Latest BOX AFD

000
FXUS61 KBOX 110907
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
407 AM EST SUN FEB 11 2007

.SHORT TERM /TODAY THROUGH MONDAY/...
11/00Z MODELS ARE IN DECENT AGREEMENT WITH THEIR OVERALL SYNOPTIC
PATTERN. BUT START TO DIFFER IN THE DETAILS BY LATE MONDAY. 10/21Z
SREF ENSEMBLE MEAN SUPPORTED THE GFS PRETTY WELL. AS HPC POINTED
OUT...THIS IS SIGNIFICANT BECAUSE 2/3 OF THE SREF MEMBERS ARE NAM/ETA
BASED. SO...USED THE GFS TO TWEAK PREVIOUS FORECAST THROUGH MONDAY.

NOT THAT MUCH NEEDED CHANGING. HIGH PRESSURE EXPECTED TO REACH THE
NC COAST BY TONIGHT...THEN MOVE OFFSHORE TONIGHT. MEANWHILE...A LOW
PRESSURE WEST OF JAMES BAY EARLY THIS MORNING...SHOULD MOVE INTO
QUEBEC BY THIS EVENING. THE COLD FRONT ASSOCIATED WITH THIS LOW
PRESSURE SHOULD CROSS SOUTHERN NEW ENGLAND MONDAY.

LIKED THE NEW GRIDDED MOS PRODUCT WE HAVE FOR TEMPERATURES...AND USED
IT TO TWEAK PREVIOUS FORECAST TEMPERATURES. THIS GRIDDED MOS IS BASED
OFF THE GFS EQUATIONS...AND ENSEMBLES THE PRESENT AND PREVIOUS RUN.

DRY WEATHER EXPECTED THROUGH MONDAY.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE RIDGES INTO NEW ENGLAND MON NIGHT AND TUE...SETTING
THE STAGE FOR PLENTY OF COLD AIR AS COASTAL SYSTEM APPROACHES FOR
MIDWEEK.

WHILE WE STILL HAVE A VARIETY OF SOLUTIONS OFFERED BY 00Z MODELS...
ENVELOPE OF POSSIBLE SOLUTIONS IS NARROWING AND WE ARE BECOMING MORE
CONFIDENT THAT A SIGNIFICANT COASTAL STORM WILL IMPACT SOUTHERN NEW
ENGLAND FROM LATE TUE INTO EARLY THU.

DIFFERENCE IN THESE SOLUTIONS STILL LIES WITH HOW MODELS HANDLE
UPPER FLOW OVER SOUTHERN CANADA. ONE CAMP REPRESENTED BY NAM...ECMWF
AND UKMET ALLOWS FOR SOME OF THIS ENERGY TO BREAK OFF AND INTERACT
WITH SOUTHERN STREAM SHORT WAVE...SHARPENING FLOW ALONG E COAST AND
TAKING LOW INSIDE 40/70 BENCHMARK. THIS WOULD RESULT IN AN OVERALL
WARMER SOLUTION WITH RAIN/WIND ALONG COAST AND HEAVIER SNOWS FOCUSED
ACROSS INTERIOR. OTHER CAMP REPRESENTED BY GFS...CANADIAN AND SREF
MEAN MAINTAINS MORE SEPARATION BETWEEN TWO STREAMS AND ALLOWS FOR
SOMEWHAT FLATTER FLOW...WHICH ALLOWS COASTAL LOW TO PASS A BIT
FARTHER OFFSHORE EITHER OVER OR JUST OUTSIDE 40/70. THIS COLDER
SOLUTION RESULTS IN MORE WIDESPREAD HEAVY SNOWS AND STRONG WINDS FOR
MUCH OF SOUTHERN NEW ENGLAND.

COORDINATION WITH HPC AND SURROUNDING OFFICES SUGGESTS MORE OFFSHORE
SOLUTION SHOWN BY GFS IS MORE LIKELY SCENARIO AT THIS TIME...
ESPECIALLY GIVEN FACT IT HAS SUPPORT FROM ENSEMBLE MEAN WHICH IS
SLOWER TO BRING UPPER TROUGH INTO NORTHERN NEW ENGLAND AND HAS LESS
RIDGING OVER REGION.

THAT SAID...WE CERTAINLY ARE NOT YET CONFIDENT ENOUGH TO JUMP
COMPLETELY ONTO 00Z GFS SOLUTION WHICH BRINGS SNOWSTORM OF ALMOST
EPIC PROPORTIONS TO SOUTHERN NEW ENGLAND. IN FACT IF IT WERE TO
VERIFY...WE WOULD BE MEASURING SNOW IN FEET OVER MOST OF REGION AND
ALSO BE DEALING WITH 60-70 MPH WINDS ON COASTAL PLAIN AS SYSTEM
UNDERGOES RAPID DEEPENING JUST OFFSHORE. WHILE IT DOES REMAIN WITHIN
REALM OF POSSIBILITY THAT SYSTEM WILL DEEPEN THAT RAPIDLY AND BRING
A REAL THREAT OF SNOW AND HIGH WINDS...WE ARE STILL A FEW DAYS AWAY
AND NEED TO WORK OUT DETAILS ONCE PROJECTED TRACK BECOMES MORE
CERTAIN. WE DO THINK FUTURE RUNS WILL SHOW SOME VARIABILITY IN TRACK
AND AMOUNT OF DEEPENING...THOUGH IT SHOULD END UP SOMEWHERE NEAR
40/70.

