The Omega-Weather Type

If then even the high level wind field ( jet stream ) moves around this vertically extended high pressure cell, the upper air flow track over northern Europe takes a curvature looking like an uppercase Omega (Fig. 4.26). Therefore this well-known weather situation, coined by bright sunshine and extended in space, is regarded as the Omega-weather type. 

Often such an undisturbed weather period continues for 10 day s in many years it has been responsible for the sunny and dry high in May, and the highs in the Indian summer at the Baltic Sea. 

Monday. August 4,2003 12 UTC ECMWF Forecast t + 120 VT Saturday, August 9,2003 12 UTC SCO hPa Height 

FIGURE 4.26 Typical Omega-weather type—also over the Baltic Sea (500 hPa surface) on August 4, 2003, 1200 UTC (ECMWF, with pennission). Color figure on CD, Chapter 20.4. 

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