Marine Interpretation Message
Issued by NWS

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000
AGNT40 KWNM 250218
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
918 PM EST SAT JAN 24 2015

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


THE IR SAT IMG SHOW CONV OVR MOST OF THE WTRS WITH LGTHNG OVR THE
NT2 WTRS MAINLY POST FRNTL. AT 00Z LOW PRES 973 MB OVR MAINE WTRS
HAS CLD FRNT STRCTCHNG SW ALONG THE WRMN PARTS OF THE REGION. HGH
PRES 1027 MB NR 38N45W MAINATSINS A RIDGE W OF THE REGION. INLAND
LOW PRES 988 MB OVR CANADA HAS A CLD FRNT ACRS THE GRT LAKES.THE
PRES GRDNT IS VERY TIGHT OVR THE REGION AND THE MAX OBS WINDS ARE
IN THE GALE FORCE RANGE WITH HGST WINDS NE. LAST ASCAT PASS WAS AT
1416Z AS DESCRIBED BELOW. THE SEAS ARE HGST OVR THE WRN PARTS OF
THE CNTRL WTRS WITH 26 FT PEAK AND ELSEWHERE THE RANGE IS BTWN 10
AND 25 FT. THE LAST JASON PASS OVR THE REGION WAS AT 1600Z HAD 12
FT OVR THE BALT CNYN WTRS. THE GLB MDLS HV INITIALIZED WELL AND
WILL RETAIN MOST OF THE WTRNG IN THE PREVIOUS FCST. IN THE SHORT
TERM THE LOW PRES OVR THE REGION WILL ZOOM NE BUT ANOTHER CLD FRNT
WILL QUICKLY MOVE INTO THE WTRS AND STRENGTHEN THE PRES GRDNT
AGAIN.

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

OVER THE SHORT TERM...AS THE STRENGTHENING SFC LOW NOW NR
40N72W CONTS TO TRACK NEWD EARLIER 1416Z ASCAT-A AND 1509Z
ASCAT-B PASSES CONFIRMED THAT SLY STORM FORCE WINDS WERE PRESENT
IMMED IN ADVANCE OF ITS TRAILING COLD FRONT ACRS THE NTT2 WTRS NR
THE GULF STREAM. PER A CONSENSUS OF THE NEW 12Z MDLS...THIS LOW
SHULD MOV FAR ENUF NE THAT BY THE START OF THE TONITE FCST PERIOD
THESE PREFRONTAL STORM FORCE SLY WINDS SHULD BE LIMITED TO THE FAR
SE NT1 AND FAR NE NT2 WTRS...THEN BCM SUB STORM FORCE SHORTLY
AFTER MIDNIGHT. IN THE POSTFRONTAL GRADIENT BY LATE TONITE ALL OF
THE MDLS FCST WINDS BCMG SUBGALE...BUT THEN IN RESPONSE TO A
SCNDRY COLD FRONT RACING OFSHR SUN...MAINLY PER THE 12Z GFS/NAM
30M BL WINDS (THO EVEN THE USUALLY CONSERVATIVE 12Z UKMET/ECMWF
ALSO FCST SOLID 25-30 KT BL WINDS)...EXPECT THE WNWLY GRADIENT TO
RESTRENGTHEN TO MARGINAL GALE FORCE ACRS THE ERN NT1 AND NERN NT2
WTRS FOR A BRIEF PERIOD. THEREFORE SINCE ITS WINDS LOOK
REPRESENTATIVE...PLAN ON POPULATING OUR SHORT TERM FCST WIND GRIDS
WITH THE 12Z GFS 30M BL WINDS FOR TONITE THRU SUN NITE. SO AS A
RESULT NO SIG IMMED SHORT TERM CHNGS WL BE MADE TO THE PREV OFSHR
FCSTS.

