Physical Processes that Increase Precipitation Intensity
What increases precipitation efficiency and potential rainfall rates?
Long residence time of droplets in warm-cloud layer
- Deep, above-freezing cloud layer: 3-4 km (ɰ km SE)
- Weak to moderate updraft within that layer
Low-centroid storms, warm rain process
Well-defined high-?e inflow in low levels
High precipitable water values, high environmental RH
- Minimal condensate loss
- Less evaporative cooling, weaker outflows (won’t disrupt inflow)
Rapid replenishment of moisture from low level flow
What additional process is needed for anomalously high rainfall rates?
Enhanced low-level lift from low-level moist flow into a boundary
- Meteorological (front, rain-cooled air such as a mesohigh)