Figure 3 is the AWC's graphic presentation of the forecast lowest freezing level
, an important data point.
With unstable conditions from cold air advection at 10,000 feet, clouds were crowded along the higher peaks, with bases at 7500 feet and a freezing level
at 8500 feet.
Stronger thunderstorms, lower freezing levels
, and higher ground elevations all play a role.
Hail is produced in the cold, high regions of the storm, but once it falls beneath the freezing level
(typically between 7,000' and 15,000' AGL, depending on location and season), it starts to melt.
He explained that the punch hole cloud was formed when the water temperature in the cloud reached below freezing level
but the water did not freeze as it had a lack of ice nucleation particles.
Any failure in the monotonicity assumption for temperature with height is a significant issue with HCA in winter weather because the HCA depends upon the existence of only one freezing level
through which precipitation falls.
Now the upper extent of the cloud is far above the freezing level
, the duration of the water droplets at this height and its cold temperatures ensures rapid sublimation to ice.
The weather changes quickly and the freezing level
can drop down to as low as 1,500 feet in the spring.
Since temperatures in catchment areas have already reached at freezing level
so no significant improvements in the reservoirs is expected during coming weeks.
In such clouds, warm rain processes act below the freezing level
(the height at which the temperature is at 0[degrees]C), but ice particles are also initiated above the freezing level
that interact with the supercooled liquid cloud droplets in a variety of ways.
With a temperature right at the freezing level
, coupled with a brisk wind, the longer grip also made it much easier for cold hands to hold onto the Mini-Revolvers.
He added: "The freezing level
was around 3,000 feet with a light wind.