Weather Forecasts

About Speedwell Forecast Products

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FastCast^TM: The FastCast forecast viewer shows the latest output from four forecast models with the particular aim of showing the change in the forecast as fast as possible. The models are ECMWF Ensemble; the ECMWF Operational; the GFS Ensemble and the GFS Operational. These are processed rapidly as each time step of the model is received. FastCast forecasts give the trading markets a very quick appraisal of any change in the forecast from the previous run. Click here for more information on FastCast. Click here to see the FastCast viewer with example sites.

New February 2013. Click here to see our Beta of FastCast showing any four regions simultaneously.

Forecast DashboardThe Speedwell Forecast Dashboard is a fast and convenient way to view all of your Speedwell site-specific forecast products. The Dashboard displays Speedwell downscaled forecasts for temperature & precipitation from four forecast models: ECMWF Ensemble, ECMWF Operational, GFS Ensemble and GFS Operational. Please click here for more information. Click here to see the product with example sites.

15-Day Site-Specific Downscaled Ensemble Forecast: Covering sites in the USA, Canada, Europe, Australia, China, Japan and South America. These probabilistic probabilistic multi-member ensemble forecasts based on the ECMWF and GFS models. They are available as a data feed by FTP or graphically via our web site. Click here to see our forecast viewer showing example forecast sites.

Monthly (32-day) Downscaled ECMWF Site-Specific Ensemble Forecast: Covering sites in the USA, Canada, Europe, Australia, China and Japan. These 51-member forecasts are available as a data feed by FTP and graphically via our web site. Based on the ECMWF model which uses a coupled ocean-atmospheric mode after day 10.The monthly forecast is issued twice per week..on Mondays and Thursdays. Click here to see our forecast viewer showing example forecast sites (please select Monthly tab)

Population-Weighted Basket Forecasts -FlexIndex Used to model regional energy demand, each FlexIndex is a fully downscaled probabilistic forecast based on both the CMWF and GFS models. As part of the product we also provide a history of the weighted basket and cleaned daily feeds. Available for a range of countries and configurable to user requirements. Click here to see all our weighted baskets on our map tool. For a trial or further details please contact us here.

European Power Report: the Power Report provides a graphical representation of weather conditions in the coming week summarising temperature, rainfall and wind. Click here for more information. Click here to see archived example reports.

US Gas-Weighted Degree Day report. Produced in conjunction with Commodity Weather Group, CWG. Provides the best possible information to anticipate the EIA natural gas storage and withdrawal reports by combining recent weather data and forecasts. Click here for information about the product. Click here to see the WDD Data Viewer.

The Market Report. A summary showing the impact of the change in the ECMWF forecast over the last 24 hours on the fair-value price of CME weather futures. Click here to see an information sheet about this product. Click here to see the product

Historic Forecast Archives. Speedwell are able to provide archives of historic forecasts. We can provide archives of ECMWF and GFS forecasts for a period of 18 months. We can also provide n the U.S. National Weather Service (NWS) GFS MOS extended forecast from the June 2000 to present. This is a 7-Day forecast offering daily maximum and minimum temperature.

Speedwell site-specific ensemble forecasts are available for over 1,000 sites across the world covering 15-day and monthly periods. Our ensemble forecast is a fully downscaled probabilistic forecast which captures information that is normally lost in a traditional deterministic forecast: the confidence of the forecast at each time step.

The product is based on the forecast models run by two of the world's leading numerical prediction centres: the European Centre for Medium Range Weather Forecasting (ECMWF) and the GFS model. The outputs of both models are grid-based and need to be "downscaled" to produce the site-specific forecasts necessary for energy and agriculture. The downscaling process requires accurate "ground truth": ie the availability of actual data for the site concerned for which we draw on our data base of tens of thousands of weather stations.

