Storm Report: Nov. 30th – Dec. 1st, 2007
Maricopa County, AZ
Engineering Division, Flood Warning Branch
TABLE OF CONTENTS
Meteorology 2
Precipitation 4
Runoff 9
ALERT System Alarms 13
TABLES
Table 1 Summary of Strorm-total Reports 4
Table 2 Storm-total, 24-hour Intensity and 24-hour Return Periods 4
FIGURES
Figure I Colorized infrared satellite photos from Nov. 25 & Dec. 1 2
Figure II Temperature/Dewpoint plot at Gila Bend Landfill Wx Station 3
Figure III Temperature/Dewpoint plot at Carefree Ranch Wx Station 3
Figure IV Plot of selected storm-total rainfall values vs. elevation 5
Figure V Isohyetal map of storm-total values from ALERT gages only 6
Figure VI Storm-total rainfall depth map derived from radar data only 7
Figure VII Storm-total rainfall depth map derived from radar & gage data. 7
Figure VIII Storm-total rainfall depth map derived from gage data & radar 8
Figure IX Storm hyetograph – hourly values at Cooks Mesa and 7 Springs 8
Figure X Cave Buttes Dam impoundment graphic 9
Figure XI Storm hydrograph, 09512280 – Cave Creek blw Cottonwood Cr 10
Figure XII Storm hydrograph, gage 4923 – Cave Cr. @ Spur Cross 10
Figure XIII Storm hydrograph, gage 5583 – Cline Creek 11
Figure XIV Storm hydrograph, gage 5638 – New River Fire 11
Figure XV Storm hydrograph, gage 5543 – Scatter Wash 12
Figure XVI Storm hydrograph, gage 4963 – Seven Springs Wash 12
A special thank you to the NWS, USGS and Unisys for supplying several of the figures in this report.
METEOROLOGY
Starting on Sunday November 25th, a weather disturbance began to develop in the eastern Pacific Ocean west of the Baja peninsula (see left panel in Figure I below). It remained quasi-stationary for about three days, and its counter-clockwise circulation entrained considerable sub-tropical moisture. Some of this mid and upper-level moisture streamed north into the southwestern U.S. resulting in mainly high clouds Tuesday the 27th and Wednesday the 28th.
On Thursday the 29th another weather disturbance formed off the coast of Oregon and northern California and moved southeast along the coast. This coastal disturbance interacted with the Baja system, absorbing it and moving east into Arizona on November 30th (right panel below).
The combination of copious Pacific moisture associated with the Baja remnants and dynamic triggers within the coastal system resulted in about 30 hours (Friday morning to Saturday afternoon) of moderate to locally heavy rain bands moving east across central Arizona, with the heaviest rain over the higher terrain of northeast Maricopa County.
The two disturbances moved off to the east late Saturday December 1st returning dry conditions to our state by Saturday night. A good portion of the central Arizona mountains were shrouded in fog on the morning of December 2nd.
Figure II above shows a plot of temperature and dewpoint at our Gila Bend Landfill weather station in southwest Maricopa County – elevation 750 feet.
Figure III above shows a plot of temperature and dewpoint at our Carefree Ranch weather station in northeast Maricopa County – elevation 2,960 feet.
PRECIPITATION
Summary Statistics
Total automated rain gages: 301
Total operational automated rain gages: 292
Gages that failed to operate during the storm: 4640, 4820, 5175, 5260, 5430, 5610, 5670, 5910, and 6900 – mostly due to plugged funnels because of mostly dry conditions for the previous two months.
