I wonder why there are so many contrails in the Treasure Valley sky- Numerous callers and e-mailers
The skies over Boise are nice and blue - and it is the warmest day of the year so far. But many are noticing a high number of contrails over Valley skies.
Contrails are those white streaks you see high in the air caused by the exhaust from jets. They are formed by condensation of moisture from jet engines.
But on this beautiful spring day - the trails are numerous, and criss cross skies over Boise and elsewhere. We've had a bunch of calls questioning why we're seeing so many.
A large part of it could be weather: with warm temperatures down near the ground and cooler temperatures aloft, the contrails form - and without a high abundance of wind, they don't dissipate as quickly as they might otherwise.
Patty Miller with the Boise Airport: "Everyone looks up and goes 'yoo hoo! It's nice weather hey what's that?'"
Miller checked with a number of sources - and there is no cloud seeding or other activity going on that would increase the number of planes in the air. Mountain Home Air Force Base says they are doing some training south of Mountain Home, but meteorologist Joel Tannenholz with the National Weather Service says the contrails are more likely from commercial jets due to the altitude.
We also checked with the Federal Aviation Administration and the Boise Airport Tower - neither agency knows of anything unusual that would boost the number of trails in the air.
Watching video of the contrails forming showed a commercial jet leaving a trail that didn't dissipate for several minutes - and even at that point stayed together like a long cloud through the sky.