As part of the ongoing cost-cutting with the Federal Government, the National Weather Service (NWS) announced yesterday (March 20, 2025) that it is reducing or ceasing altogether weather balloon launches at several locations across the country. While these data are primarily used for weather forecasting, they are also used in the air dispersion modeling world and their lack of availability may become an issue for some locations in the coming years. Here’s why.
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The preprocessor AERMET is used to create meteorological data for use in AERMOD. One of the inputs to AERMET is NWS rawinsonde data, which are upper air observations collected from weather balloons that are released into the atmosphere twice per day (in the United States, that basically means at sunrise and sunset). These data provide information on the vertical structure of the atmosphere.
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The map above shows where the NWS is going to curtail or stop weather balloon launches. Red stations are those that won’t have any weather balloon launches, and the orange stations are those that will be reduced to just one per day. Specifically:
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No weather balloon launches:
·        Rapid City, SD
·        Omaha, NE
·        Albany, NY
·        Gray, ME
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Only one weather balloon launch per day:
·        Grand Junction, CO
·        Riverton, WY
·        Aberdeen, SD
·        North Platte, NE
·        Green Bay, WI
·        Gaylord, MI
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So if you’re trying to do an AERMOD analysis in the future and you’re close to one of these locations, developing those AERMOD-ready meteorological data files will be more tricky. You’ll need to find another source of representative upper air data or you’ll need to use prognostic meteorological data in your AERMOD modeling.Â
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All in all this is by no means a fatal flaw in modeling if you’re near these stations, it just means that in these areas the creation of the meteorological data files for AERMOD modeling could be different in the future.