION...
MODERATE TO HIGH CONFIDENCE THROUGH SUNDAY NIGHT.
EXPECT SIGNIFICANT WAVE ACTIVITY TO CONTINUE TO BE GENERATED EAST
OF THE CAROLINA COAST DUE TO PERSISTENT LOW PRES THERE AND
REASONABLY SIGNIFICANT S TO SE FETCH. SWELLS SHOULD CONTINUE TO
PROPAGATE NORTH INTO OUR SOUTH COASTAL WATERS. NOTED 5 TO 8 FT
SWELLS INTO THE OUTER SOUTH COASTAL WATERS. UP TO 7 FT SE OF BID
AND 5 FT A MILE S OF THE MVY COASTLINE. HAVE EXPANDED THE SCA FOR
HAZARDOUS SEAS IN SPACE TO INCLUDE RI SOUND AND PORTIONS OF BLOCK
ISLAND SOUND...AND HAVE EXPANDED IN TIME THROUGH SUN NIGHT. EXPECT
THE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP CURRENTS
ALONG EXPOSED S COAST BEACHES.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MODERATE CONFIDENCE. THE MAIN CONCERN WILL BE FOR SOME OF THE
REMNANTS OF TROPICAL STORM ALBERTO BEING ABSORBED INTO A LOW
PRESSURE SYSTEM. THIS SYSTEM IS THEN EXPECTED TO PASS NEAR OR
SOUTHEAST OF THE BENCHMARK MON NIGHT. SWELL FROM THIS SYSTEM WILL
RESULT IN SCA SEAS ACROSS OUR SOUTHERN AND EASTERN WATERS MON NIGHT
INTO AT LEAST PART OF WED. A PERIOD OF MARGINAL 20 TO 25 KNOT WIND
GUSTS ARE POSSIBLE LATE MON AND EARLY TUE ACROSS OUR SOUTHEAST
WATERS. HOWEVER...THE STRONGEST WINDS WILL BE CONFINED TO THE EAST
OF THE CENTER OVER THE OFFSHORE WATERS. MARINERS PLANNING TO TRAVEL
OFFSHORE SHOULD KEEP ALERT OF THE LATEST WEATHER FORECASTS.
WILL CONTINUE TO HIGHLIGHT THIS CONCERN IN OUR HAZARDOUS WEATHER
OUTLOOK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
MONDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT MONDAY
FOR ANZ235-237.
&&
$$
SYNOPSIS...FRANK
NEAR TERM...EVT/THOMPSON
SHORT TERM...THOMPSON
LONG TERM...FRANK
AVIATION...EVT/FRANK
MARINE...EVT/FRANK
000
FXUS61 KBOX 200707
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
305 AM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE WILL KEEP THE WEATHER DRY ALONG WITH WARM
TEMPERATURES JUST INLAND FROM THE COAST THROUGH SUNDAY. LOW
PRESSURE TRACKING UP THE COAST WILL BRING INCREASING CLOUDS AND A
CHANCE OF SHOWERS ALONG THE SOUTH COAST LATE SUNDAY NIGHT...AND
THEN LIKELY BRING RAIN SHOWERS TO THE REGION MONDAY AND MONDAY
NIGHT. SCT SHOWERS MAY LINGER THROUGH MIDWEEK. DRY WEATHER IS
EXPECTED FOR THE END OF THE COMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
245 AM UPDATE...
BAND OF CIRRUS CLOUDS HAS SLOWLY MOVED ACROSS E CT/RI/SE MA SINCE
02Z AS SEEN ON IR SATELLITE. OTHERWISE...MAINLY CLEAR SKIES AND
LIGHT OR CALM WINDS ACROSS THE REGION AS HIGH PRES RIDGE AXIS SITS
ACROSS NORTHERN NEW ENGLAND AT 06Z.
HAVE UPDATED GRIDS TO BRING CONDITIONS CURRENT...THOUGH DEWPTS ARE
STILL PROBLEMATIC. READINGS ARE ALL OVER THE PLACE...THOUGH MAINLY
IN THE 40S EXCEPT FOR A FEW LOW 50S. WITH THE HIGHER THAN FORECAST
DEWPTS AND TEMPS FALLING THANKS TO RADIATIONAL COOLING...WOULD NOT
BE SURPRISED TO SEE SOME PATCHY FOG DEVELOP IN SOME OF THE NORMALLY
SUSCEPTIBLE LOCATIONS THROUGH SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SUNDAY...THE AIR MASS WILL HAVE WARMED SLIGHTLY FROM TODAY
ALTHOUGH NOT QUITE AS MUCH AS ORIGINALLY MODELED. ANTICIPATE HIGH
TEMPERATURES GENERALLY IN THE LOW 80S INLAND WITH A FEW SPOTS
POSSIBLY MAKING IT TO 85 DEGREES. IN CONTRAST THE LIGHT PRES
GRADIENT WILL SET THE STAGE FOR SEA BREEZES ALONG ALL COASTS WHERE
HIGH TEMPERATURES WILL GENERALLY BE 65 TO 75 DEGREES. EXPECT SKIES
TO REMAIN CLEAR OR MOSTLY CLEAR WITH PERHAPS JUST SOME HIGH CLOUDS
SHOWING UP ALONG THE SOUTH COAST LATE IN THE DAY.
