Mesoscale Processes and Severe Convective

WeatherSection 3.5 a,b

Richard H. Johnson and Brian E. Mapes

Presented to you by: Elizabeth Polito

Talk Overview

• Storm-Generated Mesoscale Processes– Local Effects– Advective Effects

• Examine/breakdown 6 schematics

Storm-Generated Mesoscale Processes

• Encourage storm development, severity, longevity – Cold pool lifting– Vortex tilting/stretching

• Weaken Storm– Rapid spreading of cold pools– Cloud shading

• Discuss processes in terms of being local or advective

Storm-Generated Mesoscale Processes

Terrancewill discusstheseprocesses

Local Effects• Radiation

– Timescales• ~1-2 h - not important in evolution but maybe in new

development• ~6-12 h - MCSs timescale: cloud-radiative interactions aid in

longevity (through mass circulation build up)– Increase total precipitation

• Microphysical Processes (phase changes or particle evolution)– Cold pool production– MCSs– Microbursts

• Cold Pools

• Downdraft outflows– FFD/RFD

Advective Effects: Cold Pools

• Tornado family formation

Advective Effects

Advective Effects: Advection of Condensate

• Note vertically sheared environment– Vertical vorticity

couplets

Advective Effects: Vortex Tilting

Advective Effects: Vortex Tilting

Advective Effects: Vortex Tilting

Advective Effects: Vortex Tilting Example: Bow Echo

• Takes place in storm itself– Front-to-rear– Rear-to-front

Advective Effects: Vortex Tilting

Advective Effects: Vortex Tilting

Advective Effects: Vortex Tilting