Its been raining a lot lately.
When I was leaving for the store I left between the rain showers.
As I was leaving I was driving across the parking lot to check my mail and I saw the strangest thing.

Above me in the sky, I saw a column of rain that looked to be about 5-10 feet in diameter and I followed it down to the parking lot I was crossing.
I passed thru it and looked up to see if there was any other rain coming down and nothing but that one column snaking its way down from a cloud.

Inside this column of rain it was literally pouring while outside the column not a drop?
I have never witnessed rain in such a way. It startled me.
I sat at my mailbox and watched it and I saw it end as it left the cloud and watched that cease till it reached the ground.
It was like someone suddenly turned off a hose.
What could cause this to happen?
There were no aircraft overhead, no trees or tall buildings nearby?
It was like only one part of the cloud was raining?

I've seen rain fronts that soak one side of the house but not the other.
This was different, it wasn't a front, it was a column?

Could have been a micro burst. They pop up once in awhile when the conditions are just right

Tom, from what you're describing, I've seen a lot of those over the ocean down in the Keys. At times it happened over land too. Just one column of rain passing through but nothing all around it. It's pretty bizarre to see. Not sure what causes that?

I think of microbursts as a small cloud releasing rain all at once.
What I saw was a large cloud releasing rain only from a small point and not even at its center.
Like I said, its been raining off and on all day, the sky is full of clouds that are pretty low in the sky. They are moving very slowly towards the south. From where I am located, that is towards the Gulf not coming from the Gulf.

Had this occurred on a dry day, I'm sure the resultant wet spot would have only been about 20 feet in diameter. Plus, it wasn't just a drizzle it was a flat out downpour.

It looked like someone had tipped a sprinkler then suddenly capped the flow.
As unnatural as I have ever seen and I love watching storms.

If it had moved with me it would be like a classic Charlie Brown storm following him. But it didn't traverse, it was fixed. I did notice there was no apparent movement in the cloud cover at that time.

I have a theory, tho I'm not a meteorologist.
I'm thinking condensation weakened the cloud at a certain point and the moisture funneled thru its weakest point.

We get them alot here in Arizona during the monsoon. You can see them across the desert just hitting one spot or several of them doing that at once. I have driven into town and hit some like you said, roads flooded but before I actually make it a quarter mile it is dry and stays that way.