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000
NOUS46 KMTR 241808
PNSMTR
CAZ006-505>513-516>518-528>530-250300-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1107 AM PDT FRI OCT 24 2014

OCTOBER 20TH THROUGH 24TH IS CALIFORNIA FLOOD PREPAREDNESS WEEK!
THE NATIONAL WEATHER SERVICE FORECAST OFFICE FOR THE SAN FRANCISCO
AND MONTEREY BAY AREAS WILL FEATURE A DIFFERENT EDUCATIONAL TOPIC
EACH DAY DURING THE PREPAREDNESS WEEK.

TODAY`S TOPIC: FLOOD SAFETY AND FLOOD INFORMATION TOOLS

FLOODING IS THE LEADING CAUSE OF WEATHER-RELATED DEATHS IN THE U.S.
CLAIMING ON AVERAGE NEARLY ONE HUNDRED LIVES A YEAR.  MOST OF THESE
DEATHS OCCUR IN MOTOR VEHICLES WHEN PEOPLE ATTEMPT TO DRIVE THROUGH
FLOODED ROADWAYS.  MANY OTHER LIVES ARE LOST WHEN PEOPLE WALK INTO
OR NEAR FLOOD WATERS.  THIS HAPPENS BECAUSE PEOPLE UNDERESTIMATE THE
FORCE AND POWER OF WATER, ESPECIALLY WHEN IT IS MOVING.  THE GOOD
NEWS IS THESE TYPES OF DEATHS AND RELATED INJURIES ARE PREVENTABLE
WITH THE RIGHT KNOWLEDGE.

JUST SIX INCHES OF FAST-MOVING WATER CAN KNOCK OVER AN ADULT.  AND IT
ONLY TAKES TWELVE TO EIGHTEEN INCHES OF FLOWING WATER TO CARRY AWAY
MOST VEHICLES, INCLUDING LARGE SUVS.  IF YOU COME TO AN AREA THAT IS
COVERED WITH WATER, YOU WILL LIKELY NOT KNOW THE DEPTH OF THE WATER
OR THE CONDITION OF THE GROUND UNDER THE WATER.  THIS IS ESPECIALLY
TRUE AT NIGHT WHEN YOUR VISION IS MORE LIMITED.  PLAY IT SMART, PLAY
IT SAFE.  WHETHER DRIVING OR WALKING, ANY TIME YOU COME TO A FLOODED
ROAD, WALKWAY, OR PATH, FOLLOW THIS SIMPLE RULE: TURN AROUND DON?T
DROWN.  TURN AROUND DONT DROWN, TADD FOR SHORT, IS A NOAA NATIONAL
WEATHER SERVICE CAMPAIGN USED TO EDUCATE PEOPLE ABOUT THE HAZARDS OF
WALKING, OR DRIVING A VEHICLE, THROUGH FLOOD WATERS.

HERE ARE A FEW MORE TIPS TO KEEP YOU SAVE DURING A FLOOD:
ALWAYS PLAN AHEAD AND KNOW THE RISKS BEFORE FLOODING HAPPENS.
MONITOR NOAA ALL-HAZARDS RADIO, OR YOUR FAVORITE NEWS SOURCE,
FOR VITAL WEATHER-RELATED INFORMATION BEFORE, DURING, AND AFTER ANY
DISASTER INCLUDING FLOODING. IF FLOODING IS EXPECTED OR IS
OCCURRING, GET TO HIGHER GROUND FAST! LEAVE TYPICAL FLOOD AREAS SUCH
AS CANYONS, DITCHES, RAVINES, DIPS, OR LOW SPOTS.
AVOID AREAS ALREADY FLOODED, ESPECIALLY IF THE WATER IS FLOWING FAST.
DO NOT ATTEMPT TO CROSS FLOWING STREAMS.  TURN AROUND DONT DROWN!
NEVER DRIVE THROUGH FLOODED ROADWAYS.  ROAD BEDS MAY BE WASHED OUT
UNDER MURKY FLOOD WATERS.  TURN AROUND DONT DROWN! DO NOT CAMP OR
PARK YOUR VEHICLE ALONG STREAMS AND WASHES, PARTICULARLY DURING
THREATENING CONDITIONS. BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS
HARDER TO RECOGNIZE FLOOD DANGERS. NEVER CROSS ANY BARRIERS THAT ARE
PUT IN PLACE BY EMERGENCY OFFICIALS.  NOT ONLY IS THIS DANGEROUS,
BUT MANY STATES AND COMMUNITIES HAVE LAWS AGAINST IT AND LEVY STEEP
FINES AND POINTS AGAINST DRIVING RECORDS FOR PEOPLE THAT IGNORE
BARRICADES OR OTHER ROAD CLOSURE INDICATORS. ALWAYS PLAY IT SAFE,
TURN AROUND DONT DROWN!

