Basic suspension gumpf
When you hit a bump the forks need to compress to absorb it.
The damping that controls how fast this happens is the compression damping (no adjuster on the storm)
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Once it has absorbed the bump the forks then need to extend to their original start position.
This is rebound damping and is the slot adjuster on top of the fork legs
If you turn the screw clockwise (inwards - harder) this means that the forks will extend slower
If you turn it anti-clockwise (outwards - softer) the forks will extend faster
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The spring in the forks has a static length and a spring rate. It is the spring rate that dictates how stiff the spring is.
For example 10Newtons/cm means that to compress the spring 1cm requires a force of 10N acting on it.
If you artificially shorten the spring (preload it) by 1cm then you will need to apply a force of 20N to feel 1cm of movement, 30N to feel 2 cm etc
The nut on top of the forks is the preload adjuster.
If you turn it clockwise (inwards) it applies more preload and the spring feels stiffer
initially. Lots of people do this to try to stiffen up the standard soggy front end but as you can see from the example it just makes the ride feel harsher over the first cm of movement but it still collapses at the same rate after that. The only cure for the soggy front is stiffer springs
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So to get back to your problem, 5 things would make the forks feel harsh
1. Compression damping too stiff/hard -the forks can't compress fast enough to absorb the bump and so the whole bike jumps
Solution - no adjusters so replace the fork oil with thinner oil (ie less damping) is the only option.
Reality - compression damping on the storm is too little, not too much. Unlikely to be this unless the previous owner replaced the oil
2. Rebound damping too soft -the forks absorb the bump OK but then spring back violently. Feels very like 1 above
Solution - turn rebound damping clockwise to make it firmer/slower
Reality - you'll almost run out of adjusment before you find the right level
3. Too much preload -its taking too much force before the spring starts to absorb
Solution - remove some of the preload (turn nut anti-clockwise)
Reality - the preload should only be used to set the static sag ie the amount the forks compress to take the weight of the bike
4. Springs too stiff
Solution - fit softer springs
Reality - Unless the previous owner has replaced the springs this ain't gonna be it
5. Bottoming out - the forks are running out of travel and hitting the bump stops. Any further bumps are transmitted directly to the rest of the bike
Solution - make sure the preload is not too soft/little then fit stiffer springs
Reality - quite possible
What to do next
Set the preload correctly
How?
Get a friend to help hold the bike.
Apply front brake and pull up on the bars til the suspension is at maximum extension
Measure from the lip of the fork seal to the bottom of the yoke (measurement A)
Lower the bike GENTLY and let it come to rest
Measure again (measurement B)
Compress the forks and GENTLY release them
Measure again (measurement C)
You need an average of B & C (B+C /2)
Take this away from A to give your static sag measurement
Off the top of my head this should be 26-30mm
If it is less you need to add more preload
If it is more you need to reduce the preload
Set the rebound
How?
Compress the forks and let them bounce back up. This is the hard to describe bit coz its not black and white.
You are looking for the fastest possible return speed BUT UNDER CONTROL ie it doesn't ping back and then bounce up and down until it comes to rest
Ride the bike
How?
Buggered if I know 
Hope this is of some use and hasn't just sent you to sleep
Feel free to ask if you need any clarification/help/etc
Ben
