The rain record and the rain model point in different directions.
- observedThe twenty-year archive moved -4% — a mild observed drying.
- estimatedThe 2050 projection says +42% — a strongly wetter future.
- derivedNeither cancels the other: the archive is what happened, the model is one projection. Design for the envelope — storage for the drying record, drainage for the wet projection.
What to doSize water systems for both ends of the envelope: weight the archive for the next decade, the model for the 2040s, and verify against local records.
Lands on: any plan that depends on rain · confidence medium