Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 300233
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
1033 PM EDT SUN MAY 29 2016

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

15Z ASCAT WINDS SHOWED A LARGE AREA OF 30 KT ON THE SW SIDE OF TD
BONNIE...AND 20Z ALTIMETER WIND RETRIEVALS INDC 20 KT OR SO OFF
THE S CAROLINA COAST. CRNT SFC RPRTS INDC 15 TO 20 KT INVOF
BONNIE...BUT MAY HAVE MISSED HIGHEST WINDS. THE 18Z GFS AND 12Z
GFS/ECMWF ALL INDC BONNIE WL TRACK SLOWLY NE NEAR THE
COAST INTO THU...BEFORE SLOWLY SPEEDING UP FRI AS IT STARTS
GETTING DRAWN INTO AN UPR TROF MOVING IN FROM THE W. THE 12Z
ECMWF/UKMET HAVE BEEN A BIT FASTER WITH THE NE ACCELERATION OVER
THE PAST SEVL DAYS...WHILE THE GFS HAS REMAINED CONSISTENTLY
SLOWER. ATTM WOULD FAVOR A TRACK CLOSER TO THE GFS...AS IT HAS
BEEN VERIFYING A BIT BETTER WITH THIS SYS.

OTRW...THE GOES WV IMGRY INDC A SHORTWAVE TROF OVER THE GREAT
LAKES REGION MOVING E...AS AN UPR RIDGE DRIFTS E THRU NRN NT2. THE
12Z/18Z MODELS ARE IN DECENT AGRMT ON THE SHORTWAVE AND ASSOC SFC
FRONT MOVING THRU NT1 MON INTO TUE...AND THE GFS INDC 25 KT IN THE
SW FLOW OVER THE GULF OF MAINE AHEAD OF THE FRONTAL BNDRY. THE
MODELS ALSO INDC A WK H5 VORT NE OF BONNIE WL DVLP A SFC TROF OVER
THE NRN NT2 WATERS MON NIGHT INTO TUE...AND INCREASE WINDS TO 25
KT. THE PREV FCST HAD 25 KT WITH BOTH FEATURES...WHICH STILL LOOKS
RSNBL...SO PLANNING ON MAINTAINING THAT INTNSTY FOR THE UPDATE
PKG.

IN THE EXTENDED...THE GFS/ECWMF INDC A RIDGE WL BUILD OVER NT1
FROM THE N...AS ANOTHER FRONTAL BNDRY DVLPS OVER NRN NT2 IN
ADVANCE OF BONNIE. THE 18Z GFS AND 12Z ECMWF/UKMET/GEM ARE NOT
ALL THAT DIFFERENT ON SYNOP FEATURES...WITH SOME DIFFERENCES ON
THE DETAILS. THE PREV FCST FAVORED THE 12Z GFS FOR THE FCST...AND
ATTM PLANNING ON STAYING WITH IT FOR THE REMAINDER OF THE FCST AS
IT HAS NOT CHANGES MUCH FROM THE 18Z RUN...AND IS SUPPORTED THE
CONSENSUS OF OTHER GLOBAL SOLNS.

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

OVER THE SHORT TERM...THE MOST SIG WEATHER FEATURE WL CONT TO BE
TROPICAL DEPRESSION BONNIE. IN RGRDS TO THE FCST TRACK OF THIS
T.D....IN GNRL THE NEW 12Z MDLS AGREE THAT THE SYSTEM WL TRACK
EVER SO SLOWLY NE FM ITS CURRENT POSITION NR THE S AND N CAROLINA
COASTS TONITE INTO TUE NITE...REACHING A POINT NR CP HATTERAS WED
MORNING. THE 12Z GFS (AND TO A SLIGHTLY LESSER DEGREE THE 12Z
ECMWF) REMAINS CONSISTENT VS ITS PREV RESPECTIVE RUNS IN FCSTG A
SLOWER MOTION THAN FCST BY THE 12Z GEM/UKMET. OVERALL WULD FAVOR
THE 12Z GFS TRACK SINCE IS SPRTD BY THE 12Z GEFS MEAN AND QUITE
CLOSE TO THE LATEST NHC FCST TRACK. THEREFORE DO NOT ANTICIPATE
NHC MAKING ANY MAJOR SHORT TERM CHNGS TO THEIR PREV FCST TRACK FOR
BONNIE. OTHERWISE OVER THE SHORT TERM...THE 12Z MDLS SHARE SMLR
TIMING FOR A WEAK COLD FRONT TO APRCH FM THE NW MON...THEN PUSH
OFSHR INTO THE NT1 WTRS LATE MON NITE INTO TUE WHL WKNG. THEN TUE
NITE THE MDLS AGAIN SHARE SMLR TIMING FOR ANOTHER WEAK COLD FRONT
TO PUSH S ACRS THE NT1 AND NRN NT2 WTRS. WITH THE 12Z GFS SOLUTION
LOOKING REPRESENTATIVE...PLAN ON POPULATING OUR FCST WIND GRIDS
WITH A 50/50 BLEND OF ITS 30M AND 10M BL WINDS FOR TONITE THRU TUE
NITE...WITH ADDITIONAL EDITS IN THE VCNTY OF BONNIE TO ADHERE TO
THE NHC ADVSRY.

IN THE LONG RANGE...IN GNRL THE 12Z GLOBAL MDLS FCST THE
POST-TROPICAL/REMNANT LOW OF BONNIE TO CONT TO EVER SO SLOWLY
TRACK NE ACRS THE CNTRL/NERN NT2 WTRS WED THRU FRI NITE ALONG THE
THEN STNRY FRONT. AS A COMPROMISE WULD FAVOR THE FCST TIMING OF
THE 12Z GFS WHICH LOOKS LK A RSNBL COMPROMISE BTWN THE FASTER 12Z
UKMET AND SLOWER 12Z ECMWF AND IS IN LINE WITH THE LATEST NHC FCST
TRACK. SO IN ANTICIPATION OF NHC MAINTAINING WINDS UP TO 25 KT
NEAR BONNIE...PLAN ON POPULATING WITH THE SLIGHTLY STRONGER 12Z
GFS 30M BL WINDS FOR WED THRU FRI NITE.

SEAS...THE 12Z WAVEWATCH III AND 12Z ECWMF WAM MDLS HV BOTH
INITIALIZED WELL (GNRLY WITHIN 1 FT OF THE LATEST SFC OBS). BUT
SINCE OVERALL THE 12Z GFS WL BE THE FAVORED SOLUTION...PLAN ON
POPULATING OUR FCST WAVE GRIDS WITH ITS ASCD 12Z WAVEWATCH III
SEAS THRU FRI NITE...WITH SM ADDITIONAL EDITS LKLY IN THE VCNTY OF
BONNIE.

.EXTRATROPICAL STORM SURGE GUIDANCE...N/A.

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER KELLS/VUKITS. OCEAN PREDICTION CENTER.



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