What does it mean when the forecast predicts a 40% chance of rain?
100256
A 40% chance of rain means that wherever you are in the weather forecast area there's a 40% chance that some rain will fall on you during the time period of the forecast. Also means that there's a 60% chance that it won't rain where you are.
310990
Thundershowers. It doesnt mean it will be raining thunder! It means that there will be little thunder with more rain.
440664
Lower pressure is indicative of rain and higher indicative of fair weather.  Think about how low the pressure is in a tornado or hurricane, like they're sucking, which they are (like a vaccuum).  29.93 is likely fair weather unless the barometric pressure is falling.  You should have a needle you can adjust.  Put it on the current reading and check it again in a couple hours.  If it's falling then rain is likely coming.  If it rises, then clear.
1107510
-40 F or -40 C is a good estimate
383352
check to see if he/she has predicited the correct weather for the past few days,  you should be able then to work out a % of there probable giving you a correct predicition!
1027903
I'm not completely sure, but I do know that the ring signals that the next day will be rainy. Perhaps it has something to do with an incoming front. Or a rise in humidity.
502323
Weather is a chaotic system; predicting it is difficult and only as accurate as the input data. Most TV and newspaper weather is very generalized - mass media is just entertainment and advertising, so you really shouldn't expect more than that. Military and agricultural forecasts are much more accurate but aren't free. It's been mathematically demonstrated that, even with the very best data possible, weather forecasts will never, ever be able to predict much more than 14 days out. Beyond that, things are just too chaotic.\n\nFor an example of truly accurate non-media weather forecasts, checkout SkyBit:\nhttp://www.skybit.com/cgi-bin/nav.cgi
919916
Just a silly way to answer.\n\nIf it is Saturday, it is Saturday, but if it rains, then it is a rainy day.
932423
I would say your chances are 40/60.
508839
It means that over the forecast area, any spot has only a 30% chance of getting rain. Conditions may change throughout the day and it may be that no area at all will get any rain. (The chances were, after all, only 30%.)
1151127
Meteorology is just a semi-educated guessing game.  The only accurate forecast is that there will be weather all day long!  For more info, my Rasta friend, you may care to join me and a few of my friends.... http://groups.yahoo.com/group/Rollin_Stoners/\n\nOnly God knows for sure!  Thank you, I send my blessings...... Johnnie sent me!  ;-)
543424
Weather forecasters predict weather up to 10 days in advance. Their accuracy drops drastically after 2-3 days. Most weathermen predict weather by themselves for the next 24 hours. After that, they rely on computer models. So when a weatherman says it will be sunny and 90 degrees in three days, he is relying almost completely on his computer models. The fact is, computer models change constantly because the weather changes constantly. For example, cold fronts speed up, slow down, and stall. A weatherman could know how cold it'll get after the cold front, but he won't know exactly when. The only really reliable forecast is the 2-3 day forecast. The type of weather will almost always be right (sunny, partly cloudy, rainy) and the tempature will be within a couple degrees. 7 day forecasts are not really reliable, but they do give you a picture. \nOverall, weather forecasts are unreliable because the causes of weather (air pressure, jet stream, moisture) are unreliable. Weather is one of the things that make man look small and weak.
779403
To me, it just means that it's as normal as rain is.  After all - think how bad things would be if you DIDN'T have rain!
16954
It means "probability less than 5%", as in probability of occurrence or frequency of occurrence.
1162559
12 Zulu time NAM (a weather model that guesses future weather) is predicting the uplift of air (convection) a little better than the GFS (another weather model that guesses future weather)...and based upon the NAM model, will lower the possibility of precipitation (pops) to 40 percent chance across the northern half of the county (CWA) for early this evening...as we are in between two areas of lower pressure (trough). I'll take a cold beer as payment. Thanks.
331961
It indicates a drop in pressure which usually means windy weather on the way and probably rain too.
533042
Well now for an answer that is actually worth something:\n\nWeather stations around the country keep track of ALL the conditions every hour of every day of every year.  Temperature, rainfall, humidity, wind, cloud cover, barametric presure, etc...\n\nIn the future when the weatherman appears on the news and say that tomorrow there is a 60% chance of rain, they mean that when they looked at the past records to similar days--days when the temperature, humidity, cloud cover, barametric pressure, etc... was identical, it rained 60% of the time.  Of course it is not 100% accurate but they use previous events to predict future events.\n\nIt is the exact same thing that doctors do.  They look to previous symptoms and what disease they led to, so when YOU go to the doctor with those same symptoms, they know that you are on the same road to the same disease.