1. Mesoscale Processes and Severe Convective Weather Section 3.5 a,b Richard H. Johnson and Brian E. Mapes Presented to you by: Elizabeth Polito

2. Talk Overview Storm-Generated Mesoscale Processes –Local Effects –Advective Effects Examine/breakdown 6 schematics

3. 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

4. Storm-Generated Mesoscale Processes Terrance will discuss these processes

5. 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

6. Cold Pools Downdraft outflows –FFD/RFD Advective Effects: Cold Pools

7. Tornado family formation Advective Effects

8. Advective Effects: Advection of Condensate

9. Note vertically sheared environment –Vertical vorticity couplets Advective Effects: Vortex Tilting

12. Advective Effects: Vortex Tilting Example: Bow Echo

13. Takes place in storm itself –Front-to-rear –Rear-to-front Advective Effects: Vortex Tilting