It’s likely that you’ve seen some of the commercials on another station over the last 5 or 6 months, and if you have, you know that a lot has been made about 5 minutes. A relatively short length of time, but in the case of a severe weather situation, it could seem like an eternity, especially if someone is witholding, or doesn’t have access to what could be some life saving information. I guess in that sense you’ve probably raised your eyebrows once or twice when you’ve seen the commercials as it has been made to appear that there is a big discrepancy in the weather information being delivered to television.

Whether it is a lack of understanding or a concious decision to mis-lead, I’ll leave that up to you. I’m going tell you what is really happening with the National Weather Service Radar (NEXRAD) when severe storms threaten our area. Storms exist in the atmosphere in 3 dimensions. They are so many miles wide, so many miles long and so many miles tall (think of it as the x,y and z axis from your high school geometry class). When thunderstorms are present, NEXRAD scans at many different angles to the horizon, or what we call “tilts”. The image below depicts how increasing angles of the radar beam can give a 3 dimensional picture of the atmosphere.

In severe weather, or scan mode 21 (below), NEXRAD sends out and receives radar signals at 9 different angles to the horizon. The scheme begins by doing a 360 degree scan at half a degree above the horizon, it then performs a 360 degree scan at 1.5 degrees above the horizon and repeats this process by ending with a 360 degree scan at 19.5 degrees above the horizon line. This produces a volumetric or 3D picture of the atmosphere in a process that takes 5 minutes to complete. Each of these tilts arrives independently in our Live HD Doppler as they occur, we just don’t typically show you these individual scans as storms start to not really look like storms at the higher tilts and the reflectivity doesn’t represent precipitation that is falling from the storm.

So why do we need all of these tilts? By scanning in 3 dimensions we are able to ascertain depth of rotation (knowing that a storm has a tight circulation from its base through a 20,000′ layer makes you more concerned about a potential tornado), hail core positions and height within an updraft before they fall out the storm, intense updraft and storm height (typically the higher the storm top the greater chance of severe weather occuring). In contrast, the image below shows how a television station owned radar operates. It only scans one level. Scanning like this gives us very little to no information about the severity and potentially life-threatening imapact a storm may have.

In the image on the right, a bounded weak echo region (BWER- depicted below right in what would be the space between the high heel and the rest of the shoe) will show a tornado’s location when a hook echo is present. Note the difference in seeing the entire storm structure in 3D versus one slice on the left. Just under the 13 in our logo, you can see an overshooting top, also an indication of enhanced storm strength. In the single slice, you have no idea that one is present.

In the image above,  our sister ABC station in Houston, TX uses 3D NEXRAD imagery to show the intensity of rain bands in Hurricane Dolly as it came on shore near Houston. Note under the abc13 logo how a band that looks pretty intense at the surface (typical radar view you see on TV looks intense), but the slice shows that precipitation isn’t as intense higher up, so rainfall rates are weakening within that band. Below, you see a 3D radar image that allows us to see the condensation funnel of an actual tornado that moved through Moore, OK in a significant tornado outbreak that occured on May 3rd, 1999. A 2D radar image at one tilt just doesn’t give us all of the information, storms don’t exist in 2D.

Do you want the whole story or just a slice of it? You decide.

I’ve gotten several comments and emails from people over the last couple of weeks on the virtual severe weather center that I made and I thought I’d explain it a little bit and the thought that went into it.

Our weather graphics system has the capability to be “interactive” when we are standing in front of the maps at the weather wall (chroma-key wall). You may have noticed us put spotlights over certain areas before on the satellite/radar pictures, draw cold front or arrows, circle things, make current temperatures grow, etc. One of the things we can do interactively is “launch” to another map, sort of like the link in a webpage.

Using this linking concept, I created the virtual severe weather center to contain everything I need during severe weather to keep you informed and ahead of the storm. It is a set of two graphics…the first contains a direct video feed to STORMTRACKER 13 Live 3D Doppler Radar (that I can then control by flipping a switch on my clicker), the satellite/radar loop (I use to show how storms developed and to help give a sense of movement), the active watches/warnings, severe storm reports. In addition to our Live 3D Doppler, the second graphic also contains my severe storm outlook and what to do if a Severe Thunderstorm or Tornado producing storm moves into your area.

