August 28, 2008 Storm Statistics

Readings From Weather Bus.com:

First Measurable Rain Time: August 28, 2008 at 7:55pm
Last Measurable Rain Time: August 28, 2008 at 10:30pm
Storm Total: 0.38in.
Max Rain Rate: 3.29in/hr @ 9:04pm
Peak Wind Gust: E @ 18mph @ 9:01pm
Total Lightning: 206,780

Comments:
Several areas (lines) of thunderstorms developed to the east-northeast of the valley during the evening on August 28th. These lines of thunderstorms were generally moving to the west-southwest. As these thunderstorms moved into a very moist and unstable atmosphere over the valley, they strengthened into strong to severe thunderstorms, resulting in severe wind damage, heavy rainfall, hail and a tremendous amount of lightning. The below summary will be broken down into the distinct lines of severe storms that moved through the valley in order to focus on the major events from each 'wave'.

The first area of thunderstorms moved through the extreme east valley starting around 7:45pm, with the first measurable rainfall at our location occurring at 7:55pm. As this area of thunderstorms continued to move to the southwest, it strengthened considerably over Chandler, Gilbert and Sun Lakes, from about 8:00pm to 8:40pm. At 8:25pm, a measured wind gust of 77mph was reported by the AWOS station at Chandler Airport. At 8:30pm, 0.22in. of rainfall in five minutes was reported five miles south of Chandler, and also 0.50in. of rain in ten minutes was reported at the same time three miles east-northeast of Chandler. At 8:40pm, an estimated rainfall total of 0.50in in thirty minutes was reported 5miles west of Chandler. This line of strong to severe thunderstorms continued to strengthened and was moving into Maricopa by 8:55pm. Doppler radar velocity imagery at 8:50pm, depicted a line of strong winds in the 40mph to 70mph range from southwest of Guadalupe, stretching down toward Maricopa. This storm also produced sizable hail to the southwest of Guadalupe, with 0.75in in diameter hail being reported at 8:50pm, seven miles southwest of Guadalupe as well as four miles southwest of Guadalupe. The Doppler Radar loop (1.4 degree tilt) to the right/above, shows the progression of the storm from 7:40pm to 9:04pm.

The loop to the left is the Doppler Radar imagery (1.4 degree tilt) from 8:46pm to 10:14pm, showing the second line of severe thunderstorms which moved through the valley. The second, and later to become the most destructive, line of thunderstorms moved into eastern Maricopa County and north central Pinal County around 8:30pm. The first measurable rain at our location with the storm occurred at 8:59pm. Very heavy rainfall occurred with this storm in the area, resulting in 0.27in. of rainfall occurring in seven minutes at our location! Additional reports received by the NWS from Apache Junction and Gold Canyon, during this time frame included 0.50in of rainfall in nine minutes one mile southwest of Kings Ranch, and a remarkable 1.20in. occurring within twenty-five minutes two miles northwest of Apache Junction. By 9:09pm, Doppler Radar indicated a line thunderstorms from Fountain Hills down to Queen Creek, which were moving to the west. This is when things became very interesting... (The loop below is the Doppler Radar Velcoity imagery (0.6 degree tilt) from 9:04pm to 9:47pm) At 9:19pm, strong to severe thunderstorms were in a line from just to the west of Fountain Hills to Sun Lakes, with the velocity imagery showing two distinct areas of strong winds moving to the west. One was located in between Higley and Gilbert, with the second located in Mesa, between Power Rd and Lindsey Rd around McKellips. This was verified by a spotter report of estimated winds of 75mph, occurring at 9:20pm, at Recker and Brown. This line of severe thunderstorms continued moving to the west and at 9:28pm, Doppler Radar velocity imagery estimated winds speeds in Chandler (at 647feet off the ground) to be in the 80mph to 85mph range, with the strong winds in eastern Tempe strengthening to near 70mph, at 871feet off the ground. Severe thunderstorms, with very strong straight line winds in excess of 75mph continued to move toward Phoenix from the east. By 9:33pm, Doppler Radar velocity imagery indicated the strongest wind speeds at the time to be in the area contained east/west by Hayden Rd and Priest and north/south by McDowell and University. See the velocity radar image below showing this area as well as the corresponding photos we took yesterday of the damage in the area due to these high winds. The area of strong damaging winds continued to move to the west, and even strengthened, with a large area of wind speeds estimated by the Doppler radar (between 1,250 and 1,550 feet off the ground) to be in excess of 100mph at 9:37pm, over/near Phoenix Sky Harbor airport. At 9:38pm, the ASOS station at Phoenix Sky Harbor recorded a wind gust of 75mph from the east! This line of severe thunderstorms moved into downtown Phoenix around 9:50pm and by 10:30pm, had weakened considerably and moved off to the west-southwest. Click the images below to view full-size.
9:33pm Velocity Image 1 Image 2 Image 3


