The rest of the hurricane season may be more active
For this year, the Atlantic and Caribbean tropical storm and hurricane season has been relatively quiet. To date, there have been only 4 named storms. Of those 4 systems, only one became a hurricane, which was Barry. On July 13, Barry made landfall on Intracoastal City, La. as a Category 1 storm. Barry weakened to a tropical storm after moving inland, but did cause extensive damage to Lafayette, Lake Charles and Baton Rouge, La.
The Atlantic and Caribbean tropical storm and hurricane season began on June 1 and the most active period is typically from mid-August through mid-October with the climatological peak of activity around Sept. 10. The normal number of named storms for an entire season that ends on Nov. 30 is about 12 based on a 30-year average.
With a weak El Nino, the warmer-than-normal sea-surface temperature phenomenon, most forecasters were leaning toward a year with near-normal named storms. However, as ocean waters are cooling along the Equatorial regions, it’s quite possible that tropical conditions in the Atlantic and Caribbean may become more active between now through October.
Earlier this year, the National Oceanic and Atmospheric Administration (NOAA) predicted 9 to 15 named storms with 4 to 8 of them to become hurricanes. Recently, NOAA updated its prediction to 10-17 named storms with 5-9 of them becoming hurricane strength. They also foresee that 2-4 of the hurricanes expected to form will become major, at least a Category 3, before the season ends later this year.
One reason for the lower number of storms in the tropics was the strong wind shear, thanks in part to a weak El Nino, that inhibited the development of these systems. The air was also much drier and there were periods of dust from the Sahara Desert in Africa that moved over the tropical regions in the Atlantic Ocean that reduced thunderstorm development. However, atmospheric conditions are changing, and ocean temperatures have cooled a bit that may increase tropical activity.
Last year, the 2018 season, was the third consecutive year with above-average named storms. There were 15 named storms and 8 of them were hurricanes. Two major storms, Florence and Michael, made landfall in the U.S. In 2018, there was over $50 billion in damage to the U.S., especially along the southeastern coastline, due to tropical storms and hurricanes.
Since records began, there have been only six seasons, including 2017, that had more than one Category 5 hurricane. In 2005, the record year with a record 28 named storms and 15 hurricanes, there were a record-tying five Category 4 hurricanes and a record Category 5 storms that formed. However, Katrina weakened to a Category 3 when it made landfall in Louisiana.
On Oct. 10, 2018, Hurricane Michael made landfall as a Category 5 hurricane with sustained winds at 160 miles per hour. It was the strongest storm of the season and third-strongest hurricane to make landfall in the U.S. in terms of its central pressure. Michael caused more than $25 billion in property damage and in Central America, damage estimates were over $100 billion.
To be classified as a Category 5 hurricane, “sustained” winds must be at least 156 miles per hour. Since 1851, there have been 34 hurricanes that reached Category 5 status. Amazingly enough, only four of these hurricanes made landfall in the U.S. as a Category 5, including Michael.
The 2017 Atlantic hurricane season was also a very destructive year. There were 17 named storms and 6 major hurricanes. It was the fifth-most active season since records began in 1851. Last year also had the highest number of hurricanes since 2005.
That year, 2017, was also the costliest tropical cyclone season on record with a price tag of $282.22 billion. That figure accounted for about 25 percent of all the combined natural disasters in the United States from 1980 until 2017. And, this didn’t include the major wildfires in the West, plus all the floods and droughts across the rest of the country.
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In terms of our local weather, daytime temperatures have been relatively pleasant. Readings toward the middle to the end of the week are expected to climb into the upper 80s and low 90s.
Last week’s storm pushed our rainfall total to .88 inches at Cliff’s station in northwestern Coeur d’Alene. The normal for August is 1.23 inches. High pressure is expected to keep conditions dry through the rest of the month, so this will be the third month in a row with below-normal precipitation. However, we did receive more moisture this summer when compared to the ones of 2018 and 2017.
As we move into September, temperatures should cool down with the possibility of some showers during the first week of the month. September’s rainfall is expected to be closer to normal, but we should turn wetter later in the fall with above-normal moisture totals forecast for the winter of 2019-20. And, as usual, time will tell.
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Contact Randy Mann at randy@longrangeweather.com