Our house appears to be in the Twilight Zone. Any idea why?

October 6, 2013 7:45 AM

It appears to be raining only in in 20-foot circle on the street in front of our house. Yes, I know how weird that sounds. It's going on right now. Hoping someone can think of some reason why.

Last night, a neighbor rang our doorbell and said there is a wet spot on on street in front of our house - a wet spot they noticed some 10 hours earlier. Then I grabbed a flashlight (we live in a wooded area with no street lighting) and sure enough, the pavement was wet and so was the grass. Picture a 20-foot circle half on the grass, half on the street. (I should note that there is only a 10-foot strip of grass then old growth woods in front of the house. We're talking trees up to 80 feet high.) Curiously, though the pavement and grass were wet, the dirt is somewhat dry. Then I feel a spritzing as if it's starting to rain. Okay, odd. Then I walk back toward our house and, wait, it's not raining over here. Yep, only in the mystery 20 foot circle. So, okay, gotta be a water main break shooting water up in the air, right? Can't see or hear anything like that. Still, we call the water company. They send a guy out. He checks our meter and the lines and other stuff then proclaims, "In 27 years I've never seen anything like this. My conclusion is that it's raining only in a 20 foot circle in front of your house." He says they'll come back tomorrow (today) in the daylight to check again. Well, it's morning here. I've been up there. Neighbors have been up there. Friends have been up there. No one can figure it out. It still appears to be raining only in a 20-foot circle in front of our house. I thought maybe airline ice got caught in a tree. My wife thinks the one 80-foot tree directly above it has tapped a root into the water main, is sucking water up and letting it out. Yes, these are our best theories. Some other info that may or may not be important: There's very odd weather for the Philadelphia region right now. It's in the 80s and very humid. Rare for October. Another point ... when you shine a spotlight upward at night, you can see the drops falling from above the power lines. I've also walked up and down both sides of the road in case it's springing up from a neighbor's lot and somehow blowing/creeping across the canopy. Other than that, I got nothing. Anybody got any ideas or do I open a shrine?

posted by lpsguy to Home & Garden (20 answers total)

Could it be aphids having another cycle due to the warm weather?
posted by Marie Mon Dieu at 8:00 AM on October 6, 2013

Seconding aphids. You're not the only one.

Also, I have noticed this under some trees (also in Philly) where there's a circle of wetness on the ground/the tree is dripping. I always assumed it rained overnight and water was just caught in the trees, but now I'm betting it's aphids.
posted by DoubleLune at 8:16 AM on October 6, 2013

Put a clean bowl or bucket out and collect some of the water, might prove useful in testing the aphid theory?
posted by LobsterMitten at 8:17 AM on October 6, 2013

Response by poster: The aphid theory is an interesting one. But there is absolutely no stickiness. It appears to be clear water. But it's almost impossible to collect even though the ground is clearly wet. We even tried to lay a pool water test strip in it to see if there were chlorine traces that would identify it as public water. It really appears to be water.
posted by lpsguy at 8:36 AM on October 6, 2013

Some trees do lose water from their leaves, called transpiration. Usually this just goes up into the air, but if it's that humid, and there's enough water, perhaps the water is just collecting and condensing on the leaves, and falling. Are there any other trees of that same species nearby, and can you see if it's damp under them as well? The water mains theory is interesting, I've never heard of that.
posted by The otter lady at 9:54 AM on October 6, 2013

That article linked by DoubleLune is like something out of The Onion! Hilarious. Anyway, there's a cluster of weeping willows on my regular walk that sprinkle me with a fine mist of water every time I pass. They're along the bank of a small creek. The mist isn't sticky at all, it really feels like a mist of pure water. In trying to figure out what was going on, I found this. So I wouldn't give up on the aphid theory just because it's not sticky.
posted by HotToddy at 10:12 AM on October 6, 2013

Aphid honeydew is not sticky. The reason that aphids excrete so much is that sap is mostly water, with sugar and a little protein; they extract the protein and some of the sugar and excrete the rest so they can suck more.

