Radar guides

Five guides cover the fundamentals, each with its own set of deeper pages. Start with how to read weather radar if you are new to the data; go straight to tornadoes on radar or squall lines and bow echoes if you are reading a storm right now. Every page states what radar cannot tell you as plainly as what it can.

• How to read weather radarWhat the colors mean, why velocity matters more than reflectivity, and what the radar physically cannot see.
  • What is NEXRAD?
  • Weather radar colors: what they mean
  • Correlation coefficient on radar
  • How to read radar velocity
  • What is virga, and why radar shows rain that never lands
  • What is a cumulonimbus cloud?
  • Mammatus clouds: what they are and why they form
• Tornadoes on radarHook echoes, velocity couplets and debris signatures — and how confident each one should make you.
  • The hook echo
  • The tornado debris signature
  • The El Reno tornado of 2013, on radar
  • Wedge, rope and rain-wrapped tornadoes
  • Funnel clouds, landspouts and gustnadoes
  • Tornado Alley, Dixie Alley and tornado season
  • The EF scale: how an EF5 rating is assigned
• The supercell, on radarMesocyclone, BWER, rear-flank downdraft — what a rotating updraft does to the data.
  • What is a mesocyclone?
  • Wall clouds, and what radar shows beneath them
  • The rear-flank downdraft
  • Hail on radar, and the hail size chart
  • How do tornadoes form?
• Squall lines, bow echoes and derechosOrganized linear convection, why bowing means damaging wind, and what actually qualifies as a derecho.
  • What is a derecho?
  • Bow echoes on radar
  • What is a microburst?
  • What is a shelf cloud?
  • QLCS tornadoes: the ones a squall line spins up
• Outlooks and forecast modelsWhat the SPC categories mean, and the most common way people misread a convection-allowing model.
  • The SPC convective outlook, explained
  • The HRRR model: what it is and how to read it
  • Tornado watch vs. warning: what each one means
  • The dryline, and other boundaries radar can see

Every figure in these guides is unmodified output from WeatherStory Radar — full-resolution Level II read straight from NOAA’s public archive. Nothing is thresholded, smoothed or decimated, and nothing is simulated.