National Weather Service Weather Forecast Office

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
855 AM CDT TUE MAR 19 2013

...FLOOD SAFETY AWARENESS WEEK...

THE NATIONAL WEATHER SERVICE HAS DESIGNATED MARCH 18 TO 22 AS FLOOD
SAFETY AWARENESS WEEK.  THE PURPOSE OF FLOOD SAFETY AWARENESS WEEK
IS TO RAISE PUBLIC AWARENESS OF THE DANGERS OF FLOODING...AND WAYS
TO PROTECT LIFE AND PROPERTY.

TODAYS TOPIC OF INFORMATION IS...TYPES OF FLOODS.

IT FLOODS SOMEWHERE IN THE UNITED STATES OR ITS TERRITORIES NEARLY
EVERY DAY OF THE YEAR. FLOODING CAUSES MORE DAMAGE IN THE UNITED
STATES THAN ANY OTHER WEATHER RELATED EVENT...WITH AN AVERAGE OF
$8 BILLION PER YEAR AND ABOUT 95 FATALITIES.  FLOODING CAN OCCUR ANY
TIME OF YEAR...SOMETIMES VERY QUICKLY. BEING PREPARED IN ADVANCE AND
KNOWING A FEW FLOOD SAFETY TIPS WILL HELP YOU AND YOUR FAMILY
SURVIVE A FLOOD IF IT HAPPENS IN YOUR AREA.

A FLOOD IS DEFINED AS ANY HIGH FLOW...OVERFLOW...OR INUNDATION BY
WATER WHICH CAUSES OR THREATENS DAMAGE.  THIS USUALLY OCCURS WITH
PROLONGED RAINFALL OVER SEVERAL DAYS...INTENSE RAINFALL OVER A SHORT
PERIOD OF TIME...OR WHEN AN ICE OR DEBRIS JAM CAUSES A RIVER OR
CREEK TO OVERFLOW AND FLOOD THE SURROUNDING AREA. OTHER FACTORS THAT
CAN CAUSE OR WORSEN FLOODING ARE MELTING SNOW IN THE WINTER AND
EARLY SPRING...THUNDERSTORMS IN THE SPRING AND SUMMER...AND TROPICAL
SYSTEMS IN THE LATE SUMMER AND FALL.

...FLASH FLOODING
A FLASH FLOOD IS DEFINED AS A RAPID AND EXTREME FLOW OF HIGH WATER
INTO A NORMALLY DRY AREA...OR A RAPID WATER LEVEL RISE IN A CREEK OR
RIVER ABOVE A PREDETERMINED FLOOD LEVEL.  ONGOING FLOODING CAN
INTENSIFY TO FLASH FLOODING IN CASES WHERE INTENSE RAINFALL RESULTS
IN A RAPID SURGE OF RISING FLOOD WATERS. COMMONLY IT OCCURS WITHIN
6 HOURS OF A HEAVY RAINFALL EVENT. HOWEVER FLASH FLOODS CAN ALSO
OCCUR WITHIN HOURS OR EVEN MINUTES IF A DAM OR LEVEE FAILS...
FOLLOWING A SUDDEN RELEASE OF WATER HELD BY AN ICE OR DEBRIS JAM...
OR RAPID PONDING OF WATER CAUSED BY TORRENTIAL RAINFALL.  FLASH
FLOODS CAN EVEN OCCUR IN AREAS AWAY FROM THE CAUSATIVE EVENT. FLASH
FLOODS CAN CATCH PEOPLE OFF GUARD AND UNPREPARED. YOU MAY ONLY HAVE
A FEW MINUTES WARNING THAT THESE DEADLY AND SUDDEN FLOODS ARE
COMING. IF YOU LIVE IN AREAS PRONE TO FLASH FLOODS...PLAN NOW TO
PROTECT YOUR FAMILY AND PROPERTY.

...RIVER FLOODING
WITH RIVER FLOODING...THE NWS USES DIFFERENT CATEGORIES TO CONVEY
THE EXPECTED FLOOD SEVERITY. THESE CATEGORIES ARE: MINOR...
MODERATE...AND MAJOR FLOODING. EACH CATEGORY HAS A DEFINITION BASED
ON PROPERTY DAMAGE AND PUBLIC THREAT AND ARE CLOSELY COORDINATED BY
THE LOCAL NWS OFFICE...THE SERVICING RIVER FORECAST CENTER...OR
RFC...AND OTHER EMERGENCY AND PUBLIC OFFICIALS.  HERE ARE THE
OFFICIAL DEFINITIONS OF THESE CATEGORIES...

