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The hurricane forecast is out and fewer storms are predicted.
Forecasters from Colorado State University on Thursday predicted that the 2023 Atlantic hurricane season would produce slightly fewer storms than average. The researchers, in their early season forecast, called for 13 named storms, 6 hurricanes and 2 major hurricanes, thanks to expected development of El Niño conditions in the Pacific later this year. El Niño is a cyclical pattern of warmer than average sea surface temperatures in portions of the Pacific Ocean that also increase wind shear in areas of the Atlantic, reducing the chance of tropical storms forming. El Niño conditions at the moment are neutral, meaning water temperatures in the Pacific are at average levels. And while there is “considerable uncertainty” about its strength, El Niño conditions are expected to be in full force at the height of the hurricane season in July, August and September. Philip Klotzbach, the university’s lead hurricane season forecaster, said very warm tropical and subtropical Atlantic sea surface temperatures also are helping keep the chance of hurricanes close to normal. “Sea surface temperatures in the eastern and central tropical Atlantic are much warmer than normal, so if a robust El Niño does not develop, the potential for an active Atlantic hurricane season still exists,” the forecast warned.
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The Colorado State University early Atlantic Hurricane Season forecast by the numbers.
We had three years of La Nina which supports hurricanes!
The expected shift to El Niño conditions follow a three-year period of La Niña conditions in the Pacific, with cooler than normal sea surface temperatures. That weather pattern results in reduced wind shear in the Atlantic, and was a determining factor in the more active hurricane seasons in recent years. An average hurricane season, based on 1991-2020 records, includes 14.4 named storms, 7.2 hurricanes and 3.2 major hurricanes of Category 3 or above. Colorado State researchers base their predictions on a 40-year history of identifying hurricane season predictive patterns, by comparing the upcoming season’s expected patterns with past seasons, and through the use of a variety of computer models. The forecast is predicting a 44% chance of at least one major hurricane hitting somewhere along the entire U.S. continental coastline, which compares with an average of 43% chance of a strike, based on records from 1880 to 2020. The chance along the Gulf Coast, from the Florida Panhandle to Brownsville, Texas, is 28%, compared to the long-term average of 27%.
This is the latest official prediction of change in the “El Niño-Southern Oscillation”, the changes in sea surface temperatures from lower than normal or La Niña conditions to higher than normal, El Niño conditions.
(NOAA)
The numbers are higher as the last three years were higher.
Even with the lower storm predictions, forecasters warn that it only takes one tropical storm or hurricane to cause serious flooding or wind damage. In a note on Twitter, Benjamin Schott, meteorologist in charge of the Slidell office of the National Weather Service, pointed out that the past seasons that Colorado State compared with 2023 include 1969, when Category 5 Hurricane Camille hit Louisiana and Mississippi; 2002, when Hurricane Isidore dropped nearly 16 inches of rain on Metairie; and 2012, when Hurricane Isaac’s storm surge devastated LaPlace. The early forecast also predicts a 45% chance of at least a tropical storm hitting Plaquemines Parish, a 42% chance for St. Bernard Parish, 39% chance for Jefferson Parish and 33% for Orleans Parish. The probabilities are based on one or more storms occurring within 50 miles of a location. The early April forecast is the first of a series of forecasts by Colorado State during the year, with an update expected just before the official beginning of the season on June 1.
This map shows sea surface temperature anomalies — darker red colors mean above average water temperatures — for 14 days in March and April. The blob in the Gulf of Mexico is likely the remains of the Loop Current, deep warm water that breaks off each year or so from the Gulf Stream.
(NOAA National Centers for Environmental Prediction)
NOAA will be issuing its own seasonal forecast in May.
This is good news but as they say, we only need one to hurt us.