Hurricane season waning in Atlantic

We recently passed the climatological peak of hurricane season for the Atlantic on Sept. 10. Though across the Inland Northwest, we are too far away to feel any direct effects weatherwise from these types of storms, we are definitely affected economically when such storms wreak havoc in other parts of the country. In August, the National Oceanic and Atmospheric Administration issued an updated Atlantic hurricane season forecast. The outlook called for a likely range of 13 to 16 named storms, with seven to nine hurricanes and three to five major hurricanes (those of category 3 or higher). So far it has been a pretty active month in the tropical Atlantic, with three named storms as of Sept. 19. For the season there have been nine named storms, including Hurricane Dean and Hurricane Felix which both had top winds of 165 mph. Fortunately, neither of these category 5 hurricanes made landfall in the United States. Hurricane Humberto, the first hurricane to hit the United States in 2 years, impacted folks on the Texas and Louisiana coasts Sept. 13. Though it was a minimal hurricane at landfall, with maximum winds of 85 mph, it surprised many, including the forecasters at the National Hurricane Center. Humberto broke records by growing from a tropical depression to a full-scale hurricane faster than any other storm in history. Across the U.S. there have been 34 fatalities so far this year which can be attributed either directly or indirectly to tropical storms. Eighteen fatalities occurred as a result of tropical storm Erin, which brought disastrous flooding to parts of Texas, Missouri and Oklahoma.

Operating under the same umbrella agency, NOAA, as the National Weather Service, the National Hurricane Center is responsible for issuing warnings and advisories related to tropical storms and hurricanes. Forecasters at the NHC are constantly tracking conditions in the tropical waters for signs of activity. Before a storm becomes a hurricane, it starts as a tropical wave or disturbance. This is seen as an area of organized thunderstorm activity over the warm ocean waters. When certain air pressure criteria are met, and the sustained winds over the area are between 23 to 39 mph, the disturbance is upgraded to a tropical depression. When conditions reach tropical storm status, meaning maximum sustained winds of at least 39 mph but less than 74 mph, the storm is given a name. The storm reaches hurricane status (retaining its name) when winds reach 74 mph. Of all the tropical storms that form across the oceans, only about half intensify to become hurricanes.

The costliest hurricane to strike the United States was Katrina in 2005, resulting in more than $80 billion in damages. It was not the deadliest hurricane though, despite fatalities totaling more than 1,800. The deadliest hurricane to ever strike the mainland U.S. was a category 4 unnamed storm which killed more than 8,000 people in the Galveston, Texas, area in September 1900. The winner in the category of most intense hurricane to hit the U.S. goes to an unnamed storm which struck the Florida Keys in 1935 and had a minimum central pressure of 26.35 inches of mercury (Katrina was ranked third in this category). Hurricane season continues until Nov. 30.

Welcome rain

Locally, welcome rains arrived on Sept. 18 to end a previously rainless month. Despite a morning of gray skies and showers, only .09 inches of rain was measured in Coeur d’Alene, leaving the area still nearly 3 inches below normal for yearly rainfall. Though showers also moved through the Spokane area, not a drop fell at the Spokane airport.