MINOR FLOODING USUALLY HAS MINIMAL OR NO PROPERTY DAMAGE...BUT THERE
COULD BE SOME LEVEL OF PUBLIC THREAT OR INCONVENIENCE. MANY TIMES
YOU WILL HEAR THIS REFERRED TO AS NUISANCE FLOODING.

MODERATE FLOODING GENERALLY HAS SOME INUNDATION OF STRUCTURES AND
ROADS NEAR CREEKS AND RIVERS. SOME EVACUATIONS OF PEOPLE AND
TRANSFER OF PROPERTY TO HIGHER GROUND CAN BECOME NECESSARY WITH
MODERATE FLOODING.

MAJOR FLOODING OCCURS WITH EXTENSIVE INUNDATION OF STRUCTURES AND
ROADS. SIGNIFICANT EVACUATIONS OF PEOPLE AND TRANSFER OF PROPERTY TO
HIGHER GROUND IS OFTEN NECESSARY.

AN ADDITIONAL CATEGORY OF FLOODING IS RECORD FLOODING. THIS IS
FLOODING WHICH EQUALS OR EXCEEDS THE HIGHEST STAGE OR DISCHARGE
OBSERVED AT A GIVEN LOCATION DURING THE PERIOD OF RECORD. THE
HIGHEST STAGE ON RECORD IS NOT NECESSARILY ABOVE THE OTHER THREE
FLOOD CATEGORIES...ESPECIALLY IF THE PERIOD OF RECORD IS SHORT.

ONE OTHER THING TO NOTE:  FLOOD CATEGORIES DO NOT EXIST FOR ALL
FORECAST POINTS OR FLOOD LOCATIONS. BUT THAT DOES NOT MEAN THEY DO
NOT EXPERIENCE FLOODING!  CONTACT YOUR LOCAL NWS OFFICE FOR MORE
INFORMATION ON FLOOD CATEGORIES.

RAINFALL FROM TROPICAL CYCLONE REMNANTS CAN ALSO CAUSE FLOODING IN
OUR AREA IF CONDITIONS ARE RIGHT. FLASH FLOODING CAN OCCUR IN
CREEKS...RIVERS...AND URBAN AREAS WITHIN A FEW MINUTES OR HOURS OF
EXCESSIVE RAINFALL. STREETS CAN BECOME SWIFT MOVING RIVERS...AND
UNDERPASSES CAN BECOME DEATH TRAPS. RIVER FLOODING CAN OCCUR FROM
HEAVY RAINS ASSOCIATED WITH DECAYING TROPICAL SYSTEMS...AND IN
EXTREME CASES...RIVER FLOODS CAN LAST A WEEK OR MORE.  JUST BECAUSE
WE DO NOT LIVE NEAR THE COAST DOES NOT MEAN WE CANNOT BE IMPACTED BY
A TROPICAL SYSTEM.

AND ALWAYS REMEMBER...WHEN APPROACHING A FLOODED AREA...MAKE THE
RIGHT CHOICE AND TURN AROUND...DONT DROWN.

KNOWING YOUR FLOOD RISK...HOW TO PREPARE FOR AND ACTIONS TO TAKE
BEFORE...DURING...AND AFTER A FLOOD CAN SAVE YOU TIME...MONEY...AND
MAYBE EVEN YOUR LIFE.  PREPARE NOW...AND BE A FORCE OF NATURE!

JOIN US TOMORROW FOR INFORMATION ON TURN AROUND...DONT DROWN.

&&

IMPORTANT FLOOD-RELATED WEBSITES

NWS:         HTTP://WWW.WEATHER.GOV

NWS AHPS:    HTTP://WATER.WEATHER.GOV/AHPS

NWS MOBILE:  HTTP://MOBILE.WEATHER.GOV

NWS FLOOD SAFETY AWARENESS:   HTTP://WWW.FLOODSAFETY.NOAA.GOV

NATIONAL HURRICANE CENTER:    HTTP://WWW.NHC.NOAA.GOV

WEATHER READY NATION:  HTTP://WWW.NWS.NOAA.GOV/COM/WEATHERREADYNATION

BE A FORCE OF NATURE:
  HTTP://WWW.NWS.NOAA.GOV/COM/WEATHERREADYNATION/FORCE.HTML

$$