Identify and interpret fields and derived products
Presentation during the event week on Convection in June 2008.
Kris Bedka (University of Wisconsin) and John Mecikalski (University of Alabama) gave a presentation on the Convective Initiation (CI) method. The 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.
This session was continued by the Portuguese Met Service (IM). Besides the diagnostic tools from Numerical Weather Prediction models currently in use, satellite and radar products were addressed, including automatic warnings, e.g. for hail.
Presentation during the event week on Convection in June 2008.
Marianne Koenig (EUMETSAT) demonstrated the GII product. For the forecaster this was a very interesting talk as it showed the advantages the use of GII has to a model. Case studies saw the potential the GII product has and which added value(!) the GII has to a normal model run.
The lecture was followed by Maurice Schmeitz from KNMI on the development and verification of a new model output statistics (MOS) system, which is intended to help the forecasters to decide whether a weather alarm for severe thunderstorms should be issued.
Presentation during the event week on Convection in June 2008.
Marianne Koenig (EUMETSAT) demonstrated the GII product. For the forecaster this was a very interesting talk as it showed the advantages the use of GII has to a model. Case studies saw the potential the GII product has and which added value(!) the GII has to a normal model run. The session was followed by Jenni Teittinen from the Finnish Meteorological Institute who talked about warnings and the assessment of warnings in Finland.
Presentation during the event week on Convection in June 2008.
Guy Kelman (Hebrew University of Jerusalem) also showed some more examples of nowcasting convection over the States. The session was followed by a very good presentation of Natasa Strelec Mahovic (DHMZ) who in depth presented what material and products the Forecaster have available in Croatia when they start their working day and the day turns out to be convective.
Presentation during the event week on Convection in June 2008.
Guy Kelman (Hebrew University of Jerusalem) explained the relationship between cloud top temperature and effective radius and emphasised the advantage this can have on the lead time and the possibility to nowcast areas with a high potential of severe convection. The session was followed by Wilfried Jacobs (DWD) on the Automatic weather and product monitoring (Automon).
Case study on the abundant rainfall on 23 September 2008 in Valencia and Alicante.
On 23 September 2008 an amazing amount 326 mm in three hours was recorded in Sueca in the Province of Valancia. The convective events leading up to this event are discussed in this small case study by Ramon Vazquez. The satellite images as well as the radar and data from the ground are presented and discussed.
On 7th October 2008 a cold front crossed northwestern part of the Iberian Peninsula, producing large amounts of precipitation and causing disruption of same activities in the affected areas.
In northwestern Portugal, a maximum of 41 mm in 6 hours was obtained in an automatic weather station (AWS) in a mountain area and a maximum of 20 mm in 1 hour in a coastal area, both reaching the orange warning lower threshold for meteoalarm (40mm in 6 hours and 20mm in 1 hour, respectively). The Portuguese meteorological service (IM) issued a yellow warning with 24 hours advance, and the orange warning has been issued 7 hours before the beginning of the period of heaviest precipitation.
The 23rd of July was marked by a fast transition of a cold front (about 80 km/h) from west to east which went along with severe thunderstorms and hail.
The 23rd of July was marked by a fast transition of a cold front (about 80 km/h) from west to east which went along with severe thunderstorms and hail. The catastrophic event caused enormous agricultural damage and the Austrian farmer alliance reported that about 60 000 hectare arable lands were devastated. The destruction mostly caused by hail was estimated to sum up 15 million euro. On this account people insist on investigations to find out what exactly caused the event. Besides on the meteorological perspective there is always great interest in improving forecast methods and forecast tools. In principle the following report provides a detailed analysis of the weather event. Basically the high potential of prefrontal thunderstorms was known, although there were diverse estimations about its development. It was the change of the wind direction due to the interaction between the convergence line and the foehn that induced the following weather development. Contributing to the wiki case studies this report should lead to a better understanding of the atmospheric conditions that special day and introduce new now casting-products (GII and SAI).
On September 12th 2010 a major PV anomaly, in the rear of a cold front, moved over France and hit Germany and Switzerland in the late evening and also Austria during the night. On the front side of this anomaly convective cells developed and brought some rain showers and thunderstorms.
On September 12th 2010 a major PV anomaly, in the rear of a cold front, moved over France and hit Germany and Switzerland in the late evening and also Austria during the night. On the front side of this anomaly convective cells developed and brought some rain showers and thunderstorms. At first the ECMWF-model, especially the 00 UTC run from September 12th, was lacking performance shifted the PV maximum more westward. In this case study we analyse not only the synoptic situation, but also the model error. In the following we take a look at the MPEF (Meteosat Product Extraction Facility) Divergence product, how it works and whether it would have been helpful in this case as a nowcasting tool.
At 18 August 2011 a severe thunderstorm system developed over Belgium. This case study investigates the synoptic situation in which the windstorm developed using satellite, radar, NWP fields and lightning data.
On 18 August 2011 a severe thunderstorm system developed over Belgium. It initiated over France and then passed over Belgium, the Netherlands and Germany. The studied thunderstorm grew fast and was long-lived. It was extremely severe; particularly the downdraft was extremely strong. The most intense part of the windstorm hit the Pukkelpop festival organized close to the city of Hasselt. There were 60 thousand people at the festival, staying mainly at the camping site. The strong wind flattened tents, uprooted trees, brought down festival light towers and TV screens, and caused a stage to collapse. Five people were killed and 140 people injured in the storm, ten of them seriously. The aim of this case study is to describe the synoptic situation in which the windstorm was initiated and developed, and to describe its characteristics by means of satellite, radar and lightning data and numerical simulation.
In this module, we will introduce the concept of Total Precipitable Water (TPW) and show how satellite-based products help in estimating the amount of water vapour in the atmosphere.
In this module, we will introduce the concept of "Total Precipitable Water" (TPW) and show how satellite-based products help in estimating the amount of water vapour in the atmosphere. The module starts with an overview on measuring principles and algorithms on how to retrieve the water vapour content of the atmosphere. In the second chapter, you will learn more about the different TPW products from geostationary and polar orbiting satellites. Finally you will see some practical applications of TPW products in nowcasting precipitation events.
Go to the Product Tutorial ...
The purpose of this tutorial is to help the reader understand and use the SEVIRI Physical Retrieval (SPhR) product of the EUMETSAT Nowcasting SAF.
The purpose of this tutorial is to help the reader understand and use the SEVIRI Physical Retrieval (SPhR) product. SPhR's purpose is to provide information on convective environmental parameters, particularly on moisture content and atmospheric instability. These parameters are crucial in studying the potential for deep convection, and in predicting the development of convective clouds. Moisture, instability and a lifting (trigger) mechanism are needed for the formation of deep convection.