Rainfall Records
Record Rainfall Explained: Inches Per Hour, Tropical Moisture, Training Storms, and Gauges
How record rainfall happens, why training storms are dangerous, and how rain gauges measure extreme totals.
Quick answer: Record rainfall occurs when very moist air keeps producing heavy rain over the same area long enough to overwhelm drainage and waterways.
Training storms
Training happens when storms move over the same location repeatedly like cars on a track.
It can create extreme totals even if each individual storm is not long-lived.
Moisture supply
Tropical moisture, atmospheric rivers, slow fronts, and stalled boundaries can all support heavy rain.
Warm air can hold more water vapor, increasing rainfall potential.
Measurement issues
Rain gauges can overflow, clog, or miss wind-driven rain.
Radar estimates help fill gaps but still need ground truth.