Dynamical Effects of Storm Generated Mesoscale Processes and Pressure perturbationsOver viewGeneration of Mesoscale Pressure fieldsIllustration for signs on updraftIllustration for non-linear hodographsEvolution of storms into Tornadic phaseCold pool interactionsCold pool and wind shear interactionsProposed events leading to Mesoscale influencesDivergence of the horizontal momentum equationQuestions??Terrance SeddonOver viewDynamical effectsGeneration of Mesoscale Pressure fieldsEvolution of supercells to the tornadic phaseCold pool interactionsPressure perturbationGeneration of Mesoscale Pressure fieldsDynamic effects of lifting, such as lifting pressure gradients on the flanks of updrafts, contribute to the splitting of stormsDynamic lowering of midlevel pressures induces updraft growth on both signs of the updraft,P’NL=-ζ2Illustration for signs on updrafIllustration for non-linear hodographsEvolution of storms into Tornadic phaseThis evolution is not completely understood, but some things are known about what is needed to cause it.They must injest streamwise vorticity into updraftsBaroclinic vorticities must generate along forward-flank downdraftsMesoscale Vortex breakdownThe final ingredient can also happen to the tornado vorticity itself, resulting in smaller scale suction vorticitiesCold pool interactionsCold pools are responsible for new convective development.With a proper balance between cold pools and low level shear, continual regeneration of storms is possible, but not required for long lived storms.This balance is usually complicated by other sources of vorcitiyCold pool and wind shear interactionsTop pictures show a zero shear environment, with wind speeds the same all the way upLower pictures show an environment where the wind speeds are faster near the surface and decrease as they go up.Proposed events leading to Mesoscale influencesStepsReferenced figuresInitial updraft leans down shear due to ambient shear (a)Cold pool develops and counteracts the down shear tilt. (b)Cold pool overwhelms the updraft and creates a rear-inflow jet. (c)Divergence of the horizontal momentum