Marine Interpretation Message
Issued by NWS

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000
AGNT40 KWNM 140201
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
901 PM EST SAT FEB 13 2016

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.

STG CAA CONTS ACRS THE MUCH OF THE OFFSHR WTRS WITH THE NRN AREAS
THE MOST AFFECTED AS AN UPR CLOSED LOW MOVS E ACRS THE NEW ENGLAND
WTRS TNGT. THE MULTIGRID WWIII LOOKS UNDERDONE WITH SEAS WITH THE
ECMWF WAM APPRG TO BETTER APPROX CONDS. WHERE BUOY OBS WERE AVLBL
MAINLY ACRS THE NRN OFFSHR WTRS SEAS APRD TO BE SVRL FT LWR THAN
WWIII INDICATES. STGST CAA OCCURS OVNGT INTO EARLY SUN AND SEAS
SHUD CONT TO BUILD TNGT...THEN DMNSH SUN AS STG INLAND HIGH PRES
BUILDS EWD INTO THE WTRS LATER SUN AND SUN NGT. THE STG HIGH PRES
MOVS E OVR THE WTRS LATE SUN AND SUN NGT. MDLS STILL ARE HAVG
PROBS WITH THE DVLPG LOW THAT MOVS E OVR THE SE US MON...AND THEN
NE TOWARDS THE MID ATLC COAST MON NGT INTO TUE. AM NOT CONFDT WITH
STRENGTH OF S TO SE FLOW ASSOC WITH THE DVLPG LOW AS IT MOVS NE
TUE AND TUE NGT. THE GFS/GEM ARE CLOSEST TO THE COAST WHILE THE
UKMET/ECMWF ARE FURTHER INLAND. THE GFS IS SHOWING STORM CONDS
DVLPG...BUT WL NOT MAKING ANY CHANGES UNTIL DIFFS WITH MDLS
IMPROVES. WL LOOK FOR ANY CHANGES WHEN 00Z MDL GUID COMES IN AND
ADJST LATER TNGT.

-----------------------------------------------------------------
PREVIOUS DISCUSSION...

14Z AND 1450Z HIGH RESOLUTION ASCAT OVERPASSES ONLY COVERED
OFFSHORE AND COASTAL WATERS E OF ABOUT 71W AND DID CONFIRM
WIDESPREAD GALES S OF 40N. THE HIGHER 12Z GFS 30M BOUNDARY LAYER
WINDS APPEARED TO BE BEST INITIALIZED THIS MORNING IN SOME OF
THE STRONGEST OFFSHORE COLD AIR ADVECTION SEEN THIS WINTER
SEASON. 12Z MODELS ARE IN GOOD AGREEMENT THAT AS UPPER SHORTWAVE
STRENGTHENS BASE OF UPPER TROF OVER THE GULF OF MAINE TONIGHT
SHOULD SEE INCREASING WINDS OVER EASTERN GULF OF MAINE AND
GEORGES BANK. PAST TWO RUNS OF THE GFS ARE NOT AS STRONG WITH
SURFACE WINDS AS YESTERDAYS RUNS. WILL UPDATE WIND GRIDS WITH
THE 12Z GFS 30M WINDS THROUGH SUN...WHICH WILL RESULT IN LITTLE
OR NO CHANGE TO PREVIOUS WARNINGS.

ONCE THE STRONG HIGH PRESSURE RIDGE PASSES E ACROSS THE OFFSHORE
WATERS SUN NIGHT AND MON THE 12Z MODELS...NAMELY GFS AND
ECMWF... ARE IN BETTER AGREEMENT WITH MID/UPPER LEVEL SHORTWAVE
TROF APPROACHING THE MID ATLC COAST NEAR DELMARVA PENINSULA TUE.
ALTHOUGH THE ABOVE MODELS ARE IN GOOD OVERALL AGREEMENT WITH THE
TIMING OF THE COLD FRONT THERE REMAINS SIGNIFIANT DETAIL
DIFFERENCES AT THE SURFACE WITH DEVELOPING LOW(S) ALONG FRONT...
WHICH SHOULD BE WHERE FOCUS OF HIGHEST PRE FRONTAL WINDS WILL
OCCUR. 12Z GFS IS MUCH STRONGER UKMET AND ECMWF WITH THIS
FRONTAL WAVE AND ADVERTISES STORM FORCE WINDS OVER OUTER MID
ATLC WATERS TUE INTO TUE NIGHT. ALTHOUGH THERE IS POTENTIAL FOR
STORM FORCE WINDS DO NOT YET HAVE FORECAST CONFIDENCE ON TIMING
OF LOW AND WHERE STORM WINDS MAY DEVELOP. SO PLAN TO USE THE 12Z
GFS 10M WINDS SUN NIGHT THROUGH TUE NIGHT BUT WILL LIMIT THE S
WINDS AHEAD OF THE FRONT TO 45 KT TUE INTO TUE NIGHT. HAVE WELL
ABOVE AVERAGE FORECAST CONFIDENCE WITH THESE GALES.

