Weather
Ioannis Pytharoulis shows past cases of Medicanes, the description of their structure and characteristics.
Length: 50 min
Author: Ioannis Pytharoulis (Aristotle University of Thessaloniki)
The Mediterranean tropical-like cyclones are intense sub-synoptic maritime lows with strong winds, axisymmetric warm-core structure and tropical cyclone features, such as a cloud-free eye and spiral deep convection. They are frequently referred to as medicanes (MEDIterranean hurriCANES) due to their resemblance to tropical cyclones. Despite their low frequency (of about 1.1-1.6 systems per year), medicanes constitute a serious natural hazard to life, property and the environment of the coastal regions of the Mediterranean basin and the Black Sea. Their accurate prediction is a challenge for the numerical weather prediction models. This presentation includes some past cases of medicanes, the description of their structure and characteristics, criteria that are used to define them, the development mechanisms, climatology, consequences and finally a detailed case study of medicane Qendresa (November 2014).
Ivan Tsonevsky demonstrates two recent EFI/SOT products for forecasting severe thunderstorms, their interpretation and practical use.
Length: 50 min
Author: Ivan Tsonevsky (ECMWF)
ECMWF provides the Extreme Forecast Index (EFI) and Shift Of Tails (SOT) as tools to help forecasting anomalous and extreme weather by measuring the difference between the Cumulative Distribution Function (CDF) of the real-time ensemble forecast and the model climate (M-climate) CDF. The definition of the EFI and SOT will be presented alongside the M-climate configuration. Verification results and EFI/SOT products will be shown with examples to demonstrate their use and interpretation. Some advantages and limitations of the EFI and SOT will be discussed. Examples focused on the available EFI/SOT for marine forecasting will be given as well. Two recent EFI/SOT products for forecasting severe thunderstorms and their interpretation and practical use will be demonstrated.
Zorana Jelenak describes how altimeters work, how data is used for everyday marine forecasting at NOAA and assimilation.
Length: 60 min
Author: Zorana Jelenak (NOAA)
Altimeter data have been used to produce maps of sea surface height, geostrophic velocity, significant wave height and wind speed. This information is of proven use to mariners as well as to the scientific community. Uses of the data include commercial and recreational vessel routing, ocean acoustics, input to geographic information systems developed for the fishing industry, identification of marine mammal habitats, fisheries management and monitoring ocean debris. Such information is accessible in near-real time (within 3 to 48 hours) and to improve weather forecasting models by assimilation. 25 years of data makes it possible to study the whole ocean or regional areas for offshore industries or navigation. In hurricane studies altimetry measures very high waves and strong winds, but also helps identify sea surface height anomalies which can be used as proxies of the warm currents - hurricanes energy source. The lecture will describe how altimeters work, how data is used for everyday marine forecasting at NOAA and assimilation, devoteting special attention to data accuracy and limitations.
Jean Bidlot gives an overview on the ECMWF wave model products.
Length: 50 min
Author: Jean Bidlot (ECMWF)
Wave models are able to give a very detailed description of the conditions at the surface of the oceans. The mean sea state is fully described by the 2d wave spectrum. This detailed description is however not always very practical and the bulk of the information contained in the 2d spectrum is usually reduced in the form of a set of integrated parameters, from a simple few such as significant wave height, mean wave direction and mean wave period, to more sophisticated parameters that described distinct part of the wave fields. Recent advances in the understanding of wave dynamics have lead to the development of new set of parameters that give information on the possible largest single wave that might exist over a certain area within a certain time frame. It is now possible to describe the sea state with different level of complexity depending on the user needs.
Michael Folmer presents examples of relevant applications of Sentinel-3A data.
Length: 55 min
Author: Michael Folmer (NOAA)
The EUMETSAT-operated Copernicus Sentinel-3A satellite has been providing near-real time data to the marine community since mid-2016, and will be soon be joined in operations by its sister, Sentinel-3B. This presentation will give an overview of the available Sentinel-3 marine products, with a primary focus on data streams associated by the altimeter (SRAL) and sea surface temperature radiometer (SLSTR). Examples of the relevant applications will be presented, along with a discussion of how users can best access data and monitor its quality.
Ad Stoffelen focuses on scatterometer winds, how good they are and what aspects need attention.
Length: 60 min
Author: Ad Stoffelen (KNMI)
Winds over sea are essential for marine forecasting and used in nowcasting and numerical weather prediction (NWP) to aid in off-shore activities (energy sector, transport, fisheries and recreation), particularly to secure safety of life and property. Winds over sea are observed by satellites and available from NWP model forecasts. Most satellite winds over sea are provided by scatterometers; they provide swath fields of both wind speed and wind direction from polar satellites. Currently, winds from EUMETSAT’s MetOp-A, MetOpB and the Indian ScatSat-1 are operationally available and provide good coverage around 9:00 and 21:00 local solar time (LST). Very soon they will be complemented by a few more. The lecture focuses on what scatterometer winds really represent, how good they are and what aspects need attention when applying these winds in your routine operations alongside with NWP model winds.