By 10:00pm, a third area of thunderstorms was beginning to take shape, once again, across eastern Maricopa County. A new line of strong to severe thunderstorms, at 10:30pm, was located from north of Fountain Hills, stretching down toward Higley, with the strongest part of the storm being located just to the south of Fountain Hills. This line of thunderstorms continued to move to the west, while yet another area of thunderstorms developed behind it and was also moving to the west-southwest.

These lines of strong to severe thunderstorms caused extensive damage across much of the valley, along with some locations receiving a large amount of rainfall. When all was said and done, our location recorded a storm total of 0.38in..

Another astonishing aspect of these thunderstorms was the incredible amount of lightning. During the storms we recorded 206,780 strokes of lightning!!! The most active minute occurred at 9:25pm, when 1,321 strokes were recorded. In fact, at 9:18pm, 36strokes of lightning occurred within one second! Below is the table breaking down the lightning count:
Cloud-to-Ground Positive: 15,827
Cloud-to-Ground Negative: 81,026
Cloud-to-Cloud Positive: 36,541
Cloud-to-Cloud Negative: 73,386
TOTAL: 206,780

Below are rain totals reported to us by the public. Weather Bus.com thanks you for your reports! (Reports are ordered from newest to oldest.)

Location: Montesa
Report Time: 28th of August 2008 9:43PM EST
Reporter: Don Ham
Rain Total: 0.50in.
Comments: Heavy rain at times and a spectacular light show with lighting all around us.

Location: Apache Junction - Ironwood and McKellips
Report Time: 29th of August 2008 9:12AM EST
Reporter: DzrtRat67
Rain Total: 0.37in.
Comments: Wow! What a show! Can\'t wait to see the lightning totals for that one.

Location: Gold Canyon Golf Course Area
Report Time: 29th of August 2008 9:00AM EST
Reporter: Deb
Rain Total: 0.60in.
Comments: 8:00pm through overnight

Location: Scottsdale FLW and 101
Report Time: 29th of August 2008 8:23AM EST
Reporter: Steven Steinke
Rain Total: 0.78in.
Comments: Near continuous lightning and windswept rains from training storms moving NE to SW across the area. 0.78" here.

Location: Apache Junction
Report Time: 28th of August 2008 11:15PM EST
Reporter: O/C
Rain Total: Rained
Comments: Lightning, Lightning, Heavy rain.

Location: Y at AJ
Report Time: 28th of August 2008 12:12AM EST
Reporter: Bob
Rain Total: 0.98in.
(The above rain totals were reported to us by the public. The accuracy of these reports is unknown.)

We thank you again for your reports! If it rained at your location, let us know by using the menu toward the top of the page (Public Reports --> Rain Reports). Your report will be added to this page.

Below are the storm reports received by the National Weather Service in Phoenix:
 PRELIMINARY LOCAL STORM REPORT...SUMMARY
 NATIONAL WEATHER SERVICE PHOENIX AZ
 
 ..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
 ..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
             ..REMARKS..
 
