Data for each balloon are available in these Charts and Data, and data for each of the beacons are available here. For each beacon, click on the "T" for a map of the balloon track and click on "D" for the data reported by the beacon. Copy this data into a spreadsheet and you can parse out the time (the time (UTC) following ":/" is the GPS time, which is better than the server time posted near the beginning of each line). The altitude (ft MSL) follows "/A=" later in the string. Latitude and longitude (in DDDmin.min) are in there as well.