Marine Interpretation Message
Issued by NWS

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259
AGNT40 KWNM 091356
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
855 AM EST TUE 9 FEB 2016

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

A SHIP REPORTED 995 MB AND 40 KT AT 12Z JUST SE OF THE
DEVELOPING LOW WHICH WAS CENTERED NEAR 35.5N71W. THIS SHIP IS AN
EXCELLENT OBSERVER WITH MEAN WIND SPEED ERROR LESS THAN 1 KT AND
SLP ERROR NEAR ZERO OVER 30 PLUS OBSERVATION HISTORY. THIS
SURFACE LOW IS A FEW MB DEEPER THAN LATEST MODELS INDICATING
THIS MORNING. AM CONTINUING TO FAVOR THE HIGHER GFS 30M WINDS
WITH THIS LOW AND WILL NOT BE MAKING SIGNIFICANT ADJUSTMENTS TO
PREVIOUS WARNINGS. THERE REMAINS SOME POTENTIAL THAT WINDS OVER
SE QUADRANT OF LOW WILL REACH HURRICANE FORCE LATE THIS
AFTERNOON THROUGH THIS EVENING BUT THESE WINDS WOULD BE E AND SE
OF OUTER OFFSHORE WATERS. BY LATER THIS WEEK MODELS HAVE NOT
COME INTO ANY BETTER AGREEMENT WITH THE POSSIBLE DEVELOPING SFC
LOW OVER THE SOUTHERN NT2 WATERS FRI AND FRI NIGHT. 06Z GFS
TRENDED SIGNIFICANTLY STRONGER FROM ITS PREVIOUS COUPLE
RUNS...AND LOOKS TOO AMPLIFIED WITH THE MID/UPPER LEVEL
SHORTWAVE FRI NIGHT. AT THE SURFACE 06Z GFS IS NOW SHOWING GALES
OVER OUTER WATERS S OF BALTIMORE CANYON LATE FRI AND FRI NIGHT.
WILL KEEP CONTINUITY WHICH DOWNPLAYS THIS DEVELOPING LOW AS
UKMET AND GLOBAL GEM ARE WEAKER WHILE ECMWF LACKS THE SHORTWAVE.


WAVEWATCH III AND ECMWF WAM ARE DOING A MUCH BETTER JOB WITH
OFFSHORE AND COASTAL WAVE HEIGHTS THIS MORNING THAN HAS BEEN THE
CASE OVER THE LAST 24 TO 36 HOURS. GUIDANCE IS STILL A FEW FT
UNDERDONE OVER OUTER NT2 WATERS S OF HATTERAS CANYON. A 10Z
ALTIKA ALTIMETER OVERPASS HAD RETURNS AS HIGH AS 28 FT OVER
NORTHEASTERN MOST NT2 WATERS WHILE 1030Z JASON-2 HAD 20 TO 25 FT
NEAR THE NORTH WALL OF THE GULF STREAM OVER ZONE ANZ920...NEARLY
 DOUBLE WHAT GUIDANCE WAS INDICATING.

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

OVER THE SHORT TERM...THE NEW 00Z MDLS CONT TO FCST A VERY
PROGRESSIVE AND ACTIVE PATTERN TO CONT. FOR THE DVLPG SFC LOW
NOW MOVG NE OFF THE N CAROLINA COAST...WULD FAVOR THE LESS
PROGRESSIVE FCST TRACKS OF THE SMLR 00Z GFS/UKMET/ECMWF VS THE
FASTER 00Z GLOBAL GEM. IN RGRDS TO THE FCST GRADIENTS ASCD WITH
THIS SYSTEM...BASED ON THE ASCD COLD AIR ADVECTION AND NEGATIVE
STATIC STABILITY FCSTD...AS WAS DONE PREVLY WL FAVOR THE SMWHT
STRONGER 00Z GFS 30M BL WINDS AND WL POPULATE OUR FCST WIND
GRIDS WITH THESE WINDS FOR TODAY.