THEN FURTHER OUT INTO THE LONG RANGE...THE 12Z MDLS REMAIN IN
RSNBLY GOOD AGRMT THAT IN RESPONSE TO AN UPR TROF DIGGING TWDS
THE E COAST SUN NITE/MON...GAINING NEGATIVE TILT MON NITE...THEN
TRANSITIONING INTO A CLOSED UPR LOW TUE THAT TRACKS NE ACRS THE
NT1 WTRS TUE/TUE NITE AN ASCD DVLPG SFC LOW WL MOVE OFF THE MID
ATLC COAST MON...THEN TRACK SLOWLY NE ACRS THE OFSHR WTRS MON NITE
INTO TUE NITE WHL INTENSFYG. VS IS PREV 00Z AND 06Z RUNS...THE 12Z
GFS HAS TRENDED SLIGHTLY SLOWER AND SLIGHTLY DEEPER WITH ITS FCST
LOW. THE 12Z GEFS MEAN SPRTS THIS SLOWER AND STRONGER 12Z GFS
TREND. THE 12Z GEM/UKMET FCST NRLY IDENTICAL SOLUTIONS TO THE 12Z
GFS...BUT ARE BOTH SLIGHTLY SLOWER. ON THE OTHER HAND THE 12Z
ECMWF HAS COME IN AND SMLR TO ITS PREV 00Z RUN IT LOOKS LIKE A
SLOW OUTLIER AS IT IS SM 12-18 HRS SLOWER THAN THE OTHER 12Z
GLOBAL MDL SOLUTIONS. THEREFORE IN REGARDS TO THE FCST TRACK OF
THIS SYSTEM...WL FAVOR THE 12Z GFS TRACK...BUT IN DEFERENCE TO THE
OTHER 12Z GLOBAL MDLS AND THE LATEST WPC MEDIUM RANGE GUIDANCE WL
SLOW IT DOWN BY 6 HRS ON AVERAGE. IN REGARDS TO THE ASCD FCST
GRADIENTS...WITH ALL THE 12Z MDLS FCSTG SMLR CNTRL PRESSURES FOR
THE LOW...BLV THE 12Z GFS 30M BL WINDS LOOK REPRESENTATIVE.
THEREFORE PLAN ON CONTG TO POPULATE WITH THE 12Z GFS 30M BL WINDS
FOR MON THRU TUE NITE...TIME SHIFTED 6 HRS SLOWER. WITH THE NEW
12Z GFS TRACK BEING SLIGHTLY FURTHER W THAN ITS PREV RUNS WL BE
EXPANDING THE PREVLY FCSTD MOD CONFIDENCE PSBL GALE/STORM WRNGS
FURTHER WWD MON NITE INTO TUE. THEN LATE IN THE LONG RANGE THE 12Z
GLOBAL MDLS FCST YET ANOTHER CLIPPER-TYPE SFC LOW TO APRCH THE E
COAST THU NITE. IN COMPARISON TO THE OTHER 12Z GLOBAL MDLS...THE
12Z GFS LOOKS A LTL TOO PROGRESSIVE WITH THIS SYSTEM. THEREFORE WL
CONT TO POPULATE WITH THE 12Z GFS 30M BL WINDS ON WED THRU THU
NITE...BUT AGAIN WL TIME SHIFT THEM 6 HOURS SLOWER.

.SEAS...THE HIGHER 12Z WAVEWATCH III HAS INITIALIZED BETTER THAN
THE 12Z ECMWF WAM AND HENCE WL BE USED TO POPULATE OUR SHORT TERM
WAVE GRIDS TONITE THRU MON. THEN TO MATCH UP WITH THE 12Z GFS FCST
WINDS...WL CONT TO POPULATE WITH THE 12Z WAVEWATCH III MON NITE
THRU THU NITE...TIME SHIFTED 6 HRS SLOWER.

.EXTRATROPICAL STORM SURGE GUIDANCE...IN THE WNWLY GRADIENT IN
THE WAKE OF THE STRONG LOW MOVG OFF TO THE NE...THE 12Z ESTOFS
FCSTS A MR SIG NEGATIVE SURGE ALONG THE COAST THAN THE 12Z ETSS
THRU SUN. BELIEVE A COMPROMISE BTWN THE TWO MDLS FOR THIS NEGATIVE
SURGE WL WORK OUT BEST. THEN LATE MON INTO TUE IN THE STRONG NELY
GRADIENT FCST TO DVLP N OF THE SECOND DVLPG LOW...BOTH THE 12Z
ESTOFS AND 12Z ETSS FCST POSITIVE SURGE VALUES GNRLY IN THE 2-3 FT
RANGE TO DVLP ALONG THE COASTS N OF THE LOW...WHICH IF ITS TRACK
TRENDS FURTHER W MAY NOT BE HIGH ENUF. SO THIS WL HAVE TO BE
MONITORED CLOSELY IN THE SUBSEQUENT RUNS.


.WARNINGS...PRELIMINARY.

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

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

$$

.FORECASTER MUSONDA/VUKITS. OCEAN PREDICTION CENTER.


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