There were some other worldly looking clouds hovering over the Three Sisters mountains this morning. I took this iPhone photo minutes after the sun illuminated them.
Lenticular clouds are sometimes mistaken for spaceships. You can see why.
How Lenticular Clouds Form
The Cascade Mountains create a perfect environment for lenticular clouds; we see them quite often. Here’s how they form, courtesy of the National Weather Service’s Albuquerque office.
“Known as Altocumulus Standing Lenticular (ACSL) or Altocumulus Standing Lenticularis clouds, they are associated with waves in the atmosphere that develop when relatively stable, fast moving air is forced up and over a topographic barrier that is oriented more or less perpendicular to the direction from which the upper-level wind is blowing. This deflection creates a gravity wave downwind of the topographic barrier not unlike a wave you might generate by throwing a pebble into a pond. When sufficient moisture is present above mountain-top level, ACSL clouds develop within the crest of these mountain waves where the air is rising. ACSL clouds are continually developing and dissipating in the vicinity of the wave’s crest and immediately downwind of the crest, respectively. That is why they appear to remain stationary (hence the name) even though winds are swiftly (sometimes very swiftly) moving through the entire cloud. They are most often seen in the winter or spring when winds aloft are typically the strongest.”
Lenticular Cloud Eye Candy
As beautiful as these clouds are, a Google image search shows some even more mind-blowing photos of lenticular clouds around the world.
The images will show why they’re called lenticular clouds – many look like lenses. Enjoy!
Hope you enjoyed yesterday, because it might have been our last warm day (70+) of the year. After a frosty start, we topped out at a pleasantly warm 77 degrees, six degrees above average.
Couldn’t Crack 80
The National Weather Service forecasted a high of 82, as did weather.com. Neither forecasted a low near freezing (we hit 32.7 but had frost), so perhaps that cold start prevented us from hitting the magic 80 degree mark.
The Bend Airport’s high reached 84 after a comparatively balmy low of 42, so my reasoning holds there. What about Redmond? The airport soared to 85 after a chilly 33 degree start, an impressive 52 degree diurnal temperature swing. Hmmn…my theory doesn’t look so good after digesting those numbers. Perhaps Sisters had a bit of an inversion (cold air near the ground/warmer air above it; not the usual atmospheric setup!) that prevented the air mass from reaching its maximum temperature. More research may be needed.
Central Oregon aspens will soon look like this. Glorious!
Next Two Weeks Look Very Autumnal
So why was yesterday probably our last 70 degree day until, I don’t know, April 2018? There are several reasons, but the most important are the rapidly decreasing sun angle and length of day. Even a week after the autumnal equinox, each day we’re still losing more than three minutes of daylight. Add that to an increasingly lower sun angle and it makes it harder to hit 70.
Oh, and soon storms will start rolling in from the Pacific, and while October storms don’t pack the meteorological wallop that December ones do, clouds and cool Pacific air tend to keep high temps in the 50s and low 60s.
The long-range forecasts are not on our side either. The Climate Prediction Center and weather.com call for 50s and 60s for the next two weeks. Adding all of these ingredients together, past mid-October it’s tough for Central Oregon to squeeze out another sparkling 70 degree day.
Let’s hope the forecasts are wrong and we can eke out at least one more 70 degree day before Old Man Winter takes up residence in Central Oregon for several months.
After a wacky weather week that featured two days with highs in the 40s (!) in September and 1.12 inches of non-thunderstorm precipitation, things are slowly starting to return to normal in Central Oregon thanks to the return of high pressure.
The anomalous trough that brought the unseasonable weather has slowly started to shift east (good riddance!) as shown by this water vapor image from late Friday afternoon. We’re now in between the high pressure system (H) in the eastern Pacific and the low (L) that is now moving into the northern Rockies. Our little gray dot, sandwiched in the middle, has a couple of more cool-ish days before a nice warm up commences on Monday.
The water vapor doesn’t lie – high pressure will soon dominate our weather.
While 45 degree highs in September are not my idea of fun, the downpour and high elevation snow has put some serious hurt on the zillion or so wildfires that were burning just a few days ago. Ahh…back to our piercingly clear skies! Now that’s something else to be happy about on a Friday evening.