CASA Frequently Asked Questions and Updates

PRODUCT AND NETWORK UPDATES

Posted March 1, 2019
New Product Pulldown Menu -To accommodate the increasing number of products on the website, the product pulldown menu has been modified so that the main pull down menu only contains the main product categories and individual products can be accessed through category-level pull down menus. New product categories include Rain Accumulation, Forecast Data and Hydrology.   
 
Rain Accumulation Product updated - Accumulation period options now include 15 minutes, 30 minutes, Max 15 minutes, 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, 48 hours and 72 hours.
 
Precipitation Type Product renamed - The Precipitation Type product has been renamed ‘Hail’.
 

NEW FEATURES IN CASA WX WEBSITE

Posted March 1, 2019
Lightning Data - Through a data sharing agreement with Earth Networks (https://www.earthnetworks.com), jurisdictions participating in the CASA WX program, now have access to real-time lightning data available through the Earth Networks Total Lightning Network (ENTLN). Data is currently available for a period of three years with possibility of renewing the agreement beyond that time frame. Lightning strikes are visualized with a star icon and data can be toggled on and off by clicking on the lightning flash icon situated at the bottom of the page. Information on time and location of strike can be obtained by clicking on individual lightning strikes. Lightning data is also available via the archive. 

Forecast Data Product - The Forecast Data product category includes the following products:

  • 90 Minute Reflectivity - This is an experimental product developed by the University of Oklahoma using their ARPS forecast model, It uses CASA data, NEXRAD data and other environmental data to predict Radar Reflectivity out to 90 minutes in 5 minute intervals. This product is only available when University of Oklahoma runs the ARPS forecast model.

  • Reflectivity Nowcast - This product predicts reflectivity out to 15 minutes in 5 minute intervals. This product is always running in real time.

  • 15 Minute Rainfall Accumulation -This product predicts rainfall accumulation out to 15 minutes.    

 
FREQUENTLY ASKED QUESTIONS

How do I know if the CASA WX radar network is up and running?
The CASA WX site displays real time products from the CASA radar network.  Currently seven radars are operational.  The radars are turned on in advance of when precipitation is expected or possible and may be turned off when dry weather is expected for several consecutive days.   National Weather Service forecasts and discussions are used in conjunction with those of the Storm Prediction Center and judgment of the radar operations team to make this determination. This approach saves on the wear and tear of the radars. Occasionally the radars are turned on during clear weather to support important community events, as requested, to provide coverage in case of sudden storm initiation. There is a red circle-shaped button at the bottom of the screen in the lower navigation bar, which turns green when the network is turned on. There is a similar button to indicate the status of individual radars on their respective pages.

How often do CASA WX website products update?
Single radar products update every one to two minutes. The website is set to ‘auto-refresh’ every 30 seconds with the latest data. You can also click on the manual fresh button in the lower navigation bar to ensure that you are looking at the latest available data. Note that when the website is first accessed, it might take a short time to load.

Network level products auto-refresh when network level processing and analysis is complete. Update times for network level products vary from product to product. Note that when the website is first accessed, it might take a short time to upload.  If the user is looping the data via the play button, or has manually navigated via the next or prev buttons, auto-refresh functionality will cease.  Click the circular refresh button, or refresh the browser to return to auto-refresh mode.

How do I interpret the Winds data?
Wind arrows show the direction of the wind.  This product is great for keeping track of winds in real time as they impact your jurisdiction.  This product updates each minute.  Wind is measured at 5,000 ft and below. Navigation:  Toggle the Winds button on the bottom to see the winds.  This product is best seen at a zoomed in view.  Each time you zoom in, toggle the wind button and you will see finer scale wind arrows. You can go back and forth in time, but each time you have to toggle the winds button to replot the winds.  Winds will update if the page is auto-refreshing.

Important:   If you don’t see arrows, winds may still exist because 1) the radars can only measure wind where there is precipitation (rain, hail, sleet, snow) or other  “scatterers” (dust, debris) and 2) this wind product requires overlapping radar coverage where the radar beams cross at certain angles and at certain heights.  In addition, around the airport and skyscrapers some spurious winds may be reported by the radar.

How do I interpret the Rainfall Accumulation product?
CASA radars use dual polarization technology and this enables the accurate measurement of rainfall. CASA rain products are generated by combining the measurements from the higher frequency X-band radars with the lower frequency S-band radar (NEXRAD). Resulting rainfall measurements are accumulated over various time periods to support different phases of flood response. Note that the Max 15 Minute Accumulation product depicts the maximum rainfall accumulation over any 15 minute interval during the last hour. The product updates every minute. This product helps stormwater managers determine locations where flash flooding is most likely to occur.

Important: Accumulation products only measure the amount of rainfall that has fallen on the ground in a given location over a set time interval. It should not be interpreted as water depth level on the ground. Actual water depth or flooding depends on several other factors such as soil conditions, slope and drainage.

Historical Updates
 

CASA WX Executive Council Leadership: 
Chase Wheeler - City of Grand Prairie
William Wessel - Tarrant County

For more information contact:
Amanda Everly