This article is from the Storms FAQ, by Chris Landsea firstname.lastname@example.org with numerous contributions by others.
Globally, probably not. For the Atlantic basin, definitely not. In fact,
as documented in Landsea (1993), the number of intense hurricanes (those
hurricanes reaching Saffir-Simpson scale 3, 4, and 5 - defined in subject D1)
has actually gone *down* during the 1970s and the 1980s, both in all basin
intense hurricanes as well as those making landfall along the U.S. coastline.
"With Andrew in 1992 and the busy 1995 hurricane season, have things changed
during the 1990s?" No. Even taking into account Andrew, the period 1991 to
1994 was the *quietest* four years on record - using reliable data going back
to 1944 (Landsea et al. 1996). Of course, with a very active Atlantic
hurricane season (19 tropical storms and hurricanes, 11 hurricanes, and 5
intense hurricanes), it is quite possible that we may be moving to a regime
of more tropical cyclone activity - but one year does not a trend make.
Some more interesting tidbits about Atlantic tropical cyclones (from
Landsea et al. 1996):
* no significant change in total frequency of tropical storms and hurricanes
over 52 years (1944-1995),
* a strong *DECREASE* in numbers of intense hurricanes,
* no change in the strongest hurricanes observed each year,
* A moderate *DECREASE* in the max intensity reached by all
storms over a season,
* no hurricanes have been observed over the Caribbean Sea during
the years 1990-1994 - the longest period of lack of hurricanes in
the area since 1899. This was followed up by 3 hurricanes in
just one year - 1995 - to affect the region,
* 1991-1994 is the quietest (in terms of frequency of total storms
- 7.5 per year, hurricanes - 3.8, and intense hurricanes - 1.0)
four year period on record, since 1944.
As for the other basins, Black (1992) has identified a moderately
severe bias in the Northwest Pacific reported maximum sustained winds
during the 1940s to the 1960s that makes interpretation of trends
difficult for that region.
Nicholls (1992) has shown that the numbers of tropical cyclones
around Australia (105-165E) has decreased rather dramatically since
the mid-1980s. Some of this reduction is undoubtedly due to having more
El Nino events since that time (i.e. 1986-87, 1991-2, 1993, 1994-95).
However, even taking into account the El Nino effect, there is still a
reduction that is unexplained and may be due to changes in tropical
The other basins have not been examined for trends, partly because
the data will likely not be trustworthy before the advent of the geo-
stationary satellites in the mid-1960s. IMHO, I would suspect though
that the western portion of the Northeast Pacific, the eastern portion of
the Northwest Pacific, and the South Pacific east of 165E would have a
real upward trend of tropical cyclone occurrences because of the more
frequent El Nino events in the last decade or so (see section G2 for more
information on El Nino effects).