Yes, two times when ice started accumulating at alarming rates, you bet I descended immediately with the
freezing level never more than three minutes below.
To investigate the climatological snow level in the FRB, we used the CFSR dataset ("Synoptic-scale conditions for early February 2017" section) to compute the 1979-2010 January-February mean
freezing level during precipitation events.
For instance, if Pittsburgh is reporting -8 degrees C with light ice pellets (-PE) and a light southwest wind, the
freezing level is considered to be zero, the surface.
Stronger thunderstorms, lower
freezing levels, and higher ground elevations all play a role.
Event 15 of Table 3 was selected for updraft identification based on clear vortex tube shapes and high ZDR above the
freezing level. Figure 15 shows the (a) Doppler velocity observed by Tanokuchi radar and schematic diagram of tilting vortex tube, (b) vorticity calculated using Doppler velocity, (c) [Z.sub.DR], and (d) vertical velocity computed by dual Doppler analysis using Katsuragi and Tanokuchi radar data.
Radar algorithms had to infer precipitation type based on characteristics like storm structure and the atmospheric
freezing level.
"But temperatures will drop to around
freezing level at night so we're in for a few frosty nights.
But Monday through Thursday, the lows are expected to stay slightly above the
freezing level of 32 degrees, with daytime highs in the 40s.
On Saturday, the weather becomes chilly during night with temperatures dropping further to
freezing level.
Conditions must be ripe for formation, usually humid winter nights when air temperatures dip below the
freezing level. http://bit.ly/1VJclW2
"Today is a much colder day and as temperatures could fall below zero and the
freezing level falls to 1,300 feet through the day, any showers will fall readily as sleet and snow.
When that happens, it takes the moisture above the
freezing level and keeps it there for a long time," the senior meteorologist said.