SUNDAY NIGHT...A SOMEWHAT COMPLICATED PATTERN OF ONE OR MORE LOW
PRES CENTERS OFF THE MID ATLANTIC COAST WILL BEGIN TO BE A PLAYER
IN OUR WEATHER. EXPECT THE NORTHERN EDGE OF CLOUDS TO WORK ITS WAY
INTO SOUTHERN NEW ENGLAND SUNDAY NIGHT AND BELIEVE THERE IS A
CHANCE OF SHOWERS OR POSSIBLY DRIZZLE REACHING THE SOUTH COAST
LATE AT NIGHT. THE CLOUDS WILL KEEP TEMPERATURES MORE ELEVATED
SUNDAY NIGHT AND GENERALLY IN THE LOW TO MID 50S EXCEPT ACROSS FAR
NW MA AND SW NH WHERE MOSTLY CLEAR SKIES FOR A LONG ENOUGH PERIOD
AT NIGHT MAY ALLOW TEMPERATURES TO DROP INTO THE MID TO UPPER 40S.
DEWPOINTS WILL BEGIN RISING ALONG THE SOUTH COAST OVER THE COOLER
WATER TEMPERATURES SETTING THE STAGE FOR AREAS OF STRATUS AND FOG
TOWARD MONDAY MORNING. BOTH THE MET AND MAV GUIDANCE ARE BULLISH
ON BRINGING STRATUS AND FOG ONTO THE S COAST LATE SUN NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* PERIODS OF SHOWERS MON AND MON NIGHT
* SCATTERED SHOWERS MAY LINGER TUE-WED BUT A WASHOUT IS NOT
EXPECTED
* DRY WEATHER LIKELY FOR THE END OF THE COMING WORK WEEK
7 PM UPDATE...REFER TO NHC FOR LATEST INFO ON FIRST TROPICAL
STORM OF THE SEASON...ALBERTO. THE LOW PRES CENTER DEPICTED BY
MEDIUM RANGE MODELS ON A TRACK PASSING NEAR OR JUST SE OF THE
BENCHMARK EARLY TUE MORNING MAY CONSTITUTE REMNANTS OF TROPICAL
STORM ALBERTO.
DETAILS FROM SAT LATE AFTERNOON DISCUSSION...
MONDAY AND MONDAY NIGHT...MODERATE CONFIDENCE. THE PRESENCE OF
MULTIPLE LOW PRES CENTERS OFF THE CAROLINA AND MID ATLANTIC COAST
COMPLICATES THE PICTURE TO SOME DEGREE...ESPECIALLY SINCE THE
SOUTHERNMOST LOW CENTER HAS DEVELOPED A CONCENTRATED AREA OF
CONVECTION NEAR ITS CIRCULATION CENTER AND TAKEN ON WARM CORE
CHARACTERISTICS. WOULD EXPECT THAT THE NUMERICAL PREDICTION CENTER
MODELS MIGHT BE CHALLENGED SOME TO RESOLVE A DEVELOPING WARM CORE
SYSTEM. NEVERTHELESS...THE VARIOUS MODELS HAVE A FAIRLY TIGHT LOW
PRES CENTER WITH HIGH THETA-E VALUES NEAR ITS CENTER PASSING JUST SE
OF THE BENCHMARK LATE MON NIGHT. IT REMAINS TO BE SEEN WHETHER THIS
SYSTEM IS MORE TROPICAL OR EXTRATROPICAL AS IT APPROACHES OUR
LATITUDE. THE SENSIBLE IMPACT ON OUR WEATHER IS LIKELY TO SIMILAR
EITHER WAY WITH SHOWERS LIKELY...POSSIBLY A PERIOD OF HEAVY RAIN
ACROSS THE CAPE AND ISLANDS DEPENDING UPON THE EVENTUAL TRACK. THE
12Z ECMWF DEPICTS A HEAVY AREA OF RAIN THAT MAY BRUSH THE CAPE AND
NANTUCKET. THIS SOLUTION IS NOT TOO FAR FROM WHAT THE 12Z GFS
DEPICTS AND MAY BE ALONG THE LINES OF WHAT ACTUALLY HAPPENS.