FLOOD INFORMATION RESOURCES

NOAA NWS: AS MENTIONED IN PREVIOUS FLOOD PREPAREDNESS STATEMENTS
THIS WEEK, THE NWS WEBSITE PROVIDES UP TO DATE ADVISORY, WATCH, AND
WARNING INFORMATION OR THE U.S. AND ITS TERRITORIES.  BUT THERE IS
ADDITIONAL INFORMATION ON THAT PAGE YOU MAY NOT BE AWARE OF TO HELP
YOU BEFORE, DURING, AND AFTER  A FLOOD.
HTTP://WATER.WEATHER.GOV/AHPS2/INDEX.PHP?WFO=MTR

AMERICAN RED CROSS:
INFORMATION ON HOW TO REDUCE POTENTIAL FLOOD DAMAGE AND WHAT TO
INCLUDE IN A FAMILY DISASTER PLAN CAN BE OBTAINED FROM THE AMERICAN RED CROSS.
HTTP://WWW.REDCROSS.ORG/

FEMA:
INFORMATION ON FLOOD RISK, THE NATIONAL FLOOD INSURANCE PROGRAM,
AND DISASTER ASSISTANCE CAN BE OBTAINED FROM FEMA.
HTTP://WWW.FEMA.GOV

UNITED STATES GEOLOGICAL SURVEY:
INFORMATION ON CURRENT WATER CONDITIONS AND RESOURCES CAN BE OBTAINED
FROM THE UNITED STATES GEOLOGICAL SURVEY.
HTTP://WWW.USGS.GOV/

U.S. ARMY CORPS OF ENGINEERS:
FOR INFORMATION REGARDING DAMS, LEVEES, AND RECREATIONAL WATER BODIES
NEAR YOU CONTACT THE U.S. ARMY CORPS OF ENGINEERS.
HTTP://WWW.USACE.ARMY.MIL/

THE NATIONAL HYDROLOGIC WARNING COUNCIL...
IS A NON-PROFIT ORGANIZATION DEDICATED TO ASSISTING EMERGENCY AND
ENVIRONMENTAL MANAGEMENT OFFICIALS BY PROVIDING EXPERT ADVICE ON THE USE OF
REAL-TIME, HIGH QUALITY HYDROLOGIC INFORMATION FROM AUTOMATED REMOTE
DATA SYSTEMS, WITH THE GOALS OF PROTECTING LIVES, PROPERTY, AND THE
ENVIRONMENT.

HTTP://WWW.HYDROLOGICWARNING.ORG/:
ADDITIONAL KEY PARTNERS ARE THE ASSOCIATION OF STATE FLOODPLAIN MANAGERS,
THE NATIONAL SAFETY COUNCIL, THE FEDERAL ALLIANCE FOR SAFE HOMES,
THE WEATHER CHANNEL AND OTHER MEDIA OUTLETS, AND MANY OTHER
GOVERNMENT AND PRIVATE SECTOR ORGANIZATIONS. FOR MORE INFORMATION ON
ANY OF OUR PARTNER, CONTACT YOUR LOCAL NWS OFFICE.

AS WE WRAP UP THE 2014/2015 CALIFORNIA FLOOD PREPAREDNESS WEEK, REMEMBER,
FLOODING CAUSES MORE DAMAGE IN THE UNITED STATES THAN ANY OTHER
WEATHER R RELATED EVENT.  FLOODING CAN OCCUR IN ANY OF THE FIFTY
STATES OR U.S. TERRITORIES AT ANYTIME OF THE YEAR SOMETIMES WITH
VERY LITTLE WARNING. 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. KNOW YOUR  RISK. TURN AROUND DON?T DROWN.
EVALUATE YOUR NEED FOR FLOOD INSURANCE. VISIT WITH OUR PARTNERS TO
LEARN HOW THEY TOO CAN HELP YOU PREPARE. IT COULD SAVE YOUR LIFE.

FOR MORE INFORMATION PLEASE CONTACT YOUR LOCAL NWS OFFICE OR:

MARK STRUDLEY
NWS WEATHER FORECAST OFFICE, MONTEREY
MONTEREY, CA 93943
MARK.STRUDLEY@NOAA.GOV

&&












000
NOUS46 KMTR 241807
PNSMTR
CAZ006-505>513-516>518-528>530-240300-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1107 AM PDT FRI OCT 24 2014

OCTOBER 20TH THROUGH 24TH IS CALIFORNIA FLOOD PREPAREDNESS WEEK!
THE NATIONAL WEATHER SERVICE FORECAST OFFICE FOR THE SAN FRANCISCO
AND MONTEREY BAY AREAS WILL FEATURE A DIFFERENT EDUCATIONAL TOPIC
EACH DAY DURING THE PREPAREDNESS WEEK.

