An interesting weather observation

[FightingIrish]

I have been watching the Mt. Ashland (Oregon)weather radar for the past three hours. There has been a persistent radar return pattern north of Mt. Shasta that coincides exactly with Interstate 5 and U.S. 97. These images show weather that is apparently being created by vehicle exhaust emissions. The other intense area in the images is the town of Weed, Ca. The blue and red areas are indicating snowfall. The most intense precipitation is directly over the roadway and decreases with distance from the roadway. I'm no scientist but my guess is the particulates in the diesel exhaust are acting as condensation nuclei for the rain and snow,





http://www.tripcheck.com/popups/Cam.asp?camera=614&curRegion=7

[havocmom]

1. We live 25 miles from a good size lake; narrow but long & we see that pattern on the lake

Is there much snow near the interstate? Perhaps the heat from engines melting snow could create a 'lake affect'?

But, yeah, one might think particulates from exhaust may be a factor. Do we see it over Southern Calif though? That whole place is a road.

[FightingIrish]

2. This is kind of a unique laboratory

In this part of California, most of the vehicles are on I-5 and the surrounding area is very sparsely populated. When I first observed this today, there was no roadside snow. I watch the weather a lot and I have never seen anything like this before.

[bkkyosemite]

3. Wonder if it is seeding of the clouds......

[FightingIrish]

4. The effect is similar

Where I live they seed the winter fog with dry ice pellets to cause the water vapor to fall as snow. What is happening here is that the traffic, which is mostly truck traffic, is creating its own bad weather.

This link shows the view with animation.

http://www.wunderground.com/wundermap/?lat=41.47463&lon=-122.42889&zoom=11&type=hyb&units=english&rad=1&rad.num=6&rad.spd=25&rad.opa=70&rad.stm=0&rad.type=N0R&rad.smo=1&rad.mrg=0&wxsn=0&svr=0&cams=0&sat=0&riv=0&mm=0&hur=0&fire=0&tor=0&ndfd=0

[bkkyosemite]

5. Yes I see that, I live in Medford but am a Californian...Is this the only spot that is doing this

along 5....very interesting that the exhaust is causing this.

[bkkyosemite]

6. Went back to your link...this is the only place that is it doing it on Hwy 5 not even in Sac is

there this going on...wonder what is different on 5 and 97 near Weed.

[FightingIrish]

7. I live in Medford too. Earlier in the day this was the only

return on the Mt. Ashland radar. The linear patches at I-5 and Highway 97 were the only color showing. My guess is that there are some unique weather conditions that make this phenomenon observable on radar today. My son is an amateur meteorologist and spends a lot of time tracking the weather. He says he's never seen anything like it. The exhaust is just a theory, but I can't think of anything else that would cause it.

[bkkyosemite]

9. My niece is married to a weather man (Chico) and I can ask him.

[bhikkhu]

8. The topography was there before the road

And the road was built to follow the most level course through the mountains. Wind and weather patterns follow the same topography as well.

There may be some effect, but I would be surprised if the route chosen for I-5 didn't share a weather pattern distinguishing it from the surrounding mountains.

[FightingIrish]

10. Where the phenomenon was most pronounced and persistent

for over five hours, the terrain is flat and wide open. This is the stretch near the Weed Airport. The route of the freeway thera was not dictated by topography.

[bkkyosemite]

11. Just talked to nephew in law (Meterologist) and he said pixels are too big to be weather

it is false echo possibly from reflection from ice...but not real weather...