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<br />were occluded and weakening in intensity. A weak cold front extended southward <br /> <br />from the low and moved into a region of split flow over the project area. A <br /> <br />region.of cirrus. and mid-level cloud was frequently obseryed ahead of the.sur- <br />face front, but h~d generally decoupled from ~he clouds associate~ with the sur- <br /> <br />face front. As fronts moved over land into the Sierra Nevada, they underwent <br /> <br />frontolysis. Light and sporadic pl~ecipitation accompanied the frontal passage <br />in the Sierra Nevada. An orographic cloud often persisted for several hours <br /> <br />after frontal passage. <br /> <br />B. Storms with meridional flow characteristics near 400 N <br /> <br />Storms in a meridional dominated flow differed from the zonal flow storms in <br /> <br />the amplitude of the wave systems. The wind direction, which \~as determined by <br /> <br />the position of the wave relative to the mountain, was a key to the existence of <br /> <br />supercooled water over the Sierra Nevada. For this reason the regions where <br /> <br />supercooled water was present in meridional storms were much different from <br /> <br />those in the zonal storms. <br /> <br />, <br /> <br />Storms associated with a meridional flow pattern at 400 N were grouped into <br />two categories. The first category included cutoff lows and narrow high ampli- <br />tude troughs near 400 N. The second category included shortwaves digging down <br />the east side of a longwave ridge. <br /> <br />1) Cutoff low or large amplitude ~hortwave near 400 N <br /> <br />A schematic portrayal of the flow in a cutoff low near 400 N is depicted on <br />Fig. 3d. The cutoff center occurrE!d between 350 and 400 N latitude. This synop- <br />tic configuration provided strong southerly to southwesterly flow ahead of the <br /> <br />storm systems, shifting to northerly and sometimes northeasterly after trough <br /> <br />8 <br />