Rei Goffer on the growing global weather data gap and how Tomorrow.io’s Microwave Sounder Constellation is helping close it

Global weather forecasting is entering a new era — one driven by higher-frequency observations, AI-powered prediction systems, and increasing demand for real-time atmospheric intelligence.

But at the same time, the global observing system faces a growing challenge: many of the microwave sounders that modern forecasting depends on are aging out of service, while billions of people still live outside reliable radar coverage.

In the opening session of Tomorrow.io’s recent webinar, Beyond the Data Gaps: Continuous Global Sensing with Tomorrow.io Microwave Sounder Constellation, Co-Founder and Chief Strategy Officer Rei Goffer outlined why commercial microwave sounders have become increasingly important — and how rapid-refresh satellite constellations are helping reshape the future of weather forecasting.

Why Microwave Sounders Matter More Than Ever

Rei began by zooming out and framing the broader challenge facing the weather industry today.

For decades, microwave sounders have served as one of the foundational observation systems behind global numerical weather prediction models. These instruments provide atmospheric temperature and humidity measurements that are assimilated into forecasting systems worldwide.

According to Rei, the majority of atmospheric observations feeding operational weather models today still come from microwave sounding systems.

The problem is that most of these instruments are operated by government agencies, and many are now approaching end of life.

Over the next several years, a significant number of operational microwave sounders are expected to age out of service, while replacement systems are not being launched quickly enough to maintain current coverage levels.

As a result, the world is facing a growing atmospheric data gap.

The Global Radar Coverage Problem

At the same time, Rei highlighted another major issue: the uneven distribution of ground-based weather infrastructure.

Today, roughly 5 billion people live outside reliable weather radar coverage.

Large portions of the world — particularly across oceans, developing nations, and remote regions — lack the radar systems that support real-time precipitation monitoring and severe weather detection in more developed areas.

Historically, microwave sounders were not viewed as practical tools for real-time precipitation analysis because revisit rates were too slow. Satellites might only observe a location a few times per day, limiting their usefulness for rapidly evolving storms.

But according to Rei, that limitation is beginning to disappear.

From Occasional Observations to Continuous Global Sensing

With the expansion of Tomorrow.io’s Microwave Sounder Constellation, revisit rates have improved dramatically.

The constellation now provides approximately sub-hourly global coverage, allowing atmospheric observations to be refreshed frequently enough for:

• Real-time precipitation monitoring
• Nowcasting
• Rapid-update forecasting
• Flood prediction workflows
• Operational weather intelligence

The satellites operate at microwave frequencies specifically designed to penetrate cloud layers and observe atmospheric structures all the way down to the surface.

Unlike traditional imaging satellites, these systems are purpose-built for weather sensing.

According to Rei, the constellation now delivers observations for nearly every point on Earth roughly once per hour, with low latency that allows data to reach the ground within minutes after collection.

Feeding the Next Generation of Forecast Models

Rei also emphasized that forecasting systems themselves are evolving rapidly.

Both traditional numerical weather prediction systems and newer AI-based forecasting models require enormous volumes of observational input to improve forecast skill.

As AI weather models become more advanced, demand for high-frequency atmospheric data is growing significantly.

Tomorrow.io’s constellation is designed to help meet that demand by providing continuous global observations at scales that were previously difficult to achieve.

One statistic highlighted during the webinar illustrated the scale of that contribution: at any given moment, roughly 70% of the most recent global microwave sounding observations now come from Tomorrow.io’s constellation.

Building a New Layer of Global Weather Intelligence

Rei closed the session with a visualization showing roughly two days of atmospheric observations collected entirely from the constellation.

The animation captured tropical cyclones, frontal systems, and atmospheric movement across the globe, illustrating both the scale and frequency of the data being collected.

But for Rei, the broader message was not just about satellites — it was about operational impact.

Tomorrow.io’s platform extends beyond raw observations into:

• AI-powered weather modeling
• Operational forecasting systems
• Agentic AI weather intelligence
• Decision-support capabilities

The satellite constellation serves as the observational foundation powering those broader systems.

Closing the Global Weather Observation Gap

Rei’s presentation highlighted a growing reality across the forecasting industry: weather models are becoming more sophisticated, but they depend on increasingly large volumes of high-quality observational data.

At the same time, traditional observing systems face mounting infrastructure and coverage challenges.

By deploying a rapid-refresh commercial microwave sounding constellation, Tomorrow.io is helping fill critical gaps in the global observing network — bringing more frequent atmospheric observations to forecasting systems around the world.

As forecasting increasingly shifts toward real-time, AI-driven, data-intensive workflows, continuous global sensing may become one of the defining capabilities of the next generation of weather intelligence.