Table 1
For the period 11/30/2007 12:00 through 12/01/2007 18:00 MST:
Number of gages recording rainfall / 301 (all of them)Number of gages > = 6.00 inches / 2
Number of gages > = 5.00 inches / 6
Number of gages > = 4.00 inches / 14
Number of gages > = 3.00 inches / 29
Number of gages > = 2.00 inches / 105
Number of gages < 1.00 inch / 11
Table 2
Storm-total, 24-hour Intensity and 24-hour Return Periods for Selected Stations
Storm-total / Peak 24-Hour / 24-hr. ReturnGage Name / Gage ID / Installed / El. (ft) / Jurisdiction / Rainfall (in) / Intensity (in) / Period* (years)
Horsethief Basin / 5700 / 11/24/1986 / 6,705 / Yavapai County / 4.21 / 3.82 / 6
Camp Creek / 5955 / 7/18/2005 / 3,720 / Maricopa County / 4.13 / 3.50 / 7
Towers Mtn. / 5340 / 5/1/1992 / 7,630 / Yavapai County / 5.63 / 5.12 / 13
Rackensack Canyon / 5940 / 6/28/2007 / 4,520 / Maricopa County / 5.20 / 4.37 / 17
Seven Springs Wash / 4960 / 3/12/2002 / 3,530 / Maricopa County / 4.84 / 4.41 / 19
Fraesfield Mtn. / 5930 / 8/2/1989 / 2,690 / Scottsdale / 4.09 / 4.09 / 27
New River Fire / 5635 / 7/20/2005 / 2,485 / Maricopa County / 4.29 / 4.13 / 29
Carefree Ranch / 4930 / 7/15/1985 / 2,960 / Scottsdale / 4.88 / 4.33 / 30
Horseshoe Lake / 5890 / 9/11/2000 / 2,070 / Maricopa County / 5.16 / 4.33 / 38
Upper Cline Creek / 5545 / 11/21/2001 / 2,520 / Maricopa County / 4.57 / 4.49 / 40
Cline Creek / 5580 / 8/1/1981 / 2,170 / Maricopa County / 4.21 / 4.21 / 43
Mt. Union Wx / 5380 / 8/16/1982 / 7,495 / Yavapai County / 5.83 / 5.55 / 58
Seven Springs / 4950 / 11/12/1981 / 4,615 / Yavapai County / 6.06 / 5.67 / 100
Cooks Mesa / 5640 / 3/21/1984 / 4,570 / Yavapai County / 6.10 / 5.71 / 133
* Values estimated from NOAA Atlas 14, version 4
In Figure IV above, the blue squares are the NOAA Atlas 14 24-hr point precipitation frequency estimates (annual maximum series) for all FCDMC ALERT stations with 10 or more years of record versus the station elevation. The trend line was plotted in Microsoft Excel® using the power function option and represents an average value of the 24-hour, 100-year return period rainfall depth versus elevation. Red dots are the 24-hour measured intensity values for the selected stations in Table 2. Dots close to the line in the horizontal plane approach 100-year, 24-hour return period values.
Appendix A contains hourly rainfall values recorded at all automated ALERT rainfall stations.
Figure V above is an isohyetal map of storm-total values recorded by the automated ALERT stations. It was created using ESRI ArcView® with Spatial Analyst™. Using data that was quality-controlled after the storm, failed gages were excluded from the analysis and gages where estimates were made from radar and nearby gages were included.
Figures VI and VII above are storm-total rainfall depth maps derived by our weather products vendor, Weather Decision Technologies, Inc. , from the Phoenix NEXRAD radar data stream and from our ALERT gages. The upper figure was developed from radar data only. The lower figure was developed from the radar data and “locally corrected” using ground-truthed rainfall data from the ALERT rain gages.
Figure VIII above is a storm-total rainfall depth map derived from the Phoenix NEXRAD radar data stream and from our ALERT gages using ArcView®. It was developed from the radar data and “locally corrected” using ground-truthed rainfall data from the ALERT rain gages. Labels are placed on the map to show areas where the ALERT gage data caused the map estimates to be too low (Down) or too high (Runaway).
RUNOFF
Summary Statistics
Total automated water-level gages: 152
Total operational automated rain gages: 149
Water-level gages that recorded significant flow or impoundment: 89
Water-level gages that failed to operate during the storm: New River pool gage failed, Hassayampa River at Wagoner stream and White Tank FRS # 3 pool were out of service because of construction projects.
Appendix B contains a listing of all Water-level gages, their peak stage/flow values, the time of the peak, and an abbreviated location description.
