980514 - A strong, negative-tilt wave and large convective instability
were present in western Oklahoma and NW Texas.  We feared the dynamics
would favor a squall line and not supercells.  We were right, and chose
to abort the intercept shortly after convection was initiated.  The
combination of late day, low visibilities from smoke, and a squall line
made intercepts difficult.  TAMU launched a rawinsonde near Clinton,
Oklahoma, early in the afternoon.  TAMU and NSSL1 launched two
rawinsondes from Erick, Oklahoma, for intercomparison of sondes.  NSSL1
launched a rawinsonde south of Childress, Texas, shortly after gust
front passage.  PROBE vehicles crossed the dry line numerous times doing
east-west traverses along I-40 and again while travelling south on US-83
towards Childress.  Dewpoints dropped from 15-17C to 9C in 6-12 seconds
(6 s sampling rate).  Visibilities changed from ~3 miles on the moist
side to ~7-10 miles on the dry side.