Ahh....the uncomfortable silences

we've all had these moments where we meet someone after a really long time and we don't really know what to talk about, it could be anyone an ex bf/gf, an old classmate, a former colleague, a distant relative who looks familiar and seems nice till they ask you, 'so do you know who i am?'  these brief moments of uncomfortable silences are with us every single day just waiting to happen. so what do we say? most topics tend the the obvious non political, non controversial, universally accepted topic 'The Weather' here are some made up and some not so made up examples of these conversations

Two classmates meeting up after really long. both people stay in the same town.

Person A:  hey long time, how you been
Person B: yeah long time, i've been gud, u?
A: same here
(momentary pause, searching for topic??)
B: so wht do u do?
A: i'm in consulting, u?
B: i'm a doctor.
A: oh thats neat, so this change in weather must be resulting in a lot of coughs and colds n rite?
B: well maybe, but doesn't really affect me, i'm a gynecologist


Meeting an Ex few days after you'll 'mutually decided to end it'
A: hi, how are u?
B: i'm gud, and u?
A: i'm gud too....(OMG wht do i ask next?)
so whats with the weather here, it's hot in the morning the cold in the evening...
(the problem here is it's just a sentence not a question, so the other person is still uncertain on if u'r seeking their opinion or not, and just doesn't say anything)

but why is that we tend to turn to the weather as a conversation filler. there isn't a more boring, dry and really stupid thing to talk abt. so the next time your in conversation with someone and they bring up the weather, just know that they don't know what to talk about anymore.