Selected Hydrographs
ALERT SYSTEM ALARMS
Date-Time ID Sensor_Name Sensor_Type Alarm_Type
------
12/01/2007-20:01:19 6688 Vineyard FRS Water-level DEV upper limit
12/01/2007-17:23:29 5930 Fraesfield Mountain Rain DEV rainfall rate
12/01/2007-16:22:48 4833 Cave Creek @ Cactus Water-level DEV upper limit
12/01/2007-14:00:08 4609 Osborn @ 64th St. Wind speed DEV upper limit
12/01/2007-13:25:25 6735 Bulldog Canyon Rain DEV rainfall rate
12/01/2007-13:23:47 6709 Magma FRS Wind speed DEV upper limit
12/01/2007-11:20:37 5654 Lake Pleasant North Wind speed DEV upper limit
12/01/2007-10:31:06 4918 Cave Cr nr Cave Cr Water-level DEV upper limit
12/01/2007-10:24:17 4889 Cave Creek Water-level DEV upper limit
12/01/2007-09:38:31 5613 New River Dam Outlet Water-level DEV upper limit
12/01/2007-08:50:00 5583 Cline Creek Water-level DEV upper limit
12/01/2007-08:44:48 4950 Seven Springs Rain DEV rainfall rate
12/01/2007-08:32:21 4948 Cave Creek Fire Water-level DEV upper limit
12/01/2007-07:27:32 4960 Seven Springs Wash Rain DEV rainfall rate
12/01/2007-07:07:54 4963 Seven Springs Wash Water-level DEV upper limit
12/01/2007-07:00:49 5955 Camp Creek Rain DEV rainfall rate
12/01/2007-03:51:54 4603 IBW @ McKellips Water-level DEV upper limit
12/01/2007-03:28:51 5538 Adobe Dam Outlet Water-level DEV upper limit
12/01/2007-03:06:06 5588 Skunk Cr nr New R. Water-level DEV upper limit
12/01/2007-02:42:33 5635 New River Fire Water-level DEV rainfall rate
12/01/2007-02:25:47 6683 Powerline FRS Water-level DEV upper limit
12/01/2007-01:09:10 4923 Cave Cr.@ SpurCross Water-level DEV upper limit
12/01/2007-00:28:47 495 Baker Butte Rain DEV rainfall rate
12/01/2007-00:17:45 4947 Cave Creek Fire Water-level DEV upper limit
12/01/2007-00:07:25 4668 EFCC nr 7th Ave Water-level DEV upper limit
12/01/2007-00:05:48 5108 Delaney Wash Water-level DEV upper limit
12/01/2007-00:03:04 4618 IBW @ Indian School Water-level DEV upper limit
11/30/2007-23:56:20 5640 Cooks Mesa Rain DEV rainfall rate
11/30/2007-23:56:13 5163 Tiger Wash Water-level DEV upper limit
11/30/2007-23:47:33 5640 Cooks Mesa Rain DEV rainfall rate
11/30/2007-23:44:05 6500 Guadalupe FRS Rain DEV rainfall rate
11/30/2007-23:39:23 5934 Rackensack Canyon Wind speed DEV upper limit
11/30/2007-23:35:24 5694 Horsethief Basin Wind speed DEV upper limit
11/30/2007-22:56:46 7093 Casandro Wash Water-level DEV upper limit
11/30/2007-22:52:48 4728 Granite Reef Wash Water-level DEV upper limit
11/30/2007-22:42:33 5043 4th of July Wash Water-level DEV upper limit
11/30/2007-22:37:40 4628 IBW @ McDonald Water-level DEV upper limit
11/30/2007-22:34:07 4613 IBW @ Indian Bend Water-level DEV upper limit
11/30/2007-22:16:13 5065 Eagle Eye Rd. @ CAP Rain DEV rainfall rate
11/30/2007-21:22:20 6510 South Mountain Park Rain DEV rainfall rate
11/30/2007-21:17:24 4903 Cave Buttes Dam Water-level DEV upper limit
11/30/2007-19:53:41 4938 Reata Pass Dam Water-level DEV upper limit
11/30/2007-19:00:55 5568 Skunk Creek @ I-17 Water-level DEV upper limit
11/30/2007-19:17:02 6525 South Mtn.Park HQ Rain DEV rainfall rate
11/30/2007-19:10:11 5098 Winters Wash @ IS Rd. Water-level DEV upper limit
11/30/2007-18:46:26 4668 EFCC nr 7th Ave Water-level DEV upper limit
11/30/2007-18:44:41 4693 IBW @ Shea Blvd. Water-level DEV upper limit
11/30/2007-18:34:57 6608 Freestone Basin Water-level DEV upper limit
11/30/2007-18:31:29 4930 Carefree Ranch Rain DEV rainfall rate
11/30/2007-18:30:03 5568 Skunk Creek @ I-17 Water-level DEV upper limit
11/30/2007-16:42:08 5423 Dysart Drain @ LAFB Water-level DEV upper limit
11/30/2007-16:34:53 4823 ACDC @ 43rd Ave Water-level DEV upper limit
