Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 210650
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
250 AM EDT THU AUG 21 2014

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

OVER THE SHORT TERM...THE NEW 00Z MDLS OVERALL PRESENT NO SIG
FCST PROBLEMS. THE MDLS GNRLY AGREE THAT THE WEAK SFC LOW NOW
OVER THE NE NT2 WTRS WL SLOWLY PASS E OF THE NT2 WTRS TODAY INTO
FRI. BASED ON THE WEAK UPR LVL SPRT FCSTD WL FAVOR THE WEAKER 00Z
GFS/UKMET/ECMWF SOLUTIONS VS THE STRONGER 00Z NAM/GEM SOLUTIONS
FOR THIS SYSTEM AND AS A RESULT WL HOLD THE MAX ASCD FCST WINDS IN
ITS VCNTY TO GNRLY IN THE 15-20 KT RANGE. THEN FRI NITE TO VARYING
DEGREES THE 00Z MDLS FCST A FRONTAL LOW(S?) TO MOVE SE OFF THE MID
ATLC COAST ALONG THE TRAILING STNRY FRONT CAUSING ONLY SLIGHTLY
STRONGER GRADIENTS TO DVLP. TO MAINLY BETTER MATCH THE FCST
GRADIENTS OF THE 00Z UKMET/ECMWF...PLAN ON POPULATING OUR SHORT
TERM WIND GRIDS THRU FRI NITE WITH THE 00Z GFS 30M BL WINDS (WHICH
ARE NOT SIGLY DIFFERENT VS THE 00Z GFS 10M BL WINDS). SO SINCE A
MIX OF THE 12Z GFS 30M AND 10M WINDS WERE PREVLY USED...ANTICIPATE
MAKING ONLY MINOR SHORT TERM CHNGS IN THE NEXT OFSHR FCST PACKAGE.

IN THE LONG RANGE...BY LATE SAT/SAT NITE THE 00Z GLOBAL MDLS
GNRLY AGREE THAT THE MOST SIG FRONTAL LOWS WL PASS E OF THE NT2
WTRS WHL PULLING THE FRONT S AS A COLD FRONT INTO THE SRN NT2 WTRS
BY SAT NITE WITH A MOD STRONG ENELY GRADIENT DVLPG N OF THE FRONT
THRUT THE NT2 AND SRN NT2 WTRS. THEN LATE SUN/SUN NITE THE 00Z
MDLS ALL FCST THE FRONT TO PUSH S OF THE NT2 WTRS WITH THE MOD
STRONG ENELY GRADIENT DVLPG THRUT ALL OF THE NT2 WTRS. SO FOR THIS
ENELY GRADIENT PLAN ON USING A 50/50 BLEND OF THE 00Z GFS 30M AND
00Z ECMWF BL WINDS FOR SAT THRU SUN NITE WHICH WL RESULT IN MAX
WINDS GNRLY IN THE 15-20 KT RANGE...SMLR TO THE PREV OFSHR FCSTS.

THEN FURTHER OUT IN THE LONG RANGE...BY LATE MON/MON NITE THE
FUTURE TRACK OF THE NEXT PSBL TROPICAL CYCLONE MAY START TO
IMPACT THE SRN NT2 WTRS. VS ITS PREV RESPECTIVE RUNS...THE 00Z GFS
NOW FCSTS THIS SYSTEM TO TURN NWD MR QUICKLY MON NITE CAUSING A
SLIGHTLY STRONGER (20-25 KT) ENELY GRADIENT TO DVLP ACRS THE SRN
MOST NT2 WTRS. THE 00Z GEM IS SMLR TO THE 00Z GFS WHL THE 00Z
UKMET IS MR SUPPRESSED WITH ITS FCST TRACK AND HENCE FCSTS A
WEAKER GRADIENT ACRS THE SRN NT2 WTRS. BUT ON THE OTHER
HAND...SMLR TO ITS PREV 12Z RUN...THE 00Z ECMWF IS SIGLY FASTER IN
TURNING THIS SYSTEM NWD TO JUST SE OF THE SE MOST NT2 WTRS BY LATE
MON NITE. SO SINCE THIS SYSTEM HAS NOT EVEN BEEN CLASSIFIED YET BY
NHC AND DUE TO THE CURRENT MDL DISPARITY...FOR NOW WL INSTEAD JUST
FOCUS ON THE GNRLY SMLR GRADIENTS THAT THE 00Z GFS/ECMWF FCST ACRS
THE OFSHR WTRS AND AS A RESULT WL CONT TO USE A 50/50 BLEND OF THE
00Z GFS 30M AND 00Z ECMWF BL WINDS FOR MON THRU MON NITE.

SEAS...WITH THE DIFFERENCES BTWN THE TWO MDLS NOT EXCEEDING
1-2 FT...PLAN ON USING A 50/50 BLEND OF THE 00Z WAVEWATCH III AND
00Z ECMWF WAM THRU MON NITE.

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

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER VUKITS. OCEAN PREDICTION CENTER.


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