National Weather Service Weather Forecast Office

AS PART OF SEVERE WEATHER AWARENESS WEEK IN THE STATE OF TEXAS...THE 
NATIONAL WEATHER SERVICE WANTS YOU TO KNOW ABOUT THE DANGERS OF THE 
NUMBER ONE STORM KILLER - FLASH FLOODING.    

FEW PEOPLE REALIZE THE TRUE POWER OF WATER.  FAST-MOVING FLOOD WATERS 
ONLY SIX INCHES DEEP CAN KNOCK AN ADULT OFF THEIR FEET.  TWO FEET OF 
WATER CAN LIFT APPROXIMATELY 3000 POUNDS - THE WEIGHT OF AN AVERAGE 
SIZE VEHICLE.  VEHICLES CROSSING A FLOODED ROADWAY CAN LOOSE TRACTION 
WITH THE ROAD...ACTUALLY FLOATING IN SOME CASES... AND BECOME PART OF 
A DANGEROUS FLOOD.  FLASH FLOOD STATISTICS INDICATE THAT HALF OF THE 
ANNUAL FLOOD FATALITIES ARE VEHICLE RELATED. AGAIN...TURN AROUND 
DON’T DROWN. 

A FLASH FLOOD IS A RAPID RISE OF WATER ALONG A STREAM OR LOW-LYING 
URBAN AREA. SLOW MOVING THUNDERSTORMS...THUNDERSTORMS THAT MOVE 
REPEATEDLY OVER THE SAME AREA...AND HEAVY RAINS ASSOCIATED WITH 
TROPICAL STORMS AND HURRICANES ARE THE WEATHER MAKERS THAT PRODUCE 
FLASH FLOODS. THESE FLOODS CAN DEVELOP WITHIN MINUTES...DEPENDING ON 
THE INTENSITY AND DURATION OF THE RAIN...THE TOPOGRAPHY...THE SOIL 
CONDITIONS...AND GROUND COVER.

FLASH FLOODS CAN ROLL BOULDERS...TEAR DOWN TREES...DESTROY 
BUILDINGS...AND SCOUR OUT NEW CHANNELS. RAPIDLY RISING WATER CAN 
REACH HEIGHTS OF 30 FEET OR MORE.  WATER CAN ERODE EARTH BELOW A 
ROAD...LEADING TO UNSAFE DRIVING CONDITIONS. UNDERPASSES CAN FILL 
RAPIDLY WITH WATER...WHILE ADJACENT ROADWAYS REMAIN CLEAR.  IN URBAN 
AREAS...STORM DRAINS CAN BECOME OVERWHELMED AND FLOOD ROADS AND 
BUILDINGS. LOW SPOTS SUCH AS UNDERGROUND PARKING GARAGES AND BASEMENTS 
CAN QUICKLY FLOOD. IN RURAL AREAS...PEOPLE WHO ENJOY HUNTING... 
CAMPING...AND FISHING NEED TO STAY AWAY FROM STREAMS IF THUNDERSTORMS 
HAVE OCCURRED. WATER CAN RISE OVER TEN FEET IN LESS THAN AN HOUR WITH 
A HEAVY RAINFALL.

SO HOW CAN WE STAY SAFE FROM THE DANGERS ASSOCIATED WITH FLASH 
FLOODING?

MONITOR WEATHER RADIO AND PAY CLOSE ATTENTION TO FLASH FLOOD WARNINGS 
ISSUED BY THE NATIONAL WEATHER SERVICE.  BE ESPECIALLY CAUTIOUS AT 
NIGHT WHEN IT IS MORE DIFFICULT TO RECOGNIZE THE DANGERS OF FLASH 
FLOODING. AVOID LOW LYING AREAS THAT ARE PRONE TO FLOODING.  DON'T 
CAMP OR PARK YOUR VEHICLE ALONG STREAMS AND WASHES.  IF YOUR VEHICLE 
IS SUDDENLY CAUGHT IN RISING WATER...LEAVE IT IMMEDIATELY AND MOVE TO 
HIGHER GROUND.  LASTLY...NEVER ATTEMPT TO CROSS AREAS WHERE WATER 
COVERS THE ROAD.  REMEMBER THE FIRST SAFETY RULE OF FLASH FLOODING... 
TURN AROUND DON’T DROWN.