Guides

Radar Storm Tracking Data Sources: What Really Matters (and How Clime Uses Them)

March 10, 2026 · The Clime Team

Last updated: 2026-03-10

For most people in the U.S., the most practical way to tap into advanced storm‑tracking data is to use a radar‑centric app like Clime, which visualizes NOAA‑sourced radar and alerts in a simple map view. Power users who need raw volumes, custom algorithms, or enterprise integrations can pull NEXRAD and MRMS directly from NOAA and cloud archives.

Summary

U.S. storm‑tracking radar is built on two pillars: the NEXRAD radar network and MRMS multi‑sensor mosaics.
These data sets are openly distributed through NOAA, NCEI, and cloud platforms like AWS for developers and analysts.
Most consumer apps—including Clime—sit on top of these government feeds to deliver live radar maps, alerts, hurricane, lightning, and wildfire layers. (NCEI)
Unless you are building your own tools, a focused radar app such as Clime is usually more useful than handling raw NEXRAD files yourself.

What are the core radar data sources for storm tracking in the U.S.?

In the United States, nearly every serious storm‑tracking workflow starts with NEXRAD. This is the nationwide network of more than 150 high‑resolution S‑band Doppler radars operated by NOAA and its partners. It is the primary operational radar backbone for severe weather monitoring and short‑term forecasting. (NCEI)

On top of NEXRAD, NOAA’s Multi‑Radar/Multi‑Sensor (MRMS) system fuses many inputs—multiple radars, surface and upper‑air observations, lightning detection networks, satellite imagery, and numerical forecast models—into seamless national mosaics and specialized products. (NSSL)

In practice, the storm‑tracking stack looks like this:

NEXRAD Level‑II: raw base radar volumes (reflectivity, velocity, spectrum width) at individual sites.
NEXRAD Level‑III: more than 75 processed products—like precipitation estimates, storm structure, and storm‑tracking overlays—derived from Level‑II. (NCEI)
MRMS: 1‑km, 2‑minute updates of radar mosaics and 3D fields that smooth over individual site coverage gaps and provide national‑scale storm diagnostics. (NSSL)

At Clime, we focus on turning these NOAA‑sourced radar mosaics into an interactive map that everyday users can read at a glance, rather than exposing the raw engineering‑level data.

How does NEXRAD actually support storm tracking?

NEXRAD (often referred to as WSR‑88D in technical documents) continually scans the sky in three base quantities at Level‑II: reflectivity, mean radial velocity, and spectrum width. (NCEI) These are the building blocks of storm analysis:

Reflectivity shows where precipitation and hydrometeors are, and how intense they are.
Velocity reveals wind motion relative to the radar, which is critical for spotting rotation and wind shear.
Spectrum width helps diagnose turbulence and signal variability.

From this base data, Level‑III products are generated—over 75 different fields, including:

Precipitation estimates (hourly, storm total, digital accumulation)
Echo tops and vertically integrated liquid
Storm‑tracking products that show past movement, current location, and short‑term projected path for individual storms (generally on the order of the next hour or less). (NCEI)

These Level‑III products are what many applications—including general radar viewers, TV graphics systems, and some advanced apps—use to communicate where storms are and where they are headed.

Clime is oriented to the parts of this universe that matter most to a non‑specialist: where it’s raining or snowing, which cells look severe, where lightning and hurricanes are, and whether those hazards are close to you. We surface that via a NOAA‑based radar map, lightning tracker, hurricane tracker, and fire/hotspot layers in one interface. (climeradar.com)

What is MRMS and why does it matter for tracking dangerous storms?

NEXRAD is site‑by‑site. MRMS is the national blender.

The Multi‑Radar/Multi‑Sensor system was designed to combine:

Multiple ground‑based radars
Surface and upper‑air observations
Lightning detection networks
Satellite imagery
Numerical forecast models

into unified, high‑resolution mosaics and 3D products that update roughly every two minutes at 1‑km horizontal spacing. (NSSL)

For storm tracking, MRMS helps with:

Seamless national radar mosaics that hide individual radar coverage gaps.
Improved quantitative precipitation estimates (QPE) by integrating gauges and other sensors.
3D storm structure fields that better capture hail, updraft intensity, and other severe‑storm signatures.

