Fast runner (meteorology)
A fast runner is a particularly strong marginal depression that forms on the cold front of a central depression .
Emergence
In the westerly wind zone , which extends from the USA across the Atlantic and Europe to Asia, large areas of high pressure and low pressure move eastward. As a rule, the lows move further north than the high pressure areas. Since the air pressure differences increase with the increasing difference between cold and warm air masses, the southern Azores high and the Iceland low are strongest in autumn and spring, and thus the pressure differences are greatest. In spring it is still cold in the north and relatively warm in the south; in autumn it is already cold in the north and still relatively warm in the south. The boundary between the cold air masses in the north and the warm air masses in the south is called the “ polar front ” in meteorology .
Along the frontal zone, low pressure areas move eastwards again and again, which initially carry a warm front on their front , then a cold front in the further course. The stronger the low pressure areas, the shorter the time until the cold front has caught up with the warm front and occlusion occurs. Since the warm front once again increases the supply of warm air masses (hence its name), the already high temperature difference to the cold air masses behind the cold front increases again. As a result, a particularly strong marginal depression can form on the cold front of particularly striking low pressure areas. Such a low is called a fast runner.
Effects
Because of the higher temperature and air pressure differences, high-speed runners bring with them much more striking weather phenomena, for example strong storms and precipitation. They are hardly calculable for meteorologists. Since a high-speed runner swirls the air masses involved vigorously and pulls fronts over the affected area in rapid succession, further low pressure cores can form, which are sometimes organized in a spiral around the core of the high-speed runner.
Example from the past
Probably the most famous high-speed runner in history was the hurricane "Vincinette", which caused a storm surge in Hamburg on February 16, 1962 .
Footnotes
- ↑ Archived copy ( memento of the original from October 6, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ www.wissenschaft-online.de
- ↑ www.deutscher-wetterdienst.de ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (pdf)
- ↑ Archived copy ( Memento of the original from May 11, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ DWD press releases on 50 years of storm surge in Hamburg
