GOES-13 anomalies

On the morning of Sunday, September 23rd, the scan motor on the Sounder instrument of GOES-13 shut down after an overload within the circuitry. In response, NOAA place it into a safe mode. Later that afternoon the Imager encountered the same problem and was also place into safe mode. The overload issue was/is thought to be connected with previously noted 'noise' in the sounder/imager channels. Figure 1 below shows a 2 km water vapor image and associated noise taken at 1932 UTC on the 23rd, shortly before the imager shut down.

20120923 1932 UTC GOES-13 water vapor image with noise

Engineers continue to work on the problem, but as the repairs looked to be long term GOES-14, the spare satellite that had been out of storage for experimental SRSOR runs, was implemented as the operational GOES-E in the place of GOES-13. Currently GOES-14 is stationed at 105W and will likely remain there until GOES-13 is either fixed or deemed officially dead. Shown below in Figure 2 is GOES-14 water vapor imagery of the eastern U.S. taken September, 24th at 1945 UTC. Note the differences in the angle of the imagery due to the differing positions of GOES-13 and GOES-14. If GOES-13 does end up being declared officially dead, GOES-14 will be slowly nudged east.

20120924 1945 UTC GOES-14 water vapor imagery

During the outage, the AWC was able to get by on the GOES-15 remap data through Monday morning, at which time we were able to utilize the GOES-14 experimental data sets already being provided by CIMSS and CIRA as a back up until GOES-14 was implemented as operational. All in all, the fantastic effort of all those involved in the GOES-13/GOES-14 transition out on the East Coast as well as those in Kansas City who helped me out yesterday smoothed what could have been a major hink into no more than a few wrinkles.

 Despite the fact that the limited coverage of the eastern U.S. only lasted about twenty four hours, it was an interesting experience to see how easily forecast operations are affect by the loss of a satellite even for a short time. For example, the domain of the tropical desk at the AWC was right at the very edge of the GOES-15 remap. This, along with the radar sparse nature of the tropics, had the forecasters flying nearly blind for a little while.

Again, thanks to all those who assisted in getting the AWC back up and running so quickly.