Points to Remember. 1  Marijuana refers to the dried leaves, flowers, stems, and seeds from the hemp plant, Cannabis sativa. 2  The plant contains the mind-altering chemical delta-9-tetrahydrocannabinol (THC) and other related compounds. 3  People use marijuana by smoking, eating, drinking, and inhaling it.
A cold front is symbolized on a weather map as a line with triangles. The triangles can be thought of as icicles. Cold fronts are often coloured blue. The presence of a cold front means that cold air is advancing and pushing underneath warmer air.
Cold Fronts. A cold front is where a cold air mass is pushing into a warmer air mass. Cold fronts can produce dramatic changes in the weather. They move fast, up to twice as fast as a warm front. Cold air is dense so it is able to quickly plow a warm air mass ahead of it. Commonly, when the cold front is passing, winds become gusty; there is a sudden drop in temperature, and heavy rain, sometimes with hail, thunder, and lightning.