Settings Saved

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Map

Default map style
Dark (Matter) is for storm watching at night. Light (Positron) is easier in daylight.
Radar opacity
0.7 = balanced. Higher = radar dominates; lower = base map dominates.

Default Layers

Radar
NEXRAD precipitation from RainViewer.
NWS Alerts
Warnings, watches, advisories — colored polygons.
SPC Convective Outlook
Day 1 categorical severe risk areas (TSTM / MRGL / SLGT / ENH / MDT / HIGH).
Mesoscale Discussions
SPC-issued forecaster notes for evolving severe weather in the next 1-3 hours.
Storm Reports (24hr)
Tornadoes (red), hail (green), wind damage (blue) from spotters and officials.

Alert Surfacing

Severities to highlight
Selected severities trigger the pulsing top banner.
Extreme Severe Moderate Minor

Glossary

Reflectivity (radar) — how strongly precipitation reflects the radar beam. Higher = heavier rain or hail.

Convective Outlook — SPC's daily forecast of severe thunderstorm potential. Levels: TSTM (general thunder), MRGL (1/5), SLGT (2/5), ENH (3/5), MDT (4/5), HIGH (5/5).

Watch vs Warning — a watch means conditions favor severe weather over a wide area; a warning means severe weather is happening or imminent in a small area.

Mesoscale Discussion (MCD/MD) — SPC forecaster's short-term analysis of an evolving threat, usually preceding watch issuance.

Local Storm Report (LSR) — verified report of severe weather (tornado, hail size, wind damage, etc.) from a spotter, official, or the public.

AFD (Area Forecast Discussion) — your local NWS office's plain-English explanation of why they're forecasting what they're forecasting. The most insightful free product.

About

Stormwatch aggregates free public weather data — NEXRAD via RainViewer, NWS API for forecasts/alerts/discussions, SPC for outlooks/MCDs, IEM for storm reports. No tracking, no ads, no API keys. Source on GitHub.