30% chance of rain!?

Question

If there is a 30% chance of rain, then whyyy do the weather people put an icon of a raincloud! its more likely to Not rain!

Answer 1

What the National Weather Service means when they say 30 percent chance of rain is that 30 percent of the area they are forecasting for will rain and usually its about a 20mile radius.

However as per one of the other answers that it is hard to predict if a storm will hit that is not entirely true.

Military weather forecasters have to forecast for a 5 nautical mile radius and they have to give specifics like when it will stop end and haw fast the winds are gonna be and the size of the hail if any along with, in some cases, how much rain they will receive and usually are pretty accurate, depending on the forecaster.

In addition forecaster usually do forecast wort case due to the protection of life and property.

Answer 2

Exactly!  The Weather Channel has a 30% chance of rain all week and they show their extended forecast with 7 animated thunderstorms flashing.  Maybe during that period we get a little rain!

In the weather people's defense, it is hard to know where thunderstorms will hit, and those that get hit can get hit hard... but still... to bombard the graphics with flashing lightning bolts?

Answer 3

In 1979, the sailing Fastnet Race met a storm that took the life of 15 sailors. The BBC Shipping Forecast didn't see the secondary low coming in.

Since then, they forecast the worse-case-out. As a sailor, I am happy for that I am very sorry if you don't like the rain icon.

Answer 4

no, they dont really know. the % chance of rain is ALWAYS 50/50. either it will rain, or it wont rain

Answer 5

Because if it does rain, and there isn't a rain cloud on the forecast, then people will be complaining because it rained on their plans, and the forecast didn't show rain.

Answer 6

Because they want people to be aware that there's a chance of rain. I've seen it rain when there was only a 10% chance of rain.

Answer 7

I agree its a silly practice...and most news stations or websites, if they are any good, will actually put sunshine with only a smally raincloud indicating the chance, but still conveying that the bulk of the day will be see sun.  

I think practices like this only make meteorologists look worse.  People in the general public will not really pay attention to a weatherman on tv...but if they see rain or snow in the graphic, they will go to work and tell everyone that it is going to rain or snow.  Then if it doesn't, all those people will say "Looks like the weathermen got it wrong again".  Meanwhile, if people were paying attention in the first place, they would've heard that it was not a 100% chance of rain/snow, only a slight chance, meaning most locations wouldn't see any precipitation at all.