Power trading profits can be substantial when an energy meteorologist brings unique insight to the trading desk about the likelihood of an upcoming extreme event. Those unique insights can come from the same data everyone has, but require rigorous meteorological science, historical data, and analytical effort. The World Climate Service creates opportunities for energy meteorologists to generate those unique insights that drive trading profits. Today’s 00Z ECMWF Extended weather regime forecast shows how this works just beyond the medium range. The forecast transitions through several Euro Atlantic regimes before uncertainty increases substantially in the subseasonal period. Regime probabilities are helpful, but they become more valuable when paired with a historical analysis of regime impacts. We combined two long meteorological histories to investigate that relationship. The process is: 1) We used nine years of historical forecasts from the World Climate Service Point in Time Weather Forecast Archive API to establish a climatology from ECMWF IFS 51 member capacity-weighted wind and solar forecasts for Germany. 2) From that forecast climatology, we developed a Dunkelflaute Risk Index, or DRI, defining an event when the combined wind and solar forecast falls below the 20th percentile. Those events are the orange dots in the graphic. 3) We then combined the DRI history with our archive of observed Grams seven regime classifications to understand how Dunkelflaute risk varies by weather regime. The result provides a valuable way to interpret a subseasonal regime forecast. The risks and opportunities embedded in the ensemble means everyone else is using can then be translated into differentiated risk intelligence for power and gas trading desks by connecting the probabilities of Atlantic Ridge, Scandinavian Blocking, European Blocking, or another circulation pattern with the likelihood of Dunkelflaute events embedded in each forecasted flow regime. This does not remove the considerable uncertainty at subseasonal lead times, nor does a regime forecast determine whether a Dunkelflaute will occur. It provides an additional layer of risk information just beyond the medium range, when the details of an individual weather scenario become increasingly uncertain, but the probabilities of large-scale circulation patterns can still provide useful information about upcoming weather risks. That is where an energy meteorologist can add value. The forecast data are available to the market. The meteorological science used to extract, combine, and communicate the embedded power market risk creates the differentiated insight. The World Climate Service helps energy meteorologists amplify their meteorological expertise. #EnergyMeteorology #Dunkelflaute #WeatherRisk #EnergyTrading #SubseasonalForecasting

Weather regimes help energy meteorologists uncover the forecast risks hidden by the ensemble mean. They show which alternative weather scenarios could materially change a power trading desk's perception of weather forecast risks. Today’s 00Z ECMWF Extended weather regime forecast provides a good example for MISO renewable power. The Pacific Trough is the predominant North American regime forecast through much of October, with substantial probabilities extending into the subseasonal timeframe. Why does that matter? Our analysis of 2,645 days of observed North American regimes and MISO renewable power capacity utilization provides the historical context that frames the risks embedded in the forecast. During SON, the Pacific Trough is associated with the lowest median renewable capacity utilization of the four Lee regimes. Median utilization under the Pacific Trough is 79% of the median under the Pacific Ridge, the regime associated with the highest median utilization during SON. The forecast still contains considerable uncertainty, as the regime probabilities imply. But the power market analysis enables the meteorologist to translate the forecast into actionable risk information they can communicate with their desks. Interpretation of the ensemble mean alone cannot highlight forecast risks. Regime forecasts provide the scenarios and their probabilities. Historical regime impact analysis provides the renewable power context. The energy meteorologist translates the forecast uncertainty into actionable power market risk information. #EnergyMeteorology #RenewableEnergy #WeatherRisk #EnergyTrading #SubseasonalForecasting

Weather regimes reduce the complexity of 51 or 101 member ensemble forecasts into human digestible scenarios that highlight forecast risk. For German solar power, historical regime relationships provide context for interpreting those scenarios and communicating the likelihood of different impacts to the power desk. Today’s AIFS Ext Grams et al. 2017 regime forecast suggests benign solar power risk at the start of October. #EnergyMeteorology #SolarPower #WeatherRisk

Today’s 00Z AIFS and WXNEXT regime forecasts tell two different stories at 11-15 days: • North America: substantial model divergence. • Europe: relatively consistent. Regimes help meteorologists see at what lead times models diverge and which scenarios are driving the red and blue on the maps. #EnergyMarkets #WeatherRisk #WindPower #EnergyTrading #SubseasonalForecasting #WeatherForecasting #WeatherRegimes

European Block dominates the AIFS-ENS 6–10 day regime forecast, with its probability declining at longer leads. Around week 3, Scandinavian Trough chances increase. Why does that matter for an energy meteorologist? These Grams et al. (2017) regimes have very different historical German wind utilization distributions. As regime probabilities evolve, so does the wind risk embedded in the forecast. Weather regimes reveal the risks hidden by the ensemble mean and are available in World Climate Service. #EnergyMarkets #WeatherRisk #WindPower #EnergyTrading #SubseasonalForecasting #WeatherForecasting #WeatherRegimes