Convective outflow boundaries emanating away from thunderstorms are generated as cold, dense air descends in downdrafts then moving outward away from the convection to produce a mesoscale cold front also known as a gust front. Some gust fronts can be completely harmless or may be a precursor for an encounter with severe turbulence and dangerous low-level convective wind shear. The direction of movement of the gust front isn’t always coincident with the general motion of the thunderstorms. If the gust front is moving in advance of the convection, it should be strictly avoided. The pilot’s best defense is to recognize and characterize the gust front using METARs, ground-based radar and visible satellite imagery.

According to research meteorologist and thunderstorm expert, Dr. Charles Doswell, “cold, stable air is the ‘exhaust’ of deep, moist convection descending in downdrafts and then spreading outward like pancake batter poured on a griddle.” As a pulse-type thunderstorm reaches a point where its updraft can no longer support the load of precipitation that has accumulated inside, the precipitation load collapses down through the original updraft area. Evaporation of some of the rain cools the downdraft, making it even more dense compared to the surrounding air. When the downdraft reaches the ground, it is deflected laterally and spreads out almost uniformly in all directions producing a gust front. 

• READ MORE: Keeping an Eye on the Storm

Gust fronts are normally seen moving away from weakening thunderstorm cores. Once a gust front forms and moves away from the convection the boundary may be detected on the NWS WSR-88D NEXRAD Doppler radar as a bow-shaped line of low reflectivity returns usually 20 dBZ or less. Outflow boundaries are low level events and do not necessarily produce precipitation. Instead, the radar is detecting the density discontinuity of the boundary itself along with any dust, insects and other debris that may be carried along with the strong winds within the outflow. The gust front in southwest Missouri shows up very well on the NWS radar image out of Springfield as shown below. 

 An important observation is to note the motion of the gust front relative to the motion of the convection. In this particular case, the boundary is steadily moving south while the thunderstorm cells that produced the gust front are moving to the east. This kind of outflow boundary is usually benign especially as it gains distance from the source convection. On the other hand, a gust front that is moving in the same general direction in advance of the convection is of the most concern. These gust fronts often contain severe or extreme turbulence, strong and gusty straight line winds and low-level convective wind shear. 

As mentioned previously, gust fronts are strictly low-level events. As such, even the lowest elevation angle of the radar may overshoot the boundary if it is not close to the radar site. Shown above at 22Z, the NWS WSR-88D NEXRAD Doppler radar out of Greenville-Spartanburg, South Carolina is the closest radar site and clearly “sees” the gust front (right image). However, the NEXRAD Doppler radar out of Columbia, South Carolina (left image), is further away and misses the gust front completely. As the gust front moves away from the radar site, it may appear to dissipate, when in fact, the lowest elevation beam of the radar is simply overshooting the boundary. 

As a result, it is important to examine the NEXRAD radar mosaic image before looking at the individual radar sites.

Not all gust fronts are easy to distinguish on visible satellite imagery; the gust front could be embedded in other dense clouds or a high cirrus deck may obscure it. It is also possible that the boundary may not have enough lift or moisture to produce clouds. In many cases, however, it will clearly stand out on the visible satellite image. When the gust front contains enough moisture, as it was in this situation, cumuliform clouds may form along the boundary and move outward. This is very common in the Southeast and coastal regions along the Gulf of Mexico given the higher moisture content.  

As this particular gust front passed through my neighborhood located south of Charlotte, North Carolina, strong, gusty northerly winds persisted for about 10 minutes. As is common, the main core of the precipitation didn’t start to fall for another 10 minutes. When a gust front such as this appears on satellite or radar, it is important to monitor the METARs and ASOS or AWOS closely for the occurrence of high winds. Several airports in the vicinity reported wind gusts peaking at 30 knots. The sky cover went from being just few to scattered clouds to a broken sky with these cumuliform clouds moving rapidly through the region.

• READ MORE: The Ins and Outs of Pilot Weather Reports

As mentioned earlier, a gust front moving away from thunderstorms is a low-level event that can contain very strong updrafts and downdrafts. The graph shown above is a time series, plotting the upward and downward motion or vertical velocity in a strong gust front as it moved over a particular point on the ground. The top half of the graph is upward motion and the bottom half is downward motion. 

