The NSSL Multi-Radar Multi-Sensor (MRMS) system (formerly National Mosaic and QPE) is an experimental system designed to improve QPE and very short-term QPF for research to operations. A central focus is experimental QPE, i.e., Q2, that is based on a radar mosaic, environmental data and dynamic Z-R relations (among other things)." This document provides a tutorial for navigation through the site and descriptions of the products. The URL is nmq.ou.edu/qvs-2012.html. This document provides a tutorial for navigation through the site and descriptions of the products.

There are 4 major components of the MRMS system:

Data Ingest:

The MRMS system ingests data from a number of sensors and products from various sources:


MRMS creates and displays many experimental products derived from radar, satellite, numerical weather prediction (NWP) models and gauges, both individually and combined. 

Data and processing flow

  1. Ingest all data (they arrive at different rates)
  2. Quality control radar data
  3. Derive vertical profile of reflectivity from each radar
  4. Analyze radar data to 8 tiles and stitch the tiles together to form the CONUS 3D grid (1 km x 1 km x 31 levels)
  5. Derive hybrid scan reflectivity and other products
  6. Produce experimental Q2 products
  7. Use gauges to validate Q2 and other products


Examination of sources of precipitation data and key geographic and environmental conditions is paramount to understanding the behavior of the Q2 experimental product. Various tools are made available to compare different fields and their relationships to geographic features, such as terrain and radar location. Time series analyses can be done for up to 4 variables.


The verification section relies heavily on NWS operational gauge data streams. This section (AKA QPE Verification System - QVS) allows the users to compare gauges to any QPE product and provides several statistical metrics.

Mini-tabs - each tab contains a set of smaller tabs for various functions. The following section describes the different options on these tabs.

Overlay  Tab Image


The overlay tab allows you the ability to select state or county boundaries, rivers, roads, and cities to be plotted on your map. You may also choose to view the locations of River Forecast Centers, weather radars, or rain gauge data. Some of the these give you the ability to select either the map label (left selection box) or the overlay of that objects location (right selection box).

Mask Tab Image


Choosing the Mask tab gives you the chance to view only data you are interested in seeing. For instance, if you would only like to view a specific River Forecast Center's area then you would select the button next to RFC and then choose a basin. After clicking the Submit/Refresh button, data for only this area will show up. This button will remain selected for any other type data you observe until it is deselected.

Tool Tab Image Version 2
Tool Tab Image


Not every type of data will give you the tool function. However, when viewing this tab you will see two different options.

  • In 3D Cross Sections, the tool tab will look like the one on the right. You have the ability to choose the type of cross section you wish to view.
  • For Mosaic 3D Derived, Dual Pol, and QPE, the tool tab will look like the image on the far right. Here you can choose whether to view a single product or the difference between any two products with the same units.
Region Tab Image 2
Region Tab Image 1


The appearance of the Region Tab varies as to what type of data you are viewing. In most cases, it will look like the image on the right. In this example, you have the ability to either view then entire Continental US or click within the map and create a box around the region of most interest. In other cases, you will have two region windows available. This can be seen in the second example. Here you select a smaller region in the top map and the area is enlarged below it, giving you the chance to make more specific data selections.

Clicking on "Save Image" gives you the ability to drag and drop the image onto your desktop.

Time Tab Image


When you select this tab, you are given the chance to look at data from past events. You may select the year, month, date, and exact time. After clicking on the Submit/Refresh tab, the data will change to time you have now selected.

(Each product will have a time navigation associated with it.)

Product Tab Image 2
Product Tab Image 1


The Product Tab will look slightly different for each type of data the you view. In the example on the right, you can see the general look of this tab. You may select the specific product by clicking on that section. This will open up and allow you to view all the types of products available. You can also choose to jump forward or backward from the current image by clicking on the time selections listed under Time Jumps.

Loop Tab Image


The majority of data gives you the option of looping. You can choose the number of frames and time between those frames. You may then choose to play the loop forward, backward, or pause it on a specific image. In order to stop the loop, choose 1 frame.