Getting the latest radar scan.
Storms in 3D
The nearest weather radar's latest scans, stacked into a 3D picture of the storms around it, with this spot marked. Tap or click it, then drag to turn it and pinch or scroll to zoom. Taller, brighter cores are stronger storms.
Rain & snow amounts
How much has fallen at this spot, and how much more is expected. Amounts are inches of water; snow depth is shown underneath when it snowed.
Estimated from radar, not a rain gauge. Radar is usually within about 30% of a gauge for rain; snow and hail estimates are rougher.
Next hour
Expected rain intensity at this spot, every 5 minutes. Taller bars mean harder rain.
Past 24 hours
Rain and melted snow that fell each hour at this spot.
Nearby
Where the closest rain or snow is and where it's heading.
Arrival times: when each strength of rain should reach this spot in the next hour, if it keeps moving the same way.
All locations
Every tracked location at a glance. Select a row to switch to it.
| Location | Now | Last hour | Last 24 h |
|---|
Technical details & methodology
- dBZ (radar reflectivity)
- How strongly rain reflects the radar beam. Under 20 dBZ is drizzle or nothing; 20 to 35 is light to moderate rain; 40 and up is heavy rain; 55 and up usually means hail.
- How rain amounts are calculated
- Every ~2 minutes NOAA's MRMS radar mosaic is converted to a rain rate at this spot with the standard NEXRAD formula (Z = 300R1.4). Echo under 20 dBZ counts as dry, and anything over 53 dBZ is capped so hail doesn't count as rain. The rates are then added up over time. Gaps in the radar feed count as unknown, not dry.
- How the forecast works
- The server compares the last hour of radar scans to work out which way and how fast the rain is moving. It slides the current radar picture forward along that track, minute by minute, and adjusts for storms that are growing or fading.
- Rain or snow?
- NOAA's MRMS precipitation-type product (which uses radar plus surface and upper-air temperatures) decides whether it's rain, snow, or rain mixed with hail. Snow uses its own formula (Z = 180S2) and a lower 15 dBZ threshold, and snow depth assumes 10 inches of snow per inch of water. It doesn't separately identify sleet or freezing rain.
- Hail warnings
- From NOAA's MRMS MESH product (Maximum Estimated Size of Hail), which is calculated from how high and how strong the radar echo is in the storm. The warning shows for hail half an inch or larger at or near this spot; 1 inch or larger is severe. MESH tends to overestimate size a little. If MESH isn't available, very strong radar echo (55 dBZ or more) is shown as "possible hail". This is not an official National Weather Service warning.
- Official NWS alerts
- Watches, warnings and advisories come straight from the National Weather Service (api.weather.gov) for this exact spot, checked every 2 minutes. These are the official alerts; everything else on this page is this server's own radar estimate.
- Confidence
- Based on how clearly the rain can be tracked, how steady its movement has been, and how many scans agree. It's lower when storms are turning, speeding up, or quickly growing or fading.