Answer: It depends on your mission and how many Ben Franklins you have to spare. Your sferics (short for radio atmospherics) equipment may represent the only real-time weather you’ll ever see in your cockpit.

Sure, panel-mounted and portable weather systems deliver their product in a timely fashion, but it will never be as immediate as your sferics device. Once you understand how to interpret your real-time lightning guidance, it can become a valuable asset in your in-flight aviation toolkit. 

Choices in the Cockpit

You have two options if you want lightning data in the cockpit: You can choose from ground-based lightning sensors or onboard lightning detection from a sferics device such as a Stormscope.

A Stormscope provides real-time data but does require some basic interpretation. Ground-based lightning, on the other hand, is a bit delayed and is only available through a data link broadcast at this time. Ground-based lightning is normally coupled with other weather guidance, such as ground-based weather radar (NEXRAD), surface observations, pilot weather reports, and other forecasts.   

Ground-Based Lightning

The ground-based lightning that’s now available through the Flight Information System-Broadcast (FIS-B) comes from the National Lightning Detection Network (NLDN). This network of lightning detectors has a margin of error of 150 meters for locating a cloud-to-ground strike. The ground-based lightning sensors instantly detect the electromagnetic signals given off when lightning strikes the earth’s surface.    

With 150-meter accuracy, I’d choose ground-based lightning any day. Don’t get too excited, though. Ground-based lightning is expensive (the data is owned by private companies like Vaisala), and you’ll not likely see a high-resolution product in your cockpit anytime soon.

SiriusXM satellite weather pulls from a different lightning detection network and includes both cloud-to-ground and intracloud lightning. It produces a 0.5 nm horizontal resolution lightning product. This means that you will see a lightning bolt or other symbol arranged on your display in a 0.5 nm grid.

Even if 50 strikes were detected minutes apart near a grid point, only one symbol will be displayed for that grid point. Same is true for the FIS-B lightning.

Stormscope Advantages

A Stormscope must be viewed as a gross vectoring aid. You cannot expect to use it like onboard radar.

Nevertheless, it does alert you to thunderstorm activity and will provide you with the ability to see the truly ugly parts of a thunderstorm.  Where there’s lightning, you can also guarantee moderate or greater turbulence.   

No lightning detection equipment shows every strike, but the Stormscope will show most cloud-to-ground and intracloud strikes. This allows you to see the intensity and concentration of the strikes within a cell or line of cells with a refresh rate of two seconds. It also lets you see intracloud electrical activity that may be present in towering cumulus clouds even when no rain may be falling.

Even if no cloud-to-ground strikes are present, intracloud strikes may be present. The Stormscope can detect any strike that has some vertical component (most strikes do). This is important since there are typically more intracloud strikes than cloud-to-ground strikes.

To emphasize this point, most of the storms in the Central Plains have 10 times more intracloud strikes than cloud-to-ground strikes. Moreover, during the initial development of a thunderstorm, and in some severe storms, intracloud lightning may dominate the spectrum. 

Also keep in mind that a sferics device does not suffer from attenuation like onboard radar. That is, it can “see” the storm behind the storm to paint cells in the distance out to 200 nm, but it does not see precipitation or clouds.     

Stormscope Disadvantages

It doesn’t take a full-fledged storm, complete with lightning, to get your attention.

Intense precipitation alone is a good indicator of a strong updraft (or downdraft) and the potential for moderate to severe turbulence in the cloud. Consequently, the Stormscope does not tell you anything about the presence or intensity of precipitation or the absence of turbulence.

Never use the Stormscope as a tactical device to penetrate a line of thunderstorm cells. Visible gaps in the cells depicted on the Stormscope may fill in rapidly. Fly high and always stay visual and you will normally stay out of any serious turbulence.        

A Stormscope display is often difficult to interpret by a novice. Radial spread, splattering, buried cables, and seemingly random “clear air” strikes can create a challenge for the pilot. It may take a couple years of experience to be completely comfortable interpreting the Stormscope display. Often what you see out of your window will confirm what you see on your display.    

