A string of heavy, isolated storms last week brought timely moisture to farmers and ranchers throughout southern Idaho amid an otherwise dry summer.
An unusual, prolonged pattern of tropical moisture originating from the Gulf of California caused the wet spell, explained National Weather Service meteorologist Dan Valle.
Valle expected the moist weather pattern to change due to a cold front arriving from the northwest Sept. 7-8. He said the intense storms resulted in reports of isolated flooding throughout their path from the south.
“Throughout all of southern Idaho, pretty much everyone has been getting in on the abnormal levels of moisture,” Valle said.
Pocatello, Idaho, has been especially wet, receiving 2.64 inches of rain in just a couple of hours, contributing to flash flooding on Aug. 23 and getting 1.65 inches of rain in another storm that caused flooding on Sept. 3.
Natural Resources Conservation Service hydrologist Ron Abramovich explained most of the region’s moisture came during the first five days of September, and August will be recorded as another dry month for most Idaho farmers. Abramovich said the Big Wood River and Little Wood River basins received just 15 percent of normal August precipitation, and moisture levels ranged from 20 to 40 percent of normal for the month in the southern two-thirds of Idaho.
In September, however, southeast Idaho’s Willow, Blackfoot and Portneuf river drainages received half of their usual monthly moisture and the Goose Creek drainage in Cassia County was inundated with 114 percent of its monthly average during the first five days of the month. Raft River, which had been drained to 1 cubic foot per second, briefly spiked to 270 cubic feet per second, Abramovich said.
“The valleys got good moisture, too. It’s just what we needed to get these fall crops in good and get some moisture back in the vegetation,” Abramovich said, adding storms have also helped dampen some Idaho wildfires.
However, he’d like to see a return to a more even pattern of storms originating from the northwest for the rest of September and October.
Dryland farmers in Caribou County, who depend on moisture near fall wheat planting to help stands germinate before winter, received 1.2 inches of moisture from three recent storms, said grower Sid Cellan.
“Everyone is now starting to plant fall wheat. We should be in good shape with this year’s fall crop,” said Cellan, who shifted to planting grain Sept. 5 because fields were too wet to cut. “It’s just perfect for (planting) right now.”
The storms have saved Rockland Valley rancher James Udy thousands of dollars by enabling him to keep about 100 head of cattle grazing near Bone, Idaho, on their summer range for at least a week longer, prolonging when he’ll start feeding them his third cutting of hay. Udy said the moisture has promoted new growth of grasses and moistened existing forage, making it more palatable.
American Falls grower Jim Tiede said the storms have extended a tight irrigation season by five days. He shut off his wheel lines on Sept. 4, planning to leave them off through Sept. 10, which should save him about $25,000 in power costs alone.
In the long term, Abramovich said ocean conditions remain in a neutral pattern, as they were last winter, and dry winters commonly follow other dry winters.