GRLevelX is a suite of data processing and display programs developed by Gibson Ridge Software, LLC (GRS), to view
weather radar data. It went on the market in March 2005. It comes in three versions, all of which ingest raw data: ''GRLevel2'' and ''GRLevel2 Analyst Edition'' for viewing Level II data of the
National Weather Service (NWS), and ''GRLevel3'' for viewing Level III data. All programs are capable of rendering
dual polarization
Weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation (meteorology), precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.). Modern wea ...
data.
The software allows the user to view real-time data as well as archive data stored locally or obtained over the internet. It is used by professional forecasters and researchers for general
precipitation analysis as well as severe storm,
tornado, and
tropical cyclone monitoring and analysis. Its usage base grew to include many television weathercasters, including by
The Weather Channel severe storms expert
Greg Forbes, as well as
storm chasers,
storm spotters
Storm spotting is a form of weather spotting in which observers watch for the approach of severe weather, monitor its development and progression, and actively relay their findings to local authorities.
History
Storm spotting developed in the ...
,
emergency managers, weather enthusiasts, private sector meteorologists, and is often used within the NWS, itself.
''GRLevel2 Analyst Edition'' allows the user to take a 3D images of precipitation within clouds, such as in
supercell thunderstorms. Its integrated algorithms flag possible
hail
Hail is a form of solid precipitation. It is distinct from ice pellets (American English "sleet"), though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailstone. Ice pellets generally fal ...
,
tornado vortex signatures (TVSs), and
mesocyclones.
All GRx applications are written in
multithreaded C++ using the base
Windows APIs. Software engineer Michael Scott Gibson wrote the programs.
Overview
''GRLevel2'' is a
Windows viewer for live and archived
NEXRAD Level II data (volumetric reflectivity and velocity data). Base reflectivity, base velocity, storm relative velocity, and spectrum width sweeps for all
radar tilts can be ingested. The display has high speed zooming and panning to allow the user a quickly focus on the area of interest.
''GRLevel2 Analyst Edition'' is an advanced NEXRAD Level II analysis application to produce a high quality
volumetric display and several high resolution reflectivity-derived graphical products in addition to the standard Level II data products. Through
GIS
A geographic information system (GIS) is a type of database containing Geographic data and information, geographic data (that is, descriptions of phenomena for which location is relevant), combined with Geographic information system software, sof ...
implementation, several University-Doppler Radars can be viewed, such as the University of Missouri's
X-Band Radar.
''GRLevel3'' is a Windows viewer for live NEXRAD Level III data from the NWS Radar Product Central Collection Dissemination Service (already produced 2D images). In addition to Level III WSR-88D data, GR3 supports
TDWR
Terminal Doppler Weather Radar (TDWR) is a Doppler weather radar system with a three-dimensional "pencil beam" used primarily for the detection of hazardous wind shear conditions, precipitation, and winds aloft on and near major airports situated ...
, which is high resolution shorter range radar located at some major airports.
Gibson also wrote ''GREarth'', which overlays
satellite and other data and, like the GRLevelX radar viewers, is customizable with
GIS
A geographic information system (GIS) is a type of database containing Geographic data and information, geographic data (that is, descriptions of phenomena for which location is relevant), combined with Geographic information system software, sof ...
layers.
Algorithms
''GR2Analyst'' contains
algorithms flagging certain features in the
reflectivity data. In reflectivities, ''GR2'' extract the height above ground of the highest elevation where they are greater than 18 dBZ (echo tops), the
vertically integrated liquid water content of clouds (VIL) and the VIL divided by the Echo tops which is an indicator of possible large hail. Further algorithm use environmental information about of and heights, inputted by the user, to output a hail algorithm size. The algorithm uses any temp/height data within 48 hours of the volume scan time. If no recent data is found, it defaults to and for the heights.
The results are displayed with a high resolution of x 1 ° x grid with 256 data levels. There is an automatic extraction of the storm motion which is integrated in the algorithms for corrections.
References
{{reflist
External links
Manuals(NWS)
Graphic software in meteorology