Friday, May 14, 2021

Hints of drought in North Idaho

| March 15, 2021 1:00 AM

The first 15 days of March have been the driest in history in Coeur d’Alene, based on Cliff’s records dating back to 1895. Only 0.07 inches of rain has fallen in the first half of this month. At Spokane International Airport, there has been no measurable rain for the first 15 days.

However, despite the recent dryness, thanks to a very wet January when 5.32 inches of moisture fell, our seasonal total to date stands at 8.02 inches. The normal through March 15 is 6.88 inches.

At the airport, moisture totals are slightly below normal as 3.66 inches of rain and melted snow has fallen since Jan. 1. The normal to date in Spokane is over 3.80 inches.

Regions of the Pacific Northwest including Seattle, Portland and the Inland Northwest are still doing well with moisture supplies. However, according to the U.S. Drought Monitor, over half of the Continental U.S. is suffering from abnormally dry to exceptional drought conditions.

The Water Year across much of the West including California, Nevada and Colorado begins on Oct. 1, as the summer seasons often have very little rain. According to the U.S. Department of Agriculture, the statewide snow water content for California is near 60 to 65 percent of the historical average through the first week of March.

In California’s Central Valley, recent rains did help a bit, but most areas are less than 60 percent of normal. At Sacramento’s Executive Airport, only 6.02 inches of rain has fallen since Oct. 1, 2020. That's about 41 percent of average and I don’t see any major storms hitting the Golden State for at least the next several weeks.

Conditions are even drier in Southern California. Most stations have barely reported over 5 inches of rain since last October. Stations near Los Angeles have currently seen about 35 to 40 percent of normal moisture.

Water shortages are becoming a major concern in California. Water levels at the large reservoirs are approximately 55 to 65 percent of average for this time of year.

According to the Sacramento Bee, the current water supply has not reached the levels seen in 2014 and 2015 when the state was very dry. During that time, drought emergencies were declared and residents were not allowed to water their lawns.

Around the rest of the country, extreme drought conditions have migrated into Texas, especially the western portions. Parts of Arizona, Nevada, New Mexico, Utah and Colorado are reporting “exceptional drought” conditions.

According to the National Weather Service, thanks to the lack of a monsoon season, Las Vegas went a record 240 days from April to December of 2020 without any measurable rainfall.

Yuma, Ariz., went 242 days without any rain last year. Phoenix had 110 consecutive days without rain and the desert areas in California had over 200 days without moisture. Many stations in the Desert Southwest also reported one of the driest Februarys in history.

Last September I reported on a recent study from Columbia University that was published in Science Advances. The western U.S. has experienced one of its driest 20-year periods in approximately 1,000 years.

Despite a few wet years, the southwestern regions may be in the midst of another “megadrought,” which, according to tree ring data, can last for decades.

Since 800 A.D., evidence shows that there have been four previous megadroughts. They occurred in the late 800s, the mid-1100s, the 1200s and the late 1500s.

Researchers compared soil moisture records calculated since 2000 and concluded that the current drought is “already outdoing the three earliest ones.” The worst megadrought in the West likely occurred from 1575 to 1603.

The article also states that the ancient droughts went on at least for several decades, but the one in the 1200s lasted for nearly a century.

In other parts of the U.S., most of the Great Plains are experiencing severe to extreme drought. The dryness has recently expanded eastward into Iowa, Illinois and Indiana.

Parts of the northeastern U.S. are reporting dry to moderate drought levels. With the exception of pockets of abnormally dry areas, moisture totals in the Southeast to the Mid-Atlantic states are still at good levels.

With a very dry start to March, it’s very possible that the Inland Northwest will see drier-than-normal weather later this spring and summer season as the dry weather pattern to the south expands. But, there should be a brief wet period in May. As I’ve mentioned in other articles, our region has been experiencing wetter winter and drier-than-normal summer seasons.

We don’t see a lot of moisture this week, but there is an increasing chance of rain, and even some snow, around the Spring Equinox, the first days of spring, on Saturday.