21 • Continued from previous page the Pacific jet stream and influences weather and climate patterns globally. El Niño means the Little Boy, or Christ Child in Spanish and was first noticed in the 1600s by Spanish fishermen off the coast of South America near Peru and Ecuador. It was so named because it typically occurred around Christmas. It is an interesting fact that since 2006 the forecasting effort at CSU has been led by one of Dr. Gray’s former students. Dr. Phil Klotzbach has continued to lead tropical meteorology research since 2006. This means that 2023 is the 40th year in which the CSU has issued Atlantic Basin hurricane season forecasts. The CSU usually issues forecasts on the following dates each year — April 13, June 1, July 6 & August 3. This means that this special 2023 hurricane season edition of our Horizon Newsletter was produced by CARICAD between the June and July CSU forecasts and several weeks after the initial forecast of April 13. The matrix below presents some of the elements of the CSU’s April and June forecasts that are of general interest. 30-YEAR AVERAGE Named Storms 14.4 Named Storm days 69.4 Hurricanes 7.2 Major Hurricanes 3.2 Major Hurricane Days 7.4 Caribbean Landfall APRIL 13 55 6 2 5 49% JUNE 15 60 7 3 7 47% CHANGE - APRIL TO JUNE + 2 + 5 + 1 + 1 + 2 - 2 % The matrix makes it easy to see that the primary change between the April and June forecasts is that the CSU team predicted a more active year than in April. This brings the June forecast close to that for a normal or average year. However, the team has pointed out that there is a higher than usual level of uncertainty with the forecast because of circumstances and forces that in climatological terms are conflicting. The CSU team cites as examples the fact that although there is a high level of confidence that El Niño will be in effect in 2023, the Atlantic Ocean is expected to remain warmer than usual will probably set up pushing and pulling forces in terms of level of hurricane activity. Additionally, the weather over the African continent may be different in relation to Easterly waves in 2023. Easterly waves are regarded as one of the main origins of storms and hurricanes. Nowadays there are now many annual forecasts since Dr. Gray started in 1984. The National Oceanographic and Atmospheric Administration (NOAA) also disseminates forecasts. The major online weather services issue them as well. NOAA’s outlook for the 2023 Atlantic hurricane season, was publicised on May 25, 2023. NOAA predicts a 40% chance of a near-normal season, a 30% chance of an above-normal season and a 30% chance of a below-normal season. NOAA is forecasting a range of 12 to 17 total named storms (winds of 39 mph or higher). Of those, five to nine could become hurricanes (winds of 74 mph or higher), including one to four major hurricanes (category 3, 4 or 5; with winds of 111 mph or higher). NOAA has a 70% confidence in these ranges. • Continues on next page
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