Transcript Observations of the 11 June 2002 Dryline during IHOP - A Null Case for Convection Initiation (Cai)

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
LAPS 12km MM5
LAPS 4km MM5
S-Pol
Reflectivity
&
Refractivity
NRL-P3
Flight Level Data
Along the Dryline
ELDORA
Analysis
NRL-P3 Flight Level Data Across the Dryline
Dryline,
Roll
Boundary
and
Dropsonde
Positions
Learjet
Dropsondes
NCAR-NCEP
Reanalysis
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)
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