Time increases from left to right. As the gust front approaches, the vertical velocity of the air upward increases quickly over a one or two minute period. While the maximum vertical velocities vary with height in the outflow, a common maximum number seen is 10 m/s at about 1.4 km or 4,500 feet agl (25 knots is roughly 12 m/s for reference). As the gust front moves through, the velocities abruptly switch from an upward to a downward motion creating strong wind gusts at the surface. Most outflow boundaries don’t extend above about 2 km or 6,500 feet agl. What is remarkable is that upward to downward motion changes in just about 30 seconds over the ground point where this was observed. But imagine flying an aircraft at 150 knots through this; the up and down exchange will happen in just a few seconds producing a jarring turbulence event.

Just in case you were wondering, gust fronts are conveniently filtered out by your datalink weather broadcasts as shown above for XM-delivered satellite weather. This is because the broadcast only provides returns from actual areas of precipitation. Often outflow boundaries or gust fronts produce low reflectivity returns that fall below the threshold used to filter out other clutter not associated with actual areas of precipitation. When in flight, pay particular attention to surface observations looking for strong, gusty winds before attempting a landing at an airport when storms are approaching. 

This feature first appeared in the July/August Issue 949 of the FLYING print edition.

The post Know Your Convective Outflow Boundaries appeared first on FLYING Magazine.

SA-097 emphasized that “as little as 1/4-inch of wing-leading edge ice accumulation can increase the stall speed by 25 to 40 knots and cause sudden departure from controlled flight.”

The alert also warned that ice buildup on pitot tubes can lead to instrument failure, impacting readings for airspeed, altitude, and vertical speed.

The NTSB acknowledged that some pilots have been taught to wait for a certain amount of ice to accumulate on the leading edges before using deice boots due to concerns about ice bridging. However, the FAA’s recent tests show that modern deicing boots, from aircraft manufactured after 1960, are not prone to ice bridging.

The agency warned that performance issues may arise if deice boots are not engaged promptly when icing begins and advises pilots to refer to their operating handbooks for specific procedures on boot activation and use.

The alert also cited several accidents where failure to follow operating handbook instructions led to in-flight loss of control, underscoring the critical importance of adhering to recommended deicing practices.

Editor’s Note: This article first appeared on AVweb.

The post NTSB Issues Deicing Safety Alert appeared first on FLYING Magazine.

Answer: There are many observed cases of lightning strikes to aircraft inside or near clouds that had not previously produced natural lightning. Studies show that about 90 percent of the lightning strikes to aircraft are thought to be initiated by the presence of the aircraft itself. The scary statistic, however, is that 40 percent of all discharges involving airborne aircraft occurred in areas where no thunderstorms were reported.

Apollo 12

One of the more famous cases of aircraft-initiated lightning is the Apollo 12 launch at the Kennedy Space Center, Florida, in November 1969. The Saturn V rocket was struck not once but twice on its way into orbit.

According to the 1970 NASA findings, other than these two strikes, there was no other lightning activity reported six hours before or six hours after the launch. At the time of the launch, a cold front was moving south into the launch area. Broken towering cumulus topping out at 23,000 feet with light to moderate rain showers were reported.

Rarely Fatal

Damage to airborne aircraft struck by lightning includes minor pitting or scarring to the aircraft’s skin to complete destruction of the aircraft.

Besides direct damage at the point of entry and/or exit, indirect effects that include the loss of VHF communication, loss of navigation equipment, and loss of instrument panel gauges are also possible.

In 1963, a Pan American Airlines Boeing 707 over Elkton, Maryland, was struck by lightning while in a holding pattern at 5,000 feet. The outermost fuel tank in the left wing exploded causing two other fuel tanks to follow suit. There were no survivors.  

• READ MORE: Does the FAA Punish Pilots for Logbook Mistakes?

It’s certainly true that a catastrophic accident such as this is extremely rare, but lightning strikes to aircraft are more common than you might imagine—most of which are aircraft-initiated strikes.

Based on compiled data it is estimated that in the U.S. a commercial airliner is struck once for every 3,000 hours flown. That’s an equivalent of about one strike each year. 

Melting Level

While aircraft-initiated lightning is still being actively studied, there are a few important characteristics to consider.

