1. cold front 2. warm front 3. stationary front 4. occluded front
cold air mass is replacing warm air mass. cold fronts move quickly and can cause abrupt weather changes as well as rain and snowfall. denser cooler air slides under lighter warmer air and pushes warmer air upwards. happens directly at front.
warm air mass is replacing a cold air mass. warm air moves over denser, cooler air. weather may be rainy/foggy for several days. generally happens before front passes.
humid/warm air = showers and light rainfall dry/warm air = scattered clouds form
a front that stops moving or is moving very slowly. when the fronts meet, neither have the force to move each other. weather consists of rain/snow/fog/clouds. when front starts moving, it either turns warm or cold.
a warm front is trapped by two cold fronts. denser cooler air moves underneath less dense warm air and pushes it upward. weather may be cloudy, rainy & snowy. occluded fronts usually result in storms over an area.
heavy rain storms accompanied by thunder and lightning
where do thunderstorms form?
within large cumulonimbus clouds or thunderheads
what is needed for a thunderstorm to develop?
1. ample moisture 2. lift (upward moving air) 3. instability of the atmosphere