FLOOD03905

• County: Statewide
• Community: State of Colorado
• Stream Name: All
• Basin: Statewide
• Title: Extreme Precipitation Study: Storm Data and Interpretation from HMS Storm Files
• Date: 4/1/1997
• Prepared For: State Climatologist
• Prepared By: Henz Meteorological Services
• Floodplain - Doc Type: Educational/Technical/Reference Information

LIST OF FIGURES

FIGURE

PAGE

I. Storm Regions defined at October 1996 Workshop. 2
2. Storm of June 2,1921 affecting Dry Creek north of Pueblo. 4
3. Storm of June 3,1921. Apparent motion vectors, merger locatio a, frontal boundary,
and meso-cyclone indicated. 5
4. Important topographic features associated with the Pc'nrose flood of June 2-6, 1921. Me~ISUl.ed and
estimated rainfall indicated. 7
5. Rainfall pattern for June 16, 1965. 11
6. Rainfall pattern for June 17, 1965. 12
7. Location map showing area affeded by heavy rainf~1l1 and flooding on July 31 and August 1, 1976.
Storm inflow vector and apparent motion vector after ~'detachmcnt" of "locked in" system 21so shown.
Timing estimates are based on satellite imagery. 15
8. Topography in and around the area affected by the Frijole Creek flash flood. 18
9. Location map identifying key points affected by the Frijole Creek flash flood. 19
10. Topography in the vicinity of Cheyenne, Wyoming. Apparent storm inflow vector, formation zone,
propagation vector, quasi-stationary location, surface meso-low, frontal boundary and eventual exit
vector are indicated. 22
11. NLDN Lightning Report for Opal, Wyoming event. 24
12. Map of southwestern Wyoming. 25
13. August 17, 1990 0000 UTC (1800 LDT on August 16) soundings for Lander (LND), Salt Lake City
(SLC), and Grand Junetion (GJT). Estimated preeipitable water index for Opal,
Wyoming is 1.04 inches. 28
14. Analyses of CG data for the period 1540 LDT to 1600 LDT during the beginning of tlw Opal.,
Wyoming event of August 16, 1990. 31
15. Analyses of CG data for the period 1601 LDT to 1615 LDT when rapid development took place
during the Opal, Wyoming event of August 16, 1990. 32
16. Analyses of CG data for the period 1615 LDT to 1630 LDT during the Opal, Wyoming event of
August 16, 1990. Strike data shows distinct CG envelopes indicative of four distinct storm cells. 33
17. Analyses of CG data during the period 1631 LDT to 1645 LDT during the Opal, Wyomiug event
of August 16, 1990. CG strikes have nearly doubled since the preceding IS-minute period and four
distinct multi-cell storms are evident. Storms are bc:coming stationary and thc Opal cvent is
entering its most intcnse phase. 34
18. Analyses of CG data during the period 1646 LDT to 1700 LDT during the Opal, Wyoming eveut
of August 16, 1990. All storms arc nearly stationary ,vith fivc cells producing vcry heavy rainfall
in a west to east line from near Nutria, Wyoming to points 18 miMes to the east. 35
19. Analyses ofCG data during the period 1700 LDT to 1715 LDT during the Opal, Wyoming event of
August 16, 1990. CG production drops during this period as storms merge into two large primary
storms centers. Period of IUOSt rainfall ends about 1715 LDT. 36
20. Analyses of CG data during the period 1715 LDT to 1730 LDT during the Opal, Wyoming event of
August 16, 1990 showing little change from the preceding IS-minute period. 37
21. Analyses ofCG data during the period 1730 LDT to 1745 LDT during the Opal, Wyominl: event of
August 16, 1990 showing rapid de-intensification of storm eells. 38
22. Analyses of CG data during the period 1745 LDT to 1800 LDT during the Opal, Wyoming event of
August 16, 1990 showing only two small areas of moderate rain remaining. 39
23. Areal coverage of heavy rainfall (>1.5 inches total) for Opal, Wyoming event showing two distinct
rainfall maxima. 43
24. Important topographical features affecting the Muddy Creek llash llood of June 20, 1994. 45
25. Surfaee analysis for 0000 UTC on June 21, 1994. 47
26. Map showing topography in the vicinity of Owl Creek Pass, Colorado. Proposed inflow fetch,
formation zone, motion vector, and area of mudslides and flash flooding indicated for AUI~Wit 21,1995 50
27. NLDN Lightning Report for Owl Creek Pass event of August 21,1995. 50

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