MSG IR10.8 imagery with tendency of surface pressure and wind: time sequence

18th August 2004: 06UTC
A cold front over Western France and the Bay of Biscay can be identified in the NWP-fields. This is consistent with the relevant cloud area that will develop later into the squall line.

18th August 2004: 12UTC
At 12 UTC we recognise from the equivalent temperature
a) the cold front over Western France and
b) a convergence from the English Channel over Paris to Central France (latter indicated by a relative maximum of θe). First convective clouds developed. However, the high extending and compact clouds are near the cold front at 0 degree longitude. Over Eastern France Te is higher than 324K indicating a risk to heavy precipitation.

18th August 2004: 18UTC
The 18 UTC image clearly shows the convergence (θe) in connection with the bright cloud band extending from Eastern France to Western Germany. θe of up to 332K indicate a high risk to large precipitation amounts.

19th August 2004: 00UTC
Over Eastern France and Northern Germany the IR-image shows bright clouds. The θe at 850 hPa shows high values up to 328 K. This maximum corresponds well with the convective clouds, heavy rain and thunderstorms.