GetNexrad.exe is a tool used to view NOAA WSR-88D Nexrad doppler radar images and compute point and
area average rainfall and to generate the basin point file used by
GetRealtime.exe for automating computaion of a basin average rainfall time
series in real time. Also NASCAR racing fans can try to out best crew chiefs
like Larry McReyonlds about how near the
rain is to the race track. GetNexrad will
compute the ETA of rain cells arriving (and leaving) at the race track.
Traditional area average rainfall is obtained by rainfall gages located in or
near the area of interest and averaging the rain gage amounts using many
methods. If you’re lucky you might
find a rain gage nearby or you would have to install and maintain a network of
rain gages yourself, The tools
presented here will allow you to create point rainfall rates ANYWHERE in the US and greatly improve area averaged amounts
and best of all IT’S FREE!!!
The National Oceanic and Atmospheric Administration (NOAA) is a fantastic
government agency responsible for the majority of the weather data and alerts in
the United States.
Using the publicly available and easily accessible reflectivity data from one of
the WSR-88D class radar systems (NEXRAD), the tools presented here will show you
how to choose a location and set up virtual rainfall collection for a precise
geographical area. Please note that this is not a substitute for severe weather
alerts issued by the NWS, but GetNexrad will even sound an alarm when alerts are
NOAA’s explanation of the WSR-88D radar
Software Requirements—GetMapArea is a must for
creating the basin boundary except for point locations. Optionally
for automating real time collection, storage, and display of the
basin rainfall requires GetRealtime. These softwares are available
online for free at GetNexradHelp
The WSR-88D class radar systems have many acquisition modes for developing precipitation. The most commonly used form of radar energy return
mapping are the Base and Composite Reflectivity maps, and also the 1-Hour Total
Precipitation. The 1-Hour Total image has had additional processing to
better correlate with actual rainfall for different seasons and areas, but don't
believe it. We
can use any of these three images for the processing of localized precipitation
begin finding radars, fire up your Windows Internet Explorer and go here to
Click on the Las Vegas NV ESX radar point on the USA map Enhanced Version tab.
GetNexrad will take the information in the NOAA N0R or NCR radar image and
convert it to the one below where basin area average rainfall rate and point
rainfall rate can be displayed. (rate >> inches for
retrieval time step... knuckle head<<<me).
The N1P 1-Hour Total is treated also as a rate of inches/hour in 5-minutes.
After playing with GetNexrad, I hope you will take the next step in setting
up GetRealtime to automate retrieval, storage, and display of your basin of
interest’s rainfall amounts and learn how to compute runoff and route it. GetMapArea is an easy and fun way to get
started computing runoff.
For comparisons of Nexrad radar rainfall amounts to actual rainfall gage values go here.
For comparisons of Nexrad radar rainfall-runoff to actual USGS gage hydrographs go here.