Weather
Thomas Krennert talks about weather- and impact reports and a real-time feedback loop between forecasters and voluntary observers.
Length: 27 minutes.
Since the release of the WMO recommendations for impact based forecasts and warnings, reliable data about weather related effects on society and public life became increasingly important for operational forecasting. Particularly densely populated urban areas are vulnerable to the forces of convective weather hazards. In this regard, operational automatic station networks or remote sensing data cannot provide complete information about the ground truth like hail size, downburst related wind damage, flash floods or damage from lightning strikes. In order to fill this gap, targeted human assessment and observations are still needed. With the help of weather- and impact reports a real-time feedback loop between forecasters and voluntary observers can be established, to improve impact based warnings and thus to increase weather related disaster resilience and mitigation. In our presentation, we introduce the Austrian weather- and impact observation system "wettermelden.at" with its applications and furthermore a concept for the swift exchange of these reports on national and European levels.
Georg Pistotnik talks about how convective cells organise to single-cells, multi-cells and super-cells.
Length: 31 minutes.
According to their degree of organization, thunderstorms can conceptually be divided into single cells, multicells and supercells. Organized storms, in particular supercells, are responsible for the large majority of severe convective weather like large hail and damaging wind gusts. They are favored by high latent instability and/or strong vertical wind shear and exhibit characteristic behavior in radar and satellite data. For nowcasting purposes and timely weather warnings, it is therefore crucial to recognize organized and severe thunderstorms in remote sensing data. This presentation focuses on key properties of this distinction and illustrates some characteristic examples.
Vera Meyer investigated the influence of synoptic flow regimes over Austria on typical thunderstorm parameters.
Length: 26 minutes.
Since 2014 the Austrian thunderstorm nowcasting tool (A-TNT) monitors and nowcaststhunderstorm developments operationally based on 3D radar and lightning data. The algorithm employs an object-oriented approach observing and storing specific parameter attributes of the individual developments of convective cells. Radar data provide information about the internal precipitation structure and the probability of hail and lightning data about the electrical activity. A daily classification of the weather patterns based on a domestic development following Bissolli and Dittmann (2001) is available since 2004.
Based on a three years data sample the influence of synoptic flow regimes over Austria on typical thunderstorm parameters such as lifetime, cell size and core height, maximum and mean lightning stroke rate has been investigated as well as local thunderstorm frequencies and preferred storm paths.
Alberto de Lozar compares different cloud micro-physical schemes to better forecast thunderstorms.
Length: 25 minutes.
The goal of the SINFONY project of Deutscher Wetterdienst is to complement, refine and improve the methods of nowcasting (NWC) and numerical weather prediction (NWP) so that a continuous representation of atmospheric conditions and weather phenomena from the current time to the short-term forecast, i.e. in the period 0 to 12 hours, is possible. The pilot project focuses on summertime convective heavy-precipitation events, with the aim of providing more concise and accurate information for our warning service.
The representation of deep convection in km-scale NWP strongly depends on the parameterization of cloud processes at the microscopic scale: the cloud microphysics. Traditional NWP microphysical schemes describe each hydrometeor type (e.g. cloud water, rain, snow, graupel or ice) by one single prognostic variable. This one-moment description performs sufficiently well in many weather situations, but it is also known to produce a too coarse representation of the microphysics and dynamics of deep convective cells. Case studies have shown that a better representation can be obtained with the so-called twomoment schemes, in which each hydrometeor is represented by two prognostic variables, usually mass und number densities. Those schemes have thus the potential to produce more realistic convective dynamics, which can improve short-term forecasts of heavy-precipitation events
We employ different observational systems to evaluate how different models and microphysical parameterizations represent clouds and precipitation over Germany. We compare simulations with ICON and COSMO using different microphysical schemes (operational one-moment vs. Seifert and Beheng two-moment). All simulations are driven by the same boundary conditions from the ICON-EU analysis fields. The simulated period is spring/summer 2016, which is characterized by heavy convection over Germany. In the presentation we mainly focus on the observations from the radar network and on the observations in the visible channels from SEVIRI.
Tomas Pucik investigates the relation between AACP and hail occurrence.
Length: 23 minutes.
Above anvil cirrus plumes (AACPs) have been established in the scientific literature since 1980s. Recent improvements in the temporal and spatial resolution of the satellite data brought back attention to their potential use as an indicator of severity of convective storms. In 2018, we have identified 26 days, where damaging hail reaching at least 5 cm, causing significant economic or societal impact was reported to the European Severe Weather Database. For the selected hailstorm days, where rapid-scan imagery with 5-minute temporal resolution was available, we identified 29 very large (>= 5 cm) hail producing storms. 25 of these hailstorms did show an AACP, but only 12 of these plume producing storms could be clearly identified using the visible imagery. The range of lead time of the AACP appearance to the first hail report was very large and in about half of the cases, the plume occurred only during or after the time of the first large hail report. Due to the limited number of cases, the main purpose of the presentation is, rather than drawing conclusions, to open a discussion on the operational usability of AACPs in warnings for convective storms.
The introduction lecture is addressed to users of PPS wanting to update their application, but also to prospective new users.
Length: 66 minutes.
