FLOOD02053

• County: Weld
• County: Boulder
• Community: Weld, Boulder Counties
• Stream Name: Big Thompson River
• Title: Meteorological Aspects of the Big Thompson Flash Flood of 31 July 1976
• Date: 7/1/1977
• Prepared For: State of Colorado
• Prepared By: NOAA
• Floodplain - Doc Type: Flood Documentation Report

Contents

Page

Abstract

1

L Introduction ....,..,.....................,....... 1

2. f\.feteorological Conditions Prior to Storm
Development ....,....,..,.......,............... 4

2,1 Synoptic Scale Analyses for 1200 GMT,
31 July 1976..............................., 4
2,2 Regional Analyses from 1800 to 2200
GMT, 31 July 1976 ...............,...... 15
2,3 Analyses for 0000 GMT, I August
IM6.,...,.,."....."."."."."..,.....,.", ~

3, Conditions During the Storm Period ..... 33

3,1 Local Area Analyses ....,........,......., 33
3,2 Radar Coverage .......................... 37

""'-;';"

4, Post-Storm Conditions ..............".,..,... 47

4. I Regional Scale Analyses from 0200
to 0600 GMT, I August 1976 .......... 47
4.2 Synoptic Scale Analyses for 1200
GMT, I August 1976 ..................., 54

5, Physical Model of the Storm .............,.. 60

6. Comparison of Conditions
Associated With the Big Thompson
and Rapid City Floods.,...................... 63

7. Summary and Conclusions ........,........, 81
8, Acknowledgments ......................'....... 82

9. References,.......,.,....,......."".""..""" 83

iii