Based on the current research, it doesn’t take flying in or near a mature thunderstorm to become the victim of a lightning strike. The mere presence of the aircraft in an environment conducive to an electrical discharge is all that is necessary.

Most of the aircraft-initiated lightning strikes occur when the aircraft is flying at or near the melting level (0 degrees Celsius). The preferred temperatures include a range from plus-3 C to minus-5 C, with the highest number of incidents occurring right at the melting level.  

A few of the strikes down low are the result of an aircraft intercepting a lightning strike in progress. Essentially, this is the case of being in the wrong place at the wrong time.

On the other hand, aircraft-initiated strikes are observed the most are between 3 km and 5 km or 10,000 to 16,000 feet during the warm season. Once again, temperature is a key factor. The melting level that typically occurs is in this same range of altitudes throughout the summer months.  

Low-Topped Convection

In general, natural lightning in deep, moist convection doesn’t form until the tops of the storm build well above the melting level.

For lightning to form, three ingredients must be simultaneously present. These include vapor-born ice crystals, graupel, and supercooled liquid water. If any one of these three is missing in sufficient quantities, natural lightning doesn’t generally occur, but this not to say the cloud is void of all electrical activity—some still remains.    

Therefore, an aircraft-initiated lightning strike typically occurs within local air mass instability within low-topped convection.

Often low-topped convection doesn’t produce natural lightning. The updrafts are rather weak in comparison to those that do produce lightning. Consequently, the updrafts do not carry enough supercooled liquid water into the upper part of the cloud where it is needed. 

• READ MORE: What Are Echo Tops?

Clouds and Precipitation

An overwhelming number of lightning strikes occur within the cloud itself. Only a very small percentage of strikes occur outside of the cloud boundary or below the cloud.

Here’s the key: A very large percentage of the strikes occur within precipitation to include rain, snow, snow grains, ice pellets, and hail. It is not uncommon to find a mixture of these near the melting level. 

Keep Your Distance?

The FAA encourages all pilots to keep a safe distance from an active thunderstorm for obvious reasons.

Unfortunately, this practice alone isn’t quite enough. Even when thunderstorms (natural lightning) are not occurring or expected to occur, an aircraft-initiated lightning strike can still be a risk.

In order to avoid an encounter with lightning, the best advice is to remain in cloud-free air whenever possible, especially when the atmosphere is conditionally unstable and capable of producing marginally deep, moist convection extending well above the melting level.

While it may be difficult, the best advice is to operate outside of areas of precipitation and minimize your time in clouds and precipitation near the melting level.

The post How Can an Aircraft Get Struck by Lightning Without a Close Thunderstorm? appeared first on FLYING Magazine.

According to base officials, the storm produced wind gusts in excess of 50 mph. It came through early in the morning before the crowds had arrived, bringing with it lightning and rain.

The airshow held the day before had attracted more than 65,000 visitors, according to an U.S. Air Force spokesperson.

Of those injured, six were military medical personnel and four were civilian vendors. All were outside on the flight line when the damaging winds occurred. 

“Due to the timing of the inclement weather, spectators had not entered the event area,” the spokesperson said.

Additionally, some vendors reported damage to booths and the wind relocated many portable toilets. One building on base was struck by lightning, but there was no reported damage to the structure.

Because of damages to services, Sunday’s airshow was canceled.

Video of the show area during the storm showed flattened tents and chairs, and aircraft blowing across a water-logged ramp. There were no reports of significant damage to the larger aircraft on display. 

Airmen made several foreign object debris (FOD) walks looking for trash and parts of aircraft deposited on the ramp by the storm.

“Safety is always our first priority at McConnell, especially when it comes to hosting the community for an airshow,” the spokesman told FLYING.

The post Injuries Reported After Severe Storm Strikes Before Airshow appeared first on FLYING Magazine.

That’s because both precipitation and smoke are a possibility during the airshow (July 22-28), according to Scott Dennstaedt, author of the EZWxBrief and a FLYING contributor.

