12 Weather WEATHER Since weather and climate play such a significant part in human activity, providing timely and accurate weather warnings and forecasts is one of the most important functions of every national meteorological service (NMS). This function also gets the most attention from decision makers and the public. Indeed, because of the significant improvement in safety and protection of property through timely and accurate weather information, Government, like its counterparts worldwide, views national weather service outputs as a public service and continues to finance and support them. National Weather Service Weather information provided on a daily basis meets a broad spectrum of local and national needs such as: • Early warning for natural disaster mitigation (for the Cayman Islands: hurricanes, thunderstorms, floodproducing rain, etc.) • Information on changes in weather to help the public in planning daily personal and social activities • Advice for sustaining and improving environmental quality • Day-to-day and seasonal and climate forecasts and other products in support of weather-sensitive economic sectors All user groups rely heavily on this broad range of services to make sound decisions concerning public safety and cost efficiency. Government policy makers, international agencies and other individuals use products and services from national weather services in support of such areas as agriculture, recreation and tourism, construction, water resource management, etc. Administration and Equipment The Cayman Islands National Weather Service, under the administration of the Civil Aviation Authority, is responsible for the monitoring of meteorological events and provision of meteorological information. A good example of this would be the “cooperative upper air station” that provides critical information to the National Hurricane Center in Miami, Florida, for hurricane 155 forecasting and tracking. Surface and upper air weather observations from the service are sent to the regional meteorological centre in Washington, DC. From the centre, these observations are transmitted into a worldwide network for use by other meteorological as well as non- meteorological concerns. The data is also available for use in numerical weather prediction models for use in the production of mediumand long-term regional and global weather and climate forecasts, as well as for global aeronautical planning by the aviation community. Cayman’s service operation includes an upper-air station, surface weather observations, climate data processing, analysis and storage, as well as public and aviation forecasting. The service now has at its disposal one of the most advanced international satellite communication systems (ISCS) for the purpose of receiving and disseminating weather observations to the regional centre in Washington, and on to the rest of the world. The ISCS system also receives weather charts and alphanumeric information along with data from numerical weather prediction models (NWP). The NWP data enables the development of regular and specialized weather charts and forecasts through 120 hours or five days. Another valuable piece of equipment is a highresolution satellite system that continuously receives and displays visible, infrared and water vapor satellite pictures, at resolutions from one to four kilometres. This Weather 11 July and 2.89 inches of rainfall was recorded. Even though the hurricane season was fairly uneventful, the Cayman Islands did experience some severe weather events in 2003. Heavy rain caused major flooding on 19 January and 27 June in Grand Cayman. The very high rainfall total in January was particularly unusual and included the highest 24-hr total since records commenced in 1957. This single 24-hour total on January 18th also exceeded any previous January total on record. Flooding in both cases was localized to southwestern Grand Cayman. satellite system is an extremely valuable tool in monitoring the development of weather systems. Staffing and Training The staff consists of two fully trained junior technicians, five trained senior technicians and four trained weather forecasters. Routine hourly surface weather observations are taken at the Owen Roberts International Airport for 17 hours daily (6 a.m. through 10 p.m.) with 24-hour service envisaged for the future. Rapid advances in information and communication technology today have led to continuous improvement and refinement in weather forecasting and observing. As a result, continued professional development training of staff is required to stay abreast of the latest technological developments, operational techniques and research. During 2003, one officer completed his mid-level technician course in climatology and hydrology at the Caribbean Institute of Meteorology and Hydrology in Barbados. A second officer completed the senior technician weather forecasting course at the Institute in late October. Additionally, two officers were hired by the Civil Aviation Authority to work at the Gerrard Smith International Airport in Cayman Brac with dual responsibilities of weather observers and air traffic assistants. These officers were sent to Grand Cayman in early March to take a two-month course in weather observations. A third officer was added later in the year with all three officers scheduled to take an entry-level technician course at CIMH in Barbados February 2004. This training will provide these personnel with the skills to make quality hourly surface observations during operational hours (7 a.m. through 7 p.m.) at the Gerrard Smith airport, thus fulfilling international requirements. Weather Statistics The average annual temperature was 28.4 deg. C/83.2 deg. F. The highest monthly average temperature recorded was 29.9 deg. C/85.9 deg. F during the month of August, with the lowest monthly average of 25.3 deg. C/77.6 deg. F occurring in January. The highest recorded temperature occurred on 11 August and was 34.4 deg. C/94.0 deg. F. The lowest was 20.0 deg. C/68.0 deg. F on 10 January. The warmest day was 11 August with an average of 30.0 deg. C/86.0 deg. F. The coolest day was 20 December, with an average of 24.0 deg. C/75.3 deg. F. Rainfall totalled 1844.6 mm/72.62 ins., which is 16.21 inches higher than the 30-year normal of 56.41 inches. The wettest month was June with 392.4 mm/15.45 inches recorded. The driest month was April with 4.3 mm/ 0.17 of an inch recorded. The most rainfall in a 24-hr period was 240.1 mm/9.45 ins., on 18 January. There were 187 days free of rainfall and 178 days on which rainfall was recorded. There were 62 days on which thunder occurred. The average barometric pressure was 29.96inches/ 1014.6millibars. The highest pressure was 1023.1millibars/ 30.21inches recorded on 21 December. The lowest pressure, 1004.8millibars/29.67inches, occurred on 18 March. The average wind was from the East at 10 knots with April, June and July being the windiest months with average wind speeds of 12 knots. Annual average humidity was 77%, with the highest monthly average of 79% recorded in February, July and October, and the lowest of 75% in April, May and December. The most humid day was 1 September with a very muggy 95%, while 29 December with 58% was the lowest. There were 18 clear days, 249 partly cloudy days and 98 cloudy days. 2003 Weather Hurricane Season 2003 had an active season with 14 named storms; seven became hurricanes with three evolving into major hurricanes with wind speeds of 110mph or greater. The long-term average is 10 named storms, six becoming hurricanes, three major — Category 3 and higher or wind speeds greater than 110 mph. Despite the active season only one storm, Tropical Storm Claudette, moved through the northwest Caribbean. Claudette passed 160 miles southwest of Grand Cayman on 10 July. The storm produced cloudy skies, fresh winds and rough seas on 10- 156 Weather The staff of the National Weather Service, back row, from left: Mr. John Tibbetts (Chief Meteorological Officer), Mrs. Sharon Ebanks, Mr. Avalon Porter, Mrs. Charlene Bodden, Mr. Allan Ebanks and Mr. Gilbert Miller. Front row, from left: Messers Limardo Scott, Winston Gall, Kerry Powery and Floyd Webb. Missing from the photo is Head of Meteorological Services Fred Sambula. 157