When data are not available for a spécifie beach, the wave climate
can be estimated by extrapolating from another location, after correcting
for différences in coastal exposure, winds, and storms.
On the east, gulf, and Great Lakes coasts, local winds are often
highly correlated with the direction of longshore currents. Such wind
data are available in "Local Climatological Data" sheets published monthly
by the National Weather Service, National Océanographie and Atmospheric
Agency (NOAA) for about 300 U.S. weather stations. Other NOAA wind-data
sources include annual summaries of the Local Climatological Data by station (Local Climatological Data with Comparative Data), and weekly summaries of the observed weather (Daily Weather Maps), ail of which can be
ordered from the Superintendent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402.
Local weather data are often affected by conditions in the neighborhood of the weather station, so care should be used in extrapolating
weather records from inland stations to a coastal locality. However,
statistics on frequency and severity of storm conditions do not change
appreciably for long reaches of the coast. For example, in a study of
Texas hurricanes, Bodine (1969) felt justified in assuming no différence
in hurricane frequency along the Texas coast. In developing information
on the Standard Project Hurricane, Graham and Nunn (1959) divided the
Atlantic Coast into zones 200 miles long and the gulf coast into zones
400 miles long. Variation of most hurricane parameters within zones is
not great along straight open stretches of coast.
The use of weather charts for wave hindcasting is discussed in Section 3.4. Computer methods for generating offshore wave climate are now
(1973) under test and development. However, development of nearshore
wave climate from hindcasting is usually a time-consuming job, and the
estimate obtained may suffer in quality because of the inaccuracy of
hindcast data, and the difficulty of assessing the effect of nearshore
topography on wave statistics. At the présent time, if available at the
spécifie location, statistics based on wave-gage records are préférable
to hindcast statistics when wave data for the shallow-water conditions
are required.
.
-Ot^eï possible sources of wave climate information for office studlolainresidentslal ph°tOgraphy' newspaper records, and comments from
Data of greater detail and
office studv 8rea,
détail and reliability than that obtained in an
shoreliner
by recording the wave conditions at the
or wave papes
a*
at_least 1 year bX the use of visual observers
ticscollected at CFRC7 °f year~t0-year variation in wave height statisthat six obserJ,™ WaV! gages (ThomPson and Harris, 1972), indicates
distribution S h"*
f°r 1 year gives a reliable waU height
at Atlantic Citv
k * ô ^.percent level of occurrence. At the gage
height-distributionnfunction?tlOn *
1
Provided a useful
4-36
can be estimated by extrapolating from another location, after correcting
for différences in coastal exposure, winds, and storms.
On the east, gulf, and Great Lakes coasts, local winds are often
highly correlated with the direction of longshore currents. Such wind
data are available in "Local Climatological Data" sheets published monthly
by the National Weather Service, National Océanographie and Atmospheric
Agency (NOAA) for about 300 U.S. weather stations. Other NOAA wind-data
sources include annual summaries of the Local Climatological Data by station (Local Climatological Data with Comparative Data), and weekly summaries of the observed weather (Daily Weather Maps), ail of which can be
ordered from the Superintendent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402.
Local weather data are often affected by conditions in the neighborhood of the weather station, so care should be used in extrapolating
weather records from inland stations to a coastal locality. However,
statistics on frequency and severity of storm conditions do not change
appreciably for long reaches of the coast. For example, in a study of
Texas hurricanes, Bodine (1969) felt justified in assuming no différence
in hurricane frequency along the Texas coast. In developing information
on the Standard Project Hurricane, Graham and Nunn (1959) divided the
Atlantic Coast into zones 200 miles long and the gulf coast into zones
400 miles long. Variation of most hurricane parameters within zones is
not great along straight open stretches of coast.
The use of weather charts for wave hindcasting is discussed in Section 3.4. Computer methods for generating offshore wave climate are now
(1973) under test and development. However, development of nearshore
wave climate from hindcasting is usually a time-consuming job, and the
estimate obtained may suffer in quality because of the inaccuracy of
hindcast data, and the difficulty of assessing the effect of nearshore
topography on wave statistics. At the présent time, if available at the
spécifie location, statistics based on wave-gage records are préférable
to hindcast statistics when wave data for the shallow-water conditions
are required.
.
-Ot^eï possible sources of wave climate information for office studlolainresidentslal ph°tOgraphy' newspaper records, and comments from
Data of greater detail and
office studv 8rea,
détail and reliability than that obtained in an
shoreliner
by recording the wave conditions at the
or wave papes
a*
at_least 1 year bX the use of visual observers
ticscollected at CFRC7 °f year~t0-year variation in wave height statisthat six obserJ,™ WaV! gages (ThomPson and Harris, 1972), indicates
distribution S h"*
f°r 1 year gives a reliable waU height
at Atlantic Citv
k * ô ^.percent level of occurrence. At the gage
height-distributionnfunction?tlOn *
1
Provided a useful
4-36