Hurricanes: Their Nature and Impacts on Society - Climate Science ...

HURRICANE FORECASTS 113
In an earlier experiment, a hurricane was seeded on 13 October 1947 off the
southeast United States coast. Because it subsequently moved westward into
the Georgia coast, questions were raised among critics of weather modification
as to whether the seeding caused the abrupt change in storm track.
More recent analysis strongly suggests that the alteration in direction would
have occurred in any case. Hurricane Ginger was also seeded in 1971. However,
it was an anomalous storm with an eye wall usually below 20 000 feet
(6100 meters) <strong>and</strong> no significant quantities of supercooled water were found.
Hurricane modification ended because of equivocal research findings
including evidence that hurricanes may only infrequently be amenable to
modification because of their very large variability, questions of national <strong>and</strong>
international legal issues, <strong>and</strong> a general loss of support for weather modification
efforts (Cotton <strong>and</strong> Pielke 1995; Pielke <strong>and</strong> Glantz 1995). Currently,
further seeding experiments are not being performed. Project Stormfury was
terminated in 1983 (Willoughby et al. 1985). A policy consequence of the
inability to control hurricanes is that impacts must be mitigated by reducing
societal exposure <strong>and</strong> not by modifying event incidence.
4.5.5 VaIoe to society of forecasts
The production of a hurricane forecast is only the first step in the process of
its effective use by decision-makers. A hurricane forecast must also be
communicated through a process of -hear, underst<strong>and</strong>, believe, personalize,
respond, <strong>and</strong> confirm (as described by Sorensen <strong>and</strong> Mileti 1988). A decision
by an individual to act in response to the information about an approaching
storm, or any other extreme event for that matter, is conditioned by a wide
range of factors such as perceived risk, education, time to impact, <strong>and</strong> many
more (Sorensen 1993). Social scientists have a well developed underst<strong>and</strong>ing of
the process of natural hazards warnings <strong>and</strong> human response (see, e.g.,
Drabek 1986). The use of a forecast must be understood in the broad context
of a process from production through communication through response.
The US National Weather Service (NWS) produces <strong>and</strong> issues a number of
products related to hurricanes: hurricane watches <strong>and</strong> warnings, flash flood
watches, flash flood warnings, flash flood statements, tornado watches <strong>and</strong>
warnings, severe thunderstorm watches <strong>and</strong> warnings, severe weather statements,
<strong>and</strong> special weather statements (NOAA 1994). Once a forecast or
warning is produced it is typically distributed to a range of Federal, state, <strong>and</strong>
local agencies, including FEMA, the Corps of Engineers, <strong>and</strong> state <strong>and</strong> local
emergency management agencies. Similarly, the media -including print,
television, <strong>and</strong> radio -also receive NHC weather products <strong>and</strong> are often a
critical link in the communication process. Recently, the World Wide Web has
provided a wide range of information resources in both text <strong>and</strong> graphic
formats (http://www.nws.noaa.gov/).