MODELS THEN BRING ANOTHER UPPER SHORTWAVE TOWARD MID ATLC COAST
TUE NIGHT AND GFS IS AGAIN STRONGEST OF MODELS WITH ASSOCIATED
SURFACE LOW OFFSHORE WED AND ALSO IS FURHTER N THAN 12Z ECMWF.
GFS APPEARS TOO STORNG AND FEW IF ANY GEFS AND ECMWF EPS MEMBERS
DO NOT SUPPORT SUCH A STRONG SOLUTION. AM FAVORING GFS/ECMWF
BLEND WHICH RESULTS IN WINDS TO 30 KT NORTHERN MID ATLC WATERS
WED. WILL THEN CONTINUE TO POPULATE WITH GFS/ECMWF BLEND THROUGH
THU NIGHT. ECMWF IS STRONGER THAN GFS WITH N TO NW GRADIENT
THU/THU NIGHT AND EVEN INDICATING SOME MARGINAL GALES.

.SEAS...LATEST W ATLC SHIP AND BUOY OBSERVATIONS INDICATE THAT
WAVE HEIGHTS ARE GENERALLY IN BETWEEN THE HIGHER 12Z ECMWF WAM
AND LOWER 12Z WAVEWATCH III. USED A BLEND OF THE TWO WITH
SLIGHTLY HIGHER WEIGHT GIVEN TO ECMWF WAM THROUGH SUN NIGHT
BEFORE TRANSITIONING TO 50/50 BLEND MON THROUGH THE REMAINDER OF
THE FORECAST PERIOD.

EXTRATROPICAL STORM SURGE GUIDANCE...12Z ESTOFS APPEARS TO BE
ABOUT 1 FT OR SO TOO NEGATIVE WITH SURGE THIS AFTERNOON...WITH
12Z ETSS HAVING BETTER HANDLE CURRENTLY. ESTOFS IS LIKELY
OVERDONE WITH NEGATIVE SURGE FROM DELMARVA TO NEW ENGLAND COASTS
TONIGHT AND SUN.


.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
.ANZ800...GULF OF MAINE...
     GALE TONIGHT INTO SUN.
     HEAVY FREEZING SPRAY TONIGHT INTO SUN.
     GALE POSSIBLE TUE NIGHT.
.ANZ805...GEORGES BANK WEST OF 68W...
     HEAVY FREEZING SPRAY TONIGHT.
     GALE TONIGHT INTO SUN.
     GALE POSSIBLE TUE NIGHT.
.ANZ900...GEORGES BANK EAST OF 68W...
     GALE TONIGHT INTO SUN.
     GALE POSSIBLE TUE NIGHT.
.ANZ810...SOUTH OF NEW ENGLAND...
     GALE TONIGHT INTO SUN.
     HEAVY FREEZING SPRAY TONIGHT INTO SUN.
     GALE POSSIBLE TUE INTO TUE NIGHT.
.ANZ815...SOUTH OF LONG ISLAND...
     GALE TONIGHT.
     GALE POSSIBLE TUE.

.NT2 MID ATLC WATERS...
.ANZ820...HUDSON CANYON TO BALTIMORE CANYON...
     GALE TONIGHT.
     GALE POSSIBLE TUE.
.ANZ915...HUDSON CANYON TO THE GREAT SOUTH CHANNEL...
     GALE TONIGHT INTO SUN.
     GALE POSSIBLE TUE INTO TUE NIGHT.
.ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL...
     GALE TONIGHT INTO SUN.
     GALE POSSIBLE TUE INTO TUE NIGHT.
.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...
     GALE TONIGHT INTO SUN.
     GALE POSSIBLE TUE INTO TUE NIGHT.
.ANZ910...EAST OF THE GREAT SOUTH CHANNEL AND SOUTH OF 39N...
     GALE TONIGHT INTO SUN.
     GALE POSSIBLE TUE INTO TUE NIGHT.
.ANZ825...INNER WATERS FROM BALTIMORE CANYON TO CAPE CHARLES LIGHT...
     GALE TONIGHT.
     GALE POSSIBLE TUE.
.ANZ828...INNER WATERS FROM CAPE CHARLES LIGHT TO CURRITUCK BEACH LIGHT...
     GALE POSSIBLE TUE.
.ANZ925...OUTER WATERS FROM BALTIMORE CANYON TO HATTERAS CANYON...
     GALE TONIGHT.
     GALE POSSIBLE TUE INTO TUE NIGHT.
.ANZ830...INNER WATERS FROM CURRITUCK BEACH LIGHT TO CAPE HATTERAS...
     GALE POSSIBLE TUE.
.ANZ833...INNER WATERS FROM CAPE HATTERAS TO CAPE FEAR...
     GALE POSSIBLE TUE.
.ANZ930...OUTER WATERS FROM HATTERAS CANYON TO CAPE FEAR...
     GALE POSSIBLE TUE.
.ANZ835...INNER WATERS FROM CAPE FEAR TO 31N...
     GALE POSSIBLE TUE.
.ANZ935...OUTER WATERS FROM CAPE FEAR TO 31N...
     GALE POSSIBLE TUE.

$$

.FORECASTER ROWLAND/CLARK. OCEAN PREDICTION CENTER.


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