Severe Convective Storms An OverviewGeneral OutlineSevere Convection Classification and problemsObservations of Severe Convection Large-ScalePowerPoint PresentationObservations of Severe ConvectionObservations of Severe Convection MesoscalePrediction of Severe Convection ~Current accuracy levelsSlide 9Prediction of Severe Convection ~Lessening the threats posedProspects and Unsolved ProblemsSlide 12Severe Convection Final thoughtsSevere Convective StormsSevere Convective Storms Severe Convective Storms An OverviewAn OverviewDoswell C.A. III, 2001: Severe Convective Doswell C.A. III, 2001: Severe Convective Storms – An OverviewStorms – An OverviewSevere Convective Storms, Meteor. Severe Convective Storms, Meteor. Monogr., 28, no. 50, Amer. Meteor. Soc., 13-Monogr., 28, no. 50, Amer. Meteor. Soc., 13-2626General OutlineGeneral OutlineI.I.Severe ConvectionSevere Convection- classification, problems, issues- classification, problems, issues- distinction between non- and severe - distinction between non- and severe convection convectionII.II.Observations of Severe ConvectionObservations of Severe Convection- large-scale- large-scale- mesoscale- mesoscaleIII.III.Prediction of Severe ConvectionPrediction of Severe Convection- current accuracy- current accuracy- goals for severe convective storm - goals for severe convective storm forecasting, to mitigate threats forecasting, to mitigate threatsSevere ConvectionSevere ConvectionClassification and problemsClassification and problems>=3/4 in. hail>=3/4 in. hail>=50 knot sustained wind gusts>=50 knot sustained wind gustsTornadoTornadoShould the Should the averageaverage hail size and wind gust be hail size and wind gust be reported as reported as ““severesevere”” instead of the single largest size instead of the single largest size reported?reported?Precipitation not officially defined beyond severePrecipitation not officially defined beyond severeFlash floods and heavy rain consideration must Flash floods and heavy rain consideration must include areasinclude areas’’ hydrological circumstances hydrological circumstancesHales 2-tiered system for severe thresholdsHales 2-tiered system for severe thresholdsObservations of Severe ConvectionObservations of Severe ConvectionLarge-ScaleLarge-Scale–Rawinsonde observations are primaryRawinsonde observations are primary–PROBLEMS: PROBLEMS: - significant gaps worldwide- significant gaps worldwide- limiting analysis to the few - limiting analysis to the few ““oubreakoubreak”” events events–Fig 10: Chart idealizing significant synoptic Fig 10: Chart idealizing significant synoptic features in an outbreak of severe convective features in an outbreak of severe convective stormsstormsObservations of Severe ConvectionObservations of Severe ConvectionIngredients-based approachIngredients-based approach–conditional instabilityconditional instability–moisture moisture –a source of lifta source of liftV.S. Characteristic pattern aloneV.S. Characteristic pattern aloneObservations of Severe ConvectionObservations of Severe ConvectionMesoscaleMesoscaleSatellite images (qualitative)Satellite images (qualitative)Radar, limitedRadar, limitedImportant aspect: Convective OutflowImportant aspect: Convective OutflowProcesses Processes –free free ““internalinternal”” instabilities instabilities–forced forced ““externalexternal”” processes processes–frontsfronts–gravity wavesgravity wavesPrediction of Severe ConvectionPrediction of Severe Convection~Current accuracy levels~Current accuracy levelsProgressProgressAdvances in forecasting severe storms and Advances in forecasting severe storms and tornadoes, SEE FIG. 12tornadoes, SEE FIG. 12Increased prediction accuracyIncreased prediction accuracyBetter public awareness and communicationBetter public awareness and communicationFrustrationsFrustrationsNot as much attention to non tornadic eventsNot as much attention to non tornadic eventsFlash floods/heavy convection not offically Flash floods/heavy convection not offically ““severesevere””Hail formation and short-range forecastsHail formation and short-range forecastsPrediction of Severe ConvectionPrediction of Severe Convection~Lessening the threats posed~Lessening the threats posedNeeded outside North AmericaNeeded outside North America–systemic reporting systemic reporting –A way to including events in climatological A way to including events in climatological databasedatabase–sufficient planning for possible severe events in sufficient planning for possible severe events in areaarea’’s where threat is rares where threat is rare–public awareness, appropriate reactionspublic awareness, appropriate reactionsProspects and Unsolved ProblemsProspects and Unsolved ProblemsForecastingForecasting–Improvements in observing systems (ie radar) Improvements in observing systems (ie radar) and related forecasting systemsand related forecasting systems–Difficulties/ less progressDifficulties/ less progressTornadic vs nontornadic supercell differentiationTornadic vs nontornadic supercell differentiationForecasting nonsupercell tornado situationsForecasting nonsupercell tornado situationsSystem to forecast and mitigate flash flood damageSystem to forecast and mitigate flash flood damageProspects and Unsolved ProblemsProspects and Unsolved ProblemsWeather Modification possibilitiesWeather Modification possibilities–Public appealPublic appeal–Lack of many severe convective weather Lack of many severe convective weather processesprocessesNew ObservationsNew Observations–Doppler RADARs are likely only a beginningDoppler RADARs are likely only a beginning–Dual polarization observations possibleDual polarization observations possible–Satellite remote sensor improvementsSatellite remote sensor improvementsEconomic difficultiesEconomic difficultiesSevere ConvectionSevere ConvectionFinal thoughtsFinal thoughts Mesoscale and smaller eventsMesoscale and smaller events““ChaoticChaotic”” systems systemsImportant unobservablesImportant unobservables–Resources neededResources neededSevere Convective StormsSevere Convective StormsThis is the paradox of all science: we are both This is the paradox of all science: we are both excited and frustrated by what we do excited and frustrated by what we do notnot know, even as we create