The
evening before the arrival of Ivan the Terrible Storm to Western North
Carolina in September 2004, the clouds showed an amazing multiple
dynamics. Three
types of clouds are seen in the picture. The high clouds are
cirrus clouds. They are formed by warm, moist air flowing above
cold air and usually indicate a prelude to stormy weather on the
way. At mid level - to the right of center - is a
lenticular-like
cloud.
This mid-level cloud shows a different shape from
the lowest cumulous clouds just above the Craggy Mountains. The
three strata are better observed in the animation below.
Please have patience, the animated file is larger than 350 kilo-bytes -
it may
take awhile. In the animation, however, one can see that the
directions of the winds at various altitudes are all different.
The lowest clouds move toward the left (wind coming from
the east) forming the clouds as the winds are deflected toward the
summits of the mountains. The biggest "blob" of lenticular
cloud appears
stationary while bits an pieces travel toward the north - away from the
camera. The highest level clouds are moving
from the west - towards the right hand side of the photo.Animated
Image
The animated image consists of 11 frames taken every 40 seconds and played back at 0.2 sec per frame. Over 7 minutes of motion are compressed into about 2 seconds. The images were made on the evening of Sept. 15. The hurricane remnants (much rain, flooding, and high winds) came on the evening of Sept. 16, 2004. - Donald F. Collins