Normal hurricane season expected in Atlantic, Caribbean

May was the fourth month in a row with above normal precipitation in Coeur d’Alene. But, the final total for this month will end up at 2.89 inches, very close to the normal of 2.37 inches.

With warmer waters across the eastern Pacific Ocean, weather patterns in the West are changing. It appears we’re starting to move into a drier and warmer weather pattern. Highs will be well into the 80s through Tuesday before cooling down later in the week with the chance of showers and isolated thunderstorms. We’ll probably see some 90-degree temperatures in Coeur d’Alene and surrounding areas by the middle of June. Despite the new weather pattern, don’t be too surprised to see a few days with some afternoon showers or thunderstorms, especially near the mountains.

If we do have a new warmer “El Nino” declared this summer, then our region should see an increase in moisture in the fall. The winter of 2017-18 still looks like snowfall totals will be below normal across much of the West. It will be interesting to see if California gets a lot of rain from sub-tropical origins as is often the case, but not always, with a new El Nino.

As we move into June, the 2017 hurricane season begins this Thursday, June 1, and continues through Nov. 30. Most forecasters are predicting a relatively “normal” tropical storm and hurricane season. The average number of named storms, based on the recent 30-year average, is 12 with 6 of them becoming hurricanes and two of those hurricanes intensifying into a Category 3 or higher.

This forecast is primarily based upon the warming of sea-surface temperatures in the waters of the South-Central Pacific Ocean. Historically, we often see more tropical storm and hurricane activity during “La Nina” years when sea-surface temperatures are cooler near the Equator and warmer near the U.S. East Coast and the Gulf of Mexico. When we have a warmer “El Nino,” upper-level air-flow patterns will often shear off tropical storms which often inhibits the storm’s development.

For the 2017 season, the prediction from hurricane forecasters, as well as Cliff and myself, is 11 named storms with 4 of them becoming hurricanes. Two of the hurricanes are expected to reach Category 3 strength or higher.

Last year’s 2016 Atlantic hurricane season was the one of the most active since 2012. There were a total of 15 named storms which produced 7 hurricanes. Four of the seven hurricanes were major, a Category 3 or higher. Last year was also the costliest season since 2012 and the deadliest since 2008.

The first hurricane to form last year happened on Jan. 12 and formed in the northeastern Atlantic. The storm was named Hurricane Alex and it was the first hurricane to develop in January since 1938.

The strongest and costliest hurricane of 2016 was Hurricane Matthew. It intensified into a Category 5 storm, the highest on the widely-used Saffir-Simpson Scale. Matthew was the ninth costliest Atlantic hurricane on record as it brought widespread destruction to Haiti, Cuba, Dominican Republic, the Lucayan Archipelago and the southeastern United States. Winds topped out at 165 miles per hour and damage was estimated at over $16 billion.

Although hurricane forecasts for this year are expected to be close to the 30-year normal for this year, scientists have not found a correlation between the number of storms versus the ones the make landfall. For example, in 1992, there were only six named storms, but one of those systems intensified into Hurricane Andrew. That hurricane was a monster Category 5 storm that devastated South Florida.

However, in the active 2010 season, there were 19 named storms and 12 of them grew into hurricanes. Despite the high number of storms that formed, no hurricane or tropical storm made landfall in the United States.

The most active hurricane season in recorded history occurred in 2005. There were a total of 28 named storms with 7 “major” hurricanes. One of those big hurricanes was Katrina, the deadliest natural disaster in United States history. Damage was at least $108 billion with a death toll of approximately 6,000 people.

By the way, the least active hurricane season was in 1914. During that year, there was only one tropical storm and no hurricanes. Most recently, the 2013 Atlantic hurricane season was one of the least active seasons since 1982.

Contact Randy Mann at randy@longrangeweather.com