August 7, 2008 Storm Statistics

Readings From Weather Bus.com:

First Measurable Rain Time: August 7, 2008 at 8:55pm
Last Measurable Rain Time: August 7, 2008 at 10:15pm
Storm Total: 0.07in.
Max Rain Rate: 0.11in/hr
Peak Wind Gust: N @ 24mph
Total Lightning: 116,809

Comments:
On August 7th, thunderstorms to the north of the valley and thunderstorms to the south and east of the valley produced outflows, which later converged over the area resulting in strong to severe thunderstorms across the region during the early evening through the late night hours. For the Gold Canyon area, the majority of the heavy rainfall was seen in the southern and southeast portion of the area. The rain total at our location was 0.07in., with a peak rain rate of 0.11in/hr occurring at 9:46pm. Below is a summary of the events which occurred during the storm. We mainly focused on the outflow coming up from the south, as it had a larger impact on our weather.

By 5:45pm, to our south, two outflows which would later help to create the strong to severe thunderstorms in the valley, had developed or been enhanced. The newly formed outflow was caused by thunderstorms between Coolidge and Florence, while thunderstorms about seven miles south of Florence enhanced an outflow, which was produced by thunderstorms early in the afternoon in southern Pinal County. To the right is the Base Reflectivity (1.0° tilt) radar image (click image to enlarge), taken at 5:41pm, showing the two outflows and the thunderstorms. We have marked the outflow boundaries in yellow and the direction in white.

By 6:45pm, thunderstorms had developed along and just behind the two outflow boundaries, to the south of Florence Junction and in the eastern portion of Queen Creek. The radar image (click image to enlarge) to the left is the Base Reflectivity (1.0° tilt), from 6:45pm. The long outflow boundary marked on the radar image was producing an impressive dust storm, with a report of visibility less than one quarter mile due to blowing dust two miles north-northeast of Casa Grande, at 6:40pm.

As the two outflows from the south, interacted in between Gold Canyon and Florence Junction, a severe thunderstorm developed, around 7:20pm, just to the east of Florence, which likely produced very strong winds, hail and extremely heavy rainfall. The radar image (click image to enlarge) to the right, shows the severe thunderstorms to the east of Florence, the large outflow boundary moving into the valley from the south and east, as well as the outflow moving down from the north.

Around 7:59pm, the severe thunderstorms between Gold Canyon and Florence Junction weakened, while additional thunderstorms spread/developed into mainly the southeast portion of Gold Canyon, with the heaviest rainfall between Peralta Trails and Kings Ranch. The radar image (click image to enlarge) to the left is zoomed into the Gold Canyon region, with several roads marked for orientation purposes.

Between 7:50pm and 8:20pm, the three outflows, (1) one coming down from the north, (2) second coming down from the north-northeast, and (3) the outflow coming up from the south converged over Mesa and Tempe, resulting in strong to severe thunderstorms rapidly developing across nearly the entire eastern portion and later central portion of the valley. The loop below shows the three outflows coming together, and then producing the thunderstorms. Loop is from 7:36pm to 8:22pm, in about five minute intervals.


Thunderstorms continued across the region well into the late evening hours, resulting in very high rain totals across the valley, as well as some damage from high winds. Jacob, located a half mile northwest of N. 75th Ave and W. Deer Valley Rd, recorded 0.50in. of rainfall between 8:00pm and midnight, with a peak wind gust of 45mph, occuring at 8:15pm. Below are reports from the National Weather Service in Phoenix:

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0640 PM     DUST STORM       2 NNE CASA GRANDE       32.92N 111.72W
08/07/2008                   PINAL              AZ   TRAINED SPOTTER

            VISIBILITY LESS THAN ONE QUARTER MILE DUE TO BLOWING
            DUST...EAST OF INTERSTATE 10 NORTH OF CASA GRANDE

0743 PM     TSTM WND DMG     BUCKEYE                 33.38N 112.60W
08/07/2008                   MARICOPA           AZ   UTILITY COMPANY

            POWER OUTAGES REPORTED DUE TO DOWNED POWER
            LINES...APPROXIMATELY 70 TOTAL IN BUCKEYE AREA.

