NWP parameters
Thermal Front Parameter + Relative Topography 700/1000 hPa, IR Images: time sequence
In the following chapter the cloud configurations in satellite images are related to the thermal front parameter and the relative topography. 6-hourly sequences are shown.
Temperature Advection 700 hPa, IR Images: time sequence
The temperature advection in the lower parts of the troposphere is an important factor for increasing or decreasing potential instability. In order to get a continous overview model values are considered. 6-hourly sequences are shown.
Vertical Motion 500 hPa, WV Images: time sequence [3h]
This chapter shows the cloud configurations in WV satellite images in relation to the vertical motion (=omega) at 500 hPa. 3-hourly sequences are presented.
PV 310 K, WV Images: time sequence [6h]
The cloud configurations are related to Potential Vorticity. The triggering of convection by PV maxima and the corresponding conceptual models will be investigated. The PV-fields are only available every 6 hours.
Sounding parameters
Station Bergen: 12 UTC
The radiosounding station Bergen (Stüve-diagramme, Northern Germany) is quite representative for the relevant processes during 27 July 2006. A more detailed temp evaluation for 12 UTC is performed.
Nakamura Gusts, IR Image: 12 + 18 UTC
Gusts are derived from the radio-soundings by the method of Nakamura. A comparison to measured gusts is carried out. The situations at 12 and 18 UTC are presented.
Precipitable Water, IR Image: 12 UTC
In this chapter the amount of precipitable water measured by radio-soundings at 12 UTC is given. This parameter is strongly related to the precipitation amount.
KO-Index, IR Images: 12 + 18 UTC
This index and many others are useful for estimating the potential instability. 12 and 18 UTC are considered in this chapter.
It is always important to combine derived parameters with satellite images in order to better understand the processes and to perform a better monitoring of critical cloud features.
In the case of convection it is only of limited use to consider model fields of Omega because many models are often not able to consider all processes like orographic induced processes accurately enough. Another problem is that only local models (with less than 10 km resolution) contain the so-called non-hydrostatic formula. The data considered in this study is based upon hydrostatic equations that do not consider vertical motions in relation to convective cells. However, fields of higher resolved models are often difficult to interpret.
Temperature advection in one level is not sufficient for detecting stabilization or labilization. This is only possible with cross sections or radiosoundings.
The thermal front parameter is useful for detecting front intensification or decaying. In connection with information about potential instability critical areas could be found.
The IPV in connection with water vapour and particularly with the Airmass RGB is very helpful for an early pre-warning of severe convection or thunderstorms.