Section 3 5 3 5a 3 5b
Download
1 / 23

Section 3.5, 3.5a, 3.5b - PowerPoint PPT Presentation


  • 119 Views
  • Uploaded on

Section 3.5, 3.5a, 3.5b. Overview For Storm-generated Mesoscale processes Local Effects Advective Effects. Storm Generated Mesoscale Process. Severe storms generate host of mesoscale effects Promote storm development, severity and longevity, or Weaken storms. Recall From Table 3.3.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Section 3.5, 3.5a, 3.5b' - altessa


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Section 3 5 3 5a 3 5b

Section 3.5, 3.5a, 3.5b

Overview

For Storm-generated Mesoscale processes

Local Effects

Advective Effects


Storm generated mesoscale process
Storm Generated Mesoscale Process

  • Severe storms generate host of mesoscale effects

    • Promote storm development, severity and longevity, or

    • Weaken storms


Recall from table 3 3
Recall From Table 3.3

  • Local effect includes:

    • Radiation

    • Microphysics

      • Downdraft, cold pool production

      • Microburst generation


Local effects
Local Effects

  • Radiation

    • Cloud-radiative effects

      - may be important in the development of new storms

    • Longer life by enhancing mass circulation

    • Increase total precipiation


Local effects1
Local Effects

  • Microphysics

    • Downdraft, cold pool production

    • Microburst generation


Downdraft cold pool production
Downdraft, cold pool production

  • Occurs through evaporation and melting

  • Strength of cold pool is important to

    • Supercell’s behavior and longevity

    • Squall-line intensity and longevity

    • Baroclinic vorticity generation in tornadic storms


Microburst generation
Microburst Generation

  • Particle sizes are important in determining downdraft intensity.

    • Smaller raindrop has most conducive to strong downdrafts

  • Also, in frontal rainbands, evaporation, sublimation, and melting can have the effect of enhancing the thermal contrast across cold fronts


Advective effects overview
Advective Effects (Overview)

  • From table 3.3

  • Particle advection, fall and phase changes

    • Downdrafts generation

    • Upscale growth

  • Cold pool processes

    • Cell regeneration

    • MCS evolution


Continuing overview
Continuing Overview

  • Momentum transport/ sloping flows

    • Severe surface winds

  • Vortex tilting/ stretching

    • Vertical velocity generation

    • (supercells, MCS mesovortices)


Cold pool processes
Cold pool processes

  • Are responsible for cell regeneration in multicell storms involves cold air outflow from convective downdrafts

  • As it spreads out over a large area and becomes shallow, then the regeneration stops


Downdraft outflows
Downdraft Outflows

  • Also important in supercells where forward-flank downdrafts and rear-flank downdrafts produces storm-scale fronts

  • Special case: new mesocyclones may form at the occlusion



Special case
Special Case surface


Advection of condensate
Advection of Condensate surface

  • Development of trailing stratiform regions of squall lines



Momentum transport
Momentum Transport surface

  • Vertical transport of horizontal momentum helps to generate covergence at the leading convective line




Development of mesovortices in mcss
Development of Mesovortices in MCSs surface

  • Interaction between the downdraft and the ambient westerly shear.

  • Another tilting involves perturbation shears


Development of mesovortices in mcss1
Development of Mesovortices in MCSs surface

  • Buoyancy forces act to generate front-to-rear or rear-to-front flows

  • Tilting of perturbation shears generated by the cold pool is important in the production of line-end vortex pairs in environments with weak-to-moderate shear.


Development of mesovortices in mcss2
Development of Mesovortices in MCSs surface

  • As squall lines mature, Coriolis effects become important in the development

  • Result: eventual evolution of many squall lines to an symmetric precipitation pattern


Effects of the plume of heat and moisture
Effects of the plume of heat and moisture surface

  • Convective/advective warming of the midtroposphere is the primary mechanism for the generation of the midlevel rear-inflow jets in squall lines

  • Moistening increases buoyancy of secondary convection



ad