• READ MORE: FLYING Unveils ‘Oshkosh Live’ Video Programming Lineup

For starters, the wildfires in Canada and to the west may result in some smoky skies, Dennstaedt said. This was a factor last year, resulting in thick haze, poor visibility, and blood-red sunrises and sunsets. Photographs taken in the early morning hours had a sepia-tone look to them—a bonus if you are taking pictures of vintage aircraft.

In a forecast released Thursday, Dennstaedt predicted AirVenture attendees may smell the smoke earlier in the day but by later afternoon could expect some convective activity that should clear away the smoke due to the unstable atmosphere and ground heating up.

Dennstaedt presents an entertaining and educational look at the factors impacting aviators who are trying to get to the event as well as what to expect when they get there. The data is derived from atmospheric tools used by the National Oceanic Atmospheric Administration (NOAA).

EZWxBrief AirVenture Weather Roundup

The post Flying to AirVenture? What You Can Expect of the Oshkosh Weather appeared first on FLYING Magazine.

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.

The Atlantic hurricane season officially began June 1 and runs through November 30. While the National Oceanic and Atmospheric Administration (NOAA) has not released its official forecast for 2024 as of this writing, in an average Atlantic hurricane season the U.S. experiences 14 named storms, seven of which are hurricanes and three are major hurricanes.

Buckle up. Given the likely return of La Niña (one of three phases of the El Niño-Southern Oscillation) and record warm sea surface temperatures in February as heated as we see in mid-July, this is not good news if you were hoping for just a mediocre season. If you live and fly anywhere along the Atlantic coastal plain or the Gulf of Mexico, here’s how you can prepare for what may be a wild hurricane season.

Even though hurricane season peaks on September 10, the tropics will begin to see increased activity during the months of June, July, and August as sea surface temperatures increase and the jet stream migrates north into Canada, creating a more favorable breeding ground in the tropics. During this time, what are called tropical waves will develop in the Atlantic Ocean, Gulf of Mexico, and Caribbean Sea, forming in the tropical easterlies (winds moving from east to west). A weak area of low pressure with a closed circulation called a tropical depression may develop along one of these waves.

• READ MORE: The Ins and Outs of Pilot Weather Reports

If conditions are favorable, such as the presence of weak atmospheric wind shear over relatively warm waters, then convection can organize and strengthen into a tropical storm. Once it reaches tropical storm criteria, the National Hurricane Center (NHC) will give the storm a name. The first named storms of 2024 were Alberto and Beryl, with Chris, and Debby to follow. If you recognize a few of these names, be aware that the list is recycled every six years. The NHC points out that a name is removed from the list only “if a storm is so deadly or costly that the future use of its name for a different storm would be inappropriate for reasons of sensitivity.”

Saffir-Simpson Scale

Let’s become familiar with the Saffir-Simpson Hurricane Wind Scale. This scale from 1 to 5 was introduced in the early 1970s by the NHC, using estimates of peak wind, storm surge, and minimum central pressure to describe the destruction from both water and wind for tropical cyclones making landfall.

The Saffir-Simpson scale was simplified in 2010 to be solely determined by a one-minute-average maximum sustained wind at a height of 10 meters (33 feet) above ground level. Once a tropical cyclone reaches hurricane strength (sustained wind speed of 64 knots or greater), it is assigned a category, with a Category 1 hurricane being the weakest and a Category 5 hurricane being the strongest (sustained wind speed of 137 knots or greater). There has been some interesting discussion lately to expand this open-ended scale from 5 to 6 categories given that some of the strongest Category 5 hurricanes are well above that minimum threshold and may not truly capture the potential destruction. This change, however, is unlikely to occur any time soon.

• READ MORE: How to Wrap Your Head Around Weather

Next, you should become familiar with the NHC website, where you will find all of the official guidance published by NOAA. Each named storm, tropical depression, and tropical disturbance will be tracked along with public advisories, such as watches and warnings (e.g., hurricane watch) based on the threat to people and property. You’ll also find a public discussion for the tropics when there are no named storms and a discussion for each system being tracked.

Hurricane Graphics

One product that is ubiquitous during hurricane season is the tropical cyclone forecast cone graphic. This is designed to depict the expected track, location, and strength of the tropical cyclone over the next five days. It also shows the cone of uncertainty.

