WMOD00310 ‎(2)‎

• Project Name: Sierra Cooperative Pilot Project
• Title: The Characteristics of Evolution of Supercooled Water in Wintertime Storms Over the Sierra Nevada
• Date: 9/9/1988
• Weather Modification - Doc Type: Report

SEPTEMBER 1988

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MARK F. HEGGLI AND ROBERT M. RAUBER

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TIME (UTe)

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FIG. 12. Time-height cross section of relative humidity and winds from serial rawinsondes taken at Kingvale
between 1500 UTe: 22 December 1986 and 0900 UTe: 23 December 1986. For shading and wind conventions,
see Fig. 5. Supercooled liquid water depth and precipitation rate at Kingvale are shown on the middle panels. The
bottom panel shows the number of melt cycles of the icing rate detector in each 5-minute time interval for the
instruments at Signal Peak and Squaw Peak.

wind direction was predominately out of the south up
to 300 mb.
The increase of cloud top height near 1800 UTe 7
January was in response to the passage of an upper-

level front, evidenced by the decrease of temperature
from 1500 to 2100 above 650 mb. Precipitation in-
creased to 2 mm h -1 and supercooled water decreased
to 0.05 mm. As the front passed, the winds decreased