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1998 HURRICANE SEASON PROBABLY A TASTE OF SEASONS TO COME;
NEAR-AVERAGE PREDICTIONS FELL SHORT OF ACTUAL STORM ACTIVITY

     [  NOTE: Full version with figures at:                             ]
     [      http://tropical.atmos.colostate.edu/forecasts/index.html    ]
     [        For more information contact:                             ]
     [      David Weymiller     phone: (970) 491-6432                   ]
     [                         e-mail: Dweymiller@vines.colostate.edu   ]

	FORT COLLINS--If the theory of Colorado State University hurricane
forecaster William Gray and his associates is correct, the 14 Atlantic
Basin storms that occurred this year are just a harbinger of hurricane
seasons to come in the next few decades.

	Gray believes certain climate phenomena indicate a return to
conditions prevalent from the early 1930s to the late 1960s, when hurricane
seasons had more intense or major storms along the U.S. East Coast. The 25
years between 1970-94 were relatively quiet, records show, but the upsurge
in numbers and intensity since 1995 is likely to continue.

 	A professor of atmospheric sciences who has been issuing his
forecasts for 15 years, Gray and his colleagues underestimated the number
of storms for this season. However, beginning with the December 1997
forecast, the updated forecast continually increased the number of storms
and overall hurricane activity.

	"We forecast a slightly-above-average year for 1998 based on climate
data that has proven accurate in the past," Gray said. "Easterly
stratospheric winds, west African rainfall and the remnants of last year's
El Niño all led us to think this season would be only slightly above
average."

	Current climate signals indicate that 1999 also will be very active.
The initial 1999 forecast will be issued Dec. 4 with updates in early April,
 early June and early August of 1999.

	This season was the most destructive on record in terms of loss of
life and property damage in the Caribbean basin because of hurricanes
Georges and Mitch, according to Gray. In addition, an unusual number of
storms - three hurricanes and four tropical storms - made landfall along
the U.S. coastline. Only 1916, with nine, and 1985, with eight, had more
named storms impacting the United States, he said.

	"We were lucky because none of these seven named storms was of major
hurricane intensity," Gray said, although hurricanes Bonnie and Georges
approached major-storm status.

	Despite greatly reduced hurricane activity in 1997 due to the
strongest El Niño on record, the years 1994-98 have been the most active
four-year period of hurricane activity this century. The four consecutive
years have spawned 53 named storms, 32 hurricanes and 15 major hurricanes.

 	Gray believes this stems in part from a phenomenon called the
Atlantic Ocean thermohaline circulation, which moves Atlantic waters
northward from the vicinity of the Caribbean to an area east of Greenland.
There, the current sinks to deep levels, moves southward and flows into the
South Atlantic Ocean and beyond.

	Warm water in the conveyor belt - perhaps one degree Fahrenheit above
the average North Atlantic sea surface temperature of about 45 Fahrenheit
in the regions west of the British Isles - is associated with more intense
hurricanes and more major (Saffir-Simpson category 3-5 storms with winds of
111 mph or above) landfalling storms along the eastern seaboard, Gray said.
Cool water and low salinity tend to dampen this ocean circulation and
hurricane activity.

	Despite the team's belief that hurricane activity is increasing, team
members called for numbers only slightly above average this year. The 1998
season predicted 10 named storms, six hurricanes and two intense hurricanes
in their third and final update issued in August. The actual season total
was 14 named storms (Nicole was a late-season Eastern Atlantic anomaly),
nine hurricanes and three intense hurricanes. Long-term statistical
averages yield 9.3 tropical storms, 5.8 hurricanes and 2.2 intense
hurricanes annually.

	"We didn't anticipate such an active season," Gray said. "Given the
variables we had and prior historical records, there is no way we could
have predicted such an active hurricane season.

	"Hurricane Mitch, which wreaked such devastation on Central America,
was the strongest late-season storm on record," he said.

	Gray and research team members Chris Landsea, Paul Mielke and Kenneth
Berry rely primarily on the following factors to issue their forecasts: the
strength or weakness of El Niño; the direction of equatorial stratospheric
winds at 68,000-75,000 feet; rainfall in the West African Sahel region;
temperature and pressure readings in West Africa; Caribbean Sea-level
pressure readings; Atlantic sea-surface temperature readings; tropospheric
winds at 40,000 feet; and pressure readings in the northeast Atlantic.

	Gray said three key signals led the team to expect a much less active
season in 1998 than what actually took place, including:

	* Easterly winds from the Quasi-Biennial Oscillation, a stratospheric,
equatorial wind pattern that shifts direction every 26 to 30 months.
Easterly winds tend to inhibit tropical storm formation.
	* A very dry season in the Sahel region of West Africa in both 1997
and through July 1998. Dry conditions historically are linked with
relatively few tropical storms.
	* Residual El Niño effects in the eastern equatorial Pacific through
July. Westerly winds from El Niño tend to shear the tops off tropical
depressions and prevent them from becoming full-fledged storms.

 	"Our research shows that while we improve on climatology most of the
time, 10 to 20 percent or so of our forecasts will fail," Gray said. "The
1998 forecast fell short because global circulation variables that had good
predictive value in prior years just didn't work this time.

	"Next year we'll be calling for above-average hurricane activity, and
we believe this is a reflection of the new hurricane era we entered in
1995. We expect this trend to continue for the next few decades."
					

HURRICANE FORECASTS--1998 SEASON            ACTUAL 8/98  6/98  4/98 12/97
 1. Named Storms (9.3)*                        14    10    10    10     9
 2. Named Storm Days (46.9)                    66    50    50    50    40
 3. Hurricanes (5.8)                            9     6     6     6     5
 4. Hurricane Days (23.7)                      47    25    25    20    20
 5. Intense Hurricanes (2.2)                    3     2     2     2     2
 6. Intense Hurricane Days (4.7)                9     5     4     4     3
 7. Hurricane Destruction Potential (70.6)**  139    75    70    65    50
 8. Net Tropical Cyclone Activity (100%)      161   110%  100%   95%   90%

 * Number in ( ) represents average year totals based on 1950-1990.
** Hurricane Destruction Potential measures a hurricane's potential for
   wind- and ocean-surge damage. Tropical Storm, Hurricane and Intense
   Hurricane Days are four, six-hour periods where storms attain wind speeds
   appropriate to their category on the Saffir-Simpson scale.