Winter storm Kyrill leaves a trail of destruction

By Jochen Kerkmann and HansPeter Roesli (EUMETSAT), Maria Putsay (Hungarian Meteorological Service), Martin Setvak and Petr Novak (CHMI)

In January 2007 winter storm Kyrill (visit the origin of the name Kyrill) left a trail of destruction in southern England and Central Europe. The storm had been very well predicted by numerical weather prediction models and severe wind warnings had been issued in due time. In its initial phase, Kyrill travelled across the Atlantic Ocean at a very high speed (see animation, 17 January 06:00 UTC–18 January 17:00 UTC) without deepening too much.

Thus, it was similar to the winter storms of December 1999 (called Lothar and Martin). However, when it reached the European continent is started to slow down and spin up, converting kinetic energy into rotational energy.

Finally, on 19 January, as it moved into western Russia, it appeared on the satellite images as a fully developed cyclone with a typical spiral structure (see animation, 17 January 14:30 UTC–19 January 23:30 UTC). A curious side effect of Kyrill was observed in Switzerland where surface temperatures in Locarno (in a foehn situation) reached 24 °C (see time plot, source: MeteoSwiss).

As shown in the upper left image of the four-panel image gallery, Meteosat-8 played a crucial role in the early detection of this rapidly developing storm over the Atlantic Ocean. The image shows the so-called SatRep, or Satellite Report, which is issued every six hours by the Austrian, the Finnish and the Dutch weather services.

It represents a combination of satellite imagery with NWP data in terms of conceptual models. Currently up to 60 of these conceptual models exist and are fully described in the Manual of Synoptic Satellite Meteorology. One of the conceptual models is 'Rapid Cyclogenesis', which, in this case, is assigned to the cloud pattern east of New Foundland that later became storm Kyrill.

The upper right and lower left images show the situation at 09:00 UTC on 18 January, as seen by the MSG satellite (shown here are the Airmass RGB product and the WV6.2 channel). At this time the development of storm Kyrill was already in its advanced stage. The dark zone in the WV6.2 image and the red zone in the Airmass RGB product mark a pronounced Potential Vorticity (PV) anomaly (dynamic tropopause anomaly), which is typical for rapidly developing cyclones.

Last but not least, radar reflectivity images from the Czech weather radar network (see lower right image) document the passage of the storm over the Czech Republic. It is interesting to note that the strongest wind gusts were not recorded on the reflectivity maximum, but before and after its passage (see combined loop of radar and synoptic data, 18 January 17:00 UTC–19 January 02:00 UTC, animated source: CHMI).