[BNAWX] Public Information Statement

[EMWIN Server]

NOUS44 KOHX 191332
PNSOHX
TNZ005>011-022>034-056>066-075-077>080-093>095-191945-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
832 AM CDT TUE MAR 19 2013

...FLOOD SAFETY AWARENESS WEEK CONTINUES...

THE NATIONAL WEATHER SERVICE HAS DECLARED MARCH 18 THROUGH MARCH
22 AS FLOOD SAFETY AWARENESS WEEK. THE NATIONAL WEATHER SERVICE IN
NASHVILLE WILL FEATURE A DIFFERENT EDUCATIONAL TOPIC EACH DAY THIS
WEEK.

TODAY'S TOPIC: TYPES OF FLOODS

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 STREAM 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 CYCLONES IN THE 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 STREAM
OR CREEK 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 SIX HOURS OF A HEAVY RAIN 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. FOR EXAMPLE, AN OTHERWISE DRY ARROYO OR CANYON CA
FILL QUICKLY FROM AN UPSTREAM RAIN EVENT. FLASH FLOODS CAN CATCH
PEOPLE OFF GUARD AND UNPREPARED. YOU MAY ONLY HAVE A FEW MINUTES
WARNING THAT THESE DEADLY, 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 FLOODING,
MODERATE FLOODING, 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 THE NWS FLOOD CATEGORIES:

MINOR FLOODING USUALLY HAS MINIMAL TO NO PROPERTY DAMAGE, BUT
THERE COULD BE SOME LEVEL OF PUBLIC THREAT OR INCONVENIENCE.

MODERATE FLOODING GENERALLY HAS SOME INUNDATION OF STRUCTURES AND
ROADS NEAR STREAMS AND RIVERS. SOME EVACUATIONS OF PEOPLE AND
TRANSFER OF PROPERTY TO HIGHER ELEVATIONS 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 ELEVATIONS IS LIKELY.

AN ADDITIONAL CATEGORY OF FLOODING IS RECORD FLOODING. THIS IS
FLOODING WHICH EQUALS OR EXCEEDS THE HIGHEST STAGE OR DISCHARGE
OBSERVED AT A GIVEN SITE 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 THING TO NOTE: FLOOD CATEGORIES DO NOT EXIST FOR ALL FORECAST
POINTS OR FLOOD LOCATIONS. THAT DOES NOT MEAN THEY DO NOT FLOOD!
CONTACT YOUR LOCAL NWS OFFICE FOR MORE INFORMATION ON FLOOD
CATEGORIES.

...INLAND FLOODING FROM TROPICAL CYCLONES...
SINCE THE 1970'S, INLAND FLOODING HAS BEEN RESPONSIBLE FOR MORE
THAN HALF OF THE DEATHS ASSOCIATED WITH TROPICAL CYCLONES IN THE
UNITED STATES. TYPICALLY GREATER RAINFALL AMOUNTS AND FLOODING ARE
ASSOCIATED WITH TROPICAL CYCLONES THAT HAVE A SLOW FORWARD SPEED
OR STALL OVER AN AREA. THESE AREAS CAN BE RIGHT ALONG THE COAST
BUT THEY MAY EVEN BE HUNDREDS OF MILES AWAY FROM WHERE THE STORM
MADE LANDFALL. TROPICAL STORM LEE IS A RECENT EXAMPLE OF INLAND
FLOODING SEVERAL HUNDRED MILES AWAY FROM WHERE THE EYE MADE
LANDFALL ALONG THE LOUISIANA COAST IN 2011. THE REMNANTS OF THIS
STORM CAUSED HEAVY RAINFALL AND HISTORIC FLOODING IN WASHINGTON
D.C., PENNSYLVANIA, AND AS FAR AWAY AS NEW YORK. TEN FATALITIES,
ALL IN PENNSYLVANIA, WERE CONFIRMED AS RELATED TO THE FLOODING
ASSOCIATED WITH TROPICAL STORM LEE.

RAINFALL FROM TROPICAL CYCLONE REMNANTS CAN CAUSE FLOODING IF
CONDITIONS ARE RIGHT. FLASH FLOODING CAN OCCUR IN CREEKS, STREAMS,
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 CYCLONES, AND IN EXTREME CASES,
RIVER FLOODS CAN LAST A WEEK OR MORE. JUST BECAUSE YOU DO NOT LIVE
NEAR THE COAST DOES NOT MEAN YOU CAN NOT BE IMPACTED BY TROPICAL
CYCLONE FLOODING.

KNOWING THE DIFFERENT TYPES OF FLOODS, HOW TO PREPARE FOR THEM,
AND KNOWING THE ACTIONS TO TAKE DURING, AND AFTERWARDS CAN SAVE
YOU TIME, MONEY, AND EVEN YOUR LIFE, PREPARE NOW AND BE A FORCE OF
NATURE!

JOIN US TOMORROW FOR INFORMATION ON TURN AROUND DON'T DROWN.

&&

IMPORTANT FLOOD WEBSITES:

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

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

NWS MARINE AND COASTAL SERVICES:
HTTP://WWW.NWS.NOAA.GOV/OM/MARINE/MARINE.SHTML

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

NATIONAL WEATHER SERVICE:
HTTP://WWW.WEATHER.GOV/

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

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

$$

LAROSA


This weather bulletin was brought to you by:
http://www.nashvilleweather.net

Follow us on Facebook at:
http://www.facebook.com/nashvilleweather