I have just a cheap little rain gauge. It's 1 inch in diameter. Goes up to 6 inches in height. Does this size give an accurate recording of rainfall? If not, is there a standard "official" size of rain gauge? I'm just confused lately by the weather reports. For instance, today, I had 4 inches of rain in my gauge. The news said that Liberty (which is about 8 miles west of me) got 3/4 of an inch of rain. I've always been told that it was measured at the little municipal airport, which is only 2 miles west of me. I understand that it can pour down on one side of the road and not the other. But the reported amounts lately sure seem to be WAY off. So.. is it really just that much of a difference in where the rain is falling? Or is it my little cheap rain gauge? Here's a photo of my neighbor's pasture from this morning. Even with our saturated ground, this has to be more than 3/4 inch of rain. neighbors pasture ( photo / image / picture from cherylad's Garden )
Cheryl, I don't trust those airport rain reports. We had 3" of rain, and Waco was reporting 1.5", and Hearne was reporting 2". Our pond is overflowing, there is standing water in the drainage ditches, and any low spot has become a puddle. That doesn't happen with 1 1/2" of rain! We have a big rain gauge (records up to 6" and has a catchment at the top, so is more accurate than the ones that have a little opening) mounted on our fence, and another on the east end of the barn. If there is any discrepancy, we take the average between the two. Trust your rain gauge. I don't think there is an "official" one unless you get it from the National Weather Service. Isn't it wonderful that we are discussing rain measurement rather than drought?
Thanks for easing my mind Jane. I was beginning to think that rain gauges from the dollar store weren't any good! :-D I sent a message via FB to my favorite weatherman about the discrepancies. Usually their reports have been close enough. But here lately, they have been way off. And yes... rain instead of drought! Just when I find myself ready to complain about it... I just think back to this past summer.
Rain gauges are calculated by a specific method that involves a ratio between the diameter of the opening at the top of the gauge and the height of the cylinder. That's how gauges of all different heights and diameters can be accurate.....or it's magic, take your pick.... Differences are also caused by wind speed at that location, how close the gauge is to trees and buildings and other factors. Official National Weather Service rain reports are received from the official reporting stations in different areas....DFW International Airport in my area, the airport in Waco south of us, Houston Hobby Airport and other official report stations all over the country. Otherwise they would have millions of different locations to report on and that just isn't feasible. Therefore the amount reported from the official reporting station to the National Weather Service will always differ from front yards and back yards in any specific area. Heck the rain report from a block away from me is almost always different from what the gauge in my yard is. Always go with the gauge in your yard and don't worry about what the National Weather Service says, they may be miles away from you and what's happening there really has very little relevance to what is happen in most front yards and definitely forget about the Weather Channel. The official report at DFW International Airport is always different from my rain gauge, so when I post on here the rain amount it is either notated as "in my yard" or as "the official report".
I'm still going to bug that weatherguy until he answers me about where they are getting their reports. If it was even just an inch difference I wouldn't care. But a 4 inch difference in 2 miles?
Most TV stations have volunteers who keep them informed of the amount of rain or other precipitation in different areas. If there are several people reporting from a fairly small area then they average the totals and report that instead of saying .78 inch at this corner/1/4 inch two blocks away, etc. Have you ever looked at a weather radar when a storm is moving through? They are not solid formations that rain evenly everywhere. There are always spots that are shades of green, lighter green being less rain/darker green is heavier rain. Yellow, orange and red show up too designating the amount of rain contained in the clouds and the severity of the storm. Many, many times a storm moves over us and looking at the radar I can see that we are only in the light green area and end up getting less than 1/2 inch, while at the same time the Target less than a mile east of us will be under the yellow section and get 1-2 inches. Also when they say 100% coverage, that means everyone in an area will receive rain but not necessarily the same amount. Storms just don't work that way.
