Marine Interpretation Message
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000
AGNT40 KWNM 261330
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
830 AM EST WED NOV 26 2014

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

THE DVLPG SFC LOW IS NOW NR THE COAST NR 34N79W WITH A CNTRL PRES
OF STIL 1004 OR 1005 MB...WHICH IS LOWER THAN FCST BY ANY OF THE
LATEST MDLS EXCEPT THE 00Z UKMET. PER THE LATEST BUOY OBS WINDS
ARE GUSTING TO GALE FORCE (BUOY 41025) IN THE NELY GRADIENT IMMED
N OF ITS WARM FRONT WHL SLY GALES ARE LKLY PRESENT INVOF THE GULF
STREAM OVER THE IMMED SE QUADRANT OF THE LOW. MAX ASCD SEAS ARE
LKLY IN THE 7-11 FT RANGE WHICH ARE BEING HANLDED WELL BY THE 06Z
WAVEWATCH III AND 00Z ECMWF WAM.

OVER THE SHORT TERM...THE 06Z NAM/GFS REMAIN CONSISTENT VS THEIR
PREV RESPECTIVE RUNS AND IN LINE WITH THE OTHER 00Z GLOBAL MDLS IN
FCSTG THE LOW TO INTENSIFY AND TRACK NNE TO THE S OF LONG ISLD BY
27/00Z...PASS NE ACRS THE NT1 WTRS TONITE...THEN MOVE OFF TO THE
NE THU. THE BIGGEST FCST PROBLEM WITH THIS SYSTEM CONTS TO BE HOW
STRONG WL ITS ASCD GRADIENTS BCM. THE 06Z GEFS MEAN INDICATES THAT
THE 06Z GFS IS NOT FCSTG ITS SFC LOW TO INTENSIFY FAST ENUF...
WHICH IS EVIDENCED BY THE 06Z GFSP FCSTG A MR RAPIDLY DEEPENING
LOW. WITH THE DEEPER AND USUALLY CONSERVATIVE 00Z UKMET FCSTG
NELY 35-45 KT BL WINDS TO DVLP IN THE NW QUADRANT OF ITS LOW
TONITE...AND THE 06Z GFS FCSTG 50-60 KT 925 MB WINDS AT THE SAME
TIME...PLAN ON CONTG TO USE THE PREVLY POPULATED WINDS AND WL CONT
WITH THE PREV STORM WRNGS (THO DO HV HIGHER CONFIDENCE THAT STORM
FORCE WINDS WL DVLP IN THE GULF OF MAINE VS S OF LONG ISLD).
OTHERWISE THE ONLY OTHER SIG FCST CONCERN MAINLY PER THE 06Z
GFS/GFSP AND 00Z GEM IS WHETHER GALES WL DVLP ACRS THE SRN NT2
WTRS THU IN THE WAKE OF A SCNDRY COLD FROPA. BUT FOR NOW WL HOLD
OFF ON ANY ASCD WRNGS PER THE WEAKER 00Z UKMET/ECMWF. SO OVERALL
NO MAJOR CHNGS ARE PLANNED FOR THE NEXT OFSHR FCST PACKAGE.


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

AT 06Z BUOY 41004 REPORTED 1007 MB WITH 30 KT AND HAD 6 MB PRES
DROP. WIND ADJUSTMENT LENDS 1004 OR 1005 MB SFC LOW WHICH IS
ALREADY DEEPER THAN 00Z MODELS ARE INDICATING. OVER THE PAST
COUPLE RUNS GFS AND NAM HAVE TRENDED W WITH TRACK OF LOW ALONG
MID ATLC AND NEW ENGL COASTS AND AS A RESULT THE AXIS OF
STRONGEST NE WINDS HAS OBVIOUSLY SHIFTED NEARER SHORE NRN MID
ATLC AND NEW ENGL. AS A RESULT WILL BE MAKING SOME ADJUSTMENTS
TO PREVIOUS STORM WARNINGS. STILL HAVE AT LEAST MODERATE
FORECAST CONFIDENCT THAT WILL GET SOME STORM FORCE WINDS OVER
BACKSIDE OF LOW GIVEN GENERAL MODEL TENDENCY TO BE UNDERONE IN
SUCH E TO NE FLOW REGIMES OVER AREAS S OF LONG ISLAND AND S AND
SE OF NANTUCKET/MARTHAS VINEYARD. SOMEWHAT TROUBLING HOWEVER IS
THE TYPICALLY UNDERDONE ECMWF AND UKMET WINDS ARE MUCH WEAKER.
FORECAST DIFFICULTY IS PINNING DOWN LOCATION OF IN THIS CASE
RELATIVELY NARROW SWATH OF STRONGEST WINDS. FOR GRIDS AS A START
BLENDED 00Z GFS AND 00Z NAM 30M WINDS TODAY AND TONIGHT. OF NOTE
THE 00Z GFSP MAX WINDS ARE STRONGER THAN 00Z GFS BUT MAY BE
EITHER A RESULT OF MODEL BEING RUN AT HIGHER RESOLUTION...OR
DIFFERENCES IN DISPLAY CAPABILITIES.

