Rip Current Questions and Answers
Definitions
Forecasting
History
Rip Current Safety
Organizations/Agencies
On the Beach
Safety and Preparedness
Science
In the early 1990s forecasters in Florida NWS offices identified correlations
in high frequency rip current rescues/fatalities with certain oceanic
and atmospheric conditions. The Miami Weather Forecast Office (WFO) led
the first NWS efforts at providing the public with rip current information
on a daily basis.
The Surf Zone is the area between the high tide level
on the beach to the seaward side of the breaking waves.
The
Surf Zone Forecast provides valuable and lifesaving information on the
hazards of the surf zone to the greater beachfront community, to include
the general public and the providers of beachfront safety services, such
as lifeguards.
The SRF typically describes the following
parameters and hazards: Sky condition, precipitation, visibility,
air temperature, wind speed and direction, wave height, surf temperature,
tide information, rip currents, lightning, severe thunderstorms,
and the ultraviolet index.
Many NWS Forecast Offices issue a Surf Zone
Forecast during the traditional summer season from Memorial through Labor
Day. On the Atlantic Coast the forecast is produced from New Jersey and
all points south. Many offices issue the forecast along the Gulf of Mexico
. Our Los Angeles and San Diego offices issue the forecast for their
surf beaches.
The Surf Zone Forecast product is available through
the NWS Family of Services (FOS), NOAA Weather Wire Service, the Emergency
Manager's Weather Information Network (EMWIN). It is also available
over NOAA WeatherRadio. The SRF product began in Summer 2003 at many
coastal WFOs.
Technical concerns, such as limited nearshore data, have resulted in
local NWS decisions to not provide the Surf Zone Forecast. Future Sea
Grant research and additional data sources will enable all coastal WFOs
with surf beaches to issue the forecast in the future.
Specifically, persistent onshore wind (near normal
wind waves), swells, and reports from lifeguards are three of the main
"signals" that NWS forecasters identify when preparing a Rip Current
Outlook. NOAA forecasters utilize the latest in wave modeling - the NOAA
WaveWatch III model and other high resolution regional wave models aid
forecasters in determining when wave conditions support rip current development.
These models are also show when large swells approach from distant tropical
cyclones.
- Forecasters rely on the network of realtime NOAA Weather Buoys positioned
along our nation's coastal and offshore waters. The buoys are maintained
by the National Data Buoy Center .
- B -Forecasters now have access to numerical guidance products for
120 buoy and CMAN sites, based on the Global Forecast System model,
to better understand sea states.
- In addition, collaborative efforts between NWS offices and the local
lifeguards complete the forecast process. Lifeguards and other beach
partners play a critical role in the success of the program by providing
real time feedback for inclusion in the rip current outlook. The
reports from trained observers provide forecast verification, which
will lead to improved forecasts in the future.
National Weather Service forecasters require additional nearshore and
offshore buoys, with the addition of wave direction sensors to buoys.
Additionally, long-range Weather Service planning includes the need for
forecasters to have ready-access to high-resolution, nearshore wave models.
These models will help improve Surf Zone Forecasts and Coastal Waters
Forecasts.
A NWS Rip Current Standardization Team of marine forecasters from across
the nation recognized a need to nationally standardize rip current information
provided by the NWS to our customers and partners. This information is
provided in our Rip Current Outlook.
The Rip Current Outlook portion of the SRF provides our customers and
partners with standardized terminology for describing the rip current
hazard. With our increasingly mobile society, it's important that the
words used to describe the rip current hazard in North Carolina be the
same as the words used to describe the rip current hazard at a surf beach
in California. Failure to use consistent terminology leads to confusion
for our surf zone partners and customers.
Low, Moderate, and High
- "Low Risk" means wind and/or wave conditions are not expected
to support the development of rip currents. However, rip currents
can sometimes occur, especially in the vicinity of groins, jetties,
and piers. Know how to swim and heed the advice of the beach
patrol/lifeguards.
- "Moderate Risk" means wind and/or wave conditions support
stronger or more frequent rip currents. Only experienced surf
swimmers should enter the water.