0817 PM     TSTM WND DMG     3 S PHOENIX             33.50N 112.07W
08/07/2008                   MARICOPA           AZ   UTILITY COMPANY

            POWER OUTAGE DUE TO DOWNED POWER POLES IN CENTRAL AND
            NORTH-CENTRAL PHOENIX.

0820 PM     TSTM WND DMG     PHOENIX                 33.54N 112.07W
08/07/2008                   MARICOPA           AZ   AMATEUR RADIO

            VISIBILITY REDUCED TO ONE QUARTER MILE WITH
            DUST...PHOENIX FIRE RESPONDING TO REPORTS OF TRANSFORMER
            AND-OR POWER POLE FIRES...ESTIMATED LOCATION - DOWNTOWN
            PHOENIX...12TH STREET AND JEFFERSON

0850 PM     FLASH FLOOD      TEMPE                   33.39N 111.93W
08/07/2008                   MARICOPA           AZ   TRAINED SPOTTER

            TRAFFIC DETOURING AWAY FROM INTERSTATE
            UNDERPASSES...WATER PONDING AND STARTING TO COVER CURBS

0951 PM     FLASH FLOOD      YOUNGTOWN               33.59N 112.30W
08/07/2008                   MARICOPA           AZ   TRAINED SPOTTER

            1 INCHE RAIN MEASURED IN 30 MINUTES...VISIBILITY AT OR
            BELOW ONE QUARTER MILE DUE TO RAIN

0854 PM     TSTM WND DMG     SCOTTSDALE              33.69N 111.87W
08/07/2008                   MARICOPA           AZ   AMATEUR RADIO

            LARGE DEBRIS...TREE BRANCHES AND LEAVES IN ROADWAY...64TH
            STREET AND SHEA BLVD

0940 PM     FLASH FLOOD      5 E GLOBE               33.38N 110.67W
08/07/2008                   GILA               AZ   TRAINED SPOTTER

            WATER KNEE DEEP IN PARKING LOT REPORTED AT APACHE GOLD
            CASINO...CURRENTS STRONG THROUGH PARKING LOT...LOW
            VISIBILITY DUE TO HEAVY RAINFALL





Rainfall Totals Released From The NWS:

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
1008 AM MST FRI AUG 8 2008

...24 HOUR PRECIPITATION FOR THE PHOENIX METRO AREA ENDING
AT 10 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          10 AM   4 PM  10 PM   4 AM   24 HR
                               -4 PM -10 PM  -4 AM -10 AM   TOTAL


