January 12, 1995 Storm, Infrared Satellite Image
This is a satellite view of the same January Storm depicted in the
500 Mb upper level and surface maps. On this view, the typical "comma"
shaped cloud mass has been outlined in black; the center of the low pressure
cell is centered beneath the head of the comma. Black arrows have been
added to show the direction of wind flow around this low pressure cell.
In general terms, cold fronts are formed when cold, dry air moves down
from the north, invading territory occupied by warm air; warm fronts form
as warm air moves northward into areas occupied by cooler air. All air
flow around a low pressure cell like this one is counter-clockwise in the
northern hemisphere, opposite or clockwise in the southern hemisphere.