"Snag" wrote:
This one
was so bad because it was freezing rain falling on frozen ground . It makes
me wonder , how can it be raining when the air temp is like 29* ? Why isn't
it SNOW by the time it hits ?

Actually, freezing rain can't "fall" on anything.

In a nutshell...

All precipitation basically starts out as snow crystals inside of a cloud.
What happens after the crystals leave the cloud determines what we get at
ground level.

Snow:

If the crystals pass through air that stays below freezing from the cloud
to the ground, it remains as snow all the way to the ground and we have to
shovel it.

Rain:

If the crystals pass through air that is warm enough to melt it and that
warm layer extends all the way to the ground, it remains as rain and we get
wet.

Freezing Rain:

If the crystals pass through air that is warm enough to melt it, but there
is a very shallow layer of air that is below freezing close to ground
level, the rain freezes when it lands on the sub-freezing surface of trees,
cars, roads, etc. and we slide off the road, lose power due to downed
wires, etc.

Sleet:

If the crystals pass through air that is warm enough to melt it and then
pass through air that is cold enough and "deep" enough to refreeze it, we
get hit by little ice pellets that sting our faces.

Hail:

If the crystals pass through air that is warm enough to melt it and an
updraft sends the water droplets back up into the cloud, the water freezes
on the ice crystals in the cloud, forming an ice pellet. If this "come
down, get wet, go back up and freeze" cycle happens again, the ice pellet
gets a little bigger. If it happens multiple times, and the pellets get
very big, we end up with dented cars, broken windows and headaches.