FORT COLLINS, Colo. (BRPROUD) – Colorado State University has released a new outlook for the 2020 Atlantic hurricane season. The forecast predicts a more active season than what was previously forecast.
The current forecast predicts 24 named storms, 12 hurricanes and five major hurricanes, which is classified as a Category 3 hurricane or greater. These numbers are all higher than the original predictions that were made in April, and this includes the nine storms we have seen thus far. The initial outlook called for 16 named storms, eight hurricanes and four major hurricanes, but in additional forecasts, those numbers have increased.
Scientists at CSU expect the number of named storm days to be 100, which is almost double the 1981-2010 average of 59.4. The forecast for the number of hurricane days is 45 and is up from the 24.2-day average. The forecast for the number of major hurricane days is 11 and is up from the 6.2-day average. Another parameter of concern is accumulated cyclone energy, or ACE. It is a quantitative measure that takes into account a named storm’s potential for wind damage and storm surge destruction. The forecast for ACE is 200, which is almost twice as high as the average of 106.
While this forecast cannot predict where storms will form, there are a few probabilities to note. The probability for at least one major hurricane making landfall on the United States coastline is 74% compared to the average of 52% last century. The probability for at least one major hurricane making landfall on the East Coast including the Florida Peninsula is 49%, which is more than last century’s average of 31%. Finally, the probability for at least one major hurricane making landfall on the Gulf Coast from the Florida panhandle to Brownsville is 48%, which is higher than last century’s average of 30%.
There are a few reasons for the active season prediction. One is warm sea surface temperatures. Tropical cyclones rely on warm water as the fuel source, and more specifically, the water must be at least 80°F. Warm water usually accompanies more atmospheric instability. In the Gulf, that warm water is there, and in the tropical Atlantic, water temperatures are the fourth highest recorded behind 2005, 2010 and 2017.
The second reason is due to a very active West African monsoon. Tropical cyclones usually begin as easterly waves, a cluster of showers and storms, of the coast of West Africa. An active monsoon typically results in more robust easterly waves and more conducive upper-level winds.
The third reason is due to very low vertical wind shear. Vertical wind shear refers to the change in wind speed over height. High vertical wind shear means that the wind speed high in the atmosphere is greater than the wind speed at the surface, and this essentially causes the storm clouds to dissipate. Low vertical wind shear leads to cyclone development and intensification. The vertical wind shear in July was the second lowest since 2005.
The final reason for the forecast increase is due to the El Niño-Southern Oscillation, which is a climate pattern that involves changes in the waters in the central and eastern tropical Pacific Ocean. We are in a cool neutral phase, which means that temperatures are close to average, but they are between 0°C and -0.5°C. We are trending toward a weak La Niña by late summer, which means that water temperatures in the central and eastern tropical Pacific will be cooler than average. When La Niña occurs, there are warmer water temperatures in the Atlantic, weak wind shear, weak trade winds and less atmospheric stability.
This has already been a very active Atlantic hurricane season, but we have yet to reach the peak of it. We’ve made it through nine out of 21 named storms. If we do use all of the names on the list, we would then resort to the Greek alphabet. This has only happened once before – in 2005.
Your StormTracker team will be here to guide you through the season, and now is the time to make sure you have a plan in place for you and your loved ones. All it takes is one hurricane to make this an active season for you.