3227 Audley Houston, Texas 77098 Phone: 713-529-3076 Fax: 713-528-3538 E-mail: wrc@wxresearch.org

Houston – The end of the 2003 Atlantic hurricane season cannot come soon enough for most coastal residents. Meteorologist Jill F. Hasling of Houston based Weather Research Center suggest that all coastal residents especially Texans use the off season to prepare for what could be an active Texas hurricane season in 2004. As Ms. Hasling was reviewing the 2003 hurricane season and determining how well the Orbital Cyclone Strike Index [OCSI] performed. She took a peek at 2004. The model indicates the section of the coast with the highest probability of a land falling storm in 2004 is the West Coast of Florida with a 70% chance. Texas has the second highest risk with a 60% chance of experiencing a land falling tropical storm or hurricane. Ms. Hasling then looked to see which part of Texas had landfalls in the other years of the 2004 Phase of the OCSI. An ominous fact emerged that the two historical hurricanes which lead to the destruction of Indianola, Texas 1875 and 1886 where in the 2004 phase of the OCSI. Other years with strong Texas Storms in this phase are 1909 and 1941.

2004 could be a very active year for Texas with 6 out of the 10 years in the 2004 phase having storms which made landfall on the Texas Coast. Let hope that we have a year like the other 4 years in the phase where the storms re-curve before they make it to Texas.

Weather Research Center’s Orbital Cyclone Strike 2003 forecast for the Atlantic hurricane season verified with the landfall of Hurricane Isabel on the East Coast of the United States. The East Coast from Georgia to Maine had the highest probability of a landfall with a 64% chance of experiencing a named tropical storm or hurricane. The second highest probability of a storm landfall on a section of the United States coast was the Gulf Coast with 46% chance. This verified with Tropical Storm Bill making landfall on the Louisiana Coast, and with Hurricane Claudette and Tropical Storm Grace on the central Texas Coast.

The secondary predictors of the index did not fair as well. The OCSI called for 7 to 8 named tropical cyclones with 5 of these intensifying into hurricanes. According to the official record there were 14 named storms with 7 intensifying into hurricanes, Claudette, Danny, Erika, Fabian, Isabel, Juan and Kate. There is room to debate whether all the system deserved the tropical designation. Suspect systems are Tropical Storm Ana, Grace, and Henri.

Another interesting fact of this hurricane season was the Hurricane Claudette made landfall on the Texas coast close to the location that another hurricane in the 2003 phase of the OCSI, Hurricane Carla made landfall in 1961. Another significant hurricane which made landfall in Texas in this phase was hurricane Alicia in 1983.

The OCSI also indicated that there could be an early start of the Hurricane season. When you review the past years, which are in the 2003 phase of the OCSI [1874, 1885, 1896, 1908, 1920, 1930, 1940, 1951, 1961, 1971, 1983, and 1993], one of the years, 1908, had a hurricane which formed March 6. Ana verified this prediction when it formed on April 20 and lasted until April 24, 2003. Tropical Storm Bill made an early appearance by forming on June 29^th and making landfall in Louisiana on June 30^th.

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 Bill Gray’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, number of hurricane days and the number of storm days. The tables below give WRC’s prediction and Gray’s earliest prediction in April or May.

In Table 1 when you count the number of years when WRC’s forecast of the number of storms was within plus or minus one storm, there were eight years out of the twenty years forecast. Gray’s forecast was only within one storm five of the twenty years. WRC’s OCSI method forecast the exact number of storms four of the twenty years and Gray’s method forecast the exact number of storms three out of the twenty years.

Table 2 gives the number of hurricanes forecast each year by both WRC’s and Gray’s method. WRC forecast the number of hurricanes within one hurricane ten years out of the twenty years and Gray’s method forecast within one hurricane eight of the twenty years.

Table 3 gives the number of hurricane days forecast for each year. WRC forecast the number of days within five days eight years out of the twenty years. Gray’s method forecast the number of hurricane days within five days six years out of the twenty years.

Table 4 gives the forecast for both WRC’s and Gray’s model for the number of storm days in each year. WRC’s model forecast the number of days within ten days for ten of the twenty years. Gray’s model forecast the number of days within ten days for six of the twenty years.

This verification of the twenty years of forecast demonstrates that the WRC’ OCSI model is as accurate if not more accurate than Gray’s model. The advantage of the OCSI model is that WRC’s model can make a prediction years in advance. .

During this phase of the OSCI, storms form in the Gulf of Mexico or Bay of Campeche over 80% of the time. This has verified with Tropical Storm Bill, Tropical Storm Erika, Tropical Storm Grace, Tropical Storm Henri and Tropical Storm Larry forming in the Gulf of Mexico and the Bay of Campeche.

Table 5 is a summary of the forecast comparisons in Table 1 through 4. This table gives the number of years that each model was closest within the limits indicated.

According to Dr. Gray according to the records Hurricane Isabel was the third longest lasting hurricane since 1950. September 2003 had more major (Cat 3-4-5) hurricane days than any other September in the last 60 years except for 1961. Interesting enough 1961 is one of the years in the 2003 Phase. For other interesting coincidences see http://www.wxresearch.com/outlook/ocsicoin.htm.

The OCSI model is based on the premise that there are 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 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, http://www.wxresearch.com/outlook .

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