3 Radar Products
Each panel displays one radar product at a time. This chapter lists every product the app can show and how to control its display. For how to interpret these products, see the Radar Reading Guide.
3.1 Selecting a product
Open the panel’s radar product picker and choose from the list below. Products that sample a single sweep also let you pick an elevation tilt.
3.2 Base & derived products
| Product | What it shows |
|---|---|
| Reflectivity | Base reflectivity (0.5° by default), precipitation intensity in dBZ |
| Velocity | Base radial velocity: motion toward or away from the radar |
| Storm Relative Velocity (SRV) | Velocity with a user-set storm-motion vector subtracted |
| Azimuthal Shear | Local rotation derived from velocity (LLSD estimator, s⁻¹) |
| Composite Reflectivity | Maximum reflectivity across all elevation angles |
| Echo Tops | Storm-top height (feet) |
| VIL | Vertically Integrated Liquid: storm energy and intensity |
| Correlation Coefficient (CC) | Dual-pol uniformity: debris and hydrometeor ID |
| Differential Reflectivity (ZDR) | Dual-pol particle shape |
| Specific Differential Phase (KDP) | Dual-pol: rainfall estimation |
| Hydrometeor Classification (HC) | Dual-pol precipitation-type classification |
| Storm Total Precipitation (STP) | Accumulated rainfall over the storm |
Storm Relative Velocity, Azimuthal Shear, and Hydrometeor Classification are computed on-device from the base moments.
3.3 Elevation tilt
For products that sample a single sweep, choose the elevation angle: 0.5°, 0.9°, 1.5°, 1.8°, or 2.4° for NEXRAD. The 0.5° tilt samples closest to the ground and is the default for severe-weather work. Higher tilts look further up into the storm (useful for spotting features aloft like a BWER or storm-top divergence).
3.4 Storm Relative Velocity controls
When viewing SRV, set the storm-motion vector that gets subtracted:
- Direction: 0–360°
- Speed: 0–70 kt
Tuning these to match the storm’s actual movement makes rotation stand out clearly. See Velocity for why this helps.
3.5 Display modes
Independent of which product is selected, choose how it’s drawn:
| Mode | Effect |
|---|---|
| Normal | Standard color-mapped display |
| Contour | Contour lines at reflectivity thresholds |
| Grayscale | Grayscale with a threshold fade |
| Mask | Hides echoes below a threshold |
For Contour, Grayscale, and Mask, set the threshold (0–110 dBZ) to control which echoes appear.
Additional rendering options:
- Smooth Radar: bicubic (Catmull-Rom) smoothing of the radial data, on by default for a cleaner look.
- Range Outline: draws the radar’s coverage circle.
- Beam Blockage: overlays terrain beam-blockage so you know where coverage is degraded.
3.6 Radar data sources
- Level 3 (NEXRAD): standard live and archived NIDS products (default).
- Level 2 (Archive II): higher-resolution base moments fetched from AWS during archive replay (opt-in).
- TDWR: Terminal Doppler Weather Radar at airports; lower tilts and smaller coverage, good for low-level detail near major metros.
3.7 Color palettes
Each product category uses a selectable color palette. Change palettes, or apply a custom one, under Settings > Color Maps. See Settings.