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<br />31 <br /> <br />that the cirrus took 2-1/2 hours longer to pass over the target, doing <br /> <br />so at 2345. The last of the significant precipitation fell just before <br /> <br />. <br />. <br /> <br />the high cloud moved off (Figures 10 and 11). By 2100, the Sheridan <br /> <br />sounding was dry below 80 kPa with the front having passed there. Due <br /> <br />to the orientation of the front, almost perpendicular to the Sierra, <br /> <br />the post-frontal orographic cloud and lifting were slight, and it ap- <br /> <br />peared that mountain precipitation behind the front was from a middle <br /> <br />to upper level cloud above 78 kPa. <br /> <br />Natural seeding from the upper cloud appears to have occurred <br /> <br />during the time of heaviest precipitation, as the soundings showed the <br /> <br />mid-level cloud separation to shrink and disappear by 2100 GMT. If <br /> <br />this is the case, the satellite-observed CTT remaining very low (below <br /> <br />I ~ <br /> <br />o <br />-40 C) would indicate little potential for positive seeding results in <br /> <br />this storm, with no warmer orographic cloud remaining after the front <br /> <br />I ~ <br /> <br />passed. <br />