TODAY`S TOPIC: FLOOD SAFETY AND FLOOD INFORMATION TOOLS

FLOODING IS THE LEADING CAUSE OF WEATHER-RELATED DEATHS IN THE U.S.
CLAIMING ON AVERAGE NEARLY ONE HUNDRED LIVES A YEAR.  MOST OF THESE
DEATHS OCCUR IN MOTOR VEHICLES WHEN PEOPLE ATTEMPT TO DRIVE THROUGH
FLOODED ROADWAYS.  MANY OTHER LIVES ARE LOST WHEN PEOPLE WALK INTO
OR NEAR FLOOD WATERS.  THIS HAPPENS BECAUSE PEOPLE UNDERESTIMATE THE
FORCE AND POWER OF WATER, ESPECIALLY WHEN IT IS MOVING.  THE GOOD
NEWS IS THESE TYPES OF DEATHS AND RELATED INJURIES ARE PREVENTABLE
WITH THE RIGHT KNOWLEDGE.

JUST SIX INCHES OF FAST-MOVING WATER CAN KNOCK OVER AN ADULT.  AND IT
ONLY TAKES TWELVE TO EIGHTEEN INCHES OF FLOWING WATER TO CARRY AWAY
MOST VEHICLES, INCLUDING LARGE SUVS.  IF YOU COME TO AN AREA THAT IS
COVERED WITH WATER, YOU WILL LIKELY NOT KNOW THE DEPTH OF THE WATER
OR THE CONDITION OF THE GROUND UNDER THE WATER.  THIS IS ESPECIALLY
TRUE AT NIGHT WHEN YOUR VISION IS MORE LIMITED.  PLAY IT SMART, PLAY
IT SAFE.  WHETHER DRIVING OR WALKING, ANY TIME YOU COME TO A FLOODED
ROAD, WALKWAY, OR PATH, FOLLOW THIS SIMPLE RULE: TURN AROUND DON?T
DROWN.  TURN AROUND DONT DROWN, TADD FOR SHORT, IS A NOAA NATIONAL
WEATHER SERVICE CAMPAIGN USED TO EDUCATE PEOPLE ABOUT THE HAZARDS OF
WALKING, OR DRIVING A VEHICLE, THROUGH FLOOD WATERS.

HERE ARE A FEW MORE TIPS TO KEEP YOU SAVE DURING A FLOOD:
ALWAYS PLAN AHEAD AND KNOW THE RISKS BEFORE FLOODING HAPPENS.
MONITOR NOAA ALL-HAZARDS RADIO, OR YOUR FAVORITE NEWS SOURCE,
FOR VITAL WEATHER-RELATED INFORMATION BEFORE, DURING, AND AFTER ANY
DISASTER INCLUDING FLOODING. IF FLOODING IS EXPECTED OR IS
OCCURRING, GET TO HIGHER GROUND FAST! LEAVE TYPICAL FLOOD AREAS SUCH
AS CANYONS, DITCHES, RAVINES, DIPS, OR LOW SPOTS.
AVOID AREAS ALREADY FLOODED, ESPECIALLY IF THE WATER IS FLOWING FAST.
DO NOT ATTEMPT TO CROSS FLOWING STREAMS.  TURN AROUND DONT DROWN!
NEVER DRIVE THROUGH FLOODED ROADWAYS.  ROAD BEDS MAY BE WASHED OUT
UNDER MURKY FLOOD WATERS.  TURN AROUND DONT DROWN! DO NOT CAMP OR
PARK YOUR VEHICLE ALONG STREAMS AND WASHES, PARTICULARLY DURING
THREATENING CONDITIONS. BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS
HARDER TO RECOGNIZE FLOOD DANGERS. NEVER CROSS ANY BARRIERS THAT ARE
PUT IN PLACE BY EMERGENCY OFFICIALS.  NOT ONLY IS THIS DANGEROUS,
BUT MANY STATES AND COMMUNITIES HAVE LAWS AGAINST IT AND LEVY STEEP
FINES AND POINTS AGAINST DRIVING RECORDS FOR PEOPLE THAT IGNORE
BARRICADES OR OTHER ROAD CLOSURE INDICATORS. ALWAYS PLAY IT SAFE,
TURN AROUND DONT DROWN!