Hans Peter Roesli discusses various satellite pattern observed over the seas.
Length: 40 min
Author: Hans Peter Roesli, Switzerland
Sea and coastal areas have radiative characteristics that enhance the identification of non-meteorological features like smoke, ash or dust. Maritime inversions and atmospheric interchanges along coastal areas engender particular cloud patterns like Bénard cells, Kármán vortex streets, undular bores, ship trails, (extra) tropical cyclones or sea breeze fronts. Examples of such features will be shown and discussed, using imagery from geostationary and polar weather satellites.
Elin Björk Jónasdóttir introduces the use of high resolution limited area models, SOT and EFI products and specific risk products such as snow drift models.
Length: 35 minutes.
Winter weather in Iceland is severe on any scale. Strong winds, deep synoptic cyclones, blizzards and avalanche risk are conditions that happen every year. The island of Iceland is mountainous and to from one part of the country to another travellers have to cross at least one, and often several mountain passages or drive on roads where steep and high mountains and complex terrain control the winds.
The Icelandic Meteorological Office (IMO) does not do specific road weather forecasts but regular forecasts for all parts of Iceland as well as impact based warnings, where societal impact, including impact on traffic is a part of the evaluation process. In this session I will introduce the use of high resolution limited area models, SOT and EFI products and specific risk products such as snow drift models based on the Harmonie Arome model.
The operational GMS system, which gives forecasts every hour, and is available through a web platform for the regional traffic agencies in Flanders and Wallonia is presented.
Length: 42 minutes.
Forecasting the conditions of roads and highways is important for traffic safety and road maintenance (salting, clearing snow) decision making in Belgium. The Royal Meteorological Institute of Belgium (RMI) collaborated with the Royal Netherlands Meteorological Institute (KNMI) to adapt the KNMI road weather model for Belgian roads. It is based on a 1D radiative transfer model that makes use of meteorological input from different numerical weather prediction models and the INCA-BE nowcasting model used by the RMI weather office. The output (road surface temperature and condition) is generated for about 90 road weather station locations in Flanders and 50 in Wallonia, and is visualized through a GIS interface. We present our operational "GMS system", which gives forecasts every hour, and is available through a web platform for the regional traffic agencies in Flanders and Wallonia. After that, we give a brief introduction to the SARWS project, which RMI participates in with other Belgian partners. Crowd-sourced data is increasingly used in weather science, and road forecasting is no exception. One of the aims of the SARWS project is measuring several weather parameters in real-time from vehicle sensors, in order to enhance the RMI road weather forecasts performed, and eventually send warnings to drivers in case of dangerous conditions. In the presentation, we will highlight the first results of a field test performed by three cars in the region of Antwerp.
Thomas August gives an introduction to EUMETSATs current (IASI) and future (IASI-NG and MTG-S) hyperspectral sounders.
Length: 46 minutes.
Assessing and monitoring atmospheric thermodynamic parameters is key for weather forecasting. Space-borne hyperspectral sounders provide vertically resolved information of atmospheric temperature and humidity, and of surface and cloud properties. The future geostationary infrared sounder IRS on board Meteosat Third Generation (MTG) will deliver operational atmospheric sounding at unprecedented temporal and spatial sampling, with 4-km pixels at Nadir and covering Europe every 30 minutes. It will hence be an important complement to satellite imagery (e.g. operational MSG/SEVIRI or the future MTG/FCI instruments), where long experience exist in support to nowcasting, by allowing the detection and monitoring of atmospheric instabilities before convective clouds develop.
In this presentation, we give an introduction to EUMETSAT current (IASI) and future (IASI-NG and MTG-IRS) hyperspectral sounders, the remote-sensing principles and geophysical information contained in the so-called Level 2 (L2) products. This includes temperature and humidity profiles, cloud and surface properties and indirect parameters relating to the atmospheric stability. We give an overview of recent application studies and experiments using IASI L2 products in support to weather forecasting.
Pieter Groenemeijer reports of the tests ESSL has undertaken to check the usability of ISAI L2 temperature and humidity profiles in storm forecasting.
Length: 44 minutes.
ESSL studied the use of retrieved temperature and humidity profiles available from the Infrared Atmospheric Sounding Interferometer (IASI) instrument on the polar-orbiting Metop satellites for storm forecasting during the 2019 Testbed and for a number of cases. Parameters relevant to convective storm prediction such as CAPE, CIN and humidity at various levels were computed and a direct visual comparison between the satellite-derived and NWP-modelled profiles was made possible. We present the main conclusions of this study, addressing the usability of the products, preferred derived parameters and observed limitations.
Thomas August provides an overview of the performances of the operational hyperspectral sounding products.
Length: 34 minutes.
In this presentation, we provide an overview of the performances of the operational hyperspectral sounding products. They have been evaluated against independent reference measurements in dedicated validation studies and are continuously assessed in the routine monitoring. We introduce also the quality indicators (uncertainty estimates) provided along with the atmospheric profiles to support quality control and data acceptance on user side, accordingly to their applications.