Another big hurricane season and our first frost

It’s been another unusual season for tropical storm and hurricane activity. Last Thursday, a very strong Category 4 hurricane, Helene, hit the Big Bend region of Florida. As the storm moved inland, heavy rainfall was reported throughout the Southeast. One station in North Carolina, Busick, picked up nearly 30 inches of rain from the hurricane. Most other locations received from 5 to 15 inches of rain, especially across Georgia, Alabama, West Virginia, Virginia and South Carolina.

Helene was the strongest hurricane to hit Florida’s Big Bend region in history. It was also the third one to make landfall in this area within the last 13 months. The flooding was also catastrophic as many long-time flood records, especially in North Carolina, were broken. In addition to the heavy rainfall, wind gusts were near 100 miles per hour when the hurricane made landfall.

Hurricanes will often produce tornadoes before and after they make landfall. At least a dozen were spotted across parts of the Southeast from last Wednesday through Friday. The most tornadoes ever observed from a hurricane was 49 in 2008 from Hurricane Gustav.

As of the weekend, there have been 10 named storms that have formed in the Atlantic and Caribbean waters. In terms of named storms, it was a slow start, but six hurricanes have formed. Based on the 30-year average from 1991 to 2020, there is a new average of about 14 named storms each season. Seven out of 14 storms, on average, will form as hurricanes, with three of them becoming major hurricanes. Sept. 10 was the approximate peak of the tropical storm and hurricane season, which officially began June 1 and will end Nov. 30.

To be classified as a major hurricane, the storm would be at least a Category 3. This season marks the fifth year in a row that a major hurricane has made landfall in the U.S. According to NOAA, the last time there were five consecutive seasons of a Category 3 or higher hurricane striking the U.S. coastline was from 1915 to 1919.

Helene was the fourth named hurricane to strike the U.S. Gulf Coast this year. The other ones were Beryl, a Category 1; Debby, a Category 1; Francine, a Category 2; and Helene, a Category 4. According to Colorado State University, there have been five other seasons where four hurricanes hit the Gulf Coastal regions. The record is six, which occurred back in 1886. It’s possible that this record could be challenged in October. There is now Tropical Storm Joyce in the Atlantic and a potential formation of a tropical system in the Caribbean.

In terms of our local weather, last week was filled with freezing temperatures in some areas and very strong winds from thunderstorms. On Sept. 22, some of the outlying areas, such as Rathdrum and Athol, reported low temperatures in the upper 20s. Coeur d’Alene had a low of 40 degrees that morning. On Sept. 25, a storm did bring some much-needed showers to the region, but very strong winds accompanied the system. At the Spokane International Airport, a gust of 61 miles per hour was reported shortly after 4 p.m. At the Coeur d’Alene Airport, there was a gust of 47 miles per hour during the afternoon.

Tuesday is the first day of October, and now our attention will turn to colder weather and freezing temperatures. Low temperatures this week should still be in the mid to upper 30s in Coeur d’Alene, but the outlying areas will likely have readings below the freezing mark once again. The next best chance for freezing temperatures in the Coeur d’Alene area would be toward the middle of the month.

Since 1895, the average date for the first freeze in Coeur d’Alene is Oct. 16. The coldest reading ever recorded for October occurred Oct. 31, 1935, with a low of 8 degrees. More recently, the chilliest temperature was 19 degrees Oct. 9, 2009.

The drier-than-normal weather pattern has continued across the Inland Northwest. The recent shower activity only put our moisture total in Coeur d’Alene at 0.88 inches for September. This is below the normal of 1.48 inches. Rainfall totals for September were much lower in Spokane. At the airport, only 0.04 inches fell compared to a September normal of 0.56 inches.

It’s still looking dry across the Inland Northwest for at least the next week to 10 days. However, as we get close to the middle of the month, the long-range computer models are indicating an increasing chance of moisture along with cooler temperatures. It’s also possible that if this pattern develops in the next several weeks, we could see some snow in the higher mountains. And, with three months in a row with below-normal rainfall, the odds are very good for an above-normal precipitation pattern later this month and through the end of the year.

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Contact Randy Mann at randy@longrangeweather.com.