The EUMETSAT SAF to support Nowcasting (NWCSAF) develops two software packages, one for geostationary imagery and one for polar satellite imagery. Both packages retrieve cloud and other parameters relevant for nowcasting and other applications relying on cloud detection. For more information see www.nwcsaf.org
The Polar Platform System (PPS) software package retrieves information on clouds and precipitation from Terra, Aqua, MetOp and S-NPP. The recent release of PPS v2018 features also a number of scientific and technical updates.
The introduction lecture is addressed to users of PPS wanting to update their application, but also to prospective new users.
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Presentations (PDF):
PPS v2018 Scientific Introduction
PPS v2018 Technical Instruction
Silvia Puca introduces the H-SAF and its products.
Length: 23 minutes.
H SAF started in 2005 and aims to provide remote sensing estimates of relevant hydrological parameters: instantaneous rain rate and cumulated rainfall, soil moisture at surface and in the root zone, snow cover and water equivalent. The project involves experts from 12 national meteorological and hydrological European Institutes of Austria, Belgium, Bulgaria, Finland, France, Germany, Hungary, Italy, Poland, Romania, Slovakia and Turkey, and from ECMWF.
The H SAF main objectives are: to provide new satellite-derived products (precipitation, snow parameters and soil moisture) from existing and future satellites with sufficient time and space resolution to satisfy the needs of operational hydrology, and to perform independent validation in order to assess the usefulness of the new products for fighting against floods, landslides, avalanches, and evaluating water resources.
Stefania Camica and Lucca Brocca describe the theoretical background for using satellite SM products in flood prediction.
Length: 19+24 minutes.
Satellite soil moisture (SM) products have been largely used for flood prediction. The knowledge of initial soil moisture conditions before a rainfall event is critical to determine the magnitude of a flood event. The presentation will describe the theoretical background for using satellite SM products in flood prediction, and will show examples for understanding the critical role of initial soil moisture for predicting floods.
Simone Gabellani and Fabio Delogu describe how satellite soil moisture can be used in hydrological modelling trough data assimilation.
Length: 37+27 minutes.
The reliable estimation of hydrological variables in space and time is of fundamental importance in hydrology to improve the flood predictions and hydrological cycle description. Nowadays remotely sensed data can offer a chance to improve hydrological models especially in environments with scarce ground-based data. The presentation describes how satellite soil moisture can be used in hydrological modelling trough data assimilation.
Nicola Berni presents the impact of soil moisture products for flood and land slide warning.
Length: 17 minutes.
Umbria Region Civil Protection Early Warning center (Central Italy) is in charge of alerting and monitoring critical events for Civil Protection purposes (mainly landslides and floods). In last ten years the office has used, in cooperation with national research institutes, satellite data to improve modeling/forecasting tools performances, monitoring activities about possible impacts of severe rainfall events able to trigger floods and landslides at regional scale. In fact, the estimation of the soil water content has proved to be a key parameter for better forecast models implementation both for landslide than for flood risk issues.
Silvia Puca presents how satellite products impact the efficiency of hydro-meteorological warning.
Length: 28 minutes.
Many severe meteorological events occurred in Europe during the last decade and caused casualties and damages to the historical heritage and natural environment. Protection of civilians and safeguard of the territory are the kay mandates of a civil Protection (CP) agency. This is achieved through activities that mitigate hydro-meteorological risks, such as flooding and droughts. European CP agencies, supported by meteorological and hydrological institutes, aim to assess risk scenarios, to monitor and supervise events and risk levels, providing early warning to National and local authorities.
Near real time accurate estimations of hydrological variables such as precipitation and soil moisture are invaluable to the CP agencies, enable them to issue early warnings and plan for disaster relief at the local level.
Besides measurements of key hydrological variables by ground-based instruments, often affected by a limited spatial coverage, advanced satellite-based precipitation and soil moisture products developed within different international programs as H SAF, are available and accessible to users in near-real time.
In this study, recent severe meteorological events are selected in order to understand how the main satellite product characteristics, i.e. accuracy, spatial pattern and resolution, update frequency and latency, impact the efficiency of a hydro-meteorological early warning system at a local level in an operational framework.
Lauryna Sidlauskaite talks about the challenges of winter road weather forecasts in view of climate change.
Length: 39 minutes.
Climate change is almost literally the "hot" topic of today. Scientists agree that cars with combustion engines are one of the main sources of greenhouse gasses, however, with such vastly growing world economy, transportation of goods and people is essential. Thus, certain measures must be and are being made to reduce their negative effect on climate.
Humanity has reached a point in time, when even if greenhouse gas emissions could be reduced to pre-industrial times it will not stop the human-induced climate change and the effects of it will be felt for decades or even centuries to come. Therefore, we’re compelled to know and understand what to expect from road weather, especially in winter seasons.
In this session, the problem of lack of specific climate forecasts for winter road weather will be discussed and future climate projections for road weather patterns will be presented with Lithuania as an example. The study in question involved regular climate forecasts for 21st century for several RCPs, downscaling of data to fit Lithuania and formation several statistical indices, that better describe road weather for road maintenance workers and road users. Using the indices allows a better understanding on what’s to come and how climate change will impact road weather in the 21st century.