ALTHOUGH NOT SHOWN IN THE MODEL OUTPUTS...WONDER IF THERE MIGHT BE
AN AREA OF SUBSIDENCE THAT DEPRESSES RAINFALL MON NIGHT WELL TO THE
NW OF THE CENTER...ALTHOUGH SIGNS OF A DEFORMATION AXIS IN THE LOW
TO MID LEVELS MAY COUNTERACT THAT. THE BOTTOM LINE IS THAT IT IS
TRICKY AS TO HOW MUCH QPF TO FORECAST MON NIGHT AND IT IS STILL TOO
SOON TO BE CONFIDENT ON THE EXACT TRACK OF ANY SURFACE LOW CENTER.
THIS SYSTEM MAY HAVE A FAIRLY SIGNIFICANT...ALBEIT TIGHT WIND
FIELD. MOST OF THAT WIND MAY REMAIN OFFSHORE BUT TOO SOON TO BE
SURE. NE OR N GUSTS TO 25 OR 30 KT NOT TOTALLY OUT OF THE QUESTION
FOR ACK FOR A BRIEF PERIOD EARLY TUE MORNING BUT AGAIN WILL DEPEND
UPON THE EXACT TRACK AND STRUCTURE OF THE LOW PRES PASSING BY.
CHANCES ARE WHATEVER WIND FIELD EXISTS ON THE NW SIDE WILL DROP
OFF RAPIDLY AS IS TYPICAL WITH ACCELERATING TROPICAL AND
EXTRATROPICAL LOWS TURNING NE.
FOR TEMPERATURES MON AND MON NIGHT...HAVE GONE WITH A BLEND OF MAV
AND MET BIAS CORRECTED GRIDS. EXPECT RELATIVELY MODEST DIURNAL
RANGES WITH THE CLOUDS.
TUESDAY AND WEDNESDAY...CONTINUE TO HAVE LOW TO MODERATE
CONFIDENCE AS CONSIDERABLE MOISTURE AND WEAK UPLIFT WOULD APPEAR
TO SUPPORT SCATTERED SHOWERS. BY WED...THINKING IT MIGHT NOT BE SO
WET AS JUST MOSTLY CLOUDY. HAVE GONE WITH A BLEND OF GMOS AND
TEMPS THAT WOULD BE IMPLIED FROM THE ECMWF MODEL.
THURSDAY THROUGH SATURDAY...MODERATE CONFIDENCE. APPEARS THAT
LARGE SCALE UPPER LEVEL RIDGING IN THE EAST IN RESPONSE TO AN
ANOMALOUSLY DEEP WEST COAST TROF SHOULD RESULT IN DRY AND WARM
SENSIBLE WEATHER. IN FACT...SATURDAY MAY TURN OUT TO BE VERY WARM
WITH 850 MB TEMPS OF 18+C VERY PLAUSIBLE. THE GFS QUITE
AGGRESSIVELY AND THE ECMWF NOT QUITE SO ROBUSTLY ATTEMPT TO SLIDE
A COLD FRONT SOUTH THRU NEW ENGLAND LATE SAT OR SAT NIGHT BUT VERY
LOW CONFIDENCE ON THIS FEATURE SO FAR OUT...ESPECIALLY SINCE THE
LONG WAVE PATTERN WOULD SEEM TO FAVOR BUILDING HEIGHTS OVER THE
AREA. FOR NOW HAVE LEANED TOWARD THE WARM AND DRY SIDE THRU SAT
WITH JUST SLIGHT CHANCE POPS SAT AFTERNOON AND EVENING.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
THROUGH 12Z...HIGH CONFIDENCE.
EXPECT VFR CONDITIONS. MAY SEE LOCAL MVFR-IFR VSBYS IN PATCHY FOG
AT A FEW OF THE NORMALLY SUSCEPTIBLE AIRPORT LOCATIONS LIKE KORE OR
KEEN.
TODAY...HIGH CONFIDENCE.
VFR CONDITIONS. ANY LOCAL MVFR-IFR VSBYS THAT MAY DEVELOP WILL
IMPROVE BY 14Z. SEA BREEZES DEVELOPING DURING THE AFTERNOON ALONG
THE COAST WITH LIGHT PRESSURE GRADIENT DUE TO HIGH PRESSURE.
TONIGHT...MODERATE CONFIDENCE.
VFR TO START FOR ALL AREAS. MVFR-IFR CIGS/VSBYS MOVE IN ACROSS S
RI/S COASTAL MA IN STRATUS AND AREAS OF FOG AROUND MIDNIGHT...THEN
MOVES N THROUGH THE NIGHT. SCT SHOWERS ALSO MOVE IN FROM S-N.
MONDAY...MODERATE CONFIDENCE.
CONDITIONS LOWER TO MVFR-IFR ACROSS THE REGION AS SHOWERS AND AREAS
OF FOG CONTINUE TO MOVE N...LOWEST ALONG THE COAST WITH LOCAL LIFR
CONDITIONS. CONDITIONS MAINLY VFR-MVFR ACROSS SW NH/NW MA. GENERAL
E-SE WINDS 10 KT OR LESS. ISOLD TSTMS POSSIBLE.
