1. Huaqing Cai NCAR/ASP/ATD Wen-Chau Lee Tammy M. Weckwerth NCAR/ATD
Observations of 11 June Dryline During IHOP -- A Null Case for Convection Initiation
Huaqing Cai
NCAR/ASP/ATD
Wen-Chau Lee
Tammy M. Weckwerth
NCAR/ATD

2. LAPS 12km MM5
LAPS 4km MM5

4. S-Pol
Reflectivity
&
Refractivity

5. NRL-P3
Flight Level Data
Along the Dryline

6. ELDORA
Analysis

7. NRL-P3 Flight Level Data Across the Dryline

9. Dryline, Roll Boundary and Dropsonde Positions

17. Learjet
Dropsondes

18. NCAR-NCEP
Reanalysis

19. Summary of Factors Detrimental to CI on 11 June Case
A relatively weak updraft (1-2 m/s) and an overall dry boundary layer (40% relative humidity)
A substantial dry layer 200 mb deep directly above the CBL
Relatively strong shear between boundary layer and middle level winds (~15 m/s)

20. Summary of Factors Detrimental to CI on 11 June Case (cont’d)
Middle level subsidence over the dryline in the Oklahoma panhandle region
Not very favorable instability near the dryline