Radial Spread

As the name suggests, the biggest Stormscope error is the distance calculation along the radial from the aircraft.

The placement of the strike azimuthally is pretty accurate. However, how far to place the strike from the aircraft along the detected radial is a bit more complicated and prone to error.

Lightning strikes are not all made equally. When the sferics devices were invented back in the mid-1970s, they measured the distance of the cloud-to-ground strike based on the strength of the signal (amperage) generated by the strike. An average strike signature of 19,000 amperes is used to determine the approximate distance of the strike.

Statistically, 98 percent of the return strokes have a peak current between 7,000 and 28,000 amperes. That creates the potential for error in the distance calculation. This error is a useful approximation, however, in that strokes of stronger intensity appear closer and strokes of weaker intensity appear farther away. 

In strike mode on the Stormscope, strikes are displayed based on a specific strike signature, whereas cell mode on the newer Stormscope models uses a clustering algorithm that attempts to organize these strikes around a single location or cell.

Cell mode will even remove strikes that are not part of a mature cell. Most thunderstorm outbreaks are a result of a line of storms. Cell mode provides a more accurate representation to the extent of the line of thunderstorms.

Radial spread is not necessarily always a bad thing. You can use it to your advantage to distinguish between false or clear air strikes and a real thunderstorm. Most of the strikes of a real storm will be of the typical strike signature and be placed appropriately.

As mentioned above, stronger than average strikes will be painted closer to the airplane. Looking at this in strike mode, a line of these stronger strikes will protrude toward the aircraft.  The result is a stingray-looking appearance to the strikes.    

You can confirm this by clearing the display.  The same stingray pattern should reappear with the tail protruding once again toward the airplane.

Clear Frequently

Clearing the Stormscope display frequently is a must.  How quickly the display “snaps back” will provide you with an indication of the intensity of the storm or line of storms.

You should be sure to give these storms an extra-wide berth.  Clearing the Stormscope in “clear air” will also remove any false strikes that may be displayed allowing you to focus on real cells that may be building in the distance.

Aging

Both ground-based and onboard lightning use a specific symbol to indicate the age of the data.

For Stormscope data shown on the Garmin 430/530, a lightning symbol is displayed for the most recent strikes (first six seconds the symbol is bolded). The symbol changes to a large plus  sign after one minute followed by a small plus  sign for strikes that are at least two minutes old. Finally, it is removed from the display after the strike is three minutes old.

Cells with lots of recent strikes will often contain the most severe updrafts and may not have much of a ground-based radar signature. Cells with lots of older strikes signify steady-state rainfall reaching the surface that may include significant downdrafts. 

Flight Strategy

A nice feature of a Stormscope is that you can quickly assess the convective picture out to 200 nm while still safely on the ground. Same is true for lightning received from the SiriusXM datalink broadcast.

However, for those with lightning from FIS-B, you won’t receive a broadcast until you are well above traffic pattern altitude unless your departure airport has an ADS-B tower on the field.  

As soon as your Stormscope is turned on, within a few minutes you’ll get a pretty good picture of the challenging weather ahead. If you are flying IFR, you may want to negotiate your clearance or initial headings with ATC to steer clear of the areas you are painting on your display. I’ve canceled or delayed a few flights based strictly on the initial Stormscope picture while I was still on the ramp. 

Another goal is to fly as high as allowable. You will benefit from being able to get above the haze layer, and the higher altitude will allow you to see the larger buildups and towering cumulus from a greater distance.

If you are flying IFR and you are continually asking for more than 30 degrees of heading change to get around small cells or significant buildups, then you should call it quits. You are too close, or you are making decisions too late.

Visual or not, the goal is to keep the strikes (in cell mode) out of the 25-mile-range ring on your Stormscope. If one or two strikes pop into this area, don’t worry. Just keep most of the strikes outside of this 25-mile ring.      

Don’t discount the value of a sferics device.  Add one of the data link cockpit weather solutions as a compliment, and you will have a great set of tools to steer clear of convective weather all year long.

