From Earth Science Picture Of The Day; November 13, 2015:

Fog Above Vouraikos River in Greece
Photographer: Stavros Hios; Summary Authors: Stavros Hios, Jim Foster

The misty course shown above follows the hidden Vouraikos River in southern Greece. On this clear, autumn morning, cool air collecting in the river valley dropped the temperature to the dew point forming a dense layer of fog (radiation fog or valley fog).

This type of fog is commonly observed during the autumn season when the nighttime period is longer than the daylight period, particularly if the air near the surface is relatively moist and winds are calm. Photo taken from the highlands of Achaea, near Kalavrita, Greece, on October 19, 2015.

Orographic Lift!

As an air parcel reaches the windward side of the mountain, it rises upwards and quickly expands and cools off. With the right conditions, clouds will form and rain will occur. As the air parcel passes over the top, it’ll being to sink and compress along the leeward side. This is why you have the ran shadow effect on the leeward side! 

In Southern California, our Santana winds are due to the same physical processes. As the warm winds blow from the desert and into the mountain canyons, the air parcel is compressed and super-heated. This leads to intense drying of flash fuels, high wind, and with our overgrown forests, it becomes the perfect condition for the fire storms we experience. 

storm surge

风暴潮或称暴潮(storm surge)是由热带气旋温带气旋、冷锋的强风作用和气压骤变等强烈的天气系统引起的海面异常升降现象,又称“风暴增水”、“风暴海啸”、“气象海啸”或“风潮”。风暴潮会使受到影响的海区的潮位大大地超过正常。如果风暴潮恰好与影响海区涨潮相重叠,就会使水位暴涨,海水涌进内陆,造成巨大破坏。如1953年2月发生在荷兰沿岸的强大风暴潮,使水位高出正常潮位3米多。洪水冲毁了防护堤,淹没土地80万英亩,导致2000余人死亡。又如1970年11月12-13日发生在孟加拉湾沿岸地区的一次风暴潮,曾导致30余万人死亡和100多万人无家可归。
Frontal precipitation

frontal precipitation

  • cold front
  • warm front

non-frontal precipitation


冷锋的降雨原理:在冷空气与暖空气的交界面,冷空气快速切入暖空气下方,迫使暖空气迅速爬升,遇冷凝结成雨(或雪);暖锋的降雨原理:在冷暖空气交界面,冷空气开始撤离,暖空气则顺势缓缓爬升至冷空气上方,冷凝成雨; 静止锋的降雨原理:冷空气与暖空气势力相当,遂在交界处形成大范围的降雨带; 囚锢锋的降雨型态则较为复杂,端看属于哪种囚锢锋(冷锋型囚锢、暖锋型囚锢、中性囚锢)而定。