FLOOD INFORMATION RESOURCES

NOAA NWS: AS MENTIONED IN PREVIOUS FLOOD PREPAREDNESS STATEMENTS
THIS WEEK, THE NWS WEBSITE PROVIDES UP TO DATE ADVISORY, WATCH, AND
WARNING INFORMATION OR THE U.S. AND ITS TERRITORIES.  BUT THERE IS
ADDITIONAL INFORMATION ON THAT PAGE YOU MAY NOT BE AWARE OF TO HELP
YOU BEFORE, DURING, AND AFTER  A FLOOD.
HTTP://WATER.WEATHER.GOV/AHPS2/INDEX.PHP?WFO=MTR

AMERICAN RED CROSS:
INFORMATION ON HOW TO REDUCE POTENTIAL FLOOD DAMAGE AND WHAT TO
INCLUDE IN A FAMILY DISASTER PLAN CAN BE OBTAINED FROM THE AMERICAN RED CROSS.
HTTP://WWW.REDCROSS.ORG/

FEMA:
INFORMATION ON FLOOD RISK, THE NATIONAL FLOOD INSURANCE PROGRAM,
AND DISASTER ASSISTANCE CAN BE OBTAINED FROM FEMA.
HTTP://WWW.FEMA.GOV

UNITED STATES GEOLOGICAL SURVEY:
INFORMATION ON CURRENT WATER CONDITIONS AND RESOURCES CAN BE OBTAINED
FROM THE UNITED STATES GEOLOGICAL SURVEY.
HTTP://WWW.USGS.GOV/

U.S. ARMY CORPS OF ENGINEERS:
FOR INFORMATION REGARDING DAMS, LEVEES, AND RECREATIONAL WATER BODIES
NEAR YOU CONTACT THE U.S. ARMY CORPS OF ENGINEERS.
HTTP://WWW.USACE.ARMY.MIL/

THE NATIONAL HYDROLOGIC WARNING COUNCIL...
IS A NON-PROFIT ORGANIZATION DEDICATED TO ASSISTING EMERGENCY AND
ENVIRONMENTAL MANAGEMENT OFFICIALS BY PROVIDING EXPERT ADVICE ON THE USE OF
REAL-TIME, HIGH QUALITY HYDROLOGIC INFORMATION FROM AUTOMATED REMOTE
DATA SYSTEMS, WITH THE GOALS OF PROTECTING LIVES, PROPERTY, AND THE
ENVIRONMENT.

HTTP://WWW.HYDROLOGICWARNING.ORG/:
ADDITIONAL KEY PARTNERS ARE THE ASSOCIATION OF STATE FLOODPLAIN MANAGERS,
THE NATIONAL SAFETY COUNCIL, THE FEDERAL ALLIANCE FOR SAFE HOMES,
THE WEATHER CHANNEL AND OTHER MEDIA OUTLETS, AND MANY OTHER
GOVERNMENT AND PRIVATE SECTOR ORGANIZATIONS. FOR MORE INFORMATION ON
ANY OF OUR PARTNER, CONTACT YOUR LOCAL NWS OFFICE.

AS WE WRAP UP THE 2014/2015 CALIFORNIA FLOOD PREPAREDNESS WEEK, REMEMBER,
FLOODING CAUSES MORE DAMAGE IN THE UNITED STATES THAN ANY OTHER
WEATHER R RELATED EVENT.  FLOODING CAN OCCUR IN ANY OF THE FIFTY
STATES OR U.S. TERRITORIES AT ANYTIME OF THE YEAR SOMETIMES WITH
VERY LITTLE WARNING. 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. KNOW YOUR  RISK. TURN AROUND DON?T DROWN.
EVALUATE YOUR NEED FOR FLOOD INSURANCE. VISIT WITH OUR PARTNERS TO
LEARN HOW THEY TOO CAN HELP YOU PREPARE. IT COULD SAVE YOUR LIFE.

FOR MORE INFORMATION PLEASE CONTACT YOUR LOCAL NWS OFFICE OR:

MARK STRUDLEY
NWS WEATHER FORECAST OFFICE, MONTEREY
MONTEREY, CA 93943
MARK.STRUDLEY@NOAA.GOV

&&









000
NOUS46 KMTR 231500
PNSMTR
CAZ006-505>513-516>518-528>530-240300-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
800 AM PDT THU OCT 23 2014

OCTOBER 20TH THROUGH 24TH IS CALIFORNIA FLOOD PREPAREDNESS WEEK!
THE NATIONAL WEATHER SERVICE FORECAST OFFICE FOR THE SAN
FRANCISCO AND MONTEREY BAY AREAS WILL FEATURE A DIFFERENT
EDUCATIONAL TOPIC EACH DAY DURING THE PREPAREDNESS WEEK.

