Physics Photo of the Week
Warren Wilson College
January 28, 2005
Clouds before Ivan
evening before the arrival of Ivan the Terrible Storm to Western North
Carolina in September 2004, the clouds showed an amazing multiple
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
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 -
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
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.
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
of Sept. 15. The hurricane remnants (much rain, flooding, and
high winds) came on the evening of Sept. 16, 2004.
- Donald F. Collins
Physics Photo of the Week is
published weekly during the academic year on Fridays by the Warren
Wilson College Physics
Department. These photos feature an interesting phenomena in
the world around us. Students, faculty, and others are invited to
submit digital (or film) photographs for publication and
explanation. Atmospheric phenomena are especially welcome.
Please send any photos to firstname.lastname@example.org.
here to see all Physics Photo of the Week for 2005
to see all Physics Photo of the Week for 2004.