Warm, Occluded, and Stationary Fronts

Warm Fronts: occurs when a warm air mass slides over a cold air mass Relatively stable Moves slower than a cold front Long transition from cold air to warm air (warm air moves slowly) Temperature gradually rises Clouds and precipitation (lighter rain that lasts longer) Red line with semi-circles in the direction of warm front movement

Red line with semi-circles in the direction of warm front movement

OCCLUDED FRONT: when a cool front catches up with a warm front. Made of 3 air masses, in order from front to back, are cold, warm, and then cold again. Causes a drop in temperature Fierce weather at the occlusion (precipitation and shifting winds are typical)

OCCLUDED FRONT Purple line with alternating triangles and semi-circles in the SAME DIRECTION.

STATIONARY FRONT = when air masses are stopped by a barrier, such as a mountain range, or when they are stopped by each other. May bring days of rain, drizzle, and fog.

STATIONARY FRONT Weather map = alternating blue triangles pointing in the direction of the cold front and red semi-circles point in the direction of the warm front (OPPOSITE DIRECTIONS).

WEATHER SYMBOLS

WEATHER SYMBOLS “L” stands for a low-pressure area. Where warm air is rising, carrying moisture that then condenses into clouds. Cloudy skies and rain. “Light” air   

WEATHER SYMBOLS “H” stands for a high-pressure area.   “H” stands for a high-pressure area. Air is heavier and sinking towards the ground. Clear skies because the air is sinking. “Heavy air”

WEATHER SYMBOLS   Dark lines = ISOBARS = measurements of atmospheric pressure “bar” refers to atmospheric pressure (“barometer”) The closer the lines are together, the windier it is (higher wind speeds).