According to the NHC, “the cone represents the probable track of the center of a tropical cyclone where the entire track can be expected to remain within the cone roughly 60-70 percent of the time.” Of course, the cone tends to get wider with forecast lead time. In other words, there’s more certainty with a forecast that is valid in 48 hours (smaller cone) versus one that is valid in 120 hours (larger cone).

Currently, the graphic only includes those watches and warnings along coastal regions. Starting in 2024, the NHC will be issuing an experimental tropical cyclone forecast cone graphic that also includes inland tropical storm and hurricane watches and warnings in effect for the contiguous U.S. Recommendations from social science research suggest that the addition of inland watches and warnings to the cone graphic will help communicate inland wind risk during tropical cyclone events while not overcomplicating the current version of the graphic with too many data layers.

Electrification of Hurricanes

It’s probably not a surprise to hear that a healthy squall line moving through the Midwest can generate lightning at a rate of more than one strike per second for an extended period of time. But what about in a tropical storm or hurricane? You might be astonished to learn that, on average, a hurricane rarely produces more than a single lightning strike every 10 minutes. While there are some hurricanes and tropical storms that are highly electrified (especially when making landfall), don’t let your guard down—many are not.

No GA pilot is going to fly through the center of a tropical storm or hurricane on purpose. There’s typically plenty of advance warning from the NHC on the location and track of these powerful weather systems. However, once the tropical system makes landfall and weakens, how safe is it to fly through some of the precipitation remnants of the storm? A dissipating tropical system over land can contain some nasty convective turbulence and even small EF0 and EF1 tornadoes. Consequently, it is not unusual for the Storm Prediction Center (SPC) to issue a tornado watch for most tropical systems making landfall.

• READ MORE: Flying Through the Center of a Trough Should Have Been Uneventful

The precipitation signature as depicted on a ground-based radar mosaic associated with tropical cyclone remnants may not look too threatening to the average pilot.

First, it is often void of lightning, unlike what you might see with other convective outbreaks. Also, the automated surface observations in the area may only include +RA for heavy rainfall. In other words, you may not see +TSRA implying lightning exists as well as rain. Second, the ground-based radar mosaic may not have much of a true cellular structure with high reflectivity gradients that we often see with other deep, moist convection.

Despite the lack of lightning and a relatively benign-looking radar image, tropical system remnants should be treated as if they were that intense squall line in the Midwest. After such a tropical system makes landfall and begins to rapidly dissipate into a tropical depression or extra-tropical cyclone, it will move inland carrying similar risks.

This is evidenced by the remnants of Hurricane Katrina in 2005. This was a powerful storm that made landfall as a strong Category 3 hurricane at the end of August near New Orleans and moved north into the Tennessee and Ohio valleys as it dissipated.

Even after the storm was declared as extra-tropical, tornado watches were issued just to the east of Katrina’s track along the central and southern Appalachian Mountains and into the Mid-Atlantic. It is important to understand that the lack of lightning does not imply the lack of dangerous convective turbulence.

In order for lightning to form within deep, moist convection, three ingredients must be present in the right location of the cloud. This includes ice crystals, supercooled liquid water, and a “soft hail” particle called graupel.

Updrafts in tropical systems are actually quite limited, usually no more than 1,500 feet per minute. These updrafts are far from upright, owing to the strong horizontal wind shear present. According to hurricane researcher Dr. Robert Black, “while there is some presence of electrical fields, the graupel-liquid water-ice combination turns out to be at the wrong place at the wrong temperature and in insufficient volume to give the spatial charge distribution to produce a lightning discharge.”

In layman’s terms, little supercooled liquid water gets carried high enough to the level necessary to electrify the cloud. This continues to be true even after the tropical system makes landfall and dissipates inland.

The most serious electrification occurs in the outer rain bands as they spiral outward from the center of the storm. These can often look a lot like that Midwest frontal convection. Most convective cells along that squall line in the Great Plains or Midwest often move in a northeasterly direction based on the shift of the air mass and the winds aloft.

However, this may not be the case for these tropical cyclone bands. You may find these cells moving in a northerly or even westerly motion depending on the track of the tropical system.

Remain Outside of the Northeast Quadrant

If you split the storm into four quadrants based on its forward movement, the most intense atmospheric shear occurs in the northeast quadrant. This is typically where you will find the highest storm surge at landfall and where tornado watches are usually issued. As the system makes landfall, moves inland, dissipates, and becomes extra-tropical, you will find the northeast quadrant should be strictly avoided.

