National Weather Service United States Department of Commerce

Welcome to FAQs about the National Weather Service’s new radar webpage located at radar.weather.gov and launched on December 17, 2020. We redesigned our radar viewer to improve our services to the public. On the new page, we provide more radar products and radar images are updated more frequently and at four times higher resolution than before. Our GIS-based webpage allows users to integrate our radar data into their own platforms. Learn more. If you have suggestions or feedback, please email nws.radarfeedback@noaa.gov.

How do I use the new map?

The primary features of the map are:

  1. Application menu customized for the radar site
  2. Common help for the National Weather Service sites
  3. Select a view to customize the map
  4. Search for a location on the map
  5. Additional map options
  6. Map controls (zoom and loop)
  7. Map time for the selected radar product(s)
  8. Map legend for the selected radar product(s)

How do I reset the map?

Select the map options and then choose "Reset Map."

What will no longer be available?

Radar overlays for file downloads:

  • Topo, counties, rivers, highways, cities
  • Warnings
  • Legend

See changes in downloads for more information.

How do I display warnings?

Storm-based warnings display by default on the "National radar mosaic" and "Radar station products" views. You can select to display all warnings on these views by using the view options (three vertical dots).

The "All hazardous conditions" and "Weather for a location" view displays all warnings by default. The hazards view also has a quick-toggle to filter by storm-based.

What products are available?

For national mosaics (Conus, Alaska, Hawaii, Guam and Puerto Rico):

  • BREF.RAW (Raw Base Reflectivity)
    A display of echo intensity measured in dBZ. Scientists use these products to detect precipitation, evaluate storm structure, locate boundaries, and determine hail potential. Data values are actual reflectivity values (uses the 0.5 degree elevation).
  • BREF.QCD (QCd Base Reflectivity)
    A display of echo intensity measured in dBZ (with ground clutter / non-precipitation echoes removed). Scientists use these products to detect precipitation, evaluate storm structure, locate boundaries, and determine hail potential. Data values are actual reflectivity values (uses the 0.5 degree elevation cut).
  • CREF.RAW (Raw Composite Reflectivity)
    Composite Reflectivity is a display of maximum reflectivity for the total volume within the range of the radar. These products reveal the highest reflectivities in all echoes, examine storm structure features, and determine the intensity of storms.
  • CREF.QCD (QCd Composite Reflectivity)
    Composite Reflectivity is a display of maximum reflectivity for the total volume within the range of the radar. These products reveal the highest reflectivities in all echoes, examine storm structure features, and determine the intensity of storms. With ground clutter / non-precipitation echoes removed.
  • PCPN.TYP (Precipitation Type)
    Algorithm which classifies radar echoes into one of seven categories: 1) warm stratiform rain, 2) cool stratiform rain, 3) convective rain, 4) tropical/stratiform rain mix, 5) tropical/convective rain mix, 6) hail, and 7) snow. The primary use of the SPT is for automatic selection of Z-R relationships and for computing Surface Precipitation Rates (SPRs) from the Seamless Hybrid Scan Reflectivity (SHSR) mosaic.

    TC: Tropical Convective  TS: Tropical Stratiform  CS: Cool Stratiform  H: Hail  C: Convective  S: Snow  WS: Warm Stratiform
  • NEET.V18 (Echo Tops)
    An image of the echo top heights color-coded in user-defined increments. Scientists use this product for a quick estimation of the most intense convection and higher echo tops, as an aid in identification of storm structure features, and for pilot briefing purposes.

For WSR-88D (NWS, DOD, FAA):

  • BREF.RAW (Super Resolution Base Reflectivity)
    A display of echo intensity measured in dBZ. Scientists use these products to detect precipitation, evaluate storm structure, locate boundaries, and determine hail potential. Data values are actual reflectivity values.
  • BVEL.RAW (Super Resolution Base Velocity)
    A measure of the radial component of the wind either toward the radar (negative values) or away from the radar (positive values). Cool colors (green) represent negative values and warm colors (red) represent positive values. Scientists use these products to estimate wind speed and direction, locate boundaries, locate severe weather signatures, and identify suspected areas of turbulence. Data values are actual velocity values.
  • BDHC (N0H) (Dual-Pol Precipitation Type)
    Hydrometeor Classification is a computer algorithm output that determines the most likely classification of the targets in the radar volume. The product displays the predefined categories that were most likely the cause of the radar echo at that location. 