- High Risk" means wind and/or wave conditions support dangerous
rip currents. Rip Currents are life-threatening to anyone entering
the surf.
The NWS does not issue, and will not issue, Rip Current Advisories
or Warnings. That action within a given jurisdiction is the responsibility
of the local beach patrol, local lifeguards, or local law enforcement
officials.
The Rip Current Outlook is a forecast of expected
rip current conditions. The colored flags posted on surf beaches are
the purview of the local beach patrol, lifeguards, or local law enforcement
officials. These colored flags refer to one of any number of surf zone
hazards. The colored flags reflect actual, current surf zone hazards.
The media is an important partner in the dissemination of our Rip Current
Outlooks. We're hoping more coastal television and radio stations will
report the Rip Current Outlook in their weather broadcasts each day.
The media will play a valuable role in increasing the public's rip
current awareness, just as they have in NWS safety campaigns for other
weather hazards, such as lightning.
The Warning Coordination Meteorologist (WCM)
at each office is a primary link between the WFO and the community. Many
WCMs work with local lifeguards, Chambers of Commerce,
local governments, and community groups to establish those partnerships
critical to a successful rip current education program, which must include
local scientists from Sea Grant universities, rip current outlooks from
the NWS, and the protection and warnings provided by lifeguards to beachgoers.
Long period swells sometimes result in minimal wave action where the
ocean surface is hardly perturbed, yet there is a greater than normal
transport of wave energy into the surf zone which may result in an elevated
rip current risk.
Rip Current Outlooks are issued during the "swimming
season" which
is defined by the local National Weather Service Office. In the mid/northern
latitudes the waters are simply too cold for most swimmers during the
winter.
Good question. Sometimes the amount of water crashing
into the surf zone can overwhelm many of the seaward flowing currents
in the near shore ocean circulation. Very strong rip currents can still
occur in these conditions, but they might be more widely spaced along
the coast and hence more difficult to locate.
Swimming in the ocean is not the same as swimming
in a swimming pool. We are providing people with guidance to help them
make educated decisions. We encourage all persons to consult with on-duty
lifeguards about all surf zone hazards for the day.
Rip currents are currents of water flowing
away from the shore at surf beaches. They typically extend from near the
shoreline, through the surf zone and past the line of breaking waves. (The
surf zone is the area between the high tide level on the beach to the seaward
side of breaking waves.)
No. A rip current is a horizontal flow of water
moving in the offshore direction. Rip currents do not pull people under the
water–-they carry people away from the shore.
Yes. There is spirited discussion and disagreement among coastal scientists on the
existence of a nearshore process called "undertow," and hence there is not an agreed
on definition for this word. Undertow is a term often and incorrectly used
for rip currents. The best explanation for what many people attribute to "undertow" is
as follows: After a wave breaks and runs up the beach, most of the water flows seaward;
this "backwash" of water can trip waders, move them seaward, and make them susceptible
to immersion from the next incoming wave; however, there is no surf zone force that
pulls people under the water.
These terms, though once commonly used in certain
regions, are incorrect. The National Weather Service, Sea Grant, and the
USLA are working together to use consistent terminology to provide a clear
rip current safety message to the public.
People get in trouble when they are moved so far offshore that they
are unable to get back to the beach. This may be due to any combination
of fear, panic, exhaustion, or lack of swimming skills.
Rip currents are formed when waves break near the
shoreline, piling up water between the breaking waves and the beach. One
of the ways that this water returns to sea is to form a rip current, a narrow
jet of water moving swiftly
away from shore, roughly perpendicular to the shoreline.
Rip currents can be found on many surf beaches every day. Rip currents
most typically form at low spots or breaks in sandbars, and also near
structures such as groins, jetties and piers. Rip currents can occur
at any beach with breaking waves, including the Great Lakes .
Rip currents can be as narrow as 10 or 20 feet in
width
though some may be up to
10 times wider. The length of the rip current also varies.
Rip currents begin to slow down as they move offshore, beyond the breaking
waves, but sometimes extend for hundreds of feet beyond the surf zone.