As we make our way through hurricane season this year, keep a close eye on the tropics and heed the guidance from the NHC. Even weak storms making landfall can add significant hazards for most aircraft. The convection associated with these storms is not the normal kind we experience during the warm season. Therefore, you can’t assume that the same ground-based signatures you might steer away from with normal convection will be present with this tropical convection.

Last, but not least, don’t use the lack of lightning to be your guide to determine what precipitation is safe to fly through. Assume there is ample wind shear in the atmosphere regardless of how it appears on radar. It may prove not to be a fair match for your aircraft or skill set.

This feature first appeared in the May 2024/Issue 948 of FLYING’s print edition.

The post Keeping an Eye on the Storm appeared first on FLYING Magazine.

Answer: In general aviation, one of the most cumbersome things to do while in flight is to file a pilot weather report, more commonly known as a PIREP. This has created the unfortunate situation that on any given day 98 percent of the PIREPs in the system are typically describing weather conditions at or above 18,000 feet.

It wasn’t all that long ago that the Enroute Flight Advisory Service (EFAS) was available primarily for pilots to receive weather updates while they were flying to their destination. More importantly, EFAS was the main outlet to file a PIREP such that it was guaranteed to be input into the system and become available for other pilots to see. This service was also called Flight Watch.

Given that EFAS was organized by Air Route Traffic Control Centers (ARTCC), you simply put 122.0 MHz into your radio, keyed the mic, and referenced them by a particular center’s airspace you were located within. For example, if you were in the Jacksonville Center’s airspace in Florida, your initial call might have been, “Jacksonville Flight Watch, Skyhawk One Two Three Whiskey X-ray, 30 miles southwest of the Brunswick V-O-R at five thousand five hundred.” Then as long as you were more than 5,000 feet above the ground, someone from Flight Watch came on the frequency, and you engaged in a two-way conversation to file your PIREP.

• READ MORE: The Ins and Outs of Pilot Weather Reports

However, EFAS was terminated on October 1, 2015. This now leaves the arduous task of finding the right Flight Service Station (FSS) frequency, making contact, and hoping someone on the other end responds to your call. The frequency you use to transmit and receive is dependent on your location. Pull out your VFR sectional (paper or electronic version), find the nearest VOR to your location, and look for the frequency located on the top of the VOR information box.

Of course, the correct frequency to use may also be available through your avionics or one of the many heavyweight electronic flight bag apps.

This is the frequency you will use to transmit and receive. Below the box is the name of the particular FSS to use in your initial call. For example, if you are near the Brunswick VORTAC in Georgia, your initial call may be, “Macon Radio, Skyhawk One Two Three Whiskey X-ray, transmitting and receiving on 122.2, over.” This is the easy case.

• READ MORE: How to Wrap Your Head Around Weather

If there’s an “R” shown at the end of the frequency (e.g., 122.1R), then that means FSS will receive on this frequency and you will transmit on this frequency. And you’ll need to be sure you listen for its response over the VOR frequency. Make sure your volume is turned up and not muted on your VOR radio.

This column first appeared in the May 2024/Issue 948 of FLYING’s print edition.

The post How Do I File a Pilot Weather Report Online? appeared first on FLYING Magazine.

Northrop Grumman, I needed something that would challenge my mind, body, and spirit. There were two options on the table. I had just graduated with my master’s degree and was seriously thinking of taking the next leap of faith and earning a doctorate.

But that was quickly overshadowed by my second option—my childhood dream of learning to fly. And I wasn’t disappointed. It did challenge my mind, body, and spirit every step of the way.

What intrigued me the most about learning to fly was that it required mastering many disciplines. In other words, it’s more than just jumping into an airplane and learning stick-and-rudder skills. You have to become entrenched in subjects such as aerodynamics, radio navigation, geography, radio communications, airspace, map reading, legal, medical, and my favorite discipline, meteorology.

Despite my background as a research meteorologist, my aviation weather background was limited when I was a student pilot. So, I was very excited to discover what more I might learn about weather in addition to all of these other disciplines. If you are a student pilot, here are some tips that will help you achieve a good foundation with respect to weather.

