Randy Mann weather: Big storms on record pace

Thanks to the current sea-surface temperature pattern, this is another active tropical storm and hurricane season.

As of the weekend, there had been 20 named storms compared to the normal of about 13.

This is the third-most-active season in history, tying it with 1933. There have been seven hurricanes through September. Hurricane Ida was a monster Category 4 hurricane that made landfall in Louisiana. Major flooding was seen from Ida as well as the impacts from Tropical Storm Fred and Hurricane Henri.

Over the last two years combined, a record 18 named storms have made landfall in the U.S. And, since the start of the 2020 season last June, 50 named storms formed in the Atlantic and Caribbean waters.

The state that has seen the most activity is Louisiana. Since the beginning of the 2020 season, this state experienced four hurricanes and two tropical storms with some regions, such as Lake Charles, being hit more than once.

Louisiana has also been impacted by a record two Category 4 storms, Laura in 2020 and Ida in 2021. Winds were near an incredible 150 mph as the storms made landfall.

According to the National Oceanic and Atmospheric Administration, tropical storm and hurricane activity have dramatically increased since 2017. For example, their data says that from 2009 to 2016, only 13 named storms made landfall in the United States.

Tropical storms and hurricanes track to the west in the Atlantic and Caribbean waters as they typically follow the circulation around a large high-pressure system, which is called the Bermuda High. This big dome of air will circulate clockwise and the tropical storms that form will travel underneath the high-pressure system, directing them to the west.

Depending on the high’s exact location, the tropical storms and hurricanes will usually move northward, following the high’s circulation, into the Gulf of Mexico or up the East Coast. To the north, the Polar Jet Stream will direct storms from the west to easterly direction.

As I mentioned last week, sea-surface temperatures along the Equatorial region have been near or slightly cooler than normal. Ocean waters in the Atlantic Ocean are currently warmer than normal, which has likely fueled the development of tropical storms and hurricanes.

During El Nino years, when ocean waters along the Equator are warmer than normal, we’ll often have less development of named storms as the upper-level winds change and will often create wind shear and prohibit major storm development.

Last year was the most active and sixth-costliest Atlantic hurricane season in recorded history. For 2021, it is already the fourth-costliest in history. In 2020, there were a record 30 named storms that led to over $51 billion in damage. This year has already topped that figure with damage near $70 billion.

The 2017 season was the costliest tropical cyclone season on record with a price tag of nearly $300 billion. That figure accounted for about 25 percent of all the combined natural disasters in the United States from 1980 until 2017.

The official tropical storm and hurricane season begins on June 1 and ends on Nov. 30. Based on the 30-year average, there are about 13 named storms. Six of those storms become hurricanes with two of them in the “major” Category 3 or above.

This season was the sixth consecutive season with above-average named storms in the Atlantic and Caribbean regions. It was also the seventh year in a row that a tropical or subtropical cyclone developed before the official start of the season on June 1. The old record was four years in a row from 1951 through the 1954 seasons.

LOCAL WEATHER

In terms of our local weather, it’s been a very dry first 10 days of October. The overall weather pattern for the rest of the month will have a pattern of sun and showers across North Idaho and the rest of the Inland Northwest. A few of these storm systems will be colder, so there will be a chance of snow in the mountains. The air masses may also be cold enough to bring the possibility of a few snowflakes in the lower elevations, but only if there’s enough moisture left with these systems.

If we were to see some measurable snowfall this month, it would be a record third October in a row with snow. In 2019, Cliff measured 5.5 inches. The all-time October record was 7.9 inches in 2020.

Based on the current sea-surface temperature patterns, the chances are also better than 50/50 for a white Christmas in Coeur d’Alene and surrounding regions. We’ll have more details with our annual snowfall forecast in the coming weeks.

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Contact Randy Mann at randy@longrangeweather.com