Pressure jump at launch

The first pressure value reported by the sonde after launch (939.1) is
much lower than that reported at the surface (946.1).  This may result
from jarring at launch, failure of the system to detect launch, or
other problem.  The absolute altitude for this sounding and ascent rates
for the first 30 seconds will be incorrect.

• Relative Humidity (hybrid-b grid)(rh)
• North Latitude(lat)
• base time in epoch(base_time)
• Dry Bulb Temperature(tdry)
• Wind Direction(deg)
• Retrieved pressure profile(pres)
• lon(lon)
• Ascent rate(asc)
• Wind status(wstat)
• Wind Speed(wspd)
• Dewpoint Temperature(dp)
• -180.0 - +180.0(alt)
• Time offset from base_time(time_offset)

• Easterly Wind Component(u_wind)
• Dry Bulb Temperature(tdry)
• Retrieved pressure profile(pres)
• -180.0 - +180.0(alt)
• Ascent rate(asc)
• Dewpoint Temperature(dp)
• Wind Direction(deg)
• Relative Humidity (hybrid-b grid)(rh)
• Wind status(wstat)
• base time in epoch(base_time)
• Wind Speed(wspd)
• lon(lon)
• V wind component(v_wind)
• Time offset from base_time(time_offset)
• North Latitude(lat)