KBOS TAF...MODERATE TO HIGH CONFIDENCE IN VFR CONDITIONS THROUGH
12Z MONDAY. MODERATE CONFIDENCE OF CONDITIONS LOWERING TO MAINLY IN
CIGS BUT PATCHY FOG AS WELL. EXPECT SEA BREEZE DURING THIS
AFTERNOON...THEN GENERAL E-SE WINDS FOR TONIGHT AND SUNDAY AROUND
APPROACHING LOW PRES. ISOLD TSTM POSSIBLE MONDAY AFTERNOON.
KBDL TAF...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND MIDNIGHT
SUNDAY. MODERATE CONFIDENCE OF MVFR CIGS WORKING N TO THE AIRPORT
BY DAYBREAK MON. ISOLD TSTM POSSIBLE DURING MONDAY.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT INTO EARLY TUESDAY..MODERATE CONFIDENCE. MVFR TO IFR
CONDITIONS LIKELY IN PERIODS OF SHOWERS/LOW CLOUDS AND AREAS OF FOG.
LATE TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE. VFR MAY
BE MIXED WITH PERIODS OF MVFR-IFR CONDITIONS IN LOW CLOUDS/FOG
PATCHES...ESPECIALLY AT NIGHT AND DURING THE EARLY MORNING.
THURSDAY...MODERATE CONFIDENCE OF VFR OR BECOMING VFR ALL AREAS.
&&
.MARINE...
1025 PM UPDATE...
NOTED HIGH SOUTH SWELLS STILL PROPAGATING ACROSS THE OUTER WATERS...
UP TO 7 FEET AT BUOYS 44097 AND 44008 AT 02Z. ADJUSTED SEAS JUST A
TAD...OTHERWISE REMAINDER OF PREVIOUS FORECAST LOOKS GOOD.
PREVIOUS DISCUSSION...
MODERATE TO HIGH CONFIDENCE THROUGH SUNDAY NIGHT.
EXPECT SIGNIFICANT WAVE ACTIVITY TO CONTINUE TO BE GENERATED EAST
OF THE CAROLINA COAST DUE TO PERSISTENT LOW PRES THERE AND
REASONABLY SIGNIFICANT S TO SE FETCH. SWELLS SHOULD CONTINUE TO
PROPAGATE NORTH INTO OUR SOUTH COASTAL WATERS. NOTED 5 TO 8 FT
SWELLS INTO THE OUTER SOUTH COASTAL WATERS. UP TO 7 FT SE OF BID
AND 5 FT A MILE S OF THE MVY COASTLINE. HAVE EXPANDED THE SCA FOR
HAZARDOUS SEAS IN SPACE TO INCLUDE RI SOUND AND PORTIONS OF BLOCK
ISLAND SOUND...AND HAVE EXPANDED IN TIME THROUGH SUN NIGHT. EXPECT
THE SWELLS TO ALSO PRODUCE MODERATE TO HIGH RISK OF RIP CURRENTS
ALONG EXPOSED S COAST BEACHES.
OUTLOOK...MONDAY THROUGH THURSDAY...
MODERATE CONFIDENCE. EXPECT TO CONTINUE TO EXPERIENCE SCA SEAS
ALONG EXPOSED S COASTAL WATERS AS WELL AS DEVELOP ALONG EXPOSED E
COASTAL WATERS. THERE IS A LOW PROBABILITY OF STRONG SCA GUSTS OR
EVEN MARGINAL GALE GUSTS NEAR AND SE OF NANTUCKET LATE MON NIGHT
AND TUE MORNING...DEPENDING UPON EXACT TRACK OF LOW. THERE IS
ALSO A LOW PROBABILITY OF SEAS REACHING ABOVE 10 FEET FOR A TIME
MON NIGHT AND TUE MORNING S AND E OF NANTUCKET. THIS WILL NEED TO
BE WATCHED. IN HWO SUGGESTED THAT MARINERS PAY EXTRA ATTENTION TO
FORECASTS FOR THIS TIME PERIOD...ESPECIALLY THOSE WITH PLANS TO
SAIL TO GEORGES BANK AND OTHER OFFSHORE WATERS. THE OTHER CONCERN
WILL BE FOR SOME FOG TO AFFECT THE WATERS DUE TO CONSIDERABLE LOW
LEVEL MOISTURE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT
MONDAY FOR ANZ235-237-254>256.
&&
$$
SYNOPSIS...THOMPSON
NEAR TERM...EVT/THOMPSON
SHORT TERM...THOMPSON
LONG TERM...THOMPSON
AVIATION...EVT/THOMPSON
MARINE...EVT/THOMPSON
| 
