Convective Meteorology (Mesoscale Dynamics)

Convective Meteorology (Mesoscale Dynamics) Seminar Characterizing the occurrence and spatial heterogeneity of liquid, ice and mixed phase clouds over the Southern Ocean using in situ observations John D’Alessandro   Friday, March 19th 3:00pm Join Google Meet https://meet.google.com/ksh-txvg-kni Low level clouds over the Southern Ocean are an essential component controlling the energy budget over the region, […]

Convective Meteorology (Mesoscale Dynamics) Seminar Exploring Observational Tornado Debris Signature Hypotheses Using Radar Simulations and Large-Eddy Simulations Rachael Cross Friday, March 12th 3:00pm   Join Google Meet https://meet.google.com/ksh-txvg-kni Tornadoes can loft various types and sizes of debris, sometimes resulting in a polarimetric radar signature called the TDS (Tornado Debris Signature). The presence of a TDS in the radar data […]

Convective Meteorology (Mesoscale Dynamics) Investigating GLM flash optical energy measurements with ABI and MRMS datasets Kevin Thiel Friday, February 26th 3:00 pm Join Google Meet https://meet.google.com/ksh-txvg-kni Abstract: Recent deployment of the Geostationary Lightning Mapper (GLM) on the GOES-R series of satellites provides a new perspective of convection that can be utilized by the severe storms […]

Convective Meteorology (Mesoscale Dynamics) Seminar   Modeling CCN effects on Electrification within High and Low Precipitation Supercells   Jessica Blair   Friday, February 19th 3:00pm   Join Google Meet https://meet.google.com/ksh-txvg-kni   Cloud condensation nuclei (CCN) affect both the electric and dynamic evolution of storms, but the effects on storm electrification in different storm modes have not […]

Convective Meteorology (Mesoscale Dynamics) Seminar Preliminary Analysis of Hail Size Prediction using Deep Learning Models     Amanda Burke Friday, February 12th 3:30pm   Join Google Meet https://meet.google.com/ksh-txvg-kni   Using Deep learning (DL) models to predict different atmospheric phenomena has rapidly grown in the past few years. The ability to learn both spatial and temporal data patterns, instead of distributions, highlights one reason why DL […]

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 […]

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 […]