V2 action in Colorado

Well VORTEX2 is over - and I am very happy to be back in Norman to start looking at all the data! V2-2010 was exciting with a number of interesting cases to examine over the next few years. I want to thank my fellow steering committee members, as well as all of the V2 PIs and their students from across the country who helped make it happen. I also want to thank my colleagues here in Norman for all of their support - VORTEX2 would not have been as successful without their unselfish dedication to the mission.

NSSL/FRDD Rm 3332, 120 David L. Boren Boulevard, Norman, OK 73072
Lastest Update:
May 24, 2018

Research Interests

Recent History:

From August 2012 to June 2016, I was the project manager for NOAA's Warn on Forecast program which researchs NWP methods to predict hazardous weather from convective resolving models. Dr. Pam Heinselman now leads the WoF program for NSSL. program management.

I have returned to my preferred role as the chief scientist for the WoF program where I continue to study storm-scale data assimilation methods, convective predictability, and continue my research toward improving numerical methods for non-hydrostatic models.

    As part of that work, I am interested in a number of related scientific problems....

  1. Nonhydrostatic atmospheric model development (particularily numerical methods used to solve the compressible Euler equations)
  2. The use of ensemble Kalman filter data assimilation techniques for storm-scale analysis and prediction
  3. Dynamics and predictability of severe storms and tornadogenesis
  4. Radar and other in situ observations of supercell thunderstorms

Professional History

I have a broad set of research interests which generally are focused on numerical analysis, simulation, and forecasts of severe convection and tornadoes. My original research interests in supercells and tornadoes can be traced back to nearly my high school days in the late 1970s. While obtaining my undergraduate and Master's degrees at University of Oklahoma in the 1980s, I became an avid storm chaser and eventually was fortunate enough to be able to work on some of the first in situ deployments of instruments near severe storms with my mentors: Howie Bluestein (OU) and later Don Burgess and Bob Davies-Jones (NSSL). I got the modeling bug while doing my work with Dr. Tzvi Gal-Chen on satellite temperature assimilation for my Master's degree, and was fortunate enough to be able to work on a Ph.D. with Dr. Bob Wilhelmson at the University of Illinois on numerical simulations of tornadogenesis. This work was facilitated by the newly formed NSF computing center, the National Center for Supercomputing Applications, where I became very involved with the newly developing paradigm of "computational science" that is now ubiquitous across most scientific disciplines. During most of the 1990s I was a professor of Atmospheric Sciences at Texas A&M University. In 1999 I was very fortunate to be able to return to my meteorological roots here in Norman as a scientist at the National Severe Storms Lab. My work today continues to focus on severe storms and tornadoes. I very much believe (and history I think demonstrates this clearly) that increasing our scientific understanding of these phenomena directly leads to better forecasts and warnings for the public.

Current Research Interests and Associated Publications

Dynamics of severe storms and tornadoes

Dahl, J., M. D. Parker and L. J. Wicker, 2014: The roles of ambient and storm-generated vorticity in the development of near-ground rotation in a simulated supercell. J. Atmos. Sci., 3027-3051. PDF Available Here

Dawson II, D. T., E. R. Mansell, Y. Jungsun, L. J. Wicker, M. R. Kumjian, and M. Xue 2014: Low-level Zdr Signatures in Supercell Forward Flanks: The Role of Size Sorting and Melting Hail. J. Atmos. Sci. 71, 276-299. PDF Available Here

Observation and analyses of supercells and tornadoes

Skinner, P. S., C. C. Weiss, L. J. Wicker, C. K. Potvin, D. C. Dowell, 2015: Forcing mechanisms for an internal rear-flank downdraft momentum surge in the 18 May 2010 Dumas, Texas supercell. Mon. Wea. Rev., 143, 4305–4330, PDF available here.

Potvin, C. K., L.J. Wicker, D. Betten, M. I. Biggerstaff, and A. Shapiro, 2013: Comparison between storm-scale dual-Doppler and EnKF wind analyses: The 29-30 May 2004 Geary, Oklahoma, supercell thunderstorm. Mon. Wea. Rev., 141, 1612-1628, PDF available here.

Recent papers on the development of data assimilation methods for convective storms

Yussouf, N., D. C. Dowell, L. J. Wicker, K. Knopfmeier, and D. M. Wheatley, 2015: Storm-scale data assimilation and ensemble forecasts for the 27 April 2011 severe weather outbreak in Alabama., Mon. Wea. Rev., 143, 3044-3066. PDF Available Here

Sobash, R. A. and L. J. Wicker, 2015: On the impact of additive noise in storm-scale EnKF experiments., Mon. Wea. Rev., 143, 3067-3086. PDF Available Here

Dawson II, D. T., L. J. Wicker, E. R. Mansell, and M. Xue 2013: Low-level Polarimetric Radar Signatures in EnKF Analyses and Forecasts of the 8 May 2003 Oklahoma City Tornadic Supercell: Impact of Multi-moment Microphysics and Comparisons with Observations. Advances In Meteorology, Article ID 818394, 13 pp., PDF Available Here

Numerical methods for nonhydrostatic models

Flyer, N., G. Barnett, L. J. Wicker, 2016: Enhancing finite differences with radial basis functions: Experiments on the Navier–Stokes equations. J. Comp. Phys., 316 39-62. DOI: PDF Available Here

Wicker, L. J., 2009: A two-step Adams-Bashforth-Moulton split-explicit integrator for compressible atmospheric models. Mon. Wea. Rev., 137 3588-3595. DOI: PDF Available Here

Wicker, L. J., and W. C. Skamarock, 2002: Time-splitting methods for elastic models using forward time schemes. Mon. Wea. Rev., 130, 2088–2097.

To search my complete list of recent publications, please see NSSL's Publications Search or download my curriculum vitae below.

Current Vitae

Louis J. Wicker (.pdf, last updated 24 May 2018)

Other Interests

Using Git and Dropbox

How to Use Git and Dropbox

Python in computational science

Lou's Python Page

Reproducible research in computational science

Reproducible Research Blog offsite ink warning

Randy LeVeque: Wave propagation software, computational science, and reproducible research offsite ink warning (.pdf, 412 kB)

Randy LeVeque: Python tools for reproducible research on hyperbolic problems offsite ink warning



Lectures 1-4

Problem Set for NWP

FDA Numerical Analysis notes and examples