    BI: Biological  GC: Clutter  IC: Ice Crystals  DS: Dry Snow  WS: Wet Snow  RA: Rain  HR: Heavy Rain  BD: Big Drops  GR: Graupel  HA: Hail-Rain  UK: Unknown
  • BDZD (N0X) (Dual-Pol Differential Reflectivity)
    Differential Reflectivity values are measurements related to the returned energy difference between the vertical and horizontal radar pulses. Large positive values indicate that targets are generally much larger horizontally than vertically. Values near zero indicate the targets are generally spherical. Negative values indicate targets are larger in the vertical than in the horizontal.
  • BEET (EET) (High Resolution Echo Tops)
    An image of the echo top heights color-coded in user-defined increments. Scientists use this product for a quick estimation of the most intense convection and higher echo tops, as an aid in identification of storm structure features, and for pilot briefing purposes.
  • BOHP (N1P) (One Hour Precipitation Accumulation)
    A display of estimated one-hour precipitation accumulation on a 1.1-nm x 1-degree grid using the Precipitation Processing System (PPS) algorithm. This product assesses rainfall intensities for flash flood warnings, urban flood statements, and special weather statements. These are in inches and uses a dynamic scale, based on precipitation rate.
  • BSRM (N0S) (Storm Relative Motion)
    When the motion of storms is subtracted from the wind field, the result is a picture of the wind as if the storms were stationary. Color indices are the same as base velocity. Comparing the storm relative motion image with base velocity image helps identify the rotating storm.
  • BSTP (NTP) (Storm Total Precipitation)
    The estimated storm total precipitation accumulation on a 1.1-nm x 1-degree grid continuously updated since the precipitation event began. This product uses the PPS algorithm. Scientists use this product to locate flood potential over urban or rural areas, estimate total basin runoff, and provide rainfall data 24 hours a day. These are in inches and uses a dynamic scale, based on precipitation rate.
  • CREF (NCR) (Composite Reflectivity)
    Composite Reflectivity is a display of maximum reflectivity for the total volume within the range of the radar. These products reveal the highest reflectivities in all echoes, examine storm structure features, and determine the intensity of storms.
  • HVIL (DVL) (High Resolution VIL)
    The water content of a column of air, which is color-coded and plotted on a 124-nm map. This product is an effective hail indicator, used to locate most significant storms, and to identify areas of heavy rainfall.
  • BDSA (DTA) (Digital Storm Total)
    Storm Total precipitation accumulation is available on a .13 nm x 1 degree grid. The dual-polarization QPE algorithm is used and 256 possible data levels are available. These are in inches and uses a dynamic scale, based on precipitation rate.
    {Legend coming soon}
  • BNOU (NOU) (Base Velocity)
    A measure of the radial component of the wind either toward the radar (negative values) or away from the radar (positive values). Cool colors (green) represent negative values and warm colors (red) represent positive values. Scientists use these products to estimate wind speed and direction, locate boundaries, locate severe weather signatures, and identify suspected areas of turbulence. Data values are actual velocity values.

For TDWR (FAA):

  • BNET (NET) (Echo Tops)
    An image of the echo top heights color-coded in user-defined increments. This product is used for a quick estimation of the most intense convection and higher echo tops, as an aid in identification of storm structure features, and for pilot briefing purposes.
  • BREF (TZL) (Long Range Base Reflectivity)
    A display of echo intensity measured in dBZ.  These products are used to detect precipitation, evaluate storm structure, locate boundaries, and determine hail potential.  Digital Reflectivity data are measured at an elevation angle of 0.6 degrees with a maximum range of 225 nm.
  • BVEL (TV0) (Short Range Velocity)
    A measure of the radial component of the wind either toward the radar (negative values) or away from the radar (positive values). Cool colors (green) represent negative values and warm colors (red) represent positive values. These products are used to estimate wind speed and direction, locate boundaries, locate severe weather signatures, and identify suspected areas of turbulence. The three lowest elevations angles are available, with a maximum range of 48 nm.
  • BVIL (NVL) (VIL)
    The water content of a 2.2 x 2.2 nm column of air, which is color-coded and plotted on a 124-nm map. This product is used as an effective hail indicator, to locate most significant storms, and to identify areas of heavy rainfall.
  • CREF (NCR) (Composite Reflectivity)
    A display of maximum reflectivity for the total volume within the range of the radar. This product is used to reveal the highest reflectivities in all echoes, examine storm structure features, and determine intensity of storms.

How do I get information on available OGC GIS Services?

Please visit IDPGIS web services for details on the different OGC compliant services offered.

How do I generate a KML file?

KML is based on the selected view. Select the view options (three vertical dots), and click the link to download the KML if available.

Where can I download files?

Radar geoTIFS are available at https://mrms.ncep.noaa.gov/data/RIDGEII. Warnings can be retrieved from the OGC WMS Services at https://preview-opengeo.ncep.noaa.gov/geoserver

Why do I get a blank/no image on an individual radar?

This is normally caused by a radar being offline due to maintenance or a repair needed. You can confirm by comparing it to the "National radar mosaic" view or visiting the radar status site.

How do I save my preferences?

As you use the radar site, the browser address bar will automatically update with the a unqiue URL that will preserve the options you selected. Simply use your brower bookmark feature to save it for your next visit. On mobile devices, you can also save the bookmark as an icon on the home screen.

How do I display radar for my location?

If you click the map the site will automatically select the "Weather for your location" view, which includes radar, warnings, and the forecast. You can also search for a specific location by name, zip code, or using geolocation if enabled on your device.

How do I consume OGC compliant service in my own application?

The OGC compliant services are available from the IDPGIS GeoServer.

Video tutorials