WMOD00315

• Title: Investigations of Winter Storms Over the Wasatch Plateau During the 1991 Utah/NOAA Field Program
• Prepared For: Utah Department of Natural Resources Division of Water Resources
• Prepared By: Arlen W. Huggins, Melanie A. Wetzel, Patricia A. Walsh
• Date: 10/1/1992
• State: UT
• Weather Modification - Doc Type: Report

Figure 3.66. Surface and 500 mb analyses for 0500 11 March 1991. ........... 3-87
Figure 3.67. Temporal plots of meteorological data from the DOT site for 10 March
1991 during Storm Period 13. ............................... 3-88
Figure 3.68. Same as Fig. 3.67, except for 11 March 1991 during Storm Period 13. . 3-89
Figure 3.69. Time versus height plot of maximum dB~ recorded by the vertically-
pointing K.-band radar at the DOT site from 0400-1000 11 March 1991. . . . . . 3-91
Figure 3.70. Same as Fig. 3.69, except for the period 0900-1500 11 March 1991. . . . 3-92
Figure 3.71a. GOES-7 infrared image taken at 0600 11 March 1991. . . . . . . . . . . . 3-93
Figure 3.71b. Same as Fig. 3.71a, except for 1000 11 March 1991. . . . . . . . . . . . . 3-94
Figure 3.72. Same as Fig. 3.71, except for 1700 11 March 1991. . . . . . . . . . . . . . 3-95
Figure 3.73. Surface and 500 mb analyses for 0500 14 March 1991. ........... 3-96
Figure 3.74. Temporal plots of meteorological data from the DOT site for 14 March
1991 during Storm Period 14. ............................... 3-98
Figure 3.75. GOES-7 infrared image taken at 0900 MST 14 March 1991. . . . . . . . . 3-99
Figure 3.76. Potential and equivalent potential temperatures plotted versus height for
Mt. Pleasant soundings taken at 1200 14 March (top panel) and 1500 14 March

(bottom panel). ....................................... 3-100
Figure 3.77. Time versus height plot of maximum dB~ values recorded by the
vertically-pointing K.-band radar at the DOT site from 1000-1600 14 March

1991. ............................................. 3-101
Figure 4.1. The relative and cumulative distributions of all 6O-min liquid water depth
averages (593 total) from the 1991 Utah/NOAA Field Research Program. ..... 4-2
Figure 4.2. Relative frequency of 6O-min liquid depth averages in prefrontal and

postfrontal conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

Figure 4.3. Relative frequency of 6O-min liquid depth averages in prefrontal and
postfrontal conditions, using only the strongest six cold frontal episodes in Table

3.1. ..................................1............. .4-5

Figure 4.4. Relative frequency of 6O-min liquid depth averages stratified by the 500 mb
wind direction in which the storm developed. . . . . . . . . . . . . . . . . . . . . . . . 4-6
Figure 4.5. Comparison of Mt. Pleasant rawinsonde wind directions and speeds at the
2700 m level to 6O-min averages of wind direction and speed measured by tower-
mounted sensors at the DOT site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Figure 4.6. Relative frequency of 6O-min liquid averages stratified by wind direction at

the DOT site. ..........................................4-9
Figure 4.7. Relative frequency of the heights of water-saturated (95 % RH) layer bases
and tops from 1991 Mt. Pleasant soundings. ...................... 4-12
Figure 4.8. As in Fig. 4.7, except for temperature rather than height. .......... 4-13
Figure 4.9. Radiometer liquid depth averages displayed with simultaneous averages of
DOT wind direction and temperature. .......................... 4-15
Figure 4.10. Radiometer liquid depth averages displayed with simultaneous I-h
interpolated values of temperature at the tops of sounding saturated layers, and
wind direction averaged within the saturated layers of Mt. Pleasant soundings. 4-16
Figure 4.11. Distribution of SL W fluxes computed from 6O-min averages of radiometer
liquid depth and the averages of westerly wind speed (U component) in the
saturated layers of Mt. Pleasant soundings (interpolated to I-h increments). ... 4-18
Figure 4.12. Total SLW flux and precipitation, and their cumulative distributions
displayed by 1991 Utah/NOAA Storm Period. ..................... 4-22
Figure 4.13. Scatter plot of Storm Period SLWand Precipitation (from Fig. 4.12). .. 4-23
Figure 4.14. Azimuthal averages (zenith-normalized) of radiometer liquid overlaid on
terrain contours, from all 130-elevation scans taken in the period 0900-1500 16

Februat'Y. . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26

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