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08/01/2018, 8:25 am EST

Updated North Atlantic Tropical Cyclone Season Outlook

Executive Summary: The Climate Impact Company 2018 North Atlantic basin tropical cyclone season forecast is updated on August 1st as the most active part of the 2018 season is underway. The seasonal outlook is very similar to the forecast issued May 31 and includes 11 tropical cyclones, 5 hurricanes and 1 intense hurricane. This outlook includes the 3 tropical cyclones and 1 hurricane which has already occurred in 2018. The accumulated cyclone energy forecast for the 2018 season has not changed at 58 which is much lower than last year’s 226 (3rd highest on record). The seasonal activity forecast is below normal but 2 hurricanes are forecast to strike the U.S. Coast most likely in the Southeast U.S. from the eastern Gulf of Mexico. Another hurricane is forecast to emerge in the warm waters off the U.S. East Coast. The outer tropical North Atlantic is dormant due to unusually cool surface water. El Nino is approaching which inhibits seasonal activity. The evolution of El Nino has slowed in recent weeks therefore it is possible that while the number of hurricanes forecast for 2018 is confident there may be more tropical storms if El Nino fails or is delayed until late in the year.  In the East Pacific the seasonal forecast indicates 17 tropical cyclones, 9 hurricanes and 5 intense hurricanes. Regional forecast summary: The outlook is based on analog year projections adjusted for regional factors and previously issued climate forecasts by CIC. Gulf of Mexico: The eastern Gulf of Mexico is forecast to encounter 2 northward moving hurricanes, one in August and another in October moving into the Florida Panhandle. One of these hurricanes is likely an intense hurricane. Other tropical cyclone activity is likely due to the warmer than normal SSTA in the Gulf region. Mexico: Due to westerly shear produced by an approaching El Nino episode Mexico is not expected to encounter a hurricane from the east. East Coast Virginia and north: The ocean surface is warmer than normal off the Northeast Corridor Coast and at least 1 hurricane in these waters is likely and occurs in September. Due to the warm waters other tropical cyclones are possible. East Coast south of Virginia: Significant tropical cyclone activity is likely into the eastern Gulf of Mexico off the west coast of Florida. Hurricanes turning into the east coast of Florida or Southeast U.S. is less likely. Caribbean: The Caribbean Sea is forecast much less active than last year given an approaching El Nino increasing upper westerly shear.