Most probably what you are hearing is an "EAM" (Emergency Action Message) or some other transmission as part of the "HF-GCS" (High Frequency Global Communications System). 13200 USB is one of their frequencies. You will also find them on 4724, 6739, 8992, 11175, 13200, 15016 kHz, all USB, and often multiple frequencies at a given time. Note that a 13200 USB signal would fall pretty much right between 13200 and 13205 for a 5 kHz tuning step AM only RX.
Re your V24 reports: V24 often has an excellent path into California until its last couple time slots of the day, around 1530 it starts to fade, the 1620 slot is often marginal. It has been confused for a broadcast station in the past during its lead-in music. I also heard (well, recorded anyway, I was at work at that time) both of these transmissions and the one on 04/05 is most representative, the one on 04/06 was weaker than average. The nice thing about that is you can expect conditions like you had on 04/05 much of the time, particularly during the best time slots, from 1330 to 1530.