Rip current speeds can vary. Sometimes they are too
slow to be considered dangerous. However, under certain wave, tide and beach
conditions the speeds can quickly become dangerous. Rip currents have been
measured to exceed 5 mph, slower than you can run but faster than you or
even an Olympic swimmer can swim. In some cases they have been measured as
fast as 8 feet per second. This is faster than the speed at which an
Olympic swimmer can swim a 50-meter sprint.
Under most tide and sea conditions rip currents are relatively slow.
However, under certain wave, tide, and beach profile conditions the speeds
can quickly increase to become dangerous to anyone entering the surf.
The strength and speed of a rip current will likely increase as wave
height and wave period increase.
Rip currents can be found on many surf beaches every day. Rip currents most
typically form at low spots or breaks in sandbars, and also near structures
such as groins, jetties and piers. Rip currents can occur at any beach with
breaking waves, including the Great Lakes .
Under most tide and sea conditions rip currents are relatively slow. However,
under certain wave, tide, and beach profile conditions the speeds can quickly
increase to become dangerous to anyone entering the surf. The strength and
speed of a rip current will likely increase as wave height and wave period
increase.
Rip currents can be found on many surf beaches every day. Rip currents most
typically form at low spots or breaks in sandbars, and also near structures
such as groins, jetties and piers. Rip currents can occur at any beach with
breaking waves, including the Great Lakes .
Under most tide and sea conditions rip currents are relatively slow. However,
under certain wave, tide, and beach profile conditions the speeds can quickly
increase to become dangerous to anyone entering the surf. The strength and
speed of a rip current will likely increase as wave height and wave period
increase.
Signs that a rip current is present are very
subtle and difficult for the average beachgoer to identify. Look for differences
in the water color, water motion, incoming wave shape or breaking point compared
to adjacent conditions. Look for any of these clues:
- Channel of churning,
choppy water
- Area having a notable difference in water color
- Line of foam, seaweed, or debris moving steadily seaward
- Break in the incoming wave pattern
- One, all or none the clues may be visible.
Rip currents are present on many beaches every day of the year, but
they are usually too slow to be dangerous to beachgoers. However, under
certain wave, tide and beach shape conditions they can increase to dangerous
speeds.
Rip currents have long been of interest to scientists
studying waves and beaches, but only in recent years have Sea Grant and National
Weather Service research searched for ways to identify the wave and sea conditions
that create hazardous rip current velocities and to correlate the conditions
with actual rescue data from local lifeguards. What we have learned to date
is being used to identify particular days when the potential for dangerous
rip currents is higher. We refer to this information as the Rip Current Outlook
for your beach. Researchers around the country are actively searching for
better prediction and warning methods.
NOAA's National Sea Grant College Program is a nationwide
network of 30+ university-based programs supporting applied research, education
and outreach programs to promote better understanding, conservation, and
use of our coastal resources. Sea Grant engages over 3,000 scientists, engineers,
extension agents, educators, communications specialists, and students drawn
from over 300 institutions. By coordinating university scientists with outreach
specialists, decision makers, and stakeholders, Sea Grant synthesizes science-based
information and gets it to those who need it.
NOAA Sea Grant is an open and competitive,
science management, capacity building, service enterprise committed to creating
new knowledge (research) and transferring science-based information to users
through outreach (extension, education and communications) for mission-related
objectives. The Sea Grant enterprise is organized nationally and implemented
at the state and local levels in order to fully engage the network in sound
research, education and outreach (extension and communications). Sea Grant
gets resources to problems identified by coastal residents and businesses,
and local, regional, state and federal agencies. Approximately 500 competitively-funded
research projects are supported each year across the full spectrum of marine
and coastal sciences.
The national network of Sea Grant Colleges and institutional
programs is committed to the transfer of research results to government agencies,
to coastal communities and to the public. Over the past 25 years, many Sea
Grant programs have worked hard to increase public awareness of rip currents
through the use of beach and boardwalk signs, brochures, videos, seminars,
and web sites. These outreach efforts are designed to help local residents
and visitors familiarize themselves with rip currents, avoid these dangerous
coastal hazards, and understand how to swim out of a rip current.
