March 4, 2022 - 3:00 pm
March 4, 2022 - 4:00 pm
CategoriesConvective Meteorology (Mesoscale Dynamics)
Convective Meteorology (Mesoscale Dynamics)
Examining the Impacts of Assimilating Vertically Integrated Ice on two PECAN MCSs
Friday, March 4
Forecasting nocturnal mesoscale convective systems (MCSs) is challenging due to the poor handling of the timing and location of convection initiation (CI). This study investigates two nocturnal MCSs from the Plains Elevated Convection at Night (PECAN) field campaign using the Weather Research and Forecasting (WRF) model. Previous work has tested improvements in MCS simulations through a lightning data assimilation (LDA) technique. While the LDA simulations did improve CI timing and the initial location of convective cells, critical aspects of nocturnal MCS morphology were not captured. To address this, a new DA technique was developed based on the LDA method discussed in Fierro et al. (2014, 2016). Fierro et al. use lightning data to nudge a vertical column towards saturation by increasing water vapor mixing ratio. In the new method, vertically integrated ice (VII) from the multi-radar multi-sensor (MRMS) product is used in lieu of lightning to increase water vapor mixing ratio in the column. The simulations utilizing VII for water vapor nudging had a decreased CI lag time. In addition, the subsequent evolution of the nocturnal MCSs were more realistic. The results from the MCS simulations utilizing the new technique will be presented. Simulated processes related to the kinematics and placement of severe straight-line winds and their relation to mesovortices will be briefly presented.