Third Birthday Invitation Poem

strip again (and letzmals) to the high January temperatures ...

High "Agnes" was now directly
over the Alps. http://www.wetterpate.de/

In the middle and upper layers of the January heat today has reached its peak. In contrast to the hair dryer-and southwest of 5 until 9 January, the wind today, his fingers are not in the game (at least he had no direct effect on the temperature distribution). Therefore, other regions were affected (more on that at the end).

"blame" for the heat was brought up in recent days subtropical Atlantic air and the slow Absinkbewegung (subsidence) in the high "Agnes", which today reached its climax. The freezing level rose to about 3,500 feet, were on the Jungfraujoch the first time today since 5 November 2010 re-measured temperatures slightly positive (+0.7 ° C). The January-ever way, at +3.3 ° C (January 6, 1999).

Radiosonde Payerne, 16 January 2011, at noon. Left red curve: Tau-
point, right curve: temperature. The greater the distance between the two curves
is the drier the air. Blue marked (x)
the maximum values of some ground stations. Further explanation
in the text. Data source: MeteoSwiss

was interesting, especially the vertical stratification of the atmosphere (see graph): The ground inversion went smoothly in the on Absinkinversion so from the ground up was carried to an altitude of about 1600 m, a temperature increase of 10 ° C.

The temperature variation in the free atmosphere (right red line) was modified at the base stations but the sunshine (global environment, purple arrows). At the top stations in January this warming is negligible. On the one hand because of the snow, but above all because the environment can always warm up less (a lot of "air" [can not be heated directly] and little rock or grass area).

Thus, it is not surprising that it was on today, 800-1400 m warmest. The leader was once again today Disentis (1197 m) with 14.2 ° C. This could be a new record in January, at the moment but I have no access to the homogenized record levels. In the deep layers, there were now quite large temperature differences. In a few regions (such as Zurich-Kloten), it was more or less all day foggy. Here are just 4 ° C were measured, in the sunny Bern, it was almost +10 ° C.

A word about the connection between weather and extreme winter maximum temperatures. Generally bring West and Southwest locations, the highest temperatures (logical - the source of the air mass makes from ...). My colleague Louis Z'graggen by MeteoSwiss has in a study demonstrated also that: bring

• in the lowlands rather low pressure some western and southwestern documents high values (if the wind down to the floor passes through ...)
• in the middle and high altitudes bring the high-pressure specific West and Southwest layers high values (heating through fall and sunshine - like today)
• in the northern Alpine valleys shall finally have the hair dryer for the very high temperatures in the winter