We were part of a big crowd at the Central Area Senior Center in Leschi today watching the Seafair action down below. Luckily the drizzle and fog cleared right before 1pm, leaving just some low-hanging clouds that allowed a good view of the Blue Angels’ “flat” show.
Here’s our photo spread:
Boeing’s new 787 passes low through the drizzle
Looks like you caught a sonic boom on film in pic #3. See also: http://en.wikipedia.org/wiki/Prandtl%E2%80%93Glauert_singula
“Understand that these Prandtl-Glauert condensation clouds can also occur at lower speeds, and are not really a visible manifestation of some kind of a sound barrier being broken.”
http://wilk4.com/misc/soundbreak.htm
and “Finally, it should be clear that Prandtl-Glauert condensation has nothing to do with “breaking the sound barrier” and is not a Star Trek-like “burst” through Mach one. An aircraft can generate a Prandtl-Glauert condensation cloud without ever exceeding the speed of sound.”
My wife grew up in Southern California in the 60’s and is very familiar with sonic booms from military jets back then. Nothing she heard this weekend resembled that.
BTW the C-130 is called “Fat Albert”
While it is true that the Prandtl-Glauert cloud can form without a sonic boom, the fact that several (experienced) people reported hearing them over the weekend makes me think it’s quite possible this was associated with a boom. Weather, altitude, and maneuvering all affect the cone of a sonic boom. You have to be within the cone to experience the boom. Considering the low altitudes of these flights, and the fact that they were more likely to be the result of maneuvering than simply speed, the width of the cone could have been quite narrow.
http://www.daviddarling.info/encyclopedia/S/sonic_boom.html
We had sonic booms here in Seattle in the 60’s as well.
@JenB:
While your friends are quite knowledgable about sonic booms and I’m sure they are great people the Blue Angels never exceed the speed of sound during a performance.
http://www.blueangels.navy.mil/faq_iframe.htm#Q_29
I’ve lived in Seattle and watched the Blue Angels nearly every year of my life and I have never seen the cloud formations around the nose until this weekend, which is the first time in my memory that it had been this humid outside.
Hey, @JP
Thanks for thinking my friends are knowledgeable and great people. (They are IMHO.) I was actually referring to the many comments on CD News from people hearing the booms, some of whom claim to have experience with them in the past. The discussion has intrigued me, and led me to doing a bit of research on the subject. Thanks for the link.
I’m sure the weather had an impact on the formation of the Prandtl-Glauert clouds. It may also have affected the speed of sound leading to reaching Mach 1 at lower speeds. Also, note that the picture above shows an F-18 rather than a Blue Angel.
On a personal note, the weather also affected my bread dough, causing it to rise extremely slowly. My Challah turned into more of a Pan Rustic than a fluffy egg bread.
Glad you gave us that name. I never remember to check when I’m online and when I’m not….Big Boy? nope. Blue Boy? nope. Fat Boy? nope. Thank you!
(and I am one who claimed familiarity with sonic booms, but in reality that was in my childhood which was quite some time ago….and I couldn’t figure out why any of the planes could be flying that fast in this venue. I love crows, but not when I have to eat it) :)
Great pics.
Flat show let you get a good pic of the new Boeing! Nice.
As usual, tight formation flying of the Blue Angeles is AMAZING.