11/30/2007-16:29:53 4821 ACDC @ 43rd Ave Water-level DEV upper limit
11/30/2007-15:54:47 5543 Scatter Wash Water-level DEV upper limit
11/30/2007-15:45:24 4899 Cave Buttes Pool Water-level DEV upper limit
11/30/2007-15:08:44 4728 Granite Reef Wash Water-level DEV upper limit
11/30/2007-14:36:51 5955 Camp Creek Rain DEV rainfall rate
11/30/2007-14:18:55 5940 Rackensack Canyon Rain DEV rainfall rate
11/30/2007-03:14:56 5044 Gila Bend Mountains Wind speed DEV upper limit
APPENDIX A
Hourly rainfall values for all automated ALERT rainfall stations
FCD of Maricopa County ALERT System
Group Name Date Time
P1: Gages 0750-4505 01/09/2008-06:51:25
DeviceID 750 770 775 780 785 795 4500 4505
StatType dif dif dif dif dif dif dif dif
DataType precip precip precip precip precip precip precip precip
Units in in in in in in in in
12/01/07
2400 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2300 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2200 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2100 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2000 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1900 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1800 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1700 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1600 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1500 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04
1400 0.00 0.00 0.00 0.04 0.00 0.00 0.00 0.00
1300 0.00 0.00 0.04 0.00 0.00 0.00 0.00 0.00
1200 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1100 0.00 0.00 0.04 0.00 0.00 0.00 0.00 0.00
1000 0.00 0.00 0.04 0.00 0.00 0.00 0.00 0.00
0900 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0800 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0700 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0600 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0500 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0400 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0300 0.00 0.04 0.00 0.00 0.00 0.00 0.00 0.00
0200 0.00 0.00 0.00 0.12 0.00 0.00 0.00 0.00
0100 0.08 0.00 0.00 0.04 0.00 0.00 0.00 0.04
11/30/07
2400 0.08 0.04 0.08 0.04 0.08 0.08 0.12 0.16
2300 0.12 0.24 0.16 0.04 0.16 0.16 0.08 0.20
2200 0.08 0.04 0.08 0.00 0.04 0.08 0.00 0.04
2100 0.00 0.08 0.04 0.08 0.00 0.00 0.08 0.04
2000 0.04 0.00 0.08 0.12 0.04 0.00 0.04 0.12
1900 0.12 0.00 0.12 0.08 0.04 0.00 0.00 0.08
1800 0.04 0.08 0.08 0.12 0.08 0.12 0.16 0.12
1700 0.16 0.04 0.16 0.16 0.12 0.08 0.12 0.12
1600 0.24 0.12 0.16 0.20 0.16 0.08 0.12 0.20
1500 0.08 0.12 0.12 0.12 0.12 0.00 0.20 0.08
1400 0.08 0.00 0.08 0.08 0.04 0.08 0.08 0.04
1300 0.04 0.04 0.16 0.04 0.04 0.08 0.08 0.08
1200 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1100 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
1000 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0900 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0800 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0700 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0600 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0500 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0400 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0300 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0200 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0100 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
TOTALS: 1.14 0.83 1.42 1.26 0.91 0.75 1.06 1.34
FCD of Maricopa County ALERT System
Group Name Date Time
P2: Gages 4510-4545 01/09/2008-06:51:25
DeviceID 4510 4515 4520 4525 4530 4535 4540 4545
StatType dif dif dif dif dif dif dif dif