TODAY`S TOPIC: COASTAL FLOODING

CALIFORNIAS COASTLINE IS APPROXIMATELY 850 MILES LONG, MAKING IT
ONE OF THE LONGEST STATE COASTLINES IN AMERICA (ONLY ALASKA`S AND
FLORIDA`S COASTLINES ARE LONGER). WHEN TIDAL AREAS, ESTUARIES,
AND DELTAS ARE INCLUDED, CALIFORNIAS COASTLINE GROWS TO
APPROXIMATELY 3,425 MILES.

WHEN MOST PEOPLE THINK ABOUT COASTAL HAZARDS, IT IS MOST LIKELY
THAT TIDES, WAVES, AND RIP CURRENTS COME TO MIND OR MAYBE EVEN
TSUNAMIS. WHILE THESE ARE IMPORTANT COASTAL HAZARDS TO BE AWARE
OF, COASTAL FLOODING IS TYPICALLY A RESULT OF HOW RIVERS INTERACT
WITH THE ESTUARIES AND LAGOONS THAT THEY FILL AT THE COAST. AS
SUCH, COASTAL FLOODING IS AN EVER-PRESENT HAZARD THAT CAN OCCUR
YEAR-ROUND AND CAN EXTEND WELL INLAND. RIVERS ALONG THE OFTEN
MOUNTAINOUS, TERRACED COASTLINE OF CALIFORNIA MAY BE ENTRENCHED IN
CANYONS FOR MUCH OF THEIR LENGTH, LIMITING FLOOD THREAT DURING
WINTER STORMS TO ONLY ROADWAYS AND STRUCTURES IN THE VALLEY FLOOR.
BUT THEY OFTEN OPEN INTO FLOODPLAINS BEFORE ENTERING THE SEA,
DISTRIBUTING FLOOD THREAT ACROSS A MORE EXPANSIVE AREA.
FLOODPLAINS IN THESE COASTAL SETTINGS CAN BE INUNDATED WITH
VARIABLE FREQUENCY BY RIVERINE AND ESTUARINE WATERS. PARTICULARLY
IMPORTANT AND COMMON ALONG THE CALIFORNIA COAST ARE RIVER MOUTHS
THAT ARE CONTROLLED, IN PART, BY BEACH-BARRIER BARS THAT FORM
SEASONALLY. BEACH-BARRIER BARS EPISODICALLY AND NATURALLY CLOSE
RIVER MOUTHS, TYPICALLY DURING THE SPRING, SUMMER, AND FALL WHEN
RIVER FLOWS ARE INSUFFICIENT TO KEEP THE RIVER MOUTH CLEAR OF
ALONGSHORE SEDIMENT DELIVERY AND ACCUMULATION FROM THE OCEAN. WHEN
RIVER FLOWS WANE AND BEACH BARS BLOCK THE SURFACE CONNECTION OF
THE RIVER WITH THE OCEAN, ESTUARIES CAN FILL UP WITH RIVER WATERS
THAT CONTINUE TO TRICKLE IN, CREATING BACKWATER COASTAL LAGOONS
THAT CAN EXTEND MILES INLAND, DEPENDING ON THE CONFIGURATION OF
THE VALLEY. RECONNECTION AND DRAINING OF THESE LAGOONS OCCURS
NATURALLY, ALTHOUGH IN MANY LOCATIONS DRAINAGE OCCURS AT A STAGE
ABOVE LOW-ELEVATION INFRASTRUCTURE. ARTIFICIAL DRAINAGE OF THESE
LAGOONS BELOW CRITICAL FLOOD LEVELS IS THE PRIMARY AND HISTORICAL
TACTIC EMPLOYED BY LOCAL WATER MANAGEMENT AGENCIES; HOWEVER, THIS
PRACTICE HAS FALLEN OUT OF FAVOR BECAUSE OF THE THREAT THIS
IMPOSES ON ENVIRONMENTAL RESOURCES AND HABITAT. MUCH RESEARCH AND
PLANNING IS CURRENTLY BEING DIRECTED TOWARDS DEVELOPING STRATEGIES
TO MANAGE WATER LEVELS IN ESTUARIES AND LAGOONS THAT REDUCE FLOOD
THREAT WHILE SIMULTANEOUSLY MANAGING THE ECOSYSTEM IN A
SUSTAINABLE, HEALTHY MANNER.