Many operational centers, researchers, and commercial platforms use MRMS behind the scenes for more robust depictions of where the most dangerous parts of a storm are located.

For most U.S. residents, the benefit of MRMS shows up indirectly: cleaner national radar maps, better heavy‑rain detection, and more reliable severe‑weather depictions in the tools they already use.

How do you actually access NEXRAD and MRMS data (without losing your weekend)?

If you want to work directly with the data, NOAA and its partners make it widely available:

NOAA NCEI portals provide real‑time and archival access to NEXRAD Level‑II and Level‑III data, including via NOAA Open Data Dissemination (NODD), which publishes both levels to multiple cloud providers. (NCEI)
AWS Open Data Registry hosts real‑time and historical NEXRAD data in public S3 buckets, which is ideal if you’re building your own tools, training models, or automating downloads. (AWS Open Data)
MRMS products are distributed by NOAA’s National Severe Storms Laboratory through operational data feeds and archives, giving access to precipitation estimates, hail diagnostics, rotation tracks, and more. (NSSL)

Working directly with these feeds means handling binary radar formats, large volumes of data, and evolving product sets. That’s appropriate if you’re a researcher, a meteorology student, or building a custom alerting backend.

For everyone else, apps that sit on top of these open data sources—like what we provide at Clime—are the more practical choice: you get the benefit of federal infrastructure without touching file formats or cloud buckets.

Where do consumer and enterprise apps fit into the radar data ecosystem?

Most well‑known weather apps in the U.S. use some combination of NEXRAD, MRMS, satellite data, and model output. Some examples from public documentation:

AccuWeather notes that its services use radar and satellite data from the U.S. National Weather Service and other national meteorological agencies, and it offers satellite and radar imagery through a Local Weather API for enterprise developers. (AccuWeather)
The Weather Company’s Max Storm product (used by broadcasters and enterprises) explicitly ingests National Weather Service NEXRAD Level‑II dual‑polarity radar site data, exposing variables like reflectivity, velocity, correlation coefficient, and differential reflectivity in its visualization tools. (IBM)

Those platforms are oriented toward either large‑scale media production, commercial users, or more complex forecasting workflows.

Clime, by contrast, is deliberately consumer‑first. We start from NOAA‑sourced radar mosaics and then layer on:

Live radar maps centered around your locations
Severe weather and rain alerts for saved places
Hurricane and lightning tracking overlays
Wildfire and fire/hotspot visualization for risk monitoring (climeradar.com)

For typical households, that combination covers the core "What’s happening near me, and should I change my plans?" questions that matter during storm season, without requiring enterprise contracts or technical setup.

When does it make sense to go beyond an app like Clime?

There are real scenarios where raw or enterprise data access is warranted:

Research and modeling: You might need Level‑II volumes to test new algorithms for hail detection, rotation tracking, or machine‑learning nowcasting.
Custom operations centers: Utilities, logistics companies, or emergency managers often integrate MRMS and NEXRAD feeds directly into their internal dashboards.
Broadcast and high‑end visualization: TV stations and some large organizations use systems like Max Storm or in‑house tooling for on‑air graphics, custom storm tracks, and branded storytelling.

In those cases, NOAA portals, AWS open data buckets, and commercial imagery APIs are the right entry points.

For most households, though, the added complexity doesn’t improve safety or decision‑making. A focused radar app based on reliable government data—and that’s where we focus our work at Clime—is enough to:

See incoming storms on a live map
Get notified about severe weather and rain for your saved locations
Track hurricanes, lightning, and wildfire hotspots in one place (apps.apple.com)

What we recommend

Default path: If your goal is to keep your family and plans safe around storms, use a radar‑centric app like Clime that visualizes NOAA radar, lightning, hurricanes, and wildfires with alerts—no data wrangling required. (climeradar.com)
Builder path: If you are building tools or doing research, pull NEXRAD Level‑II/III from NOAA and AWS, and MRMS from NSSL, then layer your own logic on top.
Hybrid workflow: Many weather‑savvy users keep Clime for quick situational awareness and alerts, while occasionally dipping into raw NEXRAD or specialized enterprise imagery when they need deeper analysis.
Stay practical: Let federal radar infrastructure handle the physics; choose the smallest set of tools that makes storm decisions fast and clear for you.