“Hurricane Warnings through the Media: A Cuban case-study”



“Early Warnings in Caribbean Hurricanes: A Cuban case-study”.

Dr. José Rubiera

Director

National Forecasting Center, Instituto de Meteorología.

Havana, Cuba.

Introduction:

The Cuban National Forecast Center at the Instituto de Meteorología started in 1996 a new approach on hurricane warnings. The primary idea consisted in providing the public with early warnings 3-5 days in advance. Then, more accurate forecasts and warnings are issued for the 24-48 hour period before a hurricane strikes. A case-study is presented in this paper, based on the experiences obtained with hurricane “Michelle”, a deadly Category 4 hurricane that hit Central Cuba in early November 2001.

Early Warnings in Hurricanes.

Hurricane warnings were issued with just a few hours before the hurricane strike in late XIX and early XX Centuries, with almost no time left for preparation. The great changes undergone by science and technology, mainly in the last decades of the last Century, lead to a continuos increase in accuracy and longer forecast periods. Five day forecasts are nowadays as good as three day forecast were 10 to 20 years ago. Observational technology, i.e. aircraft reconnaissance, radar and satellite techniques, give a better data coverage of oceanic areas. Weather Numerical Models, with improved physics and better data input, have produced a jump in modern forecasting techniques. Telecommunications and Internet have provided fast and reliable access of updated information to forecasters around the world.

The Cuban National Forecasting Center (NFC) started a new approach in the issuance of hurricane warning information from 1996. Early Warning Bulletins are issued 3 to 5 days in advance, at 24 hour intervals, followed by regular warnings every 6 hours, with 24 to 48 hours in advance.

The main consideration of NFC is to warn the public with enough time in advance, increasing the amount of information gradually, creating the sense of a coming danger, without panic. The historic experience of NFC’s forecasters, who have the heritage of more than a Century in hurricane forecasting, give additional advantages to Cuban Meteorological Service, besides the use all the modern techniques such as Numerical Models. The knowledge and expertise of the forecasters remain the main decision factor.

A very careful aspect is that of the wording used in the Early Warning Bulletins. The information on the tropical cyclone must be given with enough details and the general philosophy of the forecast should be explained, but not in a technical language that is not understood out of the meteorological service, but rather in plain words. The forecast itself is a compromise between incertitude, normal in any weather forecast, and the deterministic forecast that people would like to have. Instead, people should be conveyed to realize that a completely accurate forecast is impossible to have with so much time in advance, and that gradual approximations to reality will follow, urging people in the threatened area to be in contact with future warning releases to pinpoint the most probable hit area

The main actors: National Forecasting Center - Government and Civil Defense - Media.

Cuban experience with Early Warning during the last 8 years show that the best results are obtained with a combination of coordinated efforts of various main actors. On the first hand the National Forecasting Center that issues the early warning forecasts and coordinate it with Civil Defense and Government authorities. The Government and Civil Defense put their plans into action, with timely protective measures. The Media plays a very important role in conveying forecast and warnings to the people, mainly through radio and TV. A kind of conditioning reflex has been created in the public that usually watch the weather report with the forecaster located in TV station newsroom and feels that everything is normal. However, the forecaster makes the radio and TV broadcast from the NFC office whenever there is a warning posted. When he finishes, a Civil Defense officer has a broadcast from the Civil Defense Headquarters, giving guidelines on how to act and what to do when the storm arrives. In this case, people realizes that something is about to happen and pay greater attention to the information.

The frequency of information also increases with time. The Civil Defense declares an “Informative” stage 72 hours before the hurricane is forecasted to affect a particular area. In this case, the Media increases the amount of information on the hurricane. The “Alert” stage is posted 48 hours before and the “Alarm” stage 24 hours before the hurricane strike. All preparedness and evacuation should be concluded in this last stage.

Hurricane “Michelle”: A case Study.

Tropical Depression #15 formed October 29th, 2001, near Puerto Cabezas, Nicaragua. On October 31st, when the center of circulation was over water, Tropical Depression #15 was upgraded to Tropical Storm “Michelle”. It intensified rapidly. On November 1st it already was a hurricane. Upper air and surface conditions favored strengthening to major hurricane force in about 24 to 36 hours. Medium Range Forecasts and Climatology suggested that it would hit Cuba as a Cat 3-4 hurricane within a 3-4 day time frame. On November 3rd “Michelle” was a major hurricane Category 4 in the Saffir-Simpson Scale.

Shortcomings to be faced and Strenghs found to deal with this major hurricane.

The overall analysis of the meteorological situation and the facts that 1) no major hurricane has hit Cuba since 1952 and therefore two generations of Cubans didn’t know the effects of a major hurricane Cat 3 or 4 as the one that was expected. In fact, Cubans only had historical memory of Cat 1 (Georges/1998) and Cat 2 (Lili/1996) hurricanes, and 3) the hurricane was expected to hit Cuba just during the week-end, where most people rest.

However, there were also strengths that the Countryr took advantage of: 1) the majority of the population is educated, 2) people has confidence in the National Forecasting Center and Civil Defense officials, and 3) A national exercise is conducted in late May every year taking into consideration a major hurricane hitting the Country.

The Hurricane Strikes.

Hurricane “Michelle” hit Western and Central Cuba on November 4th, 2001. It was indeed a major Saffir-Simpson category 4 hurricane. Maximum sustained winds attained 220 km/h with gusts up to 250 km/h. The eye diameter was 40 kilometres wide and the diameter of Circulation was 500 kilometres.

Michelle affected 45% of Cuban territory, where 53% of the population live (5.8 million inhabitants). Economic losses were very impressive: US $ 1 866 millions. Damage to infrastructure was also very important: 166 515 houses were damaged, of which 12 579 were totally destroyed; 125 electric line towers and 9 TV and microwave towers fell down. TV signals were interrupted for 20 minutes in Central and Eastern Cuba, but signals were channelled through an optic fibre line and reception was re-establish very soon. There was great damage also made to agriculture, i.e. 54% of sugar cane planted area was affected by the hurricane. The total cost of recovery was US $785 million. All houses were re-build or repaired by the end of 2002.

Conclusions:

Notwithstanding the destruction made by this major hurricane, only five people died. This achievement was possible due to an excellent and timely forecast and Early Warning, as well as the information and preparedness delivered by forecasters through TV and radio since 96 hours before the strike. Also the full co-ordination that existed with central and local government officials and the Civil Defence, whose timely and appropriate actions and the evacuation of the population in hazardous areas, led to only a few losses of lives and the minimisation of material damages.

Success has been obtained also in weaker hurricanes Cat 1 or 2 and tropical storms that have hit Cuba in the last 8 years. The number of casualties is much less that those that happen in other countries of the region. In Hurricane “Lili”, 1996, Cat 2: no casualties; Hurricane “Georges”, 1996, Cat 1: no casualties; Tropical Storm “Irene”, 1999,: 1 fatality; Hurricane “Isidore”,2001, Cat 1: no casualties; and Hurricane “Lili”,2002,Cat2: 1 fatality.

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