|WHY DO MID-LEVELS HAVE HIGHEST|
METEOROLOGIST JEFF HABY
In the warm season thunderstorm environment, the
PBL (surface to ~5,000 ft) is warmer than the middle (5,000 ft. to
30,000 ft) and upper levels (above 30,000 ft) of a thunderstorm. Much of the precipitation that reaches the
surface from thunderstorms is in the form of rain. In the middle and upper levels of the storm, ice is much
more common than in the low levels of the storm.
Hail is at its greatest size in the middle and upper levels
of a storm. Hailstones in the upper levels of storms will be frozen solid. As the hailstones fall into
warmer above freezing air they will begin to melt. A melting hailstone has a reflectivity of a gigantic
raindrop. Reflectivity from "wet" ice is much stronger than from "solid" ice. Many hailstones melt before
reaching the surface. Thus, the region of the storm with the best combination of wet hailstones and large
hailstones will have the highest reflectivity. This often occurs in the middle levels of a storm.