When a sounding isn’t available
The 1200 UTC sounding from Hilo HI (91285) was unavailable on 29 October 2024. (Here is the sounding from 0000 UTC). When such a failure happens, there is a backup: NUCAPS profiles show thermodynamic information that is retrieved from infrared and microwave information on NOAA-20, NOAA-21 and MetopC satellites, and a profile is usually available around 1200 UTC in Hawaii. The plot below shows available NUCAPS plots over Hawaii at 1144 UTC, 29 October. Note the yellow dot over Hilo; Yellow typically means the infrared retrieval failed to converge, and the profile information is therefore coming from microwave data. (Green points show profiles where the infrared solution converged to a solution.) The profile from the yellow point over Hilo is below.
The NUCAPS profile at Hilo, below, shows a relatively moist boundary layer, a strong inversion with a top near 750 mb, and relatively moist air between 300 and 500 mb. In the Sounding Availability plot above, profiles that did converge to a solution are located northwest of Hilo, just offshore of the Big Island, and to the east of Hilo. Those profiles are shown below. They show features similar to the profile at Hilo.
When fate interferes with your ability to view rawinsondes, NUCAPS can step in and help. A good practice is to compare the profiles when rawinsondes are present so you can better understand how they compare.