How do I read a barometer? Is 29.93 meaning a good chance of rain soon?
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.
634619
It depends, if you mean the high and low when they are showing the forecast, then it means the high and low temperatures for the day. If you mean the red H and the blue L they show on the maps, then it means high pressure and low pressure.
584475
Build Your Own Barometer \n \nWhat you need:\n• clear plastic cup\n• 2-liter plastic soda bottle\n• water\n• food coloring\n• marker\n\n\nWhat to do:\n1. This tool will work best if you put it together on a rainy day (when air pressure is lower). Pour a few inches of water into a plastic cup. Add a few drops of food coloring to the water. \n\n2. Place a plastic bottle upside down inside the cup. (It should fit snugly, but should not be airtight.) The mouth of the bottle must be below the waterline but not touching the bottom of the cup. Use a marker to note the water level on the side of the cup.\n\n3. Check the barometer after a couple of days. If the weather has gotten clearer, the water level in the cup should have fallen and the level in the bottle should have risen. \n\n4. The air pressure is what causes the change in water level. When the weather is clear, air pressure is higher, but when a storm is coming, air pressure drops. As the weather cleared up, the air pressure rose, and this pushed down on the water in the cup. Thus, the water level in the cup fell and the level in the bottle rose.\n\n5. As you watch the weather reports on the news, note what the weather forecaster says about the air pressure (or "barometric pressure"). If he says it will rise, does the water level in your homemade barometer also rise? What happens if he says the pressure is falling? \n\nLearning Benefits\n• develops understanding of air pressure\n• demonstrates the relationship between air pressure and weather\n• encourages testing of hypotheses
687765
a warning means there is actually a storm heading your way, a watch means conditions are likely for one to develop
80805
Not sure about forecast, but Kestrel makes some amazing anemometers (wind meters), some with barometers and altimeters built in.
561756
Do you perhaps mean DETECTS precipitation??\n\nRADAR
895565
Look like you are going to have partly cloudy conditions.....the links to you weather...check it out!!
1145045
I wish it would rain.  I've seen days when there was a 50% chance of rain and no rain.  All it means is that some where near you you have a 3 in 10 chance of seeing some rain.
9901
http://weather.yahoo.com/forecast/USOR0275.html
857764
Try this:\n\nhttp://weather.yahoo.com/\n\nGood luck!
31056
No, it means that you should take your umbrella with you, because the humidity in the air, and the pressure system suggest it could rain.  Weather prediction isn't exact science, so basically... they never KNOW for a fact if it is raining or not... no matter what percent they give.
731275
Just set it to field altitude when on ground. Then compare bar pressure reading on alttimeter to current pressure from weather station. If they are the same you areOK
572673
93 degrees/heat index 95 degrees with a relative humidity of 39%, winds out of the southeast at 17 mph & a uv index of 7 & partly cloudy
795170
Look on yahoo weather
204598
chance of rain with wind gusts ranging 25-30mph
619141
Im in Texas and we are expecting it to be in the 90's today...no rain in sight...but in Texas they say,,,"If you dont like the weather, wait a few minutes and it will change!!"
1130540
If you mean how can we forecast the weather, it's largely a matter of  measuring teh movement or change of wind currents, humidity, and a number of other factors.  Now, most of that is fed into a computer, and it gives aprediciton of what the weather will be over a short period of time.  Or, you could use an ancient Indian weather rock:  If it's hot, the sun is out; if it's wet, it's raining; if it's swinging, the wind is blowing...