Fog!                                                            3/18

     1.  Describe the development of an occluded front as the attached cold front overtakes the attached warm
         front.

              A .  An occluded front is formed at the first point along a pair of fronts (cold and warm) where the cold front
                        overtakes the warm front.  That point is generally close to the center of the associated cyclone.  Thereafter, as
                        the attached cold front overtakes more of the attached warm front, the point of occlusion moves down the
                        frontal line, in other words the occluded portion of the frontal system grows at the expense of the cold and warm
                        fronts.  As a consequence and at the same time the point of occlusion moves farther from the cyclone center. 
                        This removes the warm sector of the cyclone from contact with the cyclone center, depriving the cyclone of an
                        important source of energy.  The cyclone generally begins to weaken as soon as the cold and warm fronts begin
                        to merge as an occluded front; the weakening continues as the point of occlusion moves down the frontal line
                        until, eventually, the whole system dissipates to the point that it can no longer be identified.