Despite some early attempts in the 19th century, national weather services did not regularly create forecasts for public consumption until the early 20th century, and many of those were made based on a handful of surface observations of dubious quality. With the invention of the balloon-borne radiosonde in the 1930s, upper-air observations became more common, and knowledge of the upper-level processes were melded into forecasting practice. WWII brought its own challenges and opportunities, expanding the number of trained meteorologists worldwide, as well as the establishment of many new observing stations in tropical and high-latitude locations, and the possibility of using radar to identify short-range severe weather. But the big change was the development of digital electronic computers, and with them the opportunity to calculate the weather. The first efforts were marginal at best, but international teams in the US and Sweden continued their efforts, and by the late 1950s, mid-atmospheric prognosis charts were being transmitted to forecast offices, which would prepare the final local forecasts. Unfortunately for the synoptic forecasters in the field offices, the new objective numerical weather prediction (NWP) products were not comparable to the old subjective forecast charts that they had used for years. The resulting push and pull between the atmospheric modelers and the synoptic meteorologists ultimately changed both groups: the atmospheric modelers used forecaster feedback to upgrade the models and the synoptic meteorologists learned to use the objective forecasts. The anticipated improvements in weather forecasting, however, did not follow immediately. As the decades passed, increasing computer power, increased data availability on the ground and in the atmosphere, due to the introduction of satellites with multiple specialized sensors, purpose-built weather radar, and other remote sensing devices, and the addition of more variables and the physics that defined them to the models led to NWP products that changed the way synoptic meteorologists made their forecasts even if it did not change their feel for the atmosphere. Those changes have continued into the 21st century, fueling the desire for specialized forecasts for multiple interest groups and the public’s desire for accurate, up-to-the-minute weather forecasts that extend up to two weeks into the future.