At least twice a day 92 NWS offices (69 in CONUS, 13 in Alaska, 9 in the Pacific and 1 in Puerto Rico) release weather balloons. These balloons go to a height of approximately 23,000 feet and gather information on their way up. This information is transmitted to the NWS office via radio signals. The information gathered from all 92 offices is then fed into a centralized computer which uses complex formulas to generate two different models. The two models are called the GFS (Global Forecast System) and the NAM (North American Mesoscale) and each gives a different perspective on the forecast. The GFS gives a forecast that goes out as far as 15 days in the future for a wide area. The NAM gives a smaller resolution forecast for a more specialized area and only goes out as far as 84 hours. Using the information from both of these models the National Weather Service forecasters can create a detailed forecast for their specific CWA (county warning area).
Typically, the NWS forecasters formulate forecasts for the next 3-7 days and update them as further information is received. New information is coming in constantly not only from updated models, but also from the radars and even weather spotters on the ground. Each National Weather Service office has three shifts per day which provide 24/7 monitoring, 365 days a year. Each shift reviews the data and makes changes as necessary to the forecast so it is updated at least three times a day and much more often during severe weather. In the event of severe weather, NWS forecasters are also responsible for issuing watches and warnings to keep the public safe and informed.
Forecast information is distributed to the general public via a graphical forecast editor (GFE). National Weather Service employees enter their forecast information into the GFE and it generates grids with all the general forecast information that the public could be looking for, such as temperature, precipitation, wave height, wind and wind direction. These grids are sent to the National Digital Forecast Database (NDFD) which converts the grid into digital format for use in GIS or viewing on the internet. Then another formatter takes the graphical image and makes it into a worded forecast and breaks it up by county. This final forecast is automatically sent to the weather radios and media outlets, as are any warning issued.
Although the forecast is the primary objective for the NWS forecasters, there are also quite a few other duties that they have during their shift. The National Weather Service, like most government agencies, does a great deal of outreach programs. They have person to person outreach, such as office tours and booths at state fairs and other conventions. Print outreach is important as well and the NWS offices frequently do media interviews for current weather events and also provide local weather interest information on the individual office's website. In addition the NWS often sponsors or assists with programs at local colleges and universities.
One integral part of the continuous outreach efforts of the National Weather Service has been the Skywarn Spotter program. This program gets the public involved by educating them to be aware of specific criteria during severe weather. This gives them the training and confidence to contact the local offices during severe weather and provide the office with important information to help track the weather event. Once an individual completes the Skywarn program they are given their own Spotter ID which they use when reporting in to the NWS office. Each NWS office covers a very wide area, which means that they rely on information from these spotters for a clear picture of what is happening on the ground since they cannot physically be in every county that they cover. For example, the CWA for my husband's office in Wakefield, VA consists of northeastern North Carolina, southeastern Virginia, south central Virginia, the eastern shore of Maryland and the lower eastern shore of Virginia. This is hundreds of miles and although they do quite a bit of travel they cannot be everywhere at once.
If you want to know more about your local NWS office simply go to www.weather.gov and either click on your location on the map or enter your zip code in the search box. Many offices have virtual tours and information about local outreach efforts on their website and you are always welcome to call the office for information as well. I hope this article has helped to give some insight as to how the National Weather Service forecasters actually do their job. Although there are many jokes made about meteorologists and the fact that they are not always 100% accurate, the fact is that these people are highly trained and work very hard around the clock to try to keep the public safe and informed. Nobody is more upset when a forecast doesn't pan out then the meteorologists and they are constantly looking for ways to improve their skills. They are passionate about their vocation and most will happily spend hours explaining the difference between cold fronts and warm fronts to anyone who asks. If you are curious about the weather, utilize the resources that they make available. After all, you are the reason that they are doing the work in the first place!
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