Rainfall, radar & storms
Weather radar volumes, radar and multi-sensor rainfall grids, rain gauges, storm tracks, and how extreme a rainfall total really was.
Rain is measured by radars that see it from kilometres away and by gauges that catch it at a point, and the two rarely agree until their differences are understood. A radar reports reflectivity on tilted cones of polar gates; turning that into millimetres takes a relationship chosen for the kind of rain, a cap for hail, and care with clutter and beam height. A gauge reports a day that ends when its observer read it.
The guides here work through one storm in detail — Hurricane Beryl's landfall in Texas on 8 July 2024 — with the NEXRAD radar at Houston, NOAA's MRMS rainfall grids and about 120 gauges, and then widen out to storm tracks, rainfall statistics and other regions. Several results are about method: the right Z–R relationship doubled the estimated rain, and matching the gauges' morning reading turned no correlation into r = 0.77.
The concepts explain reflectivity, dual polarisation and return periods; the how-to guides read radar and GRIB files and build totals and maps; and the fixes cover clutter, bright band, GRIB errors and gaps.
🧭 Start with the concepts
The ideas the how-to guides below assume you already have.
⚙️ Then do the task
Step-by-step walkthroughs with code you can copy and adapt.
- How to Read NEXRAD Level II Radar Data in Python
- How to Grid Radar Data from Polar Sweeps to a Raster in Python
- How to Read MRMS Rainfall Estimates from GRIB2 in Python
- How to Compare Radar and Gauge Rainfall in Python
- How to Estimate Rainfall from Radar Reflectivity in Python
- How to Map a Hurricane Track from IBTrACS in Python
Show every how-to guide in this topic
- How to Map Storm-Total Rainfall in Python
- How to Analyse a Rain Gauge Network in Python: Gaps, Density and Areal Rainfall
- How to Read DWD RADOLAN Radar Rainfall in Python
- How to Build Rainfall IDF Curves in Python from a Gauge Record
- How to Make a Weather Radar Loop Animation in Python
- How to Animate a Hurricane Track in Python
- How to Calculate Monthly Rainfall Totals in Python
🔧 When it breaks
The errors this topic produces, with the cause explained rather than just the command.
- Radar Rainfall Map Has Spokes and Hot Spots: Beam Blockage and Clutter
- Radar Rainfall Too High: Hail and the Bright Band
- GRIB File Won't Open with cfgrib: Fixing the Common Errors
- Storm Track Crosses the Dateline: Lines Across the Whole Map
- Rainfall Totals Come Out Wrong: Gaps, Extra Scans and Zeros That Mean Missing
Related topics
Subjects that keep coming up alongside this one, most overlap first.