AS A RESULT...WE DO THINK IT IS TIME TO HEIGHTEN AWARENESS OF THE
POTENTIAL EFFECTS OF THIS STORM VIA SPECIAL WEATHER STATEMENT AND
WILL DO SO THIS MORNING. IN ADDITION TO HEAVY SNOW AND POTENTIAL
STRONG WINDS...WE ARE ALSO CONCERNED WITH POSSIBILITY OF COASTAL
FLOODING DESPITE RELATIVELY ASTRONOMICALLY LOW TIDES. COMBINATION OF
STRONG ONSHORE WINDS AND RAPIDLY BUILDING SEAS MAY BE ABLE TO
COMPENSATE FOR THAT.

IT IS ALSO IMPORTANT TO NOTE THAT WE HAVE NOT HAD TO DEAL WITH A
SIGNIFICANT WINTER STORM SO FAR THIS SEASON...AND IMPACT OF THIS
STORM MAY BE GREATER THAN WHAT WE WOULD NORMALLY EXPECT FOR MID
FEBRUARY...ESPECIALLY SINCE MANY PEOPLE HAVE NOT HAD TO REALLY USE
THEIR WINTER DRIVING SKILLS YET!

&&

.AVIATION /09Z-06Z/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT. EXPECTING TO SEE A SCT-BKN
DECK OF MID OR HIGH CLOUDS THIS AFTERNOON AND EVENING AS A MID LEVEL
SHORTWAVE PASSES THROUGH.

&&

.MARINE...
LATEST BUOY REPORTS INDICATE SUB SMALL CRAFT ADVISORY CONDITIONS
ACROSS THE WATERS RIGHT NOW. AS A HIGH PRESSURE MOVES OFF THE NC COAST
TONIGHT...AND A LOW PRESSURE MOVES THROUGH QUEBEC...EXPECTING WEST TO
SOUTHWEST WINDS TO PICK UP WITH TIGHTENING OF THE PRESSURE GRADIENT.
THIS PRESSURE GRADIENT SHOULD REALLY TIGHTEN UP BEFORE THE PASSAGE OF
A COLD FRONT MONDAY...AND REMAIN SO WITH COLDER AIR PUSHING OUT
ACROSS THE WATERS BEHIND IT. HAVE POSTED ANOTHER SMALL CRAFT ADVISORY
FOR PORTIONS OF TONIGHT INTO MONDAY ACROSS THE OUTER COASTAL WATERS
WHERE CONFIDENCE IS HIGHEST.

IN LONGER TERM MON NIGHT THROUGH THU...MAIN CONCERN IS POTENTIAL FOR A
SIGNIFICANT OCEAN STORM IN WED TO THU TIME FRAME...AS IT FORMS OFF
CAROLINAS AND TRACKS NE. WHILE THERE ARE STILL LARGE DIFFERENCES
AMONG MODELS AS TO WHERE IT WILL TRACK...WITH ENVELOPE OF POSSIBLE
TRACKS RANGING FROM OVER SE NEW ENGLAND TO WELL OUTSIDE 40/70
BENCHMARK...WE ARE FOLLOWING GFS AND ENSEMBLE MEAN WHICH TAKE IT VERY
CLOSE TO 40/70 LATE WED.

IF WE TOOK GFS AT FACE VALUE...IT WOULD BRING STORM FORCE WINDS TO
ALL WATERS LATE WED INTO THU AS SYSTEM UNDERGOES RAPID DEEPENING OFF
CAPE COD. WE ARE NOT READY TO BUY INTO SUCH STRENGTHENING JUST
YET... BUT WE ARE CERTAINLY BECOMING MORE CONFIDENT THAT STRONG GALE
FORCE WINDS ARE LIKELY. AS A RESULT WE CAPPED WINDS AT 45KT FOR
NOW...AND LATER FORECASTS MAY VERY WELL NEED TO ADJUST THEM HIGHER
INTO STORM FORCE.

IN ADDITION TO STRONG WINDS...THIS STORM HAS POTENTIAL TO POSE
SEVERAL OTHER HAZARDS TO MARINERS INCLUDING RAPIDLY BUILDING SEAS AS
HIGH AS 20 FT. WE WILL UPDATE MARINE WEATHER STATEMENT TO HIGHLIGHT
THESE THREATS.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EST MONDAY 
     FOR ANZ250-254.

     SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST MONDAY 
     FOR ANZ255.

&&

$$

SHORT TERM...BELK
LONG TERM...JWD
AVIATION...BELK
MARINE...BELK/JWD