5G C-Band Spectrum Encroachment Degrades Weather Radar Accuracy

The FCC's auction of C-band spectrum (3.7-3.98 GHz) for 5G wireless services created harmful interference with NOAA's weather satellites and adjacent radar systems operating in nearby frequency bands. The 5G signals bleed into channels used by satellite-based passive microwave sensors that feed critical data into numerical weather prediction models, degrading the accuracy of 3-7 day weather forecasts by as much as 30%. This matters because weather forecasting is not a convenience feature — it is the backbone of disaster preparedness, agriculture planning, aviation safety, and military operations. A 30% degradation in forecast accuracy translates to billions of dollars in unmitigated storm damage, crop losses from missed frost warnings, and preventable deaths from hurricanes and tornadoes where evacuation lead times shrink. The National Weather Service issues roughly 50,000 severe weather warnings per year, and each one depends on upstream satellite and radar data quality. The reason this problem persists is structural: the FCC and NOAA operate under fundamentally different mandates with no binding arbitration mechanism. The FCC's statutory mission is to maximize spectrum utilization and economic value, while NOAA's mission is environmental monitoring. When the FCC auctioned C-band spectrum for $81 billion in revenue, the economic incentive overwhelmed scientific objections. The 220 MHz guard band that was negotiated as a compromise is insufficient according to NASA and NOAA studies, but there is no regulatory framework that forces the FCC to prioritize weather safety over telecom revenue. International bodies like the WMO have raised alarms, but U.S. domestic spectrum policy is not bound by WMO recommendations.