Weather discussion, 28 August 2008

Some interesting facts about last night's storm:

Midtown Phoenix (defined as Central Avenue E/W 2 miles from the Deck Park to Camelback Road) got hit the hardest. Over Midtown, there were three distinct storms that passed. The first was from 9.42-10pm, the second from 11-11.20pm, the third from 11.30-11.45pm. For each of the three storms, the strongest period of activity was in the trailing edge of each storm as it moved west.

National Weather Service Doppler radar indicated winds at 1,500 feet above ground to be in excess of 95 miles per hour on the first storm and slightly under that for the second storm. No winds data is available for the third storm. (The same radar indicated the strongest winds to be over 100mph just west of Sky Harbor International Airport at 9.45pm.)

By the media coverage, the hardest hit urban area was centered at the intersection of Central Avenue and Encanto Boulevard. Parts of the roof and windows from the 22-story Regency House condominium tower broke off and landed on Central Avenue, most notably on the overhead catenary wires that will power METRO when it opens 27 December 2008. Scores of east-facing windows in the Tapestry on Central condominium complex were blown out with glass shards from these windows traveling distances of over 500 feet to the west. Many roof-mounted air conditioning units on the Tapestry complex's roof were damaged or destroyed. Power lines on 3rd Avenue and 7th Street were blown over causing widespread power outages.

At this hour (9.20pm 29 August 2008), power is off in the Willo Historic District, the Encanto-Palmcroft Historic District, and other adjacent neighborhoods. Power was largely lost during the second storm that blew a transformer at 7th Street and McDowell Road.

A more scientific discussion with detailed Doppler radar images can be found from the National Weather Service's Phoenix office webpage, online at http://www.wrh.noaa.gov/psr/pns/2008/August/28thStorms.php.

Cheers-
Edward Jensen