Sugar maple sap makes maple syrup, but it takes about 40 gallons of sap to make one gallon of syrup. If you have corn syrup at home, you could dissolve 1 tsp of corn syrup in 6.5 oz. water and then see how easy it is to tell that it's not pure water. If you had a good drink you might notice that it was sweet, but you probably couldn't tell from a drop or two.
posted by brianogilvie at 10:38 AM on October 6, 2013

Response by poster: Just checked it again. Still coming down now 26 hours later. I'm attempting to collect a substantial amount. Meanwhile, the tree is an oak. No other oak trees are affected anywhere. In addition, I pulled my car into the strange zone. Droplets appeared all over the windshield and the wipers removed them cleanly; not a trace of stickiness or smearing. The corn syrup in water is indeed sticker than what we're experiencing. Thinking about charging admission.
posted by lpsguy at 11:45 AM on October 6, 2013 [2 favorites]

(I should note that there is only a 10-foot strip of grass then old growth woods in front of the house. We're talking trees up to 80 feet high.)
...
Some other info that may or may not be important: There's very odd weather for the Philadelphia region right now. It's in the 80s and very humid. Rare for October.

I think the trees are causing it, but not via aphids.

Some trees produce lots of pollen in the fall, and I think that pollen is providing condensation nuclei for all the water in your humid air as it comes out of your forested area, and that the condensation is falling to the ground as a light drizzle.
posted by jamjam at 12:00 PM on October 6, 2013

Response by poster: jamjam ... love the thought. But why one tree? And why just in a 20-foot circle?
posted by lpsguy at 12:24 PM on October 6, 2013

Response by poster: Okay, here are pictures. One is of the wet circle on a perfectly sunny 83 degree day. The other shows the droplets in a container I set out about an hour ago.
posted by lpsguy at 12:27 PM on October 6, 2013

Response by poster: Sorry, screwed up the link. Here are the pictures described above.
posted by lpsguy at 12:32 PM on October 6, 2013

If it's an oak tree, can't you just climb up it to confirm if it has aphids?
posted by HotToddy at 12:38 PM on October 6, 2013

Response by poster: It's 80 feet up, and all the lower branches have been pruned to allow the power lines to pass unimpeded.
posted by lpsguy at 12:44 PM on October 6, 2013

I once was at a campground and it rained on our site and the one next to us, and no other campsite there. In that case, it seemed to be the foggy air being blown to the campground (we were on the Washington coast), condensing on the trees, and dripping down on to us.

Could there be something like that going on? Are the trees taller than other trees nearby?
posted by The corpse in the library at 12:46 PM on October 6, 2013

What is the situation with the clouds in the air?
posted by TheRedArmy at 1:38 PM on October 6, 2013

Response by poster: It might be the tallest tree. It's a partly cloudy day here right now.
posted by lpsguy at 1:41 PM on October 6, 2013

I think The corpse in the library must be right.
posted by jamjam at 3:30 PM on October 6, 2013

Okay, I have a somewhat different thought. You may have a raccoon or other critter living up in the tree who has found a choice sleeping spot and who is relieving himself regularly from that spot. If the pee lands on other leaves on the way down, it could spatter in a larger area.

I came up with this idea only because I saw a raccoon pee on someone from a trellis about thirty feet up in what looked like a cosy sleeping spot in Central Park, NYC, the other day. The area on the ground covered a circle about 8 feet wide. Maybe higher distance, more objects in the space between, and voila! Raccoon pee rain!
posted by eleslie at 6:35 PM on October 6, 2013 [2 favorites]

Response by poster: Okay, our next door neighbor contacted a friend who runs a tree care business. He said the tree is an ash not and oak. He said that it is indeed coming from a tree and has seen this before. Said because of the odd weather patterns this year, these trees' turbo pressure is whacked. When it loses it's leaves early, as this one has, the water just comes out as mini droplets. That certainly matches everything that's been happening. But when he was asked where're all the water is coming from since it hasn't rained here in weeks, and how this could be continuous for days, he had no answer. Still, this theory seems to be the leader in the clubhouse.
posted by lpsguy at 7:35 PM on October 6, 2013 [2 favorites]