Santa Ana Wind events

[Jason Harris]

Did anyone directly experience some of the hurricane force or higher winds from the recent Santa Ana Wind events?

Does anyone have any insights into the causal dynamics of severity of this recent event in particular?

Winds were most extreme at higher elevations. Mammoth Mountain in the Sierra Nevada clocked wind gusts at 150 mph and sustained winds of at least 100 mph, which is the equivalent of a Category 2 hurricane.

In Los Angeles County, gusts of 97 mph were recorded at Whitaker Peak.

More on the way but not as strong:
http://www.kcet.org/updaily/socal_focus/weather/santa-ana-winds-to-return-to-monday-morning.html

Here's a Santa Ana wind faq:

http://www.atmos.ucla.edu/~fovell/ASother/mm5/SantaAna/santa_ana_faq.html

 

[John Fertsch]

Where i commute to work sure did - 65 to 72 mph winds out here in Mojave Desert - caused part of the posts gas station overhang to break off and caused multiple power outages around - at times visibility was less then 1 mile with a serious sand blasting to the vehicle - but where i reside - no more then 47 mph gust that took a few roof shingles... bet my roof has a checkerboard appearance now...

 

[Jeff Duda]

Does anyone have any insights into the causal dynamics of severity of this recent event in particular?

The answer to your question is contained within that FAQ. Although the synoptic-scale pressure gradient certainly can cause strong winds, the really strong gusts (those well above 40 - 50 kts) are certainly a product of mesoscale events. One such cause is
gap winds between mountain ranges or peaks. Terrain funnels air through which increases the wind speed. Other causes include breaking of mountain waves over the lee slopes, standing waves, and hydraulic jumps (where the flow trusn from subcritical - sinking over the top of the mountain and rising over the lee side - to supercritical - rising over the mountain top and sinking on the lee side). Hydraulic jumps cause significant wind accelerations on the lee side of mountains. You can also get rotors to form in the valley. I believe a rotor was responsible for a significant high wind event in Boulder some number of years ago.

 

[mwenzbauer]

That same day I experienced the high winds in Utah (80-100mph just north of Salt Lake), and had numerous friends/family with minor damage (trees down, loss of many shingles, fences blown down, power outages)... I am not sure if this local event is related to the Santa Ana winds somehow or not, but it again involves winds blowing from the northeast down steep, narrow canyons. I will say that driving thru this area during these winds was not pleasant, but at least I was not hit by any debris. These events seem to happen here every 2-3 years... seems the Santa Ana's are more frequent?

 

[Jeff Duda]

Sounds like the exact same mechanism, but those winds probably wouldn't be called "Santa Ana"s just because of the location. I'm not sure exactly the location you're talking about, but maybe "Wasatch"s would be a better term?

 

[John Farley]

I came closer to getting hit by flying debris during that event than I ever have on a storm chase. I got stuck in traffic in Albuquerque at an intersection where the stop light was out due to a power outage caused by the wind. Suddenly a strong gust of wind sent a large mat or rug flying in the air from a pickup truck in the lane next to me - and before I knew it, two shovels and a hoe, which were on the rug, were launched in the air and landed a couple feet from my car. Also had to dodge a street sign blown into the road. I'd estimate the strongest winds I encountered at 50-60 mph, but in favored areas for gap winds there were measured gusts of 88 and 85 mph.

BTW, I think the generic terms "gap wind" or "canyon wind" would be a better description for this event than the more local California term "Santa Anna wind" or other local terms such as "East Canyon Wind" in NM, as high wind events occurred in numerous locations in the West due to the combination of strong gradient winds and the effects of local terrain features. In some localities, it went beyond gap winds, as the cold air east of the NM mountains was deep enough to cause overtopping of even some mountains higher than 10,000 feet. The latter is an example of the "hydraulic jumps" phenomenon Jeff describes above, and was responsible for the 88 mph gust, which occurred at the bottom of the Sandia Peak tram. The 85 mph gust was on the lee side of a gap in the mountains.