A special 18Z radiosonde launch was done at Wilmington, Ohio. The special launch allows for direct comparison to a dervived NUCAPS sounding.

Here is the observed radiosonde data:

Here is a NUCAPS sounding from nearby:

Note that the NUCAPS sounding is not representative, especially near the surface. The surface temperature is 77F and the dew point is 55F on the derived sounding. A nearby METAR close by the NUCAPS sounding was 85F/61F.

However, if the boundary layer temperature and dew point profile is modified using nearby METAR observations (85/61), the SBCAPE is more representative to the observed sounding (1761 vs. 1688 J/kg):

Therefore, it is critical to look at the near-surface temperature and dew point profile when using NUCAPS derived soundings.

Polarimetric Researcher