La Niña, El Niño, and Atlantic Hurricane Damages in the United States

Roger A. Pielke, Jr. and Christopher W. Landsea

6 April 1999

Submitted to Bulletin of the American Meteorological Society


Tables

Table 1. Categorization of the Atlantic hurricane season into El Niño (based upon the August-September-October Niño 3.4 SST anomalies warmer than or equal to +0.4C) and La Niña (August-September-October Niña 3.4 SST anomalies cooler than or equal to -0.4C) events from 1925-97. The 10 most intense events of each type are highlighted in bold.

El Niño La Niña
1925 1933
1929 1938
1930 1942
1940 1944
1941 1945
1951 1948
1953 1949
1957 1950
1963 1954
1965 1955
1969 1956
1972 1961
1976 1964
1977 1967
1982 1970
1986 1971
1987 1973
1990 1974
1991 1975
1993 1978
1994 1988
1997 1995

Table 2. Median and mean losses (with standard deviation) by phase of ENSO cycle presented in normalized 1997 US dollars.

  Median
($)million
Mean
($)million
Standard Deviation
($)million
La Niña 3,292 5,887 6,991
Neutral 927 6,979 15,856
El Niño 152 2,056 4,228

Table 3. Levels of significance in differences in losses between phases of the ENSO cycle calculated using a two-tailed t test. Mean values calculated using a logarithmic transformation; median values are not transformed.

  La Niña Neutral
Neutral log-mean = 94%
median = 61%
 
El Niño log-mean = >99%
median = 98%
log-mean = 81%
median = 83%

Table 4. Number of damaging events that exceed certain thresholds by phase of the ENSO cycle, shown as years and percentages.

  La Niña Neutral El Niño
> $1 Billion 17 (of 22)
77%
14 (of 29)
48%
7 (of 22)
32%
>$5 Billion 8 (of 22)
36%
8 (of 29)
28%
3 (of 22)
14%
>$10 Billion 4 (of 22)
18%
6 (of 29)
21%
3 (of 22)
14%

Table 5. Levels of significance calculated using a two-tailed t test, comparing phase of ENSO cycle for three loss-exceedance thresholds.

  La Niña Neutral
Neutral >$1 Billion = 96%

>$5 Billion = 48%

>$10 Billion = 22%

 
El Niño >$1 Billion = >99%

>$5 Billion = 90%

>$10 Billion = 27%

>$1 Billion = 74%

>$5 Billion = 74%

>$10 Billion = 48%


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Roger Pielke
Environmental and Societal Impacts Group
National Center for Atmospheric Research (NCAR)
PO Box 3000
Boulder, Colorado 80307 USA
303-497-8111 (voice)
303-497-8125 (fax)
rogerp@ucar.edu

Christopher W. Landsea
AOML/Hurricane Research Division
National Oceanic & Atmospheric Administration
4301 Rickenbacker Causeway
Miami, Florida 33149 USA
(305) 361-4357 (voice)
(305) 361-4402 (fax)
landsea@aoml.noaa.gov

NCAR is sponsored by the National Science Foundation