The post Is Sferics Equipment Still Needed in the Cockpit? appeared first on FLYING Magazine.

Weather is one of the biggest variables in general aviation flight and a contributing cause of many accidents. While there is no way for us pilots to control the weather, we can modify our flight paths to prevent unplanned encounters with Mother Nature. Fortunately, doing so has become a lot easier in the past few decades. With the recent implementation of ADS-B, we have access to live weather information, either on a panel-mounted device or a tablet, without ­paying for a monthly subscription.

As a budding pilot two decades ago, I didn’t have the luxury of live weather in the cockpit or multiple apps or websites from which to obtain weather data. Pilots had to get their weather forecasts and reports from local flight service stations—FAA offices focused on ­providing information to pilots. Many years ago, I ­visited the FSS in Hawthorne, California, which has since closed. It looked much like an air route traffic control ­center—a ­windowless room filled with computer screens and several briefers who deciphered the weather data and relayed it to pilots dialing in on 800-WX-BRIEF or from a frequency while airborne.

Calling for a weather briefing was initially somewhat intimidating to me. I understood probably less than half of what the briefer was ­saying. But the call provided an opportunity to ask questions regarding the weather—a service that apps and websites don’t offer. When the briefer said, “VFR flight not recommended,” it was easy to decide to stay on the ground (before I got my ­instrument rating, that is).

Once I started flying in the clouds, things got more complicated. Understanding what the weather was doing—and, more important, where the most severe areas were—was a challenge. About a year after I started my primary flight ­training and had finished my instrument rating, I was building time toward my commercial certificate. My boyfriend at the time and I decided to make an actual cross-country flight to build multiengine time. We rented a Beechcraft BE-76 Duchess for two weeks and flew it from Torrance, California, to Martha’s Vineyard off the coast of Cape Cod in Massachusetts.

Our trip took place in the middle of summer, so we had mostly CAVU skies, which suited us West Coast ­pilots. We rarely had a chance to fly in clouds at home, but we had a scary encounter on our way back, somewhere above Pennsylvania. There were thunderstorms in the forecast, but they were scattered, and we decided to press on. We ended up in IMC, and after a while in the clouds, we started experiencing some pretty bad turbulence. In a flash of a second, all our electrical equipment went dark. No radios. We looked at each other, surprised and a bit scared.

Fortunately, the electrical ­systems came back after just a couple of minutes, though those minutes felt like hours. We called ATC immediately to let them know what happened and requested vectors away from the storm. We got out of the clouds and stayed out for the duration of the flight.

My first solo encounter with thunderstorms came in 2002 when I was flying a Liberty XL2 from California to Florida. If you’re not familiar, the XL2 is a two-seat, carbon-fiber ­airplane with a claim to fame of being the first piston-powered airplane to be certified with an engine equipped with full authority digital engine control—the 125 hp Continental ­IOF-240-B. I was the West Coast sales representative at the time and had to bring my demo airplane back to the factory in Melbourne, Florida. I had spent the night in Pecos, Texas, and continued my track through what seemed like the never-ending state of Texas in this 120-knot airplane.

My weather briefer told me there were storms east of my position, but I nevertheless decided to take off. I figured I could fly beside, below or above the weather; I was unable to fly IFR because, at that time, the airplane was only certified for VFR flight. Well, with thunderheads rising from nearly ground level to what appeared to be 20,000-plus feet, and stretching for hundreds of miles, my plan failed miserably. After flying around for a while, trying to find a way through, I diverted south and landed in Del Rio, where I spent the night.

When I first started flying with the Garmin G1000 equipped with datalink weather, I was excited. Here it was: real-time radar, metars, TAFs, winds and GPS navigation—all on a screen about the size of the TV I grew up with. However, information is only as good as what you understand and respect, so, at times, having access to real-time weather got me into trouble rather than out of it.

