Because I'm at home and bored I started trying to pick up radiosonde transmissions out of the Sterling Va office. I live in Chantilly Va, just a bit south of Dulles airport and I thought that it would be pretty easy to pick up at least the initial ascent. I've been monitoring between about 400-406 mhz at both 1100-1230 and 2300-0030 UTC. I know what the waveform should look like, but I've seen nothing so far, other than some digital transmissions at 400 and 403.2 Mhz which are constantly on. Looking back at the posts on this site, it looks like 401 mhz is a good place to camp, but I've still seen nothing. Am I perhaps looking at the wrong time or are the flights suspended or something? I'm using an RTL-SDR and a Nooelec Ratlsnake antenna; I realize that's not the best choice for an antenna but I feel because of the close proximity, I should be able to pick up something.