MOST LARGE AND SMALL CREEKS/RIVERS THAT MEET THE COASTLINE IN
CALIFORNIA EXHIBIT BEACH-BARRIER BARS AND SEASONALLY-IMPOUNDED
LAGOONS. EXAMPLES IN OUR AREA INCLUDE THE RUSSIAN RIVER ESTUARY
AT JENNER, THE SAN LORENZO RIVER AT THE BEACH BOARDWALK, THE
PAJARO RIVER AND THE PAJARO DUNES AREA, AND THE CARMEL RIVER AND
ITS ASSOCIATED LAGOON.

TSUNAMIS

A TSUNAMI IS A SERIES OF LONG-PERIOD WAVES (ON THE ORDER
OF TENS OF MINUTES) THAT ARE USUALLY GENERATED BY AN IMPULSIVE
DISTURBANCE THAT DISPLACES MASSIVE AMOUNTS OF WATER, SUCH AS AN
EARTHQUAKE OCCURRING ON OR NEAR THE SEA FLOOR. UNDERWATER VOLCANIC
ERUPTIONS AND LANDSLIDES CAN ALSO CAUSE TSUNAMI. THE RESULTANT
WAVES ARE MUCH THE SAME AS WAVES PROPAGATING IN A CALM POND AFTER
A ROCK IS TOSSED. WHILE TRAVELING IN THE DEEP OCEANS, TSUNAMI HAVE
EXTREMELY LONG WAVELENGTHS, OFTEN EXCEEDING 50 NM, WITH SMALL
AMPLITUDES (A FEW TENS OF CENTIMETERS) AND NEGLIGIBLE WAVE
STEEPNESS, WHICH IN THE OPEN OCEAN WOULD CAUSE NOTHING MORE THAN A
GENTLE RISE AND FALL FOR MOST VESSELS, AND POSSIBLY GO UNNOTICED.
TSUNAMI TRAVEL AT VERY HIGH SPEEDS, SOMETIMES IN EXCESS OF 400
KNOTS. ACROSS THE OPEN OCEANS, THESE HIGH-SPEED WAVES LOSE VERY
LITTLE ENERGY. AS TSUNAMI REACH THE SHALLOW WATERS NEAR THE COAST,
THEY BEGIN TO SLOW DOWN WHILE GRADUALLY GROWING STEEPER, DUE TO
THE DECREASING WATER DEPTH. THE BUILDING WALLS OF WATER CAN BECOME
EXTREMELY LARGE IN HEIGHT, REACHING TENS OF METERS (30 FEET OR
MORE) AS THEY REACH THE SHORELINE. THE EFFECTS CAN BE FURTHER
AMPLIFIED WHERE A BAY, HARBOR, OR LAGOON FUNNELS THE WAVES AS THEY
MOVE INLAND. LARGE TSUNAMI HAVE BEEN KNOWN TO RISE TO OVER 100
FEET! THE AMOUNT OF WATER AND ENERGY CONTAINED IN TSUNAMI CAN HAVE
DEVASTATING EFFECTS ON COASTAL AREAS.

COASTAL FLOODPLAINS AND ESTUARIES ARE COMMONLY USED FOR
RESIDENTIAL AND INDUSTRIAL DEVELOPMENT AND/OR RECREATIONAL
ACTIVITIES. PEOPLE INHABITING THESE AREAS, AS WELL AS THOSE
CONDUCTING BUSINESS OR RECREATIONAL PURSUITS THERE SHOULD BE
VIGILANT OF THE HAZARDS THAT MAY DEVELOP. STAY ALERT, AND LISTEN
FOR WARNINGS AND OTHER NOTIFICATIONS OF COASTAL FLOODING OTHER
HAZARDS ALONG THE COAST FROM YOUR LOCAL WEATHER SERVICE OFFICE AND
LOCAL EMERGENCY MANAGEMENT PERSONNEL.

JOIN US TOMORROW FOR INFORMATION ON FLOOD SAFETY AND FLOOD
INFORMATION TOOLS.

&&

IMPORTANT FLOOD WEBSITES

LOCAL NWS OFFICE:
HTTP://WWW.WEATHER.GOV/MTR

LOCAL RIVER FORECAST CENTER:
HTTP://WWW.CNRFC.NOAA.GOV

NWS:
HTTP://WWW.WEATHER.GOV/

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

CALIFORNIA FLOOD PREPAREDNESS:
HTTP://WWW.WATER.CA.GOV/FLOODSAFE/CA-FLOOD-PREPAREDNESS/FPW_HOME.CFM

FEMA:
HTTP://WWW.FEMA.GOV/FEMA/

MAP SERVICE CENTER:
HTTPS://MSC.FEMA.GOV

US ARMY CORPS OF ENGINEERS:
HTTP://WWW.USACE.ARMY.MIL/

$$

STRUDLEY







000
NOUS46 KMTR 221330
PNSMTR
CAZ006-505>513-516>518-528>530-230130-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
630 AM PDT WED OCT 22 2014

OCTOBER 20TH THROUGH 24TH IS CALIFORNIA FLOOD PREPAREDNESS WEEK!
THE NATIONAL WEATHER SERVICE FORECAST OFFICE FOR THE SAN FRANCISCO
AND MONTEREY BAY AREAS WILL FEATURE A DIFFERENT EDUCATIONAL TOPIC
EACH DAY DURING THE PREPAREDNESS WEEK.

