Science behind PRECIP 2022

PRECIP Conceptual Framework

The heaviest precipitation occurs where the rainfall rate is the highest for the longest time

R = I x D

  • R = rainfall accumulation
  • I = rainfall intensity
  • D = rainfall duration

Primary objective is to simplify complexity of multi-scale interactions by identifying key ingredients and processes in the two limiting cases of high intensity and long duration events in a moisture-rich environment

rainfall schematic

PRECIP Science Questions

Are the primary forcing mechanisms for extreme rainfall due to unique dynamic or thermodynamic processes, or some combination of both?

Schematic of TC scenario producing extreme rainfall in the East Asian monsoon from Bell (2020)

TC schematic

Do extreme rainfall events result from fundamentally different physical processes compared to ordinary rainfall events, or are they just due to stronger forcing and an optimal combination of ingredients?

Global Heaviest Rain Producers (R_ONLY) vs. Highest Convective Tops (H_ONLY) From Hamada et al. (2015)

Hamada et al.

What are the most important factors in predictive skill for warm season extreme rainfall, and what model improvements, physical parameterizations, or observations and their effective assimilation will result in the largest forecast improvements?

U.S. Weather Prediction Center Forecast Skill from Sukovich et al. (2014)

Sukovich et al.