Simulated radar — how to read it

The radar map shows simulated radar reflectivity in dBZ — what a weather radar would see if it scanned the ICON-D2 forecast atmosphere. It captures convective cell structure and intensity gradients much more sharply than the smooth precipitation field.

Reading dBZ

• Below 20 dBZ (light blue): drizzle, light rain, virga — no operational impact.
• 20 to 35 dBZ (blue → green): light to moderate rain, no significant convective structure.
• 35 to 45 dBZ (yellow): moderate to heavy rain, developing convection. Turbulence around, but usually traversable with care.
• 45 to 55 dBZ (orange → red): heavy convective cells. Circumnavigate, don't cross.
• Above 55 dBZ (dark red / magenta): severe cells, hail signature. Give them wide berth — 10 NM upwind minimum.

Why simulated radar beats plain precipitation for storms

Precipitation maps show the smoothed water flux to the ground. Simulated radar shows the structure: a compact 50-dBZ core embedded in a 30-dBZ shield of stratiform rain — a shape that says "cell embedded in an area of weaker rain" — is instantly obvious on the radar map and hard to see on the precipitation map. That structure is what determines whether you can route around a cell.

Combining with convection and cross-section

For convective days, use three products together:

• Convection (CAPE) tells you the fuel is present.
• Simulated radar tells you where and when that fuel is expected to be released.
• Cross-section along your route tells you the vertical depth of the cells.