TODAY`S TOPIC: DEBRIS FLOWS AND THE HYDROLOGY OF BURNED
LANDSCAPES

DEBRIS FLOWS RECALL THAT A FLOOD IS DEFINED AS ANY HIGH FLOW,
OVERFLOW, OR INUNDATION BY WATER WHICH CAUSES OR THREATENS
DAMAGE. ALTERNATIVELY, DEBRIS FLOWS ARE NOT FLOODS, BUT ARE
FLUIDIZED MASSES OF SEDIMENT AND ORGANIC MATERIALS (TREES, LOGS,
AND ANY OTHER VEGETATION THAT GETS DISLODGED AND TRANSPORTED
DOWNSLOPE) THAT FLOW DOWNSLOPE. THEY ARE TYPICALLY (ALTHOUGH NOT
ALWAYS) CAUSED BY HEAVY RAINFALL WHICH SATURATES SOILS AND
WEAKENS THE STRUCTURAL INTEGRITY OF SOIL LAYERS. MATERIALS
DISLODGED IN THIS WAY THEN FLOW DOWNSLOPE AND FOLLOW VALLEY
NETWORKS DOWN TO CREEKS AND RIVERS. DEBRIS FLOWS MAY OCCUR DURING
A STORM OR FOLLOWING A STORM. DEBRIS FLOWS CAN OCCUR DURING SMALL
STORMS WHEN CREEK LEVELS ARE RELATIVELY LOW, WHICH MEANS THAT THE
DEBRIS FLOW ITSELF MAY BE THE ONLY HAZARD PRODUCED BY THE STORM.
DEBRIS FLOWS CAN ALSO OCCUR DURING HEAVY RAINFALL EVENTS, WHERE
THE ADDITION OF DEBRIS FLOW MATERIALS TO ALREADY SWOLLEN CREEKS
AND RIVERS CAN EXACERBATE FLOODING HAZARD. PREDICTING THE EXACT
TIMING AND LOCATION OF DEBRIS FLOWS WILL ALWAYS BE IMPOSSIBLE,
BECAUSE IT WOULD REQUIRE KNOWING ALL THE INTRICACIES OF WATER AND
SOIL THROUGHOUT THE WHOLE BAY AREA. HOWEVER, THE WEATHER SERVICE
AND UNITED STATES GEOLOGICAL SURVEY ARE CURRENTLY WORKING TOGETHER
TO DEVELOP TECHNIQUES THAT WILL HELP DETERMINE THE LIKELIHOOD OF
DEBRIS FLOWS DURING A STORM EVENT. PAY ATTENTION TO FLASH FLOOD
WARNINGS ISSUED BY THE WEATHER SERVICE...INFORMATION ON DEBRIS FLOW
LIKELIHOOD WILL APPEAR IN THESE STATEMENTS.

DEBRIS FLOWS CAN BE ASSOCIATED WITH WILDFIRE BURN SCARS BECAUSE
FIRE WEAKENS ROOT NETWORKS THAT HOLD SOILS TOGETHER AND BECAUSE
FIRE REMOVES VEGETATION AND PLANT LITTER (DECAYING LEAVES,
BRANCHES, ETC) THAT PROTECTS SOIL FROM THE ENERGY OF RAINFALL
IMPACT. ADDITIONALLY, FIRE CAN CHANGE THE EFFICIENCY WITH WHICH
WATER FLOWS INTO SOILS, ACCELERATING THE WEAKENING AND
LUBRICATION OF SOILS ON HILL SLOPES. THE SOUTHERN CALIFORNIA ADAGE
OF FIRE + RAIN = DEBRIS FLOW DOES NOT ALWAYS HOLD TRUE, BUT
WILDFIRES DO ACCENTUATE DEBRIS FLOW RISK. BE EXTRA CAUTIOUS AND
VIGILANT OF DEBRIS FLOW POTENTIAL IN BURNED TERRAIN, AND KNOW HOW
TO PREPARE AND RESPOND QUICKLY.

