NOAA/National Centers for Environmental Information

Alphanumeric/Supplemental Data

Alphanumeric/Supplemental Data is unique to Level-III radar data that provides detailed information on specific parameters for an identified storm cell.

Data types that show Alphanumeric/Supplemental Data:

Storm Structure (NSS)
Viewer: Displayed is the radar indicated storm center as a circle with its cell tracking ID
Info/Data: A table displaying information on storm attributes which include maximum reflectivity, maximum velocity at lowest elevation angle, storm overhang, mass weighted storm volume, storm area base and top, storm position and storm tilt.
Hail Index (NHI)
Viewer: Hail potential is labeled as either probable (hollow triangle) or positive (filled triangle).
Info/Data: A product designed to locate storms which have the potential to produce hail. Probable means the storm is probably producing hail and positive means the storm is producing hail.
Mesocyclone (NME)
Viewer: Displayed is the radar indicated mesocyclone center as a circle with its cell tracking ID
Info/Data: This product is designed to display information regarding the existence and nature of rotations associated with thunderstorms. Numerical output includes azimuth, range, and height of the mesocyclone.
Tornado Vortex Signature (NTV)
Viewer: Displayed is the radar indicated Tornado Vortex Signature point as a circle with its cell tracking ID
Info/Data: A product which shows an intense gate to gate azimuthal shear associated with tornadic-scale rotation.
Storm Tracking Information (NST)
Viewer: Displayed is the current storm location (bright color) the forecasted movement (darker shades) in 15 minute increments
Info/Data: A product which shows the storm cell's current location and forecasted movement for each identified thunderstorm cell. This product is used to determine storm movement.

The Alphanumeric Properties window enables you to view the information (alphanumeric and supplemental) for the previously listed data types. To open the window, click View in the viewer menu, then click Alphanumeric Prop. (CTRL-A also works).

Alphanumeric Properties Window

Editable options in the Alphanumeric Properties window:

You also have the option to draw several different radar backgrounds that corresponds with the time of day of the dataset you are viewing. To do this simply click on a radar image in the Draw Radar Background list then click Load.

Below is an example of the Storm Structure alphanumeric data being displayed with the Base Refelctivity.

Storm Structure + Base Reflectivity Image