 0825 PM     TSTM WND GST     2 S CHANDLER            33.27N 111.87W
 08/28/2008  M77.00 MPH       MARICOPA           AZ   AWOS            
 
             CHANDLER AIRPORT
 
 0830 PM     HEAVY RAIN       5 S CHANDLER            33.22N 111.88W
 08/28/2008  M0.22 INCH       MARICOPA           AZ   AMATEUR RADIO   
 
             0.22 INCH IN 5 MINS
 
 0830 PM     HEAVY RAIN       3 ENE CHANDLER          33.31N 111.82W
 08/28/2008  M0.50 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             0.5 INCH RAIN IN 10 MINS
 
 0840 PM     HEAVY RAIN       5 W CHANDLER            33.29N 111.95W
 08/28/2008  E0.50 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             0.5 INCH IN 30 MINS. 
 
 0850 PM     HAIL             7 SW GUADALUPE          33.30N 112.06W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             3/4 INCH HAIL REPT LIBERTY LN AND DESERT FOOTHILLS PKWY
 
 0850 PM     HAIL             4 SW GUADALUPE          33.32N 112.00W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   NWS EMPLOYEE    
 
 0906 PM     HAIL             NW MARICOPA             33.06N 112.05W
 08/28/2008  E0.25 INCH       PINAL              AZ   TRAINED SPOTTER 
 
             1/4 INCH HAIL COMPLETELY COVERING GROUND
 
 0910 PM     HEAVY RAIN       1 SW KINGS RANCH        33.37N 111.45W
 08/28/2008  M0.50 INCH       PINAL              AZ   TRAINED SPOTTER 
 
             HALF INCH RAIN IN 9 MINUTES
 
 0912 PM     HEAVY RAIN       4 E APACHE JUNCTION     33.40N 111.48W
 08/28/2008  M0.00 INCH       PINAL              AZ   TRAINED SPOTTER 
 
             0.27 INCH RAIN IN 7 MINUTES
 
 0919 PM     HEAVY RAIN       2 NW APACHE JUNCTION    33.42N 111.57W
 08/28/2008  E0.00 INCH       PINAL              AZ   TRAINED SPOTTER 
 
             1.2 INCH IN 25 MINS
 
 0920 PM     TSTM WND GST     3 NE MESA               33.45N 111.70W
 08/28/2008  E75.00 MPH       MARICOPA           AZ   TRAINED SPOTTER 
 
             RECKER AND BROWN
 
 0920 PM     HAIL             3 NE MESA               33.45N 111.70W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             BROWN AND RECKER IN EAST MESA
 
 0921 PM     HEAVY RAIN       5 WSW APACHE JUNCTION   33.39N 111.63W
 08/28/2008  M0.00 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             0.5 INCH IN 15 MINS AT ELLSWORTH AND SOUTHERN
 
 0930 PM     TSTM WND DMG     5 SSW PARADISE VALLEY   33.47N 111.98W
 08/28/2008                   MARICOPA           AZ   TRAINED SPOTTER 
 
             TREES DOWN 48TH ST AND MCDOWELL WITH 40 MPH WINDS
 
 0938 PM     TSTM WND GST     6 NW TEMPE              33.44N 112.01W
 08/28/2008  M75.00 MPH       MARICOPA           AZ   ASOS            
 
             MEASURED ASOS AT PHX AIRPORT
 
 0940 PM     HAIL             4 SW GUADALUPE          33.32N 112.01W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             32ND AND RAY
 
 0940 PM     HAIL             4 SW GUADALUPE          33.32N 112.01W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
 0940 PM     HAIL             4 SW GUADALUPE          33.32N 112.01W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             32ND AND RAY IN AHWATUKEE
 
 1000 PM     HAIL             4 SW GUADALUPE          33.32N 112.01W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
 1010 PM     TSTM WND GST     4 SSE PHOENIX           33.48N 112.05W
 08/28/2008  M85.00 MPH       MARICOPA           AZ   AMATEUR RADIO   
 
             MEASURED WIND GUST 16TH ST AND THOMAS
 
 1015 PM     TSTM WND GST     WSW ESTRELLA            33.00N 112.42W
 08/28/2008  M69.00 MPH       MARICOPA           AZ   TRAINED SPOTTER 
 
             ESTRELLA PKWY AND ELLIOT
 
 1015 PM     DUST STORM       4 SW WADDELL            33.54N 112.41W
 08/28/2008                   MARICOPA           AZ   TRAINED SPOTTER 
 
