StormTracker user guide - Met Office

Data provenance and guidanceb. Data typesEnsemble forecast information is provided for:Label Display DefinitionEnsemble storm tracksIndividual ensemble memberstorm tracks shown, i.e. onetrack per ensemble member foreach single model. Multi-modelcombinations not available.The ensemble storm tracks showthe forecasted positions for eachensemble member of a namedstorm for every 12 hour timestepup to 15 days ahead.Ensemble mean storm tracksStrike probabilityOne ensemble mean trackshown for each model andmulti-model combination.One strike probability plumeshown for each model andmulti-model combination (basedon ensemble storm tracks of anamed storm).The ensemble mean storm trackshows the mean forecastedpositions of the mean of all theindividual ensemble membersfor every 12 hour timestep up to15 days ahead.The probability of the centre ofa named storm passing withina 75 mile radius of any locationon the map for every 12 hourtimestep up to 15 days ahead.Forming storm probabilityProbability of any storm, eitherpre-existing or forming withinthe forecast period shown inanimation for each model andmulti-model combination.The probability of a storm centrepassing within approximately190 miles (300 km) of a locationfor every 12 hour timestep up to15 days ahead.Wind speedOnly available for Met OfficeGlobal Regional EnsemblePrediction System (MOGREPS-15)model. Wind speed probabilitiesshown for entire basin selected.The probability of 10 msustained wind speed exceedinga threshold of 39 mph, 50knots (58 mph), 74 mph forevery 12 hour timestep up to 15days ahead. Note that this willestimate the large-scale flowaround storms but should notbe expected to represent thestrongest winds close to thestorm centre.* Information highlighted in grey is available to certain users only, and only for the Met Office GlobalRegional Ensemble Prediction System (MOGREPS-15) model.23 StormTracker User Guide v3