Start
December 11, 2020 - 3:00 pm
End
December 11, 2020 - 4:00 pm
Categories
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 varies with model grid spacing. A new method of calculating updraft helicity is explored that takes into account more information than the standard calculation. This method was previously shown in idealized cases and is now presented for select real world cases. The output from the new calculation method is qualitatively similar to the current calculation. Initial efforts to develop an updraft helicity that is independent of grid spacing are also presented. The distributions of updraft helicity, vertical velocity, and vertical vorticity from an idealized simulation are presented and an initial attempt at normalization is shown. This initial attempt is to simply multiply the value of updraft helicity by the model grid spacing. This brings the distributions of updraft helicity across grid spacings closer to each other, though there are still some differences, especially for higher values of updraft helicity.
