...WRITTEN BY NATIONAL WEATHER SERVICE BROWNSVILLE...

...CONTINUING HURRICANE PREPAREDNESS WEEK IN TEXAS...

...STORM SURGE AND MARINE SAFETY...

SOME OF THE HAZARDS MOST EASILY IDENTIFIED WITH HURRICANES ARE
STRONG WINDS...TORNADOES…FLOODING AND STORM SURGE.  OF 
THESE…STORM SURGE AND HIGH WAVES ARE THE MOST DESTRUCTIVE 
TO COASTAL FACILITIES AND CAN CAUSE TREMENDOUS COASTAL 
EROSION.  STORM SURGE IS SIMPLY WATER THAT IS PUSHED TOWARD THE 
SHORE BY THE FORCE OF THE WINDS SWIRLING AROUND THE STORM. 

THIS SURGE COMBINES WITH THE NORMAL TIDES TO CREATE THE 
HURRICANE STORM TIDE…WHICH CAN INCREASE THE MEAN WATER 
LEVEL 15 FEET OR MORE. AN ADDITIONAL HAZARD ALSO FORMS AS WIND 
DRIVEN WAVES DEVELOP UPON THE STORM TIDE. THIS RISE IN WATER 
LEVEL CAN CAUSE SEVERE FLOODING IN COASTAL AREAS. BECAUSE 
MUCH OF THE DENSELY POPULATED ATLANTIC AND GULF COASTLINES 
LIE LESS THAN 10 FEET ABOVE MEAN SEA LEVEL…THE DANGER FROM 
STORM TIDES IS TREMENDOUS.

BECAUSE OF THE SHALLOW COASTAL WATERS OFF THE TEXAS...STORM 
SURGES WILL BE HIGHER FOR A TROPICAL STORM OR HURRICANE 
MAKING LANDFALL VERSES THE SAME STORM HITTING OTHER PARTS 
OF THE COUNTRY.  HISTORICALLY...STORM SURGE WAS THE MAJOR 
CAUSE OF DEATH FROM HURRICANES. HOWEVER...IN THE UNITED 
STATES...IMPROVED NATIONAL WEATHER SERVICE FORECASTS AND 
EMERGENCY MANAGEMENT EVACUATIONS HAVE REDUCED THESE NUMBERS.  
THE POTENTIAL FOR LOSS OF LIFE AND PROPERTY STILL REMAINS 
GREAT AND THIS POTENTIAL IS INCREASED WHEN WARNINGS AND 
EVACUATION ORDERS ARE NOT HEEDED.

THERE IS NO SINGLE RULE OF THUMB THAT CAN BE USED BY MARINERS 
TO ENSURE AT LEAST MINIMUM SAFE SEPARATION FROM A TROPICAL 
CYCLONE. CONSTANT MONITORING OF TROPICAL CYCLONE POTENTIAL 
AND A CONTINUAL RISK ANALYSIS… WHEN USED WITH SOME FUNDAMENTAL 
GUIDELINES ARE THE BASIC RECOMMENDED TOOLS TO HELP MINIMIZE A 
TROPICAL CYCLONE’S IMPACT TO A VESSEL AT SEA OR IN PORT. 

HOWEVER…MARINERS MUST BE CAUTIONED NEVER TO LEAVE THEMSELVES 
WITH ONLY A SINGLE NAVIGATION OPTION WHEN ATTEMPTING TO AVOID 
A TROPICAL CYCLONE IN THE ATLANTIC. SEA ROOM TO MANEUVER IS 
NOT TOO SIGNIFICANT A FACTOR IN THE WIDE OPEN WATERS OF THE 
NORTH ATLANTIC, BUT CAN BECOME AN EXTREMELY SIGNIFICANT 
CONSIDERATION WHEN OPERATING IN THE CONFINED WATERS OF THE 
WESTERN CARIBBEAN SEA AND GULF OF MEXICO. MORE OFTEN THAN 
NOT, EARLY DECISIONS TO LEAVE RESTICTED MANUEVER AREAS ARE 
THE MOST SENSIBLE CHOICE. 

AT A MINIUMUM…OBTAIN LATEST MARINE PREDICTION CENTER AND 
TROPICAL PREDICTION CENTER ANALYSIS/FORECAST CHARTS INCLUDING 
SURFACE…UPPER LEVEL…AND SEA STATE CHARTS.  LOCATE AND PLOT 
TROPICAL WAVES…DISTURBANCES…AND TROPICAL CYCLONES.  IF 
AVAILABLE…EXAMINE CURRENT SATELLITE IMAGERY.  OBTAIN LATEST 
TROPICAL CYCLONE ADVISORY MESSAGES. PLOT CURRENT AND FORECAST 
POSITIONS OF ALL ACTIVE AND SUSPECTED TROPICAL CYCLONE ACTIVITY.  
PLOT COMPLETED TROPICAL CYCLONE DANGER AREA TO AVOID CHART.  
DETERMINE POSSIBLE COURSES OF ACTION (AT LEAST 2) FOR VESSEL 
TO TAKE IN ORDER TO REMAIN CLEAR OF THE DANGER.  EVALUATE 
CURRENT AND NEARBY PORT AND HURRICANE HAVEN LOCATIONS THAT 
MAY BE CONSIDERED FOR TROPICAL CYCLONE AVOIDANCE.  MAKE A 
DECISION ON A COURSE OF ACTION TO FOLLOW AND EXECUTE. CONTINUE 
TO CLOSELY MONITOR THE PROGRESS OF ANY TROPICAL CYCLONES.

FOR ADDITIONAL INFORMATION REGARDING HURRICANES OR HURRICANE 
PREPAREDNESS...PLEASE VISIT THE NATIONAL WEATHER SERVICE 
WEBSITE AT WWW.SRH.NOAA.GOV OR CONTACT YOUR LOCAL NATIONAL 
WEATHER SERVICE OFFICE.