There are a couple of flights in particular I will never forget. I was flying from the William P. Hobby Airport in Houston to the Johnson County Executive Airport in Olathe, Kansas, located at the southwestern edge of the Kansas City metropolitan area, for an event that started that same evening. Severe thunderstorms were forecast in the area, but I had the G1000 in the Cessna 400 (originally designed by Columbia Aircraft) I was flying, so I was not concerned. As I approached Kansas City, I could see all kinds of colors on the MFD on the west side of city. The Johnson County Airport was right at the edge of the color patterns on my screen. It was forecast to be bad all night, so there was no way to wait out the storm if I was going to make it to the event. I decided to go for it. After all, the airport was outside the red and magenta areas, depicting the most severe precipitation.

I was fortunate to be in an airplane built to withstand a lot of stress. The airplane was certified in the utility category, which meant it was built to withstand higher G-loads than ­airplanes certified in the normal ­category. There were strong winds, and I kept my speed up to make sure any potential wind shear didn’t bring me down. I could see lightning and weather phenomena that I can only describe as extreme—things I had not seen before or after. I landed just before really heavy rain began at the airport. Had I been forced to go around, for whatever reason, I might not be here to tell the story. I saw firsthand why I should stay well clear of thunderstorms, particularly on the downwind side.

Unfortunately, that wasn’t the only time I snubbed the bright colors on the screen. On another trip in the Cessna 400, I was flying from my home base of Colonel James Jabara Airport in Wichita, Kansas, to Olive Branch Airport in Mississippi. A very thin line of red extended for what looked like hundreds of miles across the G1000, right across my flight path. I was impatient and thought to myself: “It’s really thin—how bad can it be?” Well, let me tell you. It was bad. I have never experienced such turbulence—before or after. I even hit my head in the ceiling a couple of times. There was also heavy precipitation. I remember being thankful I was by myself because I wouldn’t have wanted to expose someone else to this debacle. Fortunately, it didn’t last long. But the experience taught me firmly never to challenge the weather gods again.

Once I learned how to properly use the in-flight weather data to my advantage, the information on the screen kept me out of the bad stuff. I flew from Addison Airport in Dallas to Jabara on a day when severe thunderstorms and tornadoes were forecast over Oklahoma. This time, I stayed upwind of the storm. It was one of the most spectacular flights I’ve ever experienced. The western edge of the angry-­looking storm was marked by a wall of ­billowing clouds, extending from the ground to tens of thousands of feet up. It was as if I were flying alongside a never-ending, living sky scraper. It appeared as though the water molecules inside the clouds were boiling—large balls of clouds kept rolling up the virtual wall. But despite the intense weather event taking place just a few miles east of me, the conditions where I was, and as far west as I could see, were perfectly clear, and there was not the slightest bump of turbulence.

In my Mooney, I have ADS-B In, which provides me with ­similar information as the G1000 in the Cessna 400. The free weather data is received by the L3 NGT-9000 Lynx, and it is displayed on its touchscreen, as well as on the Avidyne IFD 540 and 440 and Aspen Evolution 1000, all of which were installed for long-term flight testing in cooperation with the manufacturers. The combined systems, along with my experience gleaned from flying behind a variety of weather displays, help me to stay out of extreme weather.

5 Fast Tips to Stay Out of Thunderstorms

• Look at the trends. How has the shape of the storm changed in the recent past? In which direction is it going? Storm cells can change course or grow. Don’t get yourself stuck with no point of return.
• Stay upwind of the storm. If you fly downwind, you’re essentially flying into the storm. Lightning, turbulence and other dangerous weather phenomena can ­extend well beyond the edge of the precipitation.
• Respect the colors. Just because a colorful area on the screen is small doesn’t mean it won’t take you down. Stay well clear.
• Call an expert. If you have trouble understanding a weather pattern during your preflight, call 800-WX-BRIEF. The expert can clarify the data to help you make a go/no-go decision.
• Wait it out. You can never go wrong with staying on the ground when the weather gets intense. No meeting or event is worth risking your life over.

The post How to Weather the Weather appeared first on FLYING Magazine.