4th October 2007: 12UTC
This is the first image with four of eight panels that we see. If we look at the below satellite image we see that most of the convection is now tight to the eastcoast of Spain. The increased precipitation is wel reflected in the HIRLAM model. To the top left we see the precipitable water where especially in the area where the convection is bound a maximum of up to 50 mm is observed. The white lines you see in this image is the moisture convergence at 850 hPa. As you would expect with convection and severe updrafts we find a local maximum of this parameter just off the Spanish east coast. For the onset of convection you do not want to have a strong cap that you need to overwin. The top right image shows that for the region of interest the CIN is not that high. Further SE the cap is stronger with values up to 1000 J Kg-1 (hence, the lower activity seen in enhanced IR). The maximum that we find off the Spanish coast in the bottom left image is the WINDEX that tells us that there are some microbursts associated to this convective event..
Meteosat 9: Enhanced IR10.8 - 4 October 2008 12UTC
4th October 2007: 12UTC
Obvious with a case study on convection you would expect also unstable features in the model pramaters. This is fortunately reflected in the two top images. East of Spain in the Mediterranean bassin we have negative values for the lifted index and high values up to 1000 J Kg-1 for the CAPE index (right image). The combined image (ACON) in the lower right however shows that when combining all the information from the different panels that the outlook should be on the convection just of the coast off Valencia and Allicante.
Meteosat 9: Enhanced IR10.8 - 4 October 2008 12UTC
4th October 2007: 18UTC
Six hours later. The cell that we analysed before did increase and moved over Mallorca and is now found in the enhanced IR image (below) just off the coast of Spain near Catalunya. Over Algeria some new developments are taking place. The precipitable water shows for a large area high amounts of water. Other indications are the high shear we can observe in the image to the bottom right. Note that the values of CIZ6 vary between 7 to 25 m/s and give a sign of the level of convection (whether unorganised below 7 m/s, or organised convection above 7 m/s). With very high values (over 20 m/s) the vertical wind shear is a limiting vector to the intensity of organised convection.
Meteosat 9: Enhanced IR10.8 - 4 October 2008 18UTC
4th October 2007: 18UTC
Both the stability parameters CAPE and lifted index give the indications of unstable air masses. The combinations of these and also SRH is found in the bottom right image where again the combined image is seen. North of the Balearic Islands also over Algeria there are still some areas that should be monitored closely with satellite and radar as these show high potential for strong convection for future timesteps.
Meteosat 9: Enhanced IR10.8 - 4 October 2008 18UTC
