Coastal Convective Interactions Experiment

Introduction

The Coastal Convective Interactions Experiment (CCIE) addressed the lack of knowledge concerning the processes which modify existing storms during a sea breeze-cold pool boundary collision. Without this understanding, there remains little scientific basis for severe weather warnings issued for storms prior to a collision with the sea breeze. An observation based investigation was applied to quantify the various processes which modify storms during a collision and thereby fill a critical knowledge gap in coastal-plains thunderstorm dynamics. This knowledge was then applied to improve the framework for integrating sea breeze analysis with storm nowcasting and improving timeliness and accuracy of storm warnings for the public in coastal regions of Australia.

This experiment was conducted between the months of September to December in 2013 and 2015 on a net total of 30 storm days. Interactions between the sea breeze and storms are climatologically favored in the South East Queensland region of Australia, provide an ideal physical setting for the CCIE experiment. My PhD thesis is available for open access link

Field work methods

  • Mobile vehicle platform for launching unmanned airborne meteorological observers, deploying aerological soundings and a vehicle mounted weather station.
  • Fixed RASS and SODAR deployment at Pinjarra Hills
  • CP2 radar at Redbank Plains
  • Fixed mesonet deployed by UQ in the Beaudesert and Boonah Valley regions at 3 sites.
  • Portable Scanning Wind Lidar
  • Mobile Dual-Polarised X-Band Radar

Hypotheses and Objectives

This project aims to quantify the mechanisms which modify existing convection during the interaction between a SBF and an unmodified storm cold pool. To achieve this aim, the following hypotheses concerning the kinematic and thermodynamic aspects of convective interactions will need to be addressed.

  1. Deep convective updrafts are forced by the vorticity balance between the SBF, environmental boundary layer shear and a convective cold pool (RKW process) during the collision (Rotunno et al. 1988)⁠
  2. The thermodynamic properties (theta-e) of a sea breeze modified boundary layer strongly modifies the intensity of a post-interaction system through changes to convective levels and lifting potential.
  3. Do the thermodynamic properties (theta-e) of a sea breeze modified boundary layer strongly modifies the intensity of a post-interaction system through changes to convective levels and lifting potential?

This understanding of the processes driving the convective interactions will then be applied to deliver the following three objectives.

1. Construct a long-term climatology of the sea breeze and thunderstorm activity for the SEQ region

2. Detail the processes responsible for modifying convection during the interaction between thunderstorms and the sea breeze front.

3. Verification of simulated sea breeze and cold pool case study events.

4. Develop a nowcasting framework to improve the skill of storm nowcasting for coastal regions of Australia