An ensemble forecast comprises a number of "members", each of which can be viewed as a separate forecast. Each member is derived from multiple runs of the same forecast model by modifying the starting conditions which are used to initialise those models. Under certain situations, these changes of conditions can produce a big change in forecast outcomes (high uncertainty). At other times, these changes have little impact (low uncertainty).

Click here to see our forecast viewer showing example forecast sites.

How is the forecast viewed?

The forecast is available in view graphical and in tabular formats through the Speedwell website. The forecasts are also available as a data feed delivered by FTP. The data feed delivers the underlying data for each member of the forecasts.

Viewing the Forecast On the Speedwell Web Site
The Speedwell forecast may be viewed interactively in graphical and tabular format through the Speedwell website (www.SpeedwellWeather.com). Uniquely, the website also offers the user access to historical archives of forecasts as well as the means to overlay forecasts for different sites, for different forecast periods and for different weather elements (eg TMin / TMax / rain) with complete flexibility. Graphical images can easily be exported and used in external documents (subject to licence). Forecasts can be overlaid with 10-year smoothed average, previous year's value, actual outturn and forecast change from previous run. On-line verification statistics are also made available.

Some examples of website outputs are shown below:

"Box plots" with Climate Average.
The Box Plot shows the average of all ensembles, a box covering the mid quartiles, outliers and the smoothed 10-year climate average. The box plots give a clear sense of the confidence in the forecast with tighter boxes indicating less forecast uncertainty. Also shown below are thumbnails which lead the user to a clear representation of the distribution of possible outcomes.

For each day, or in the case of the seasonal forecast, for each month, the various forecasts implied by each member of the ensemble are shown in a probability distribution graph. This gives very important information about the forecast. While a tight spread shows a high degree of confidence, there are occasions when there is no single dominant outcome.

Viewing the Probability Distribution

The probability distribution graph drops each forecast member into "buckets". Thumbnails for the forecast distribution as shown above can then be inspected at full size as shown below:

"Spaghetti" Graph.
The "spaghetti" graph gives a full sense of the separate paths of each ensemble. Member 1, shown in blue below can be easily highlighted.


"Combination" Graph
The "Combination" graph combines the average forecast with recent actual data and last year's data for context.
Graphical Forecast Overlay

The data graphing options available to the user are shown below. The background image shows monthly forecasts for TMin and TMax with respective observed data and climatologies.


15-day forecast example showing a plot of the forecast average for TMax and TMin forecasts issued on 23rd March and on 4th April. Each shown with actual data.

15-day forecast example showing the overlay of TMax ensemble average with observed data, last year's data and forecast error (green).

Monthly forecast example showing a plot of the 51 member forecast average for TMax shown with smoothed climatology and outturns.

Tabular Presentation
Speedwell forecasts are also available in tabular form through the website. The table shown below presents user-selectable forecast information for a number of sites simultaneously. Forecast average, median, volatility, difference from 10-year average as well as HDD and CDD values are available.



The Single Site Daily Forecast Table presents a range of forecast data for the site selected by the user. For weather derivative traders, the example is of particular interest as it shows the difference between HDD or CDD derived from the average of the 51 members and that derived from taking the average HDD/CDD value using each of the 51 members.


Our clients
Speedwell Ensemble Forecasts are used by energy, commodity companies, banks and insurance companies in Europe and the USA.

Becoming a client
It is possible to experience the full flexibility of the Speedwell forecast product on our website immediately. Go to SpeedwellWeather.com and register for a free trial. This will give access to a limited range of forecast sites while demonstrating the comprehensive graphical viewing, overlay and forecast archive features.

Forecast Verification
In addition to the verification which can be performed by the user on the Speedwell website, we are able to provide verification statistics on 15-day and monthly products.

Forecasts and Weather Derivatives
Speedwell Ensemble Forecasts integrate automatically with the Speedwell Weather System (SWS) for pricing weather derivatives. The user can select the forecast type to use and price both using the average of the forecast and by using each ensemble member separately to correctly capture the convexity implicit in a probabilistic forecast. Please contact us for more information