How can weathermen predict 100% chance of rain - and then change their mind?
Is is just my opinion - or does 100% chance mean there's no way it can't happen?


I looked at the forecast for Wednesday and it said 100% chance of rain on Wednesday. It now says 90%.
My guess is that they will lower it by Tuesday. They usually do.

How do they have credibility when they can claim 100% and then change their mind?

The percentages are based on regional coverage. Data that had indicated 100% coverage of the region can change just prior to arrival and then it's anyone's guess...

I think the main thing is that they were predicting 100% based on the current conditions. When conditions and weather patterns change they adjust.

Yes. The percent isn't actually chance of rain, it's percent of forecast area coverage for the forecast period.

If it rains "somewhere" in their viewing area, they win.

That's a heck of a job. I wish I had it that easy.

Are we seriously discussing the credibility of weather men? Lol

My weather.com app on my Iphone now says "Chance of rain 80%". I don't know how that could be interpreted to mean a percentage of an area.

It was 100% earlier today. Now it is 80%. Funny how they lose their confidence over time.

Think about this a bunch of Bass fisherman discussing the credibility of anyone else. They have are hard time getting the weigh of their fish correct that they have in their hands and they are talking about a weatherman guessing about a weather forecast.

LOL HA LOL

Changing meteorological condition are the reason for rain chance percentages change, predictions are made days in advance
using the most recent available data. We perceive their predictions as WRONG. Many times I prefish using their wind direction data, which on tournament day blows 180 out. I take all weather predictions with a grain, a LARGE grain of salt.

The idiots had a 20% here, well the town next to me had almost 10" of rain last night. All kinds of flooding on rivers where there was no rain predicted.

Consistent, though!

- 10 days out: 100% chance of 10" of rain
- 5 days out: 50% chance of 5" of rain
- 1 day out: 10% chance of 1" of rain
- Today: 5% chance of .15" of rain

Lather. Rinse. Repeat...

You guys don't understand the difficulty in forecasting weather. We understand weather about as well as we understand the human brain. Great on some levels, virtually not at all on others. It's impossible to predict the weather with much more accuracy than we have now until major advances are made in understanding short term weather patterns and behavior. It's not simple by any stretch of the imagination.

Imagine living 100 years ago when you didn't know what the weather was going to do in 15 minutes. And at a time when exposure to the weather could very easily kill you. I'd say we have it pretty damn good with our 10 day forecasts and tornado sirens.

No one is predicting anything anymore. The "weatherman" doesn't have much input if any. Forecasts are based on computer models that analyze weather patterns and simulate what's happening next. They aren't perfect. Sometimes the weather takes an unexpected turn