             1/4 MI VIS IN DUST STORM 4 MI WEST OF LUKE AFB
 
 1043 PM     TSTM WND DMG     5 N AVONDALE            33.49N 112.36W
 08/28/2008                   MARICOPA           AZ   TRAINED SPOTTER 
 
             2 FOOT DIAM TREE DOWN
 
 1101 PM     HAIL             6 WSW FOUNTAIN HILLS    33.58N 111.84W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             FRANK LLOYD WRIGHT AND SHEA
 
 1105 PM     HAIL             5 NNE PARADISE VALLEY   33.61N 111.93W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             SCOTTSDALE AND THUNDERBIRD
 
 1105 PM     HAIL             3 S SCOTTSDALE          33.64N 111.86W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             104ST AND BELL
 
 1130 PM     HAIL             5 NNE PARADISE VALLEY   33.61N 111.93W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             SCOTTSDALE AND THUNDERBIRD
 
 1130 PM     HAIL             2 W PHOENIX             33.54N 112.10W
 08/28/2008  E0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             18TH AND GLENDALE
 
 1130 PM     TSTM WND DMG     2 W PHOENIX             33.54N 112.10W
 08/28/2008                   MARICOPA           AZ   TRAINED SPOTTER 
 
             18 INCH DIAM TREE DOWN
 
 1140 PM     HAIL             2 WSW PARADISE VALLEY   33.53N 111.98W
 08/28/2008  E1.00 INCH       MARICOPA           AZ   TRAINED SPOTTER 
 
             TATUM AND LINCOLN




Rainfall Totals Released From The NWS:

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
800 AM MST FRI AUG 29 2008

...24 HOUR PRECIPITATION FOR THE PHOENIX METRO AREA ENDING
AT 8 AM...

NOTE...IF IT RAINED AT A LOCATION...THE AMOUNT WILL BE SHOWN
ONLY IF IT IS AT LEAST 0.04...4 HUNDREDTHS OF AN INCH. ANY RAIN
AMOUNT LESS THAN 0.04 IS NOT REGISTERED AND IS SHOWN AS 0.00

                               6 HR PRECIPITATION (INCHES)
                               OLDEST  >>>>>>>>>>>  NEWEST
  ID     STATION NAME           8 AM   2 PM   8 PM   2 AM   24 HR
                               -2 PM  -8 PM  -2 AM  -8 AM   TOTAL