THEN LATE TODAY THRU WED NITE...AS THE 00Z MDLS ALL FCST A
SERIES OF UPR S/W TROFS TO SWING OFSHR THRU THE BASE OF AN ASCD
UPR L/W TROF OVER THE ERN CONUS...TO VARYING DEGREES THE MDLS
FCST A SERIES OF ASCD SFC LOWS TO TRACK E NR 40N LATE TONITE
THRU WED...FLWD BY ANOTHER LOW MOVG OFSHR IN THE VCNTY OF THE
NRN GULF OF MAINE WED NITE. AS THESE SFC LOWS PASS ACRS THE
AREA...THE MDLS ALL FCST A MOD TO STRONG WNWLY GRADIENT ACRS THE
NT2 WTRS TO SPREAD SLOWLY NWD INTO THE NT1 WTRS LATE WED/WED
NITE. OVERALL WULD FAVOR A BLENDED 00Z GFS/UKMET/ECMWF SOLUTION
FOR THIS GRADIENT. THEREFORE WL CONT TO POPULATE WITH THE 00Z
GFS 30M BL WINDS THRU WED NITE...WITH SM ADDITIONAL EDITS IN
DEFERENCE TO THE 00Z UKMET/ECMWF.

IN THE LONG RANGE...ON THU/THU NITE WL FAVOR THE 00Z GFS
SOLUTION OF THE SFC LOW PASSING E OF THE AREA AND ITS ASCD
MOD/STRONG WNWLY GRADIENT SHIFTING NEWD WITH IT. THEREFORE WL
POPULATE WITH A 50/50 BLEND OF THE 00Z GFS 30M AND 10M BL WINDS
ON THU/THU NITE. THEN LATER IN THE LONG RANGE THE DISPARITY
INCREASES BTWN THE 00Z GLOBAL MDLS. THE 00Z GFS/GEM/UKMET ALL
FCST A STRONGER DVLPG SFC LOW THAN THE 00Z ECMWF TO CROSS SRN
NT2 WTRS FRI INTO FRI NITE. SINCE THE 00Z GEFS MEAN ALSO
INDICATES THAT THE 00Z GFS IS LKLY TOO STRONG WITH THIS
SYSTEM...WL CONT TO POPULATE WITH A 50/50 BLEND OF THE 00Z GFS
30M AND 10M WINDS FRI...WITH SM ADDITIONAL EDITS TO DCRS THE
WINDS ACRS THE SRN NT2 WTRS. THEN FRI NITE INTO SAT NITE...SINCE
ITS MR IN LINE WITH THE LATEST WPC MEDIUM RANGE GUIDANCE...WL
FAVOR THE LESS PROGRESSIVE 00Z ECMWF SOLUTION OF A SFC LOW
CONSOLIDATING JUST E OF THE NT1 WTRS LATE SAT/SAT NITE WITH A
MOD TO STRONG NWLY GRADIENT DVLPG THRUT MUCH OF THE WTRS.
THEREFORE WL TRANSITION TO POPULATING WITH THE 00Z ECMWF BL
WINDS FOR FRI NITE THRU SAT NITE.

.SEAS...THE SLIGHTLY HIGHER 00Z ECMWF WAM HAD INITIALIZED BETTER
THAN THE 00Z WAVEWATCH III BUT BY LATER THIS MORNING THEIR
DIFFERENCES NARROW. THEREFORE WL POPULATE WITH A 50/50 BLEND OF
THE TWO MDLS FOR TODAY THRU WED NITE. PREFER ALL 00Z WAVEWATCH
III FCST SEAS THU THRU FRI...AND THEN WL TRANSITION TO ALL 00Z
ECMWF WAM FCST SEAS FOR FRI NITE THRU SAT NITE SINCE THE 00Z
ECMWF WL BCM FAVORED.

.EXTRATROPICAL STORM SURGE GUIDANCE...AS THE STRONG WLY GRADIENT
IS FCST BY THE 00Z GFS TO SPREAD NWD...SMLR TO ITS PREV
RESPECTIVE RUNS THE 00Z ESTOFS CONTS TO FCST A HIGHER NEGATIVE
SURGE TO DVLP FM THE SE COAST NWD UP THE COAST TODAY INTO FRI
THAN FCST BY THE 00Z ETSS...WHICH IS LKLY OVERDONE.

.WARNINGS...PRELIMINARY.

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

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

$$

.FORECASTER CLARK/VUKITS. OCEAN PREDICTION CENTER.



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