NOAA's National Climatic Data Center
Veach-Baley Federal Building
151 Patton Avenue
Asheville, NC 28801-5001
Telephone: +1 828.257.3019
Mr. Stevens received his Bachelor of Science degree in Meteorology from the University of Oklahoma and his Master of Science degree in Atmospheric Science from Colorado State University. His master's thesis was centered around the transition from warm cloud to rain and its relationship to several meteorological variables, using data from the Atmospheric Radiation Measurement program's station on Nauru Island. Using statistical techniques, Mr. Stevens studied the correlation between these variables and the onset of rain, in the hopes of improving satellite algorithms, which detect rainfall. As an undergraduate, Mr. Stevens also completed an internship with the Oklahoma Climatological Survey, in which he investigated decadal warming trends using the Oklahoma Mesonet, and he presented these findings at the 2006 AMS Annual Meeting in Atlanta, GA.
Mr. Stevens joined CICS-NC as a research associate on March 8, 2010.
This project involves the development of a re-analyzed, homogenous precipitation record for the continental United States, using radar-based software developed at the National Severe Storms Laboratory in Norman, OK.
This task is part of an effort to create a homogenous precipitation record based on existing data collected from NOAA’s array of NEXRAD radars, distributed throughout the United States. With nearly universal coverage over the United States and very high temporal frequency (5-10 minutes), radar offers the ability to see at a much higher resolution than gauge networks or satellites alone.
The development of a high-resolution precipitation dataset will allow those in both research and operations to have access to information which can increase our understanding of the role of environment on rain and snowfall, allow for small-scale studies of topographical effects on storm systems, as well as provide for more precise hydrological warnings in advance of flooding events.
Using the NMQ/Q2 software from Norman, OK, the reanalysis has been completed over a pilot domain covering nine radars in North and South Carolina. This has resulted in the process being adapted from its current real-time use at NSSL to a re-analysis mode that can be run in parallel supercomputing systems, using archived NEXRAD data as input.
The resulting five-minute rainrates obtained from this process can be quickly accumulated into precipitation totals over any desirable time period. Figure 1 shows the radar-only precipitation estimate for September 7, 2004, over the Carolinas region, as the remnants of Hurricane Frances inundated the area. While this image shows estimates using radar alone, the process, in its full capacity, allows for the integration of gauge networks, lightning data, and eventually satellite overpasses.
This work has been presented in an invited talk to the NC State Climate Office (Jun 2011), at the AMS Conference on Applied Climatology (Jul 2011, Asheville, NC), and at the Fall Meeting of the American Geophysical Union (Dec 2011, San Francisco, CA).
Figure 1. 24-hour precipitation accumulation over the Carolinas region for September 7, 2004, during the rainfall associated with Hurricane Frances