AHWATUKEE
MAHA3    AHWATUKEE              0.00   0.20   1.10   0.04    1.34
APACHE JUNCTION
PMDA3    USERY MOUNTAIN PARK    0.00   0.00   0.43   0.00    0.43
KNGA3    KINGS RANCH            0.00   0.00   0.43   0.04    0.47
AVONDALE
AVOA3    AGUA FRIA @ BUCKEYE    0.00   0.00   0.08   0.00    0.08
BUCKEYE
MBUA3    BUCKEYE FRS #2         0.00   0.00   0.00   0.04    0.04
CAREFREE
ZCAA3    FRAESFIELD MOUNTAIN    0.00   0.00   0.12   0.00    0.12
CRFA3    CAREFREE RANCH         0.00   0.00   0.00   0.00    0.00
CAVECREEK
HMBA3    HUMBOLDT MOUNTAIN      0.00   0.00   0.00   0.00    0.00
CBTA3    CAVE BUTTES DAM        0.00   0.00   0.00   0.00    0.00
CHANDLER
ZCHA3    EMF @ ARIZONA AVE      0.00   0.31   0.12   0.00    0.43
GILBERT
ZGIA3    MESA TOWER             0.00   0.00   0.63   0.00    0.63
ZCPA3    CROSSROADS PARK        0.00   0.16   0.51   0.00    0.67
GLENDALE
MGLA3    CITY OF GLENDALE       0.00   0.00   0.04   0.04    0.08
MMDA3    MARYLAND @ 27TH AVE    0.00   0.00   0.20   0.00    0.20
MSXA3    ACDC @ 67TH AVE        0.00   0.00   0.04   0.00    0.04
GOODYEAR
ZGYA3    TUTHILL @ RAY RD       0.00   0.00   0.28   0.00    0.28
GUADALUPE
ZGAA3    GUADALUPE FRS          0.00   0.00   1.10   0.04    1.14
MESA
MBDA3    BROADWAY @ DOBSON      0.00   0.00   0.91   0.08    0.98
ZBLA3    BROADWAY @ LINDSAY     0.00   0.00   0.55   0.00    0.55
MBHA3    BROWN RD. @ HORNE      0.00   0.00   0.39   0.04    0.43
MEEA3    KLEINMAN PARK          0.00   0.00   0.63   0.08    0.71
FALA3    THUNDER MOUNTAIN       0.00   0.00   0.47   0.00    0.47
MLAA3    MOUNTAIN VIEW PARK     0.00   0.00   0.47   0.08    0.55
WMSA3    QUEEN CREEK RD         0.00   0.08   0.28   0.08    0.43
ZUPA3    USERY PARK WS          0.00   0.00   0.47   0.00    0.47
NEW RIVER
NEWA3    SUNUP RANCH            0.00   0.00   0.16   0.00    0.16
PARADISE VALLEY
MCLA3    CAVE CREEK LANDFILL    0.00   0.00   0.00   0.00    0.00
MCCA3    E FORK CC #1           0.00   0.00   0.31   0.00    0.31
MLDA3    LOST DOG WASH          0.00   0.00   1.14   0.00    1.14
MRPA3    REATA PASS DAMSITE     0.00   0.00   0.39   0.00    0.39
PEORIA
NRDA3    NEW RIVER DAM          0.28   0.00   0.00   0.00    0.28
MBLA3    NEW RIVER @ BELL RD    0.00   0.00   0.00   0.00    0.00
PHOENIX
MBTA3    CESAR CHAVEZ PARK      0.00   0.00   1.06   0.00    1.06
MMIA3    MISSOURI @ 16TH ST     0.00   0.00   0.71   0.04    0.75
MOXA3    OLD XCUT @ MCDOWELL    0.00   0.00   1.57   0.00    1.57
MPAA3    PAPAGO PARK            0.00   0.00   1.26   0.00    1.26
MPPA3    PERRY PARK             0.00   0.00   1.69   0.00    1.69
ADBA3    ADOBE DAM              0.00   0.00   0.00   0.00    0.00
MPHA3    SKUNK CREEK @ I-17     0.00   0.00   0.00   0.00    0.00
MPMA3    JEFFERSON @ 4TH AVE    0.00   0.00   1.69   0.00    1.69
MROA3    ROESER @ 2ND ST        0.00   0.00   1.57   0.00    1.57
SOMA3    SOUTH MOUNTAIN         0.00   0.00   0.98   0.00    0.98
ZSFA3    SOUTH MOUNTAIN FAN     0.00   0.00   1.22   0.00    1.22
MTHA3    THOMAS & 16TH ST       0.00   0.00   1.50   0.00    1.50
MTQA3    THOMAS @ 48TH ST       0.00   0.00   1.10   0.00    1.10
QUEEN CREEK
ZQRA3    QUEEN CR @ RITTENHO    0.00   0.04   0.08   0.00    0.12
ZQCA3    QUEEN CREEK LANDFIL    0.00   0.08   0.20   0.00    0.28
QNCA3    EMF @ QUEEN CREEK R    0.00   0.16   1.10   0.00    1.26
SCOTTSDALE
SDLA3    INDIAN BEND WASH @     0.00   0.00   0.91   0.00    0.91
ZMDA3    MCDOWELL MOUNTAIN P    0.00   0.00   0.47   0.00    0.47
MPJA3    PIMA @ JOMAX             M      M    0.28   0.00    0.28
SUN CITY
MSWA3    SUN CITY WEST          0.00   0.00   0.00   0.00    0.00
SURPRISE
MDYA3    DYSART @ BELL RD       0.00   0.00   0.00   0.00    0.00
MCFA3    MCMICKEN FLOODWAY      0.00   0.00   0.00   0.00    0.00
TEMPE
MSPA3    SALT RIVER @ PRIEST    0.00   0.00   1.42   0.00    1.42
MTEA3    ASU SOUTH              0.00   0.00   1.46   0.00    1.46