000
AGXX40 KNHC 040811
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
411 AM EDT FRI OCT 4 2013

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN
SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND
64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS.

...GULF OF MEXICO...

MODEL PREFERENCE: OFFICIAL TRACK FOR KAREN BLENDED WITH PREVIOUS 
OFFICIAL FCST. USED NWPS TO GENERATE WAVES. MODERATE CONFIDENCE.

T.S. KAREN STRUGGLING TO INTENSIFY BEYOND ITS CURRENT INTENSITY 
IN HOSTILE MID-UPPER LEVEL ENVIRONMENT OF HIGH VERTICAL SHEAR. 
EXPECT TROPICAL CYCLONE TO MOVE N THEN VEER NE AHEAD OF DEEP MID-
LEVEL TROUGH AND FIRST STRONG COLD FRONT OF SEASON PLUNGING DEEP 
INTO THE WESTERN GULF OF MEXICO. FORECAST BASED ON TRANSLATION 
OF CURRENT CONDITIONS NORTHWARD. PRIMARY CONCERNS ARE TIMING AND 
LOCATION OF LANDFALL WHICH IS HIGHLY DEPENDENT ON APPROACHING 
TROUGH. GLOBAL MODELS HAVE BEGUN TO DIVERGE AHEAD OF THE TROUGH 
AND CONFIDENCE IN ONE MODEL OVER THE OTHER IS LOW. WILL TRY TO 
BLEND GFS ECMWF AND UKMET TO GET MIDDLE OF ROAD CONSENSUS.

NEAR-SHORE WAVE MODEL WAS USED TO GENERATE SEAS...BUT 
OUTER SEA HEIGHTS ARE MUCH HIGHER THAN BUOY OBS...SO MAY NEED TO 
SCALE BACK SEAS A BIT AWAY FROM INNER CORE. KAREN MOVES INLAND 
EARLY SUN WITH WINDS AND SEAS QUICKLY DIMINISHING OVER N CENTRAL 
AND NE GULF. GUIDANCE SOLUTIONS IN TIGHT AGREEMENT THROUGH FIRST 
48 HOURS AND DIVERGE THEREAFTER...BY WHICH TIME KAREN SHOULD BE 
OVER LAND. COLD FRONT QUICKLY MOVES S AND E ACROSS GULF WATERS 
SAT NIGHT THROUGH MON. FRESH TO STRONG N WINDS WITH 6-7 FT SEAS 
ENTER WESTERN GULF WATERS W OF 94W SUN AND QUICKLY SPREAD E TO 
90W AND S TO BAY OF CAMPECHE THEN DIMINISH TO FRESH N BREEZE AND 
SEAS 4-5 FT BY TUE. 

...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 65W...

MODEL PREFERENCE: GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. 
GOOD CONFIDENCE.  

HIGH PRES RIDGE N OF THE REGION WILL PERSIST THROUGH SAT THEN 
RAPIDLY EXIT THE PICTURE AS DEEP TROUGH ASSOCIATED WITH KAREN 
AND FAST-MOVING COLD FRONT ENTERS THE SW N ATLC. MUCH WEAKER 
PRES GRADIENT WILL LEAD TO LIGHT TO GENTLE WINDS IN CENTRAL AND 
WESTERN CARIBBEAN SUN THROUGH TUE.

...SW N ATLANTIC INCLUDING THE BAHAMAS...

MODEL PREFERENCE: GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. 
MODERATE CONFIDENCE.

HIGH PRES RIDGE CENTERED E OF THE CAROLINAS NEAR 33N70W KEEPS  
GENTLE TO MODERATE EASTERLY WINDS ACROSS THE REGION. BIG CHANGE 
COMING SUN THROUGH TUE AS LOW PRES KAREN CROSSES SOUTHEASTERN 
U.S. AHEAD OF FAST-MOVING COLD FRONT. S-SE WINDS WILL INCREASE 
AHEAD OF THE LOW MON THEN SHIFT NW BEHIND FRONT TUE. TIMING OF 
WIND SHIFTS HIGHLY DEPENDENT ON ACTUAL MOVEMENT OF KAREN. HIGH 
CONFIDENCE IN LARGE SCALE FEATURES BUT LOW CONFIDENCE IN DETAIL. 

$$

.WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:

.GULF OF MEXICO...
GMZ011...NONE.
GMZ013...TROPICAL STORM WARNING EARLY TODAY INTO MON NIGHT. 
GMZ015...NONE.
GMZ017...NONE.
GMZ019...TROPICAL STORM WARNING EARLY TODAY INTO MON NIGHT. 
GMZ021...NONE.
GMZ023...NONE.
GMZ025...NONE.

.CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
AMZ011...NONE.
AMZ013...NONE.
AMZ015...NONE.
AMZ017...NONE.
AMZ019...NONE.
AMZ021...NONE.
AMZ023...NONE.
AMZ025...NONE.
AMZ027...NONE.
AMZ029...NONE.
AMZ031...NONE.
AMZ033...NONE.
AMZ035...NONE.
AMZ037...NONE.
AMZ039...NONE.

.SW N ATLANTIC INCLUDING THE BAHAMAS...
AMZ111...NONE.
AMZ113...NONE.
AMZ115...NONE.
AMZ117...NONE.
AMZ119...NONE.
AMZ121...NONE.
AMZ123...NONE.
AMZ125...NONE.
AMZ127...NONE.

*FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT:
HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF

NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE
NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT:
HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP

FOR ADDITIONAL INFORMATION PLEASE VISIT:
HTTP://WWW.HURRICANES.GOV/MARINE

$$
.FORECASTER MUNDELL. NATIONAL HURRICANE CENTER.