To determine whether a sounding suffered from ice up, the cloud top height was first determined qualitatively from the sounding. We then compared these qualitative cloud-top temperatures to those obtained from Channel 4 (infrared) imagery from the Geostationary Operational Environmental Satellite (GOES-13). For cases in which soundings did not ice up, there was generally good agreement between the qualitatively-determined cloud-top temperatures and those determined from the satellite data. Exceptions were noted, however, particularly in cases of boundary-layer clouds or midlevel layered clouds. In cases of sounding ice-up, significant differences (> 19 K) were often present between the qualitatively-estimated and satellite-derived cloud-top temperatures. In many such instances, the mobile soundings revealed a deep cloud extending beyond the tropopause, which is clearly unlikely in regimes of lake-effect convection. In this work, we present detailed statistics and examples of sonde ice up and offer analysis of the exceptions to the general rule noted above.