A large part of the North Atlantic Ocean has recorded the highest seawater temperatures on record for months, in a phenomenon similar to that occurring in the Mediterranean.
Overheating in the Atlantic may play a key role in a stronger and more destructive hurricane season than expected, according to the forecast update released Aug. 11 by scientists with the U.S. Oceanic and Atmospheric Administration's Center for Climate Prediction. (NOAA, a division of the National Weather Service). The previous forecast indicated that a mild to moderate hurricane season was expected this year.
Meteorologists believe that current weather and ocean conditions, such as record-breaking Atlantic sea surface temperatures, are likely to outweigh the generally limiting weather conditions associated with the ongoing El Niño event, according to a briefing note released by the World Meteorological Organization (WMO). ).
"NOAA forecasters have increased the probability of an above-normal Atlantic hurricane season to 60% (increased from the outlook issued in May, which forecast a 30% probability). The probability of near-normal activity "normal has decreased to 25%, below the 40% probability described in the May outlook. This new update gives the Atlantic a 15% chance of seeing a below-normal season," says the WMO.
NOAA's updated 2023 outlook, which covers the entire six-month hurricane season ending Nov. 30, calls for 14 to 21 named storms (winds of 39 mph or greater), of which 6 to 11 could become hurricanes (winds of 74 mph or more). Of those, 2-5 could become major hurricanes (winds of 111 mph or greater). NOAA provides these ranges with 70% confidence. These updated ranges include storms that have already formed this season.
The updated probability of the 2023 Atlantic hurricane season and the number of named storms.
The updated probability of the 2023 Atlantic hurricane season and the number of named storms.
The Atlantic Basin experienced an active start to the hurricane season with five storms reaching at least tropical storm strength, including one hurricane already. An average hurricane season produces 14 named storms, of which seven become hurricanes, including three major hurricanes.
“The main climatic factors expected to influence 2023 Atlantic hurricane activity are ongoing El Niño and the warm phase of the Atlantic Multidecadal Oscillation, including record-breaking Atlantic sea surface temperatures,” it said. Matthew Rosencrans, NOAA's chief hurricane season forecaster. Climate Prediction Center. "Given those factors, the updated outlook calls for more activity, so we urge everyone to prepare now for the season to come."
El Niño conditions are currently being observed and there is a greater than 95% chance that El Niño will continue through the Northern Hemisphere winter, according to the latest ENSO discussion from the Climate Prediction Center. El Niño generally creates weather conditions that help reduce tropical activity during the Atlantic hurricane season. So far, those limiting conditions have been slow to develop, and climate scientists forecast that the associated impacts that tend to limit tropical cyclone activity may not be present for much of the remaining hurricane season.
A forecast of below-normal wind shear, slightly below-normal Atlantic trade winds, and a near-or-above-normal West African monsoon were also key factors in shaping this updated seasonal forecast.