Over the past 20 years, Sea Grant has funded rip current research at many
of the nation's premier universities. Coastal engineers and scientists have
been working to increase our understanding of rip currents through a variety
of techniques, including field experiments in the surf zone, laboratory experiments
in wave tanks, and mathematical and computer modeling. This research has
ranged from GPS drifter studies in California's surf zone to nearshore circulation
analyses in the Great Lakes to wave basin and computer modeling of rip-current
behavior in Delaware to detailed video analyses and placement of instruments
in the surf zone for rip current measurements in North Carolina. This research
has not been limited to investigating the movement of water near the shoreline.
For example, Florida Sea Grant is funding research that examines how rip-current
rescue data correlate to certain wave conditions and characteristics.
USLA's mission is to prevent drowning and other injuries in the aquatic
environment through public education and the promotion of high standards
in aquatic rescue.
We're partnering with NOAA because together we can
greatly increase the reach of our drowning prevention message.
Each year America's surf lifeguards rescue
over 60,000 people from drowning.
- Of these, over 80% are rescues of people caught in rip currents.
- In the absence of timely rescue, we believe that over 80% of the
drowning fatalities at surf beaches are also caused by rip currents.
- We estimate that well over 100 fatalities a year are caused by rip
currents.
USLA does the following:
- The National Certification Program promulgates
minimum recommended standards for lifeguard agencies and
certifies those which demonstrate compliance.
- Public education efforts through USLA and affiliated
agencies reach an audience of over 240,000 per year.
- USLA's website ( www.usla.org )
provides public education and exchange of information
among lifesavers worldwide.
- USLA sponsored competitions on the national and international
level promote high levels of fitness and skill among
lifesavers ( www.uslanationals.org ).
- USLA gathers and disseminates statistics on lifeguard
rescues, beach attendance, and related issues annually.
- USLA is actively involved in encouraging the development
of lifeguard services in areas lacking them, especially
where drownings have occurred.
- USLA publishes Open Water Lifesaving – The United States
Lifesaving Association Manual for the training of open
water rescuers.
Rip currents were first identified by lifeguards
and information on the phenomenon was first published in the 1930's.
USLA's website provides rip current information and USLA has published
posters and brochures on rip currents for many years.
USLA affiliated agencies provide on-site public education, much of
it based on USLA educational materials. There were over 2.9 million preventive
actions provided by lifeguards and reported to USLA in 2003.
Rip Currents dangers are poorly recognized because:
- Rip current deaths occur one or two at a time and
usually attract little attention.
- They may only be a footnote
in media reporting.
- On estimate suggests that only about 50% of drowning deaths are reported
by the media.
- Unlike the drama of a hurricane or tornado, rip currents exist every
day at surf beaches throughout the U.S.
Rip current fatalities are mostly preventable
if people are educated about the phenomenon. We hope to significantly
reduce death and injury in the surf environment by making beach users
and beach overseers aware of steps they can take to avoid accidental
death and injury due to rip currents.
Avoid rip current hazards:
- Before you leave for the beach, check the latest National Weather Service
forecast for local beach conditions. Many offices issue a Surf Zone Forecast.
- Learn to swim
- If you'll be in surf, learn to swim in surf. It's not the same as a pool
or lake.
- Never swim alone.
- Swim near a lifeguard.
- Look for posted signs and warning flags, which may indicate higher than
usual hazards.
- Check with lifeguards before swimming.
- Obey all instructions provided by lifeguards.
- Be cautious. Always assume rip currents are present even if you don't
see them.
- If in doubt, don't go out!
Lifeguards are trained to: recognize rip
currents, inform the public about rip currents, and rescue people caught
in rip currents. The chance of drowning at a beach protected by lifeguards
affiliated with USLA is 1 in 18 million.
If caught in a rip current:
- Try to remain calm to conserve energy.
- Don't fight the current.
- Think of it like a treadmill you can't turn off. You want to step to
the side of it.
- Swim across the current in a direction following the shoreline.
- When out of the current, swim and angle away from the current and towards
shore.
