Public Information Statement
Issued by NWS Nashville, TN

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TNZ005>011-023>034-056>066-075-077>080-093>095-181930-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
829 AM CDT TUE MAR 18 2014

THE NATIONAL WEATHER SERVICE (NWS) HAS DECLARED MARCH 16 THROUGH
MARCH 22 AS FLOOD SAFETY AWARENESS WEEK. THE NATIONAL WEATHER
SERVICE IN NASHVILLE WILL FEATURE INFORMATION ABOUT A DIFFERENT
FLOOD TOPIC EACH DAY DURING THE AWARENESS WEEK.

TODAY`S TOPIC: TYPES OF FLOODING AND FLOODS HAZARDS

A FLOOD IS DEFINED AS ANY HIGH FLOW...OVERFLOW...OR INUNDATION OF
WATER THAT CAUSES OR THREATENS DAMAGE.  FLOODING CAN OCCUR WITH
PROLONGED RAINFALL OVER SEVERAL DAYS...INTENSE RAINFALL OVER A
SHORT PERIOD OF TIME...OR WHEN WATER FROM AN EXISTING SOURCE MOVES
TOO QUICKLY (I.E. SNOWMELT...DAM BREAK...ETC.). BRIEF DESCRIPTIONS
OF THE VARIOUS TYPES OF FLOODING YOU MAY EXPERIENCE ARE FOUND BELOW.
MORE INFORMATION ABOUT THESE FLOOD HAZARDS CAN BE FOUND ON THE NWS
FLOOD SAFETY WEBSITE AT WWW.FLOODSAFETY.NOAA.GOV.

FLASH FLOODING:
FLASH FLOODING IS A RAPID AND EXTREME FLOW OF HIGH WATER INTO A
NORMALLY DRY AREA...OR A RAPID WATER LEVEL RISE IN A STREAM OR CREEK
ABOVE A PREDETERMINED FLOOD LEVEL...BEGINNING WITHIN SIX HOURS OF
THE CAUSATIVE EVENT (I.E. INTENSE RAINFALL...DAM FAILURE...ICE JAM).

RIVER FLOODING:
RIVER FLOODING OCCURS WHEN RIVERS RISE AND OVERFLOW THEIR
BANKS...INUNDATING AREAS THAT ARE NORMALLY DRY.

BURN SCARS/DEBRIS FLOWS:
WILDFIRES BURN AWAY THE VEGETATION OF AN AREA...LEAVING BEHIND BARE
GROUND THAT TENDS TO REPEL WATER. WHEN RAIN FALLS...IT RUNS OFF A
BURN SCAR TOWARDS A LOW LYING AREA...SOMETIMES CARRYING
BRANCHES...SOIL AND OTHER DEBRIS ALONG WITH IT. WITHOUT VEGETATION
TO HOLD THE SOIL IN PLACE...FLOODING CAN PRODUCE MUD AND DEBRIS FLOWS.

SNOWMELT:
FLOODING DUE TO SNOWMELT MOST OFTEN OCCURS IN THE SPRING WHEN
WARMING TEMPERATURES QUICKLY MELT THE SNOW. THE WATER RUNS OFF
THE STILL PARTIALLY FROZEN OR ALREADY SATURATED GROUND INTO NEARBY
STREAMS AND RIVERS...CAUSING THEM TO RAPIDLY RISE AND SOMETIMES
OVERFLOW THEIR BANKS.

ICE AND DEBRIS JAMS:
A BACKUP OF WATER INTO SURROUNDING AREAS CAN OCCUR WHEN A RIVER OR
STREAM IS BLOCKED BY A BUILD-UP OF ICE OR OTHER DEBRIS.

DRY WASH:
WHEN HEAVY RAIN FALLS OVER DRY LAND...THE WATER RUSHES TOWARDS
LOW-LYING AREAS...WHICH MAY INCLUDE DRIED UP CANYON OR STREAM BEDS.
THIS CAN QUICKLY TURN A DRY CHANNEL INTO A RAGING RIVER.

DAM BREAK AND LEVEE FAILURE:
A BREAK OR FAILURE CAN OCCUR WITH LITTLE TO NO WARNING. MOST OFTEN
THEY ARE CAUSED BY WATER OVERTOPPING THE STRUCTURE...EXCESSIVE
SEEPAGE THROUGH THE SURROUNDING GROUND...OR A STRUCTURAL FAILURE.

UNDERSTANDING THE DIFFERENT FLOOD HAZARDS AND KNOWING THE ACTIONS TO
TAKE  BEFORE...DURING...AND AFTERWARDS CAN HELP YOU PROTECT YOUR
LIFE...THE LIVES OF YOUR LOVED ONES...AND YOUR PROPERTY. PREPARE NOW
BY VISITING WWW.FLOODSAFETY.NOAA.GOV.

JOIN US TOMORROW FOR INFORMATION ON TURN AROUND DON`T DROWN.


$$

TB12





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