Heavy February snows may lead to some flooding
Snowfall records just keep falling in Coeur d’Alene and the rest of the Inland Empire. Since Feb. 3, Cliff has measured nearly 60 inches of snow. It’s amazing that we’ve picked up nearly our entire seasonal snowfall average of 69.8 inches since the beginning of last month from this six-week cycle. If the moisture that fell in December and January would have been mostly snow, then our snow total would be much higher.
Although weather patterns in the Northwest are showing signs of change, it’s still possible that we could pick up more snow that would ultimately challenge the 100-inch mark once again. We still see near- to above-normal moisture for March and April across the northwestern U.S.
As of the weekend, Coeur d’Alene’s seasonal snowfall total is at 90.3 inches. For February and March combined, there has been a total of 58.9 inches, which breaks the two-month record of 57.4 inches set back in February and March of 1955.
There is also plenty of snow on the ground. Cliff measured 22 inches late last week, which, of course, is another record for so late in the season. The previous record was 16 inches in early March of 2008.
At this time of year, we often come into a weather pattern where we see more rain during the day, but snow can still fall at night. The storm on late Wednesday and Thursday did produce some rain during the day and nearly 3 inches of snow during the overnight hours. This combination leads to a lot of ice on the ground, so be careful.
In the mountains, there will be plenty of snow, assuming it doesn’t melt too fast. About 7 feet of snow has been measured at Kellogg Peak at the Silver Mountain Resort. For the season, a whopping 300 inches has fallen on the mountain. At the summit of Lookout Pass, nearly 10 feet of snow is being reported.
We’re now at a time of year when flooding is a concern across the Inland Northwest, especially with the record amount of snow on the ground. The long-range computer models are indicating that we will see warmer temperatures with the chance of rain toward the middle to the end of next week, which increases the chances of area flooding. Also, we’re going to add to the snowpack with the next storm that will arrive tonight and continue into Tuesday.
As we head into spring, officials will be carefully watching the levels of Lake Coeur d’Alene and other lakes across the region. Lake Coeur d’Alene currently stands at just over 2,121 feet, about 7 feet below the summer maximum level. Flood stage is reached when the lake hits 2,133 feet. Moderate flooding is at 2,136 feet and major flooding is at 2,138 feet.
Most of the time, the Inland Empire sees its greatest risk of high waters during the spring season. The big floods typically result from torrential thunderstorm downpours, gusty southerly winds and warm rains falling on melting snowpacks in the higher elevations.
Historically, North Idaho and the rest of the Inland Empire has seen its share of high waters. In November of 1990, there was widespread major flooding on western Washington rivers, especially the ones in the northwest, as well as several eastern Washington rivers. The Interstate 90 Lake Washington floating bridge actually sank during that time. Two deaths were recorded as damage was estimated at $250 million.
In February 1996, widespread flooding was seen in Washington, Oregon and Idaho. The rivers across the region went far above flood stage due to a “rain-on-snow” event combined with ice jams in area rivers. Temperatures were near zero degrees at the end of January, which led to ice along many rivers along with deep snows. The most severe flooding occurred on the Coeur d’Alene River basin, the St. Joe River basin and the Palouse, Orofino and Lapwai creeks. The overall damage in the region was estimated at a staggering $800 million.
At Cataldo, the flood stage along the Coeur d’Alene River is 43 feet. In February of 1996, the river went to 51.62 feet. The highest level ever recorded at Cataldo was in January 1974, when the river rose to 58.23 feet.
Perhaps the worst flood ever seen in recent times across our region happened in May and June of 1948, known as the “Greatest Spring Snowmelt Flooding.” During that time, there was widespread flooding in North Idaho and eastern Washington, especially along the Columbia River. Below Priest Rapids, Wash., the Columbia River topped at 458.65 feet, an all-time record. Flood stage is 432 feet. At Lake Pend Oreille near Hope, a crest of 2071.2 feet was measured with a flood stage of 2063.5 feet. Methow River at Pateros, Wash., hit 12.30 feet with a flood stage of only 10 feet. At the St. Joe River at Calder, a record 18.10 feet was seen.
•••
Contact Randy Mann at randy@longrangeweather.com