KPHX     PHOENIX SKY HARBOR     0.00   0.55   0.14   0.00    0.69

AHWATUKEE
MAHA3    AHWATUKEE              0.00   0.28   0.04   0.00    0.31
APACHE JUNCTION
PMDA3    USERY MOUNTAIN PARK    0.00   0.20   0.00   0.00    0.20
KNGA3    KINGS RANCH            0.00   0.00   0.00   0.00    0.00
AVONDALE
AVOA3    AGUA FRIA @ BUCKEYE    0.00   0.24   0.16   0.00    0.39
BUCKEYE
MBUA3    BUCKEYE FRS #2         0.00   0.00   0.00   0.04    0.04
CAREFREE
ZCAA3    FRAESFIELD MOUNTAIN    0.00   0.04   0.16   0.00    0.20
CRFA3    CAREFREE RANCH         0.00   0.16   0.31   0.00    0.47
CAVECREEK
HMBA3    HUMBOLDT MOUNTAIN      0.00   0.12   0.08   0.00    0.20
CBTA3    CAVE BUTTES DAM        0.00   0.00   0.24   0.00    0.24
CHANDLER
ZCHA3    EMF @ ARIZONA AVE      0.00   0.08   0.00   0.00    0.08
GILBERT
ZGIA3    MESA TOWER             0.00   0.35   0.00   0.00    0.35
ZCPA3    CROSSROADS PARK        0.00   0.24   0.04   0.00    0.28
GLENDALE
MGLA3    CITY OF GLENDALE       0.00   0.91   0.20   0.00    1.10
MMDA3    MARYLAND @ 27TH AVE    0.00   1.26   0.24   0.00    1.50
MSXA3    ACDC @ 67TH AVE        0.00   1.06   0.12   0.00    1.18
GOODYEAR
ZGYA3    TUTHILL @ RAY RD       0.00   0.47   0.04   0.00    0.51
GUADALUPE
ZGAA3    GUADALUPE FRS          0.00   0.55   0.08   0.00    0.63
MESA
MBDA3    BROADWAY @ DOBSON      0.00   0.51   0.04   0.00    0.55
ZBLA3    BROADWAY @ LINDSAY     0.00   0.79   0.00   0.00    0.79
MBHA3    BROWN RD. @ HORNE      0.00   0.87   0.00   0.00    0.87
MEEA3    KLEINMAN PARK          0.00   0.31   0.08   0.00    0.39
FALA3    THUNDER MOUNTAIN       0.00   0.12   0.00   0.00    0.12
MLAA3    MOUNTAIN VIEW PARK     0.00   0.47   0.00   0.00    0.47
WMSA3    QUEEN CREEK RD         0.00   0.43   0.00   0.00    0.43
ZUPA3    USERY PARK WS          0.00   0.31   0.00   0.00    0.31
NEW RIVER
NEWA3    SUNUP RANCH            0.00   0.43   0.00   0.00    0.43
PARADISE VALLEY
MCLA3    CAVE CREEK LANDFILL    0.00   0.04   0.08   0.00    0.12
MCCA3    E FORK CC #1           0.00   0.59   0.16   0.00    0.75
MLDA3    LOST DOG WASH          0.00   0.00   0.28   0.00    0.28
MRPA3    REATA PASS DAMSITE     0.00   0.12   0.20   0.00    0.31
PEORIA
NRDA3    NEW RIVER DAM          0.00   0.08   0.08   0.00    0.16
MBLA3    NEW RIVER @ BELL RD    0.00   0.35   0.24   0.00    0.59
PHOENIX
MBTA3    CESAR CHAVEZ PARK      0.00   0.79   0.16   0.00    0.94
MMIA3    MISSOURI @ 16TH ST     0.00   1.50   0.24   0.00    1.73
MOXA3    OLD XCUT @ MCDOWELL    0.00   0.79   0.24   0.00    1.02
MPAA3    PAPAGO PARK            0.04   0.79   0.12   0.00    0.94
MPPA3    PERRY PARK             0.00   0.83   0.16   0.00    0.98
ADBA3    ADOBE DAM              0.00   0.16   0.12   0.00    0.28
MPHA3    SKUNK CREEK @ I-17     0.00   0.00   0.12   0.00    0.12
MPMA3    JEFFERSON @ 4TH AVE    0.00   0.28   0.16   0.00    0.43
MROA3    ROESER @ 2ND ST        0.00   0.24   0.12   0.00    0.35
SOMA3    SOUTH MOUNTAIN         0.00   0.55   0.12   0.00    0.67
ZSFA3    SOUTH MOUNTAIN FAN     0.00   0.20   0.31   0.00    0.51
MTHA3    THOMAS & 16TH ST       0.00   0.67   0.00   0.00    0.67
MTQA3    THOMAS @ 48TH ST       0.00   0.35   0.28   0.00    0.63
QUEEN CREEK
ZQRA3    QUEEN CR @ RITTENHO    0.00   0.39   0.00   0.00    0.39
ZQCA3    QUEEN CREEK LANDFIL    0.00   0.00   0.00   0.00    0.00
QNCA3    EMF @ QUEEN CREEK R    0.00   0.28   0.00   0.00    0.28
SCOTTSDALE
SDLA3    INDIAN BEND WASH @     0.00   1.06   0.04   0.00    1.10
ZMDA3    MCDOWELL MOUNTAIN P    0.00   0.04   0.08   0.04    0.16
MPJA3    PIMA @ JOMAX           0.00   0.12   0.08   0.00    0.20
SUN CITY
MSWA3    SUN CITY WEST          0.00   0.00   0.08   0.00    0.08
SURPRISE
MDYA3    DYSART @ BELL RD       0.00   0.08   0.08   0.00    0.16
MCFA3    MCMICKEN FLOODWAY      0.00   0.00   0.00   0.04    0.04
TEMPE
MSPA3    SALT RIVER @ PRIEST    0.00   1.30   0.08   0.00    1.38
MTEA3    ASU SOUTH              0.00   1.10   0.04   0.00    1.14