Joel Tannenholz and Les Colin have worked at the National Weather Service for decades.
“It’s pretty much the worst ice storm in 30 years,” meteorologist Stephen Parker said. “Les doesn’t remember one like it, and he remembers everything.”
The Treasure Valley woke to a hard shell of ice Thursday morning that coated cars, homes, sidewalks and streets.
And not just a little ice. The National Weather Service measured 0.2 inches of accumulated ice at the Boise Airport, and other parts of the Treasure Valley reported it thicker than that.
What happened to cause this un-Idaho weather?
Forecasters expected warmer air and precipitation to move through the Treasure Valley overnight Wednesday and knock out some of the deep freeze by Thursday morning.
It did. But the rain that fell never changed to snow. Instead, as it went through colder air on the top of the inversion — just under 4,000 feet — and hit the valley floor, it turned to ice and kept building.
The rain started about 3 a.m. and was over by 7 a.m., when the Treasure Valley was going to work and school.
Slick conditions closed Interstate 84 for much of the day
Commutes took twice as long as normal. Just walking down the driveway — let alone a walk to school or the mailbox — was a risk of injury. And if you had to drive to Mountain Home, that wasn’t happening.
Interstate 84 was closed between Boise and Bliss because it was just too slippery.
Idaho State Police and Idaho Transportation Department made the unprecedented decision to close an 83-mile stretch of I-84 between the Broadway Avenue exit in east Boise to and Milepost 137 near Bliss.
Dozens of slide-offs and traffic crashes were reported, the ISP said. The worst was between Glenns Ferry and Bliss.
“I had a sergeant tell me at one point he looked over and counted 20 semi-trucks that had slid off the road,” Capt. Steve Richardson said. “We had one of our troops get out his patrol car (to check out a crash) and his car, unoccupied, slid across the highway and hit a different semi. I’ve been (at ISP) for 29 years and this is the worst ice storm I have ever seen.”
Another trooper who started in 1972 said he couldn’t ever remember the freeway closed just for ice.
ITD had all lanes reopened by 4 p.m.
Valley roads were especially treacherous at rush hour
Caldwell and Nampa school districts closed for the day. Boise and Meridian schools stayed open, but some kids got a late start as bus routes took longer than normal, and Boise cancelled afternoon kindergarten classes.
In Ada County, dispatchers got reports of eight crashes with injuries and 110 without — and that doesn’t include 76 reports of cars sliding off the road or being stalled out, or the 15 hit-and-run crashes law enforcement checked out.
What did highway crews do?
The Ada County Highway District had every available crew out by 2 a.m., and spent all morning applying salt, de-icer and sand on “priority routes” — main roads, intersections, hills, bridges, and areas near schools and hospitals.
ACHD crews went through about 60,000 gallons of de-icing liquid between 2 a.m. and noon, about double what they would use for a standard 2-inches-of-snow Boise day.
But crews had a hard time keeping up with the ice, which just kept piling up.
“The whole county was problematic,” said ACHD spokeswoman Christine Myron said. “With this storm, even though we expended all our resources, the best wasn’t enough in some cases.”
Where were conditions the worst?
Roads with steep grades — the Boise Foothills, especially the Warm Springs Mesa area — were the biggest problems. The Glenwood Street Hill had to be closed for a short time Thursday morning so crews could put extra sand down, Myron said. Cartwright Road between Hidden Springs and Bogus Basin Road was so slippery an ACHD truck got stuck and had to be pushed out by another.
Online readers told the Idaho Statesman that some parts of the city were particularly bad — including Broadway Avenue, Maple Grove and Victory roads, Federal Way at Idaho 21, Ustick Road, Ten Mile Road, Five Mile and Overland roads, Amity Road by Columbia Village, North Cole Road and Chinden Boulevard.
Or, as one Facebook post said: “All of them.”
So is this cold snap over?
Maybe. Thursday got to 32 degrees at the airport; the estimated low temperature for Friday morning is 22 — cold enough to refreeze any streets which were not treated with de-icer or salt.
It does look like the Treasure Valley will get a break at least through the weekend, with predicted high temperatures for Friday, Saturday and Sunday in the 40s or high 30s — with rain on Saturday possibly changing to snow late Sunday.
Patrick Orr: 377-6219, Twitter: @IDS_Orr