- If you can't escape this way, try to float or calmly tread water. Rip
current strength eventually subsides offshore. When it does, swim towards
shore.
- If at any time you feel you will be unable to reach shore, draw attention
to yourself: face the shore, wave your arms, and yell for help.
You
can help someone caught in a rip current by:
- If you see someone in trouble, get help from a lifeguard.
- If no lifeguard is available, have someone call 9-1-1.
- Throw the rip current victim something that floats – a lifejacket, a
cooler, a ball.
- Yell instructions on how to escape.
- Many have drowned trying to help others. Don't become a victim while
trying to help someone else!
Major trouble spots include:
In California:
- The prevalence and severity of rip currents is apparently greatest
in California , probably due to regular and strong surf conditions.
However, with the notable exception of California State Parks,
the hazard is fairly well managed by a network of lifeguard agencies
that make a very large number of rescues each year (over 40,000 in
2003, of which over 80% are due to rip currents).
- Beaches without lifeguards: In California , for example, there were
31 drownings reported at unguarded surf beaches in 2003 and
4 at guarded surf beaches. Considering that attendance is typically
far higher at guarded beaches (lifeguards are typically placed where
the most people swim), the safety record is significant. For Florida
in 2003, the number of drownings reported at unguarded versus guarded
beaches was 17:1.
- California State Parks: California State Parks reported 71% of all
drownings reported by California lifeguard agencies from Santa
Cruz south in 2003. This was a total of 25, most of which were probably
rip current related. Reason: Strong rips and lack of lifeguards.
In Florida:
- In Pensacola , where there has been a high incidence of rip current
deaths over the past several years, the overseers of the beaches
emphasize that no drownings have occurred where lifeguards are staffed.
- Florida , in general, has been a trouble-spot. There are extensive
areas of the coastline with no lifeguards and beach users are
often poor or nonswimmers unfamiliar with the hazard. Where lifeguard
protection is provided, it typically ends at 5 p.m.
- Florida Panhandle has been a serious trouble-spot over the past
ten years or so as tourism has increased, but provision of
lifeguards services has not increased in parallel. Some examples:
- Pensacola : Between April 2000 and the present, 21 people have
died by drowning (in unguarded areas), per the Santa Rosa Island
Authority's public safety manager.
- Panama City Beach to Pensacola : 23 people drowned in rip currents
in the summer of 2003 per the Atlanta Constitution.
- Panama City Beach : 10 died by drowning in 1994 and the community
continues to decline to provide lifeguard protection.
- Walton County : No lifeguards are provided, though several of the
2003 drowning deaths occurred place there.
- Florida
state government has established
a uniform beach flag system for
surf zone hazards
Along the Great Lakes:
- Rip currents have been involved in a number of drowning deaths in
recent years. From 2002 through 2003, 18 people died along
the shores of Lake Michigan alone.
The United States Lifesaving Association maintains a website at www.usla.org
with tips on beach safety, including rip currents. Be sure to visit the
site when you have questions.
Drowning deaths occur when people pulled offshore are unable to keep
themselves afloat and swim to shore. This may be due to any combination
of fear, panic, exhaustion, or lack of swimming skills. Rip currents
are a major hazard to all beachgoers. They can sweep even the strongest
swimmer out to sea. Rip currents are particularly dangerous for weak
and non-swimmers.
It is difficult to provide and exact
number since: the Centers for Disease Control does not maintain a national
reporting system/national database for drownings along surf beaches and
most of the nation's coastline is outside the jurisdiction of surf lifeguard
agencies.
The USLA estimates that over 80 percent of surf beach drowning deaths
(and surf beach rescues) are caused by rip currents. Applying this 80
percent estimate results in an estimated average of 64 rip current deaths
within the jurisdictions of USLA surf lifeguard agencies. Since most
of the nation's coastline is outside the jurisdiction of surf lifeguard
agencies, it seems reasonable to postulate that the actual number of
drownings caused by rip currents nationally is at least double the 64
number or higher. For the purposes of our education campaign we state
the number of rip current deaths nationally exceeds 100 per year.
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