CERN Amateur Radio Club – CARC

Receving real-time weather maps

Chasing the Sky: Receiving Real-Time Weather Maps with Ham Radio and Satellites

For radio enthusiasts, there’s something deeply satisfying about pulling weather images straight from the sky—no internet required. Whether you’re decoding a fuzzy grayscale map from an HF signal bouncing off the ionosphere or grabbing crisp satellite images as they sweep over your backyard, receiving real-time weather maps taps into the thrill of independent, hands-on radio communication. Combine that with the world of ham radio, and you’ve got a rich, rewarding hobby that blends science, engineering, and a touch of magic.

The Magic of Weather via HF Radio

Let’s start with HF (High Frequency) radio. Even before satellites dominated meteorology, weather agencies were broadcasting real-time forecasts and charts over shortwave. And guess what? They still do.

Using a shortwave receiver or a ham radio with HF capability, you can tune into WEFAX (Weather Facsimile) transmissions. These are analog signals that, when decoded properly, reveal synoptic charts, pressure maps, and marine weather forecasts. Common stations like NOAA/NMG (New Orleans) or DWD (Germany) transmit on known frequencies across the HF bands.

All you need is:

  • An HF-capable receiver (many ham radios like the Yaesu FT-891 or Icom IC-7300 will work),
  • A simple long-wire antenna strung between trees or poles,
  • And software like Fldigi or JVComm32 to decode the WEFAX signals into weather maps.

The process of hearing that buzzing audio and watching it turn into a tangible map—complete with fronts and pressure zones—is just plain awesome.

Helpful links:

Satellite Weather Maps: Direct from Orbit

If you want higher-resolution images and a real-time view of Earth from above, NOAA satellites are where it’s at. These polar-orbiting weather satellites transmit APT (Automatic Picture Transmission) or HRPT signals as they pass overhead, and with the right setup, you can decode your very own images showing cloud cover, storms, and weather patterns in near-real-time.

A typical beginner satellite weather setup includes:

  • A RTL-SDR dongle (around $30),
  • A quadrifilar helix antenna (QFH) or turnstile antenna (can be homemade from copper wire and PVC),
  • Tracking software like WXtoImg or NOAA APT Decoder,
  • And satellite pass prediction apps like Heavens Above or Gpredict.

NOAA 15, 18, and 19 are the most commonly used satellites for this purpose, transmitting around 137 MHz. You’ll be amazed at the images you can receive, complete with false-color overlays and thermal gradients.

For more advanced users, decoding HRPT signals provides higher-resolution images but requires more complex SDR hardware like an Airspy or SDRplay, and precise antenna alignment.

Helpful links:

Ham Radio: Where DIY Meets the Atmosphere

Ham radio operators often get involved in both HF and satellite weather monitoring—and in many cases, they expand their setups to include transmitting and receiving weather data using digital modes like PSK31, FT8, and Packet Radio. Some even relay local weather station data over APRS or participate in SKYWARN programs, helping the National Weather Service during storms and emergencies.

Want to take it a step further? Use your ham license to:

  • Relay weather data using packet via satellites like NO-84 or ISS digipeaters.
  • Experiment with Winlink for email and weather data over HF.
  • Monitor and report on local weather conditions using APRS + weather station combos like the Davis Vantage Vue + TNC.

The Joy of Hands-On Forecasting

There’s something uniquely satisfying about predicting the weather with nothing but your own gear and a bit of radio savvy. Whether you’re pulling down real-time satellite imagery or listening to HF weather charts crackle in over the ocean, these experiences connect you to a global system of information—without relying on the cloud (well, maybe just literal clouds).

So if you’re already deep into ham radio, or just getting started with SDR and weather monitoring, there’s never been a better time to explore the skies. Build an antenna, spin the dial, decode some images—and watch the weather come alive in real time, right from your own backyard.

More Community Resources:

Let the clouds guide your curiosity—and may your signals be clear and your skies never static.