PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1225 PM CDT TUE MAY 26 2009

...HURRICANE HAZARDS...HIGH WINDS AND TORNADOES...

HURRICANES PRODUCE A NUMBER OF WEATHER HAZARDS...INCLUDING DAMAGING
HURRICANE WINDS AND SOMETIMES TORNADOES. WINDS IN A HURRICANE
CIRCULATE COUNTER CLOCKWISE AND BECOME INCREASINGLY STRONGER AS YOU
APPROACH THE CENTER OF THE STORM...WITH THE STRONGEST WINDS IN A
REGION SURROUNDING THE CENTER CALLED THE EYE WALL. THE DESTRUCTIVE
WINDS IN THIS EYE WALL REGION REACH SUSTAINED SPEEDS OF 74 MILES PER
HOUR OR GREATER...AND WIND GUSTS CAN BE CONSIDERABLY HIGHER. WIND
SPEED USUALLY DECREASES SIGNIFICANTLY WITHIN 12 HOURS AFTER
LANDFALL. HOWEVER...WINDS CAN STAY ABOVE HURRICANE STRENGTH WELL
INLAND. IN 1970...HURRICANE CELIA GENERATED HURRICANE FORCE WINDS AS
FAR INLAND AS DEL RIO. HURRICANE IKE PRODUCED STRONG WINDS OVER A
VERY LARGE AREA...WITH HURRICANE FORCE WIND GUSTS AS FAR NORTH AS
LUFKIN.

HURRICANE FORCE WINDS CAN EASILY DESTROY POORLY CONSTRUCTED
BUILDINGS AND MOBILE HOMES. DEBRIS SUCH AS SIGNS...ROOFING MATERIAL
AND SMALL ITEMS LEFT OUTSIDE BECOME FLYING MISSILES IN HURRICANES.
EXTENSIVE DAMAGE TO TREES...TOWERS...AND UTILITY LINES FROM UPROOTED
TREES AND FALLEN POLES CAUSE CONSIDERABLE DISRUPTION...WITH EXTENDED
LOSS OF POWER NOT UNCOMMON. HIGH RISE BUILDINGS ARE ALSO VULNERABLE
TO HURRICANE FORCE WINDS...PARTICULARLY AT THE HIGHER LEVELS SINCE
WIND SPEED TENDS TO INCREASE WITH HEIGHT. IT IS NOT UNCOMMON FOR
HIGH RISE BUILDINGS TO SUFFER A GREAT DEAL OF DAMAGE DUE TO WINDOWS
BEING BLOWN OUT...AND THIS INDEED HAPPENED WITH HURRICANE IKE.

A MEASURE OF THE STRENGTH OF THE WINDS IS THE SAFFIR SIMPSON
HURRICANE WIND SCALE. A CATEGORY 1 HURRICANE HAS MAXIMUM SUSTAINED
WINDS BETWEEN 74 AND 95 MPH. SUCH A STORM CAN DO SIGNIFICANT DAMAGE
TO TREES...FENCES...AND MOBILE HOMES...BUT MOST WELL CONSTRUCTED
HOMES SUFFER RELATIVELY MINOR DAMAGE. HURRICANES WITH HIGHER WINDS
CORRESPOND TO HIGHER RATINGS ON THE SCALE. A CATEGORY 4 HURRICANE...
FOR EXAMPLE...WOULD HAVE WINDS BETWEEN 131 AND 155 MPH WHICH WOULD
USUALLY CAUSE MUCH MORE EXTENSIVE DAMAGE TO EVEN WELL BUILT HOMES.
HURRICANE IKE WAS A HIGH END CATEGORY 2 STORM WHEN IT MADE LANDFALL
WITH MAXIMUM SUSTAINED WINDS AROUND 110 MPH. THE STORM SPREAD
CATEGORY 1 LEVEL WIND GUSTS FAR INLAND...WHICH LED TO DOWNED TREES
AND EXTENSIVE POWER OUTAGES OVER A LARGE AREA...INCLUDING THE
HOUSTON METRO REGION.

A HURRICANE CAN STRENGTHEN RAPIDLY. WHEN PREPARING FOR A HURRICANE
LANDFALL...YOU SHOULD PLAN FOR A STORM AT ONE CATEGORY HIGHER
THAN FORECAST. IT IS ALSO VERY IMPORTANT TO REMEMBER THE SAFFIR
SIMPSON HURRICANE WIND SCALE DOES NOT DESCRIBE THE SURGE THREAT OF A
STORM. HURRICANE IKE...A CATEGORY 2 STORM...PRODUCED A DEVASTATING
STORM SURGE ALONG THE UPPER TEXAS AND LOUISIANA COASTS. IT IS
IMPORTANT TO HEED THE ADVICE OF LOCAL OFFICIALS WHEN ORDERED TO
EVACUATE...ESPECIALLY IN SURGE ZONES.

HURRICANES CAN ALSO PRODUCE TORNADOES THAT ADD TO THE STORMS
DESTRUCTIVE POWER. TORNADOES ARE MOST LIKELY TO OCCUR IN THE RIGHT
FRONT QUADRANT OF THE HURRICANE....OFTEN IN THE SPIRAL RAINBANDS...
WELL AWAY FROM THE CENTER OF THE HURRICANE. ONE EXAMPLE OCCURRED IN
1988 WHEN TORNADOES...ASSOCIATED WITH RAINBANDS FROM A DECAYING
HURRICANE GILBERT...HIT THE CITIES OF SAN ANTONIO AND DEL RIO AFTER
THE STORM MADE LANDFALL 125 MILES SOUTH OF BROWNSVILLE.

SOME HURRICANES SEEM TO PRODUCE NO TORNADOES...WHILE OTHERS DEVELOP
MULTIPLE TORNADOES. STUDIES HAVE SHOWN THAT MORE THAN HALF OF THE
LANDFALLING HURRICANES PRODUCE AT LEAST ONE TORNADO. HURRICANE
BEULAH...WHICH STRUCK THE SOUTH TEXAS COAST IN 1967...SPAWNED 114
TORNADOES. NO TORNADOES WERE CONFIRMED WITH HURRICANE IKE. IN
GENERAL TORNADOES ASSOCIATED WITH HURRICANES ARE LESS INTENSE THAT
THOSE THAT OCCUR IN THE GREAT PLAINS. NONETHELESS...THE EFFECTS OF
TORNADOES ADDED TO THE LARGER AREA OF HURRICANE FORCE WINDS CAN
PRODUCE SUBSTANTIAL DAMAGE.

FOR ADDITIONAL INFORMATION REGARDING HURRICANES OR HURRICANE
PREPAREDNESS...PLEASE VISIT THE NATIONAL WEATHER SERVICE WEBSITE AT
HTTP://WWW.SRH.NOAA.GOV/HGX/. THIS MESSAGE WAS SENT AS PART OF
HURRICANE PREPAREDNESS WEEK WHICH RUNS FROM MAY 24TH THROUGH MAY
30TH.

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