In my last post, I talked a bit about the National Weather Service, and how it contributes to predicting the chances of precipitation. We learned that they send up a radiosonde twice a day, from locations all over the country, to collect data about the atmosphere. Quite a bit of that data they post online for anybody to look at, and combined with other bits of data from things like satellites and ground observations, you can get an amazing picture of how things are shaping up in your area (or almost anywhere in the world!). Let’s take a look at a few of the things you can find online at the National Weather Service web site.
Current observations are an important part of determining what will happen with the weather. If you know how conditions are now, and how they have changed from the past, you can get a clue as to how they might be in the future. One tool that the NWS provides is a Surface Plot graph.
Surface Plot Chart
The official term for this is Mesonet Observations. According to wikipedia, “a mesonet is a network of automated weather stations designed to observe mesoscale meteorological phenomena. Dry lines, squall lines, and sea breezes are examples of phenomena that can be observed by mesonets. Due to the space and time scales associated with mesoscale phenomena, weather stations comprising a mesonet will be spaced closer together and report more frequently than synoptic scale observing networks, such as ASOS. The term mesonet refers to the collective group of these weather stations, and are typically owned and operated by a common entity.” So, basically, this is a series of stations that report current observations on wind speed and direction, temperature, relative humidity, and other items. If you know how to read these reports, and can spot trends, you can tell when a frontal system moves through, or when you might expect a thunderstorm. It’s good on the ground information.
One area at the NWS site that I spend a lot of time checking during stormy periods is the local weather radar image. This image gives me a great idea of where precipitation is occurring at the moment, and in what amounts and intensity. This is particularly valuable if you are going storm chasing, as you can see where the local thunderstorm cells are dumping their rain. It also provides a time-lapse ability, so you can see what direction the storm is moving. I enjoy watching the radar, especially when storms are headed my way.
Now, let’s say you’re interested in what the current forecast is for your region. The NWS is particularly good at providing that information, and does so in a wonderful graphical format. You can find out great things like temperature, wind speed and direction, dew point (handy in the summer for monsoon prediction), sky cover, precipitation, and more for up to the next week or so. This is very handy for planning activities, and the graphical format of the data is exceptional.
Finally, though by no means even close to the end of the great things you can get from the NWS, is the Weather Story that they produce from time to time. In Tucson, I tend to see these when a weather event is on the way, and right after an event. Any significant change in the expected weather pattern also seems to generate a Weather Story. Essentially, these are a couple slides that show the basics of what’s going on in the area, and what to expect in the near future. I find them interesting because it’s a good synopsis of what’s going on. I don’t know if all major locations produce weather stories, but I suspect they do.
So, there you have it…some of the free products that you can get from the NWS. These items only touch on the rich repository of information that is the National Weather Service. If you are interested in weather, I encourage you to take some time and look around. You’ll find data on things that you didn’t even know they collected data on!