nautical miles from the center. From the zone of maximum wind to the
periphery of the hurricane, the pressure continues to increase, however,
the wind speed decreases. The atmospheric pressure within the eye is the
best single index for estimating the surge potential of a hurricane. This
pressure is referred to as the c&tvtPCLL pp&ssuvë "t-ndssc (CPI). Generally
for hurricanes of fixed size, the lower the CPI, the higher the wind speeds
Hurricanes may also be characterized by other important éléments, such as
the radius of maximum winds (R) which is an index of the size of the storm,
and the speed of forward motion of the storm System (Vy). A discussion of
the formation, development and general characteristics of hurricanes is
given by Dunn and Miller (1964).
Extratropical storms that occur along the northem part of the east
coast of the United States accompanied by strong winds blowing from the
northeast quadrant are called northeasters. Nearly ail destructive northeasters hâve occurred in the period from November to April; the hurricane
season is from about June to November. A typical northeaster consists of
a single center of low pressure and the winds revolve about this center,
but wind patterns are less symmetrical than those associated with hurricanes .
3.863 Factors of Storm Surge Génération. The extent to which water
levels will départ from normal during a storm dépends on several factors.
The factors are related to the:
(a) characteristics and behavior of the storm;
(b) hydrography of the basin;
(c) initial State of the System; and
(d) other effects that can be considered extemal to the System.
Several distinct factors that may be responsible for changing water levels
during the passage of a storm may be identified as :
(a) astronomical tides
(b) direct winds
(c) atmospheric pressure différences
(d) earth’s rotation
(e) rainfall
(f) surface waves and associated wave Setup
(g) storm motion effects.
The élévation of setup or setdown in a basin dépends on storm intenSlty» path or track, overwater duration, atmospheric pressure variation,
speed of translation, storm size, and associated rainfall. Basin characinfluence water-level changes are basin size and shape,
and bottom configuration and roughness. The size of the storm relative
to the size of the basin is also important. The magnitude of storm
in F1«ures 3"41 and 3’42. Figure 3-41 shows the differM*66” observed water levels and predicted astronomical tide levels
stationsUrrpCane
(1961) at several Texas and Louisiana coast tide
wlalïî!’ ulgUre 3-42 Sh0WS high water marks obtained from a storm survey
hurricanes
riCane Carla* Harris (1963b) gives similar data from other
3-84
periphery of the hurricane, the pressure continues to increase, however,
the wind speed decreases. The atmospheric pressure within the eye is the
best single index for estimating the surge potential of a hurricane. This
pressure is referred to as the c&tvtPCLL pp&ssuvë "t-ndssc (CPI). Generally
for hurricanes of fixed size, the lower the CPI, the higher the wind speeds
Hurricanes may also be characterized by other important éléments, such as
the radius of maximum winds (R) which is an index of the size of the storm,
and the speed of forward motion of the storm System (Vy). A discussion of
the formation, development and general characteristics of hurricanes is
given by Dunn and Miller (1964).
Extratropical storms that occur along the northem part of the east
coast of the United States accompanied by strong winds blowing from the
northeast quadrant are called northeasters. Nearly ail destructive northeasters hâve occurred in the period from November to April; the hurricane
season is from about June to November. A typical northeaster consists of
a single center of low pressure and the winds revolve about this center,
but wind patterns are less symmetrical than those associated with hurricanes .
3.863 Factors of Storm Surge Génération. The extent to which water
levels will départ from normal during a storm dépends on several factors.
The factors are related to the:
(a) characteristics and behavior of the storm;
(b) hydrography of the basin;
(c) initial State of the System; and
(d) other effects that can be considered extemal to the System.
Several distinct factors that may be responsible for changing water levels
during the passage of a storm may be identified as :
(a) astronomical tides
(b) direct winds
(c) atmospheric pressure différences
(d) earth’s rotation
(e) rainfall
(f) surface waves and associated wave Setup
(g) storm motion effects.
The élévation of setup or setdown in a basin dépends on storm intenSlty» path or track, overwater duration, atmospheric pressure variation,
speed of translation, storm size, and associated rainfall. Basin characinfluence water-level changes are basin size and shape,
and bottom configuration and roughness. The size of the storm relative
to the size of the basin is also important. The magnitude of storm
in F1«ures 3"41 and 3’42. Figure 3-41 shows the differM*66” observed water levels and predicted astronomical tide levels
stationsUrrpCane
(1961) at several Texas and Louisiana coast tide
wlalïî!’ ulgUre 3-42 Sh0WS high water marks obtained from a storm survey
hurricanes
riCane Carla* Harris (1963b) gives similar data from other
3-84