A ”best practises” document was written by John Mecikalski as outcome of the CWG meeting in Krakow, Poland in November 2007 with future directions of nowcasting convection at EUMETSAT. All are invited to read through and append their information/thoughts to this document as well.
Kris Bedka published a chart describing elements of an end-to-end convection nowcast system. All are encouraged to view and share their comments to this!
The documentation is further categorised in various categories: Preconvective Conditions, Convective Inititiaton and Mature Phase. A final category deals not so much with the various stages of convection but provides information on tools and visualisation techniques for the monitoring and nowcasting of convection.
The
Global Instability Index (GII) product is one of the MSG meteorological products and describes the instability of the clear atmosphere by a number of airmass parameters. Although of highly empirical nature, the instability indices often indicate the potential for convection a few hours prior to the actual onset of convection. You can find more information on GII including some examples here. A detailed description on how the GII product functions is found in this document.
The
Convective Initiation (CI) product identifies cumulus-type clouds within an MSG image and uses the temporal evolution of the related MSG observations to identify rapidly growing cumulus as likely candidates to evolve into potentially strong convective storms up to one hour in the future. A detailed description on how the CI product work is found in this article and an actual example of a retrieval of CI over South Africa is found
here.
A domelike protrusion above a cumulonimbus anvil, representing the intrusion of an updraft through its equilibrium level, or short ”
Overshooting Tops” is the subject of an article by Kris Bedka
et al. in which MODIS, AVHRR and MSG imagery are used for detection in order to prepare for the upcoming GOES-R satellite.
IR Cold Cloud Tops product was already recommended during the workshop by Jan Kanak as being useful during summer convection season for the meteorologists and also for case studies of convective events. This product is generated from calibrated radiative temperatures of Meteosat 9 IR10.8 using the color scheme from blue to turqois to yellow and red applied over the fixed interval 200 to 240 K. Another speciality of the processing approach is the weighted average of MSG pixels during reprojection from satellite view into conical projection. Weighting function depends on satellite zenith angle. This procedure makes better picture quality even in areas of very high satellite zenith angle.
The
sandwich product which is developed by Martin Setvak, (CHMI), Lukáš Ronge (Amateur Stormchasing Society of the Czech Republic) and Ján Kaňák (SHMI) combimes the strong information of the HRV overshooting tops with the the enhanced IR10.8. Usually the overshooting tops and their downwind warm spots are observed independently, in the two stand-alone bands – the HRV band, and color-enhanced IR10.8 brightness temperature imagery. The sandwich product presents a new image product, which merges the two bands together, allowing to observe all of these features simultaneously, in one single product.
The enhancement of grey or color scales, used for visualization of thermal IR-window imagery, has been utilized since the early days of weather satellites. The purpose of this technique is obvious - to provide a human eye more details in a specific range of temperatures, details which otherwise would remain hidden. More on enhancements is found in
this article by Martin Setvak and Daniel Lindsey
Tables to help you in your research and to make
Parallax corrections are now made available for you to download. You can read a full description on how to access and read (comes with a Fortran90 program) these tables here.