Check
http://www.nwac.us/forecast/avalanche/current/zone/10/
for general avy conditions and just keep an eye on the weather.
The snowpack isn't huge this year and there is plenty of general skier, snowshoer, climber traffic that heads into the Source Lake area that you could probably follow someone's kicked steps.
It's warming up a lot the next few days with the freezing level jumping up past 7K' (I don't recall seeing a freezing level that high in a while), that's probably why the avy forecast is slightly rising.
In the pass this year the avy danger has been pretty low - temps have stayed pretty warm this winter with lots of rain or just very dense snow, making for a pretty solid snowpack.
Other than that the NF route is very fat right now, so if avy conditions are fine I'd say go for it.