GFS HAS THEN TRENDED SLIGHLY STRONGER WITH WINDS BEHIND A
SECONDARY COLD FRONT MOVING OFF THE MID ATLC THU...WITH 00Z RUN
SUGGESTING SOME MARGINAL GALES. 00Z MODELS ARE IN PRETTY GOOD
AGREMENT THAT ASSOCIATED SFC LOW WILL EXIT THE COAST NEAR VA
TIDEWATER AREA EARLY THU. BOTH 00Z ECMWF AND 00Z UKMET ARE
SUPPORTING WINDS UP TO 25 OR 30 KT OVER WATERS S OF BALT CNYN
THU AND THU NIGHT AND THEN EXPANDING NWRD FRI. BY THE WEEKEND
00Z MODELS ARE IN DECENT AGREEMENT THAT HIGH PRES WILL BUILD TO
COAST EARLY SAT AND SHIFT E OF OFFSHORE WATERS SAT NIGHT. 00Z
GFS AND 00Z ECMWF ARE IN PRETTY GOOD AGREEMENT WITH TIMING OF
COLD FRONT MOVING THROUGH GREAT LAKES AND APPROACHING NEW ENGL
SUN AND SUN NIGHT AND BOTH ARE CONSISTENT IN INDICATING
INCREASING SW WINDS TO 20 OR 25 KTN OF HATTERAS CNYN.

SEAS...00Z MWW3 SIG WV HGTS LOOK REASONABLE ATTM. BUOY 41004 HAD
8 FT AT 07Z. AS DAY GOES ON TODAY AND COASTAL LOW STRENGHTENS
THIS GUIDANCE LOOKS TOO LOW ESPECIALLY OVER AREAS COINCIDENT
WITH STRONGEST N TO NE WINDS. WITH 00Z ECMWF WAM HIGHER THAN
MWW3 USED A 3:1 BLEND TO BUMP UP FROM MWW3...THEN ADJUSTED
SLIGHTLY UPWARD FROM THERE FOR TODAY AND TONIGHT. THEREAFTER
LIKE MODEL PREFERNECES FROM WINDS USED BLEND 50/50 BLEND OF MWW3
AND ECMWF WAM FRI AND FRI NIGHT BEFORE TRANSITIONING TO ALL
ECMWF WAM SAT THROUGH REMAINDER OF FORECAST PERIOD.

.EXTRATROPICAL STORM SURGE GUIDANCE...AS THE DVLPG LOW TRACKS NE
UP THE COAST THE 00Z ESTOFS IS FASTER TO BUILD SURGE FROM NJ
COAST TO LI SOUND TO CAPE COD BAY AND ALONG ME COAST...AND IS
ALSO A BIT HIGHER THAN 00Z ETSS. WITH GFS SHIFTING TRACK OF SFC
LOW W AND NW OVER PAST COUPLE RUNS AND HIGHER WINDS NEARER SHORE
PAST COUPLE RUNS OF ETSS AND ESTOFS ARE MUCH HIGHER WITH SURGE
TODAY INTO TONIGHT. THE SLIGHTLY HIGHER ESTOFS APPEARS MORE
REASONABLE AT THIS POINT.



.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
.ANZ800...GULF OF MAINE...
     STORM TONIGHT.
     GALE THU.
.ANZ805...GEORGES BANK WEST OF 68W...
     GALE TODAY INTO THU.
.ANZ900...GEORGES BANK EAST OF 68W...
     GALE TODAY INTO THU.
.ANZ810...SOUTH OF NEW ENGLAND...
     STORM TODAY INTO TONIGHT.
.ANZ815...SOUTH OF LONG ISLAND...
     STORM TODAY INTO TONIGHT.

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

$$

.FORECASTER VUKITS/CLARK. OCEAN PREDICTION CENTER.



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