Hurricanes

Hurricane forecasts will see some changes for 2020: Here’s what will be different

Just a few weeks before hurricane season officially gets underway in the Atlantic Basin, forecasters revealed upcoming changes to the way they inform people about approaching storms. On average, 12 tropical storms – six of which become hurricanes – form over the Atlantic Ocean, Caribbean Sea or the Gulf of Mexico during hurricane season, according to the National Weather Service (NWS). The National Hurricane Center (NHC) said it’s making minor changes to the information it puts out during hurricane season, which runs six months, from June 1 to Nov. 30. According to the NHC, it will now include a graphical depiction of its storm surge forecast. Forecasters previously used only a text format to give storm surge information. The graphic forecasters plan to use in 2020 will give expected storm surge inundation values for the United States Gulf and Atlantic coasts, Puerto Rico and the U.S. Virgin Islands. “These values represent the peak height the water could reach above normally dry ground somewhere within the specified areas,” the NHC said. In addition to the storm surge graphic, forecasters will add a wind speed and wind radii forecast at 60 hours, which will include in the time-of-arrival and storm surge forecasts The new 60-hour mark also will be noted on the “cone of uncertainty” over areas possibly affected by a future storm. Previously, forecasters used a cone for 48 hours and 72 hours ahead of the storm. The NHC said that the size of the tropical cyclone track forecast error cone for the Atlantic basin will be mostly unchanged in 2020. “The cone represents the probable track of the center of a tropical cyclone and is formed by enclosing the area swept out by a set of imaginary circles placed along the forecast track (at 12, 24, 36 hours, etc.),” according to the NHC. One other tweak for Atlantic hurricane forecasts in 2020 is the addition of new local time zones for systems in the far eastern Atlantic. Tropical cyclones centered in the central and western Gulf of Mexico use Central Time, while those near the East Coast of the U.S. or Gulf have used Eastern Time. Other systems in the Atlantic basin use Atlantic Standard Time. “This however, can be problematic for systems affecting the Cabo Verde Islands or other locations in the northeastern Atlantic basin where locations are 3 to 4 hours ahead of Eastern Time,” the NHC said. So starting this year, systems far north and east will have appropriate local time zones noted in their associated forecasts. While the National Oceanic and Atmospheric Administration Climate Prediction Center will provide its initial seasonal outlook for the Atlantic basin in May, researchers at Colorado State University are predicting an above-average hurricane season this year, citing the likely absence of El Niño as a primary factor. Researchers at Colorado State are predicting 16 named storms, of which eight are forecast to become hurricanes. Four are expected to reach major hurricane strength with winds greater than 111 mph. The 2020 Atlantic Hurricane Season runs from June 1 to Nov. 30, and will include the names: Arthur, Bertha, Cristobal, Dolly, Edouard, Fay, Gonzalo, Hanna, Isaias, Josephine, Kyle, Laura, Marco, Nana, Omar, Paulette, Rene, Sally, Teddy, Vicky, and Wilfred.

For more from the NHC on the upcoming hurricane season, click on the text above.

Hurricane warning vs. hurricane watch: Here’s the difference

Between early June and late November, coastal locations from Texas to Maine are vulnerable to the wrath of hurricanes that can cause vast destruction. On average, 12 tropical storms — six of which become hurricanes — form over the Atlantic Ocean, Caribbean Sea, or the Gulf of Mexico during the hurricane season, according to the National Weather Service. In a typical two-year period, the U.S. coastline is struck by an average of three hurricanes, one of which is classified as a major hurricane with winds of 111 mph or greater. The storms can have winds ranging from 74 to over 157 mph that brings destruction from storm surge and torrential rains that have the ability to cause massive flooding. When such storms approach land, the National Hurricane Center will issue either what is known as a “hurricane watch” or “hurricane warning” for affected communities. So what’s the difference between the two? When “hurricane conditions” or sustained winds of 74 mph or higher are expected, forecasters will issue what’s known as a hurricane warning. “A warning means that hurricane conditions are expected, whereas a watch means that conditions are possible,” the National Oceanic and Atmospheric Administration’s National Ocean Service (NOS) said. Since hurricane preparedness activities become difficult once winds reach tropical storm force — which are sustained winds between 39 and 73 mph — hurricane warnings are issued 36 hours in advance of the anticipated onset of those winds to allow for “important” preparation. “During a hurricane warning, complete storm preparations and immediately leave the threatened area if directed by local officials,” according to the NOS. Hurricane warnings also can be in effect for other reasons besides wind “The warning can remain in effect when dangerously high water or a combination of dangerously high water and waves continue, even though winds may be less than hurricane force,” the National Weather Service states. A hurricane watch means that hurricane conditions — sustained winds of 74 mph or higher — are possible within the specified area. A hurricane watch is issued 48 hours in advance of the anticipated onset of tropical-storm-force winds in an area. “During a hurricane watch, prepare your home and review your plan for evacuation in case a hurricane or tropical storm warning is issued,” the NOS states. “Listen closely to instructions from local officials.”