More weather extremes and El Niño

It’s been a very dry September across the Inland Northwest.

Coeur d’Alene’s rainfall total for this month, as of Sunday, is only 0.22 inches, while 0.31 inches have been measured in Sandpoint and just 0.10 inches has been measured at the Spokane International Airport. The normal precipitation for September in Coeur d’Alene is 1.48 inches.

As we approach the full moon cycle late this month, which is also a supermoon, weather patterns will at least briefly change to the wetter side. For much of this week, there is the chance of some much-needed showers across the region. Rainfall totals by the end of September are likely to be below average, but this week’s moisture is expected to be more than the 0.18 inches that has fallen during the first three weeks of the month.

As we move into October, the first 10 days to two weeks are looking drier than normal once again. Rainfall chances should start to increase around the normally wet new moon lunar phase Oct. 14.

Weather patterns have been changing and becoming more extreme across the globe, especially this year. We’ve seen big heatwaves in Europe along with flooding rains. Torrential downpours destroyed a quarter of the city of Derna in Libya. In addition to Europe, temperature records for heat were broken during the summer season across the United States, China, North Africa and the Middle East. Scientists say that the summer of 2023 was the hottest ever recorded in the Northern Hemisphere.

The extreme weather has also led to a record number of billion-dollar disasters in the U.S. According to the National Oceanic and Atmospheric Administration, there have been $23 billion weather and climate disasters in the U.S. this year, which is already a record. Last year, there were 18 disasters with 2020 having the highest prior to this year of 22. The combined cost of those events in 2020 was approximately $117.3 billion, but in 2017, the cost was just under $400 billion.

Many of the very costly events in 2023 were severe storms, especially in the center of the country. There were at least several major tornado outbreaks during the spring season in the Great Plains and the Midwest. Another extreme event was Hurricane Idalia, a massive Category 4 hurricane that smashed into northwestern Florida and resulted in about $2-$5 billion in damage.

It’s very possible, if not likely, that the number of billion-dollar climate and weather disasters will climb. Several of the events that are not included for 2023 are Tropical Storm Hilary and the drought in the central U.S. These events are still being evaluated, according to NOAA, and calculations for total costs have not been determined.

Back in August, Tropical Storm Hilary was the first tropical storm watch to ever be issued for Southern California. The storm resulted in record flooding rains and flooding to many areas in the Southwest. By contrast, most of the spring and summer months brought drought conditions across much of the Midwest. There have been reports of damage to agricultural crops from the lack of rainfall and livestock had to be sold off earlier than usual due to the high feeding costs.

According to the U.S. Drought Monitor, extreme to exceptional drought conditions are still being reported from parts of the central U.S. Many locations southern U.S. are also experiencing massive droughts, especially in southeastern Texas, southern Louisiana and southern Alabama.

Here in the Northwest, severe to extreme drought is being reported across many parts of Washington, western Oregon, northern and central Idaho and northern Montana. The Spokane and Coeur d’Alene regions are currently indicating moderate to severe drought conditions, so the rainfall this week should help ease some of the dryness in the region.

As I’ve mentioned in previous articles, one of the big changes that has occurred is the warming of sea-surface temperatures. All government agencies, including Australia, have stated that we have an El Niño, the abnormal warming of ocean waters in the south-central Pacific Ocean. The latest information indicates this phenomenon will be very strong and gives it a 95% chance of persisting through at least the upcoming winter season.

Data from NOAA shows that sea-surface temperatures were about 2.3 degrees Fahrenheit above the long-term average in August. In early September, there are regions that are nearly 4 degrees above normal levels. In addition to the warmer waters along the equatorial regions, ocean temperatures are also warmer than normal in the Atlantic, Indian, Arctic and Southern Oceans. In terms of the entire planet, ocean temperatures are the warmest in recorded history.

During El Niño years, especially strong ones, the chances for snow in December here in the Inland Northwest are much lower. However, there has been snow around Christmas during some El Niño years, so we’ll have to wait and see how these weather patterns develop in the next several months.

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Contact Randy Mann at randy@longrangeweather.com.