Its hard to predict the exact zinc price at a particular time...

Its hard to predict the exact zinc price at a particular time however average consensus forecasts are pretty good at predicting the direction of commodity prices. So no, the chance of sub $1/lb zinc price is not the same as $1.50/lb, unless there is a very long/massive disruption at a zinc mine/smelter.
People in the zinc market know that stock is being held in private warehouses in the short term (check out zinc premium levels), if zinc consumers were worried about zinc supply they the zinc metal premiums would be through the roof. Zinc metal premiums have been in a long term downtrend over the last 1-2 years
Over the mid-long term supply and demand wins out. But yes please keep looking to the visible LME stocks which is just the tip of the icebergs. Others who wish to do more research can do some research into other data points (eg. Chinese import arbitrage, zinc premiums etc) in the zinc market to make their decision.