Its been as useful as I had hoped during severe weather events. There is no pre-planning needed, everything is at my fingertips…I just load the two graphics and as the situation changes I have everything I need to analyze the current weather situation and provide direction for you as you plan your activities and in some cases need to take action.

Let me know what you think of the virtual severe weather center, you won’t see anything like it out there and in addition to looking pretty sophisticated, it goes a long way to accomplishing our goal of keeping you ahead of the storm!

As we continue through May we really dive head first into severe thunderstorm season in Colorado and I thought I’d address what the STORMTRACKER 13 plan is to keep you informed of severe weather in your backyard over the next 4 months or so. We’ve put a lot of thought and hard work into the plan and it contains some pretty significant adjustments from where we were last year at this time. Our #1 priority is to keep our viewers informed and safe when dangerous and occasionally life threatening weather develops in our television and radio coverage areas as mandated by the Federal Communications Commission. One of our requirements to maintain a broadcast license is to disseminate severe weather bulletins from the National Weather Service when transmitted through the Emergency Alert System. Our policy is constructed to be as minimally invasive as possible to those areas that aren’t affected by the severe weather, while at the same time providing the same level of coverage for rural areas as metro locations. 

We’ve broken our coverage area into “tiers” that we’ll use as a basis for the coverage plan.

• Tier 1 includes the Colorado Springs metro area and immediate vicinity with major thoroughfares along US 24 and 94. It also includes the Pueblo metro area and US 50 from Canon City to La Junta and +/- 15 or so miles north/south of the highway.
• Tier 2 includes the rest of our DMA coverage area as defined by the FCC. It stretches from the Upper Arkansas River valley around Salida, southward along the spine of the Sangre de Cristo mountains eastward to Kansas. The state border is its southern most extent and the northern border is Teller County, El Paso County, Crowley and Kiowa Counties.
• Tier 3 technically is the southern portion of Denver’s television market, but many residents in these aqua colored areas not only get our signal better than some Denver stations, but they also commute into Colorado Springs to work. In addition, quite a few Pikes Peak Region residents travelling northward to work and play in Denver caused us to add this as an area we’ll cover during severe weather

Here’s how we’ll cover tornadoes and tornado warnings issued by the National Weather Service within these areas.

• Tier 1 - These are the most highly populated areas of southern Colorado and when a tornado warning is issued here, we’ll break into programming and stay on the air until the tornado threat passes. We’ll stay on the air for this region for several reasons. First, even a relatively weak tornado in a highly populated area can be scary and has a higher potential to cause some issues than a weak twister over pasture land. Second, with more people around there are more people with questions about the ongoing weather so it makes more sense to constantly be giving information on the air
• Tier 2 - These less populated areas will be covered with conitnuous streaming coverage on krdo.com and we’ll break into programming as necessary on television if warranted. This will likely happen as the storm approaches a town and remains capable of producing a tornado, or we get a report that a tornado has touched down or has lifted.
• Tier 3 - Storms in this area that are moving southward toward tier 2 will likely get the same coverage that a potentially tornadic storm in tier 2 gets with streaming coverage on krdo.com and necessary break-ins on tv. Storms in this area moving away from us will get an intial cut-in on television and a crawl.

Severe thunderstorms and flash flood warnings:

• Although all thunderstorms are dangerous because of cloud to ground lightning, it is generally accepted that the level of danger is slightly less with “typical” severe thunderstorms than a storm capable of producing a tornado. While there are exceptions to this (extremely large hail, or straight line wind near 100mph), we’ll cover these events slightly different from potentially tornadic storms.
• We’ll do an initial program interrupt as the storm approaches severe levels or a warning is issued and then we’ll update as necessary and attempt to do this over commercial breaks so that your program viewing isn’t disturbed. Occasionally we’ll have to cut-in to your show, but we really try our best to do it over the commercial breaks.
• Crawls at the top or bottom of the screen will also remain on the air with radar information constantly updating the storms location and the area under the warning. We’ll also type new information in the crawl between our live updates.

Remember during severe weather you can get current watches/warnings, interactive county radar, live weather data and camera images via the Neighborhood Weather Network on krdo.com!