Radar - FAQ
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Radar FAQ
How can I spot a potential tornado on the radar?
If you see a small area of strong positive velocities (yellows and oranges) right next to a small area of strong negative velocities (greens and blues)while viewing the Base Radial Velocity, this may be the signature of a mesocyclone--a rotating thunderstorm. Approximately 40% of all mesocyclones produce tornadoes. 90% of the time, the mesocyclone (and tornado) will be spinning counter-clockwise.
If the thunderstorm is moving rapidly toward or away from you, the mesocyclone may be harder to detect. In these cases, it is better to subtract off the mean velocity of the storm center, and look at the Storm Relative Mean Radial Velocity.
Where does the lightning data come from?
It is a new feature, and currently in an early "experimental" phase of integrating StrikeStar into The Weather Underground's NEXRAD Radar product.
StrikeStar is a network of Boltek lightning detectors around the United States and Canada. These detectors all send their data to our central server where the StrikeStar software developed by Astrogenic Systems triangulates their data and presents the results in near real-time.
Please note: Because of errors in sensor calibration and large distances between some sensors, lightning data may display skewed or be missing in certain regions.
If you have a Boltek detector and run Astrogenic's NexStorm software then we would like to hear from you. There are a small number of simple criteria you need to fulfill to join the network. Send an email to: lorick@strikestarus.com for further details.
How can I contact a radar station?
All of the radar stations are operated by National Weather Service. You can contact your local NWS station for more information.
Archived Historical Radar Data
Weather Underground has some radar archived and available on the history pages.
The National Climatic Data Center offers free U.S. mosaics for the past 5 years. For a fee, they can retrieve any radar image.
They also archive the raw data (not images), at: http://hurricane.ncdc.noaa.gov/pls/plhas/has.dsselect
Plymouth State College offers single-site radar images of all radar products going back 7 days.
The Texas Mesonet has the past 30 days of raw data.
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