Convective Meteorology (Mesoscale Dynamics) Seminar Cracking the TORFF Code: Testing a Neural Network Coding Scheme on Broadcaster Coverage of TORFF Events Sean Ernst Friday, February 12th 3:00pm Join Google Meet https://meet.google.com/ksh-txvg-kni Simultaneous Tornado and Flash Flood (TORFF) events are a difficult to message and potentially deadly hazardous weather threat that is common in the contiguous […]
Convective Meteorology (Mesoscale Dynamics) Seminar Investigating and Attempting to Improve Upon Updraft Helicity Jeff Milne Friday, December 11th 3:00 pm Join Google Meet https://meet.google.com/ksh-txvg-kni Updraft helicity from convection-allowing models has been used to help forecast for severe weather. However, it is only calculated between two fixed levels in the atmosphere, and it […]
School of Meteorology Colloquium Initiation Mechanisms of Nocturnal Convection Without Nearby Surface Boundaries Over the Great Plains Dylan W. Reif Friday, December 11th 2:00pm Join Google Meet: https://meet.google.com/qjf-wzby-dbu Nocturnal convection initiation accounts for nearly half of all CI events over the Great Plains over the warm season. There are three main types of CI […]
Convective Meteorology (Mesoscale Dynamics) Seminar Analysis of Tornadic Supercells Using High-Resolution, Mobile Doppler Radar Trey Greenwood Friday, December 4th 3:00pm Join Google Meet https://meet.google.com/ksh-txvg-kni Mobile Doppler radar is a critical tool in studying microscale phenomena, including tornadoes, in supercell thunderstorms at close-range; however, a relative dearth of high-quality cases documenting the tornadic life cycle has hindered the advancement of our understanding of tornado evolution, storm-scale processes related to tornadogenesis and decay, and why some supercells produce tornadoes and others do not. In this study, we analyze four tornadic events in Oklahoma during the springs of 2015 and 2019 that were documented by the Mobile Weather Radar, 2005 X-Band, Phased Array (MWR-05XP) and the Rapid X-band Polarimetric (RaXPol) radar. Analysis of each case focuses on the following points: • Tornadogenesis and decay (when applicable): whether the tornado vortex signature (TVS) builds upward or downward, • How the TVS as a function of height evolves over time, • Vortex tilt as a function of height and its evolution over time, and • Any unique features evident in the data, particularly those that yielded changes to the behavior of the vortex, such as rear-flank downdrafts surges, descending reflectivity cores, etc. The most fruitful case analyzed was a supercell that produced an EF3 tornado between Amber and Bridge Creek, Oklahoma, on 6 May 2015. While tornadogenesis was not documented by the MWR-05XP, data revealed a period of low-level vortex intensification coincident with a rapid increase in the intensity of the upper-level vortex. This concurrence has been documented in previous cases during tornadogenesis; however, in tornadogenesis cases, the vortex builds simultaneously through a deep layer, rather than separately at different levels. In addition, the vortex was found to decay in an “inside-out” manner while widening in the low-levels, as has been discovered in previous mobile Doppler radar cases. A weak-echo hole, secondary rear-flank downdraft (RFD) surge, and a scalloped RFD gust front with subtornadic vortices along it were also observed. In addition, using data from a separate tornadic supercell near Elmer, Oklahoma, on 16 May 2015, a single-Doppler velocity retrieval (SDVR) was attempted using the methods outlined in Liou et al. (2018). While the tornadic vortex and RFD gust front were retrieved, winds were northeasterly in the inflow region of the supercell, which appears to be erroneous. A potential cause and solution for this issue will be discussed.
School of Meteorology Colloquium Using Machine Learning to Generate Storm-Scale Probabilistic Severe Weather Guidance from the Warn-on-Forecast System Montgomery Flora Friday, December 4th 9:00 am Join Google Meet meet.google.com/xyu-bhuo-vzt A primary goal of the National Oceanic and Atmospheric Administration (NOAA) Warn-on-Forecast (WoF) project is to provide rapidly updating probabilistic guidance […]
School of Meteorology Colloquium Assessing Dual-Doppler Vertical Velocity Retrievals from Rapid-Scan Radar Data Joshua Gebauer Thursday, December 3rd 8:00 am Join Google Meet: https://meet.google.com/qhg-ufze-axf Vertical velocity is the most difficult wind component to accurately retrieve from dual-Doppler observations. In recent, years it has been proposed to use a vertical vorticity […]
Weather and Climate Systems Seminar Local Greenhouse Gases (GHGs) mixing evaluation with single-column WRF-VPRM Qingyu Wang Wednesday, December 2nd 3:00 pm Join Google Meet: https://meet.google.com/ssf-prpz-fqa Previous studies reveal column-averaged carbon dioxide (XCO2) simulations from the Vegetation Photosynthesis and Respiration Model (VPRM) coupled with WRF have regional mismatches compared to OCO-2 measurements in the contiguous US […]
School of Meteorology MS Thesis Defense A 13-year Trajectory-Based Analysis of Convection-Driven Changes in Upper Troposphere Lower Stratosphere Composition over the United States Emily Tinney Tuesday, December 1, 2020 11:00 am CST Join Zoom: https://oklahoma.zoom.us/j/93970293102?pwd=QTBoWVN4ZGZoMUNoWThtSndUdHBRZz09 Join our Cloud HD Video Meeting Zoom is the leader in modern enterprise video communications, […]
Jiafen Hu Test of Different Transformation Functions to Hydrometeor and Water Vapor Mixing Ratios for Direct Variational Assimilation of Radar Reflectivity Data Location: https://meet.google.com/ksh-txvg-kni Date: 2020/11/20 Time: 3:00 PM Series: Convective Meteorology (Mesoscale Dynamics) Abstract: There are many issues arose from using highly nonlinear radar reflectivity forward observation operator in three-dimensional variational data assimilation methods (3DVAR), […]
School of Meteorology MS Thesis Defense Evaluation of Flash Drought Criteria Component Stuart Edris Friday, November 20th 8:00 am Join Zoom Meeting https://oklahoma.zoom.us/j/92299356131?pwd=bis4V21ySHFyT3FmQkh3U29MNnp1Zz09 Join our Cloud HD Video Meeting Zoom is the leader in modern enterprise video communications, with an easy, reliable cloud platform for video and audio conferencing, chat, and […]