HYDROLOGY OF WILDFIRES WILDFIRES AND THE BURNED LANDSCAPES LEFT
BEHIND CAN ALTER THE WAY WATER BEHAVES DURING A STORM IN
SIGNIFICANT WAYS. A LANDSCAPE WITHOUT PLANTS, TREES, LEAF LITTER,
AND OTHER ORGANIC DEBRIS CAN ROUTE RAINFALL AND RUNOFF MORE
EFFICIENTLY TO CREEKS AND RIVERS. LIVING PLANTS ARE NO LONGER
THERE TO SOAK UP WATER (CALLED EVAPOTRANSPIRATION), AND ROOT
NETWORKS WHICH HOLD SOILS TOGETHER CAN BE DAMAGED OR COMPLETELY
BURNED AWAY, LEAVING CONDUITS BENEATH THE SURFACE THAT FUNNEL
WATER DOWNSLOPE MORE QUICKLY. FIRE CAN ALSO ALTER THE CHEMISTRY
OF SUBSURFACE LAYERS IN THE SOIL, WHICH MAY THEN REPEL WATER
(LIKE THE SAYING GOES, OFF A DUCKS BACK!). THIS EFFECT IS KNOWN AS
HYDROPHOBICITY, OR HYDROPHOBIC SOILS (LITERALLY, FEAR OF WATER).
THESE CHANGES CAN MEAN THAT MORE WATER GETS TO CREEKS AND RIVERS
FASTER, WHICH CAN CAUSE FLASH FLOODING DURING STORMS THAT WOULD
NOT NORMALLY CREATE FLOOD RISK.

WILDFIRES CAN ALSO INCREASE THE LIKELIHOOD OF DEBRIS FLOWS
OCCURRING. IF MORE RUNOFF IS FLOWING MORE QUICKLY INTO CHANNELS,
THAT WATER IS BOTH MORE LIKELY TO ERODE MORE SEDIMENT OFF OF
HILL SLOPES AND IS MORE LIKELY TO TRANSPORT HIGHER VOLUMES OF
SEDIMENT DOWN CHANNELS IN THE VALLEY BOTTOMS. THE INCREASE IN
SEDIMENT AND DEBRIS DELIVERY AND TRANSPORT IN VALLEYS AND CHANNELS
CAN RESULT IN HIGHLY DEBRIS-LADEN DEBRIS FLOWS! WILDFIRE CAN
ALSO INCREASE THE LIKELIHOOD OF DEBRIS DETACHMENT AND SOIL
INSTABILITY ON HILL SLOPES, WHICH COULD LEAD TO A DEBRIS FLOW. THIS
IS BECAUSE FIRE DESTROYS ROOTS THAT HOLD SOIL TOGETHER AND BECAUSE
HYDROPHOBIC SOILS CREATE A LAYER OF SOIL ABOVE THAT BECOMES
WATERLOGGED AND PRONE TO DETACHMENT (REMEMBER, THE HYDROPHOBIC
LAYER IS UNDERNEATH THE SURFACE). VOILA DEBRIS FLOW.

AGAIN, IN BURNED TERRAIN, BE CAUTIOUS AND VIGILANT. THE MOVEMENT
OF WATER AND DEBRIS IN BURNED TERRAIN MAY BE DIFFERENT THAN WHAT
YOU WOULD NORMALLY EXPECT AND THE RISK FROM FLOODING AND DEBRIS
FLOWS MAY BE INCREASED. STAY SAFE, AND LISTEN FOR FLASH FLOOD
WATCHES AND WARNINGS FROM THE WEATHER SERVICE AND YOUR LOCAL
EMERGENCY PERSONNEL.

JOIN US TOMORROW FOR INFORMATION ON COASTAL FLOODING HAZARDS.

&&

IMPORTANT FLOOD WEBSITES
LOCAL NWS OFFICE:
HTTP://WWW.WEATHER.GOV/MTR

LOCAL RIVER FORECAST CENTER:
HTTP://WWW.CNRFC.NOAA.GOV

NWS:
HTTP://WWW.WEATHER.GOV/

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

CALIFORNIA FLOOD PREPAREDNESS:
HTTP://WWW.WATER.CA.GOV/FLOODSAFE/CA-FLOOD-PREPAREDNESS/FPW_HOME.CFM

FEMA:
HTTP://WWW.FEMA.GOV/FEMA/

MAP SERVICE CENTER:
HTTPS://MSC.FEMA.GOV

US ARMY CORPS OF ENGINEERS:
HTTP://WWW.USACE.ARMY.MIL/

$$

STRUDLEY








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