Events

All Faculty Meeting Student Org Events Career Development School of Meteorology Colloquium Social Event/Celebration Academic Calendar National Weather Center Colloquia School of Meteorology (Defense) Boundary Layer, Urban Meteorology and Land-Surface Processes Weather and Climate Systems Convective Meteorology (Mesoscale Dynamics)

Jeff Milne – December 11

Free

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 […]

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Dylan Reif – December 11

Free

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 […]

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Trey Greenwood – December 4

Free

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.

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Montgomery Flora – December 4

Free

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 […]

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Joshua Gebauer – December 3

Free

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 […]

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Qingyu Wang – December 2

Free

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 […]

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Emily Tinney – December 1

Free

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, […]

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Jiafen Hu – November 11

Free

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), […]

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Stuart Edris – November 20

Free

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 […]

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Melanie Schroers – November 19

Free

School of Meteorology MS Thesis Defense Potential Predictability and Impacts of Subseasonal Extreme Precipitation Events in the United States   Melanie Schroers Thursday, November 19th 2:00pm Join Google Meet: https://meet.google.com/hjt-mbix-mxi   Prediction of climate extremes at the S2S time scale has become a large topic of conversation between researchers and decision makers. Long duration precipitation […]

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