Convective Meteorology (Mesoscale Dynamics)

A Comparison of Microphysical Parameterization Sensitivities in Comma-Head Snow Events and Evaluation With PIREPS

Kristen Cassady
OU School of Meteorology

30 August 2013, 3:00 PM

National Weather Center, Room 5600
120 David L. Boren Blvd.
University of Oklahoma
Norman, OK

Numerical model experiments are conducted to assess how the presence of supercooled liquid water (SLW) is dependent on the choice of microphysical parameterization for select winter storms that were observed to have elevated regions of SLW. The schemes considered include the Thompson, Milbrandt-Yau, Morrison, and NSSL. The Thompson scheme routinely produces less SLW than the other schemes. Sensitivity experiments reveal this is in large part a consequence of aggressive scavenging of cloud water from snow. In some environments, the Morrison scheme produces considerably more SLW than the other experiments. It is unclear why this happens. The output from each experiment is compared to pilot reports of icing to determine which scheme yields the most accurate results. According to all statistical measures that we tried, the Morrison scheme performs the best. However, the results are not significantly different between the schemes.

For accommodations based on disability, or more details, please contact the School of Meteorology at 325-6561. All visitors without NOAA or University of Oklahoma identification must register at the registration desk on arrival. Visitor parking is available for all University visitors. However, faculty/staff/students must have a current multi-purpose parking permit. Additional parking is available at the Lloyd Noble Center (LNC) for those individuals who do not have a parking permit. You do not need a permit to park in one of 1,200 spaces reserved for CART bus riders, although you must ride the CART shuttle to park in the reserved area. This area is on the north central side of the Lloyd Noble Center. Elsewhere at the LNC, permits are required.

The University of Oklahoma is a smoke-free / tobacco-free campus.

Convective Meteorology (Mesoscale Dynamics) Seminar Series website