Convective Meteorology (Mesoscale Dynamics)

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 […]

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.

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), […]

Convective Meteorology (Mesoscale Dynamics) Seminar   Assimilating Unmanned Aerial System (UAS) Observations into NSSL’s Warn-on-Forecast System (WoFS) to Improve Forecasts of QLCSs   Kelsey Britt Friday, November 13th, 2020 3:00 pm   Join Google Meet: https://meet.google.com/ksh-txvg-kni   The Warn-on-Forecast (WoF) project strives to produce accurate, short-term, probabilistic forecasting guidance for severe convective events and their […]

Name:     Tyler Green Title:    Impact of Assimilating WSR-88D Radar Observations for the Analysis and Prediction of the Eyewall Replacement Cycle for Hurricane Matthew (2016) using the HWRF hybrid EnVar System Location:  https://meet.google.com/ksh-txvg-kni Date:     2020/11/06 Time:     03:00 PM Series:   Convective Meteorology (Mesoscale Dynamics) Abstract: As hurricane Matthew paralleled the east coast of Florida on October 6th-7th, its […]

Convective Meteorology (Mesoscale Dynamics) Seminar   Controls on the Size Distributions of Ice Crystals in High Ice Water Content (HIWC) Regions: Results from Darwin   Peter Brechner Friday, October 30, 2020 3 pm   Join Google Meet:   https://meet.google.com/ksh-txvg-kni   Multiple occurrences of high ice water content (HIWC) regions in areas of low reflectivity have […]

Convective Meteorology (Mesoscale Dynamics) Seminar Factors Inhibiting Widespread Warm Sector Supercells in Central Oklahoma on 20 May 2019 Thomas J. Galarneau Friday, October 23, 2020 3 pm   Join Google Meet:   https://meet.google.com/ksh-txvg-kni Meet Real-time meetings by Google. Using your browser, share your video, desktop, and presentations with teammates and customers. meet.google.com     During […]

Convective Meteorology (Mesoscale Dynamics) Seminar Prediction of Tornado-Like Vortex (TLV) Embedded in the 8 May 2003 Oklahoma City Tornadic Supercell Initialized from the Sub-Kilometer Grid Spacing Analysis Produced by the Dual Resolution GSI Based EnVar Data Assimilation System    Yongming Wang   Friday, October 9th 3 pm     Join Google Meet:   https://meet.google.com/ksh-txvg-kni Meet […]

Convective Meteorology (Mesoscale Dynamics) Seminar When the atmosphere yells “Pull!”: A 22-year Evaluation of Convection Reaching the Stratosphere over the United States Dr. Cameron Homeyer  Friday, September 11th 3:00 pm  Join Google Meet:  https://meet.google.com/ksh-txvg-kni   Storms that reach and overshoot the tropopause are often severe, are responsible for delivering water to the stratosphere and exchanging […]