The Forecaster

 is a psychic child living under the bridge at 188 Trading Post in 2281.

Background
The Forecaster lost his parents a long time ago, and has been on his own since, but he's gotten used to it.

Other interactions
You can pay him 100 caps to "hear his thoughts" on "You", "Here", or "Everywhere". He is basically a fortune teller.

Bugs
Addition/correction: you will get stuck in the ground not far from Black Mountain, in the place where you met Neil. On PC, with the use of console command you can get to the road (the nearest solid ground where it is possible to stay and move normally). There will be a large amount of texture, clipping, and object interaction bugs in the area. You may see a supermutant master and few centaurs stuck in the rocks, one of the satellite dishes may fall down… If you travel a short distance from the place (say, to the nearest road post and a little further) and then come back, you'll see that all glitches are gone. (The crashed satellite dish will remain there constantly.)
 * On the PC Patch 1, the Forecaster can be seen floating in mid-air a few inches off the ground instead of on the ground in his sitting pose.
 * If you try to kill the forecaster with the sandman perk enough times, you may end up being transported to an irradiated part in the wasteland with no means of escape. (Confirmed PC and PS3.) (A note from this readers/writers, this is probably not a bug, but a glitching feature.)

Appearances
appears in Fallout: New Vegas.