On December 12 (UTC) Ron Meadows, K6RPT, launched near San Francisco, two balloons equipped with APRS/GPS trackers transmitting data on 144.390 MHz. With aprs.fi it was possible to track the balloons. In the screen shot above it can be seen, that balloon K6RPT-11 shortly after its start has reached an altitude of 120 m. The green line with red dots shows its flight path.
In early morning on December 14, in Spain, the balloon K6RPT-11 almost passed over the city Cadiz. The altitude was 33,460 m and speed was 246 km/h! The radio signals was received by CT1END in Portugal. Flight time from start: now ca. 2 days and 6 hours.
The screen shot above is from my iPad 2 when I saw this happen live.
6 hours after passing the southern tip of Spain, the balloon bursted over the Mediterranean Sea. Altitude now 4,437 m and speed 56 km/h. Its last radio signals was received by EB6AOK on Menorca.
What a flight! Total flight time ca. 2 1/2 days. The other balloon, K6RPT-12, almost reached the US east coast.
Reading : California Near Space Project, ARRL