Weather Research Center

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Press Release
For Immediate Release
August 12, 2004
For Information Contact: Dr. Bob Stacy 713-529-3076

Weather Research Center’s 2004 Atlantic Hurricane Season Prediction Verifies With Tropical Storm Bonnie Making Landfall on the West Coast of Florida.

Houston – Meteorologist Jill F. Hasling of Houston based Weather Research Center [WRC®]indicates that WRC’s 2004 OCSI [Orbital Cyclone Strike Index] prediction verifies with the landfall of Tropical Storm Bonnie. The coast with the highest probability of tropical storm or hurricane making landfall in 2004 was the West Coast of Florida with a 70% chance. Hurricane Charley is also threatening the west coast of Florida.

The forecast of the probability of landfall from a tropical storm or hurricane on different sections of the United States coast for the 2004 Atlantic hurricane season is given in the following table.




Mexico 50% 40%

Texas 60% 51%

Louisiana to Alabama 40% 59%

West Florida 70% 71% Bonnie

East Florida 30% 41%

Georgia to N. Carolina 40% 56% Alex

East Coast of US 20% 36%

Gulf Oil Blocks 70% 88% Bonnie

There is a chance of a tropical storm or hurricane as late as December. There were 6 of the years used in this Phase of the OCSI when the first storm was after August 1 which means there was a 60% chance of having a late start to the season. This verified when Alex formed August 1. The other in this Phase were years were 1875, 1897, 1941, 1952, 1962 and 1984.

Each year WRC meteorologists make secondary predictions so this model can be compared with other seasonal predictions. This year the OCSI predicts that there will be 7 named storms with 4 of these storms intensifying into hurricanes. Other parameters for the season are given in the following table.

Secondary Prediction:

Number of Storms : 7

Number of Hurricanes: 4

Number of Hurricane Days: 16

Number of Storm Days: 55

US Landfalls: 3

Cat 3 or Higher Storms: 60%


The Orbital Cyclone Strike Index [OCSI] has been used by Hasling and Freeman since 1985 to make an outlook for the section of the US coast which has the highest risk of storm landfall. Further research indicates that Weather Research Center’s [WRC’s] Orbital Cyclone Strike Index’s [OCSI] secondary prediction elements verify better over the past twenty years than Colorado State University’s Atlantic Seasonal Hurricane Activity predictions. WRC’s secondary prediction elements consist of the number of named storms in the Atlantic Basin, number of hurricanes in the Atlantic Basin and number of hurricane days and the number of storm days.

The OCSI model is based on the premise that there are planetary orbital influences that are reflected in the global circulation pattern on the sun and subsequently the global circulation pattern of the earth. The sun's orbit influences the sun spot cycle. Using this solar cycle to make an index, hurricane climatology has been summarized into an index called the OCSI. This index has been used since 1985 to make annual forecasts of which section of North America has the highest risk of experiencing a tropical storm or

hurricane. In addition to its ongoing research, the Center also provides storm and

hurricane information via the Internet through WRC Storm Navigator®. This service helps people navigate weather information on the Internet as well as providing detailed storm updates and related information. All of the Center's projections including past predictions can be found on the Internet, .

Ms. Hasling and Dr. Freeman are both Fellows and Certified Consulting Meteorologists from the American Meteorological Society as well as members of the National Council of Industrial Meteorologist.