It Isn’t Easy

First and foremost, weather is inherently difficult. It’s likely the most difficult discipline to master because of the uncertainty and complexity it brings to the table. Therefore, strive to understand what basic weather reports and forecasts the FAA effectively requires that you examine before every flight. It certainly doesn’t hide it. It’s a fairly short and succinct list that’s all documented in the new Aviation Weather Handbook (FAA-H-8083-28) and the Aeronautical Information Manual (AIM). Ultimately, knowing the nuts and bolts of this official weather guidance will help with your knowledge and practical tests and give you a head start once the ink is dry on your private pilot certificate.

Second, as a student pilot, plan to get your weather guidance from a single and reliable source. Try not to bounce around using multiple sites or apps. There are literally hundreds, if not thousands, of websites and apps that will deliver weather guidance to your fingertips such that you can become overwhelmed with all of the choices, and entropy quickly takes over. Besides, flight instructors love to show off their unique collection of weather apps on their iPhone. Sticking with the official subset of weather guidance will allow you to focus on what matters the most.

• READ MORE: Aviation Weather Center Website Upgrade—the Good, Bad, and Ugly

Once you receive your private certificate, then you can expand the weather guidance you use to include other websites and apps.

The two internet sources that should be at the top of your list include the Aviation Weather Center (aviationweather.gov) and Leidos (1800wxbrief.com). Both of these sites provide the essential weather guidance needed to make a preflight weather decision. Using one or both of these sites will help focus you on the official weather guidance the FAA demands you use.

Categorize Your Data

Third, when you look at the latest weather guidance, take a minute and characterize each product. It should fall into one of three categories: observational data, advisories, or forecasts. Knowing its category will tell you how to properly utilize that guidance. For example, if you come across a visible satellite image, that’s an example of observational data.

Observational data is always valid in the past and typically comes from sensors. What about a ground-based radar mosaic (e.g., NEXRAD)? That’s also an observation. Pilot weather reports (PIREPs) and routine surface observations (METARs) are also considered observational data. While not a pure observation, the latest surface analysis chart that is valid in the recent past will identify the major players driving the current weather systems.

• READ MORE: What Is the Criteria for Issuing a Convective SIGMET?

Observations are like the foundation when building a house. All other weather guidance you use will build on that foundation. A sturdy and well-built foundation is the key to a good preflight weather briefing. You can’t know where the weather is going until you know where it has been. Identifying the latest trends in the weather through the use of these observations is the cornerstone of this foundation. When possible, looping the guidance over time will expose these trends. Is the weather moving or stagnant? Is it strengthening or weakening over time?

Advisories such as the initial graphical AIRMETs (G-AIRMETs) snapshot, SIGMETs, and center weather advisories (CWAs) are the front lines of aviation weather. They are designed to highlight the current location of the truly ugly weather. Advisories build the structure that sits atop of this foundation. Essentially, these advisories summarize the observational data by organizing it into distinct hazards and areas of adverse weather to be avoided.

Forecasts are the springboard for how these observations and advisories will evolve over time. You can think of forecasts as the elements that protect the finished house, such as paint, shingles, and waterproofing. This also includes the alarm and surveillance system to alert you to the possible adverse weather scenarios that may occur during your flight. While forecasts are imperfect, they are still incredibly useful. Forecasts include terminal aerodrome forecasts (TAFs), convective outlooks, prog charts, and the remaining four snapshots for G-AIRMETs.

Dive into the Details…

Fourth, details matter quite a bit. Look at the guidance and identify what stands out. Don’t make a decision too early. Instead, carefully observe and gather facts. Is the precipitation occurring along the route limiting the ceiling and/or visibility? Is the precipitation expected to be showery? This is a clear indication of a convective process in place.

Are the surface observations reporting two or three mid- or low-level cloud layers? Again, this is another indication of a convective environment. This can be especially important to identify, especially when there’s a risk of thunderstorms that have yet to form.

…But Fall Back on the Big Picture

Fifth, get a sense of the big weather picture. This is likely the most difficult aspect of learning how to truly read the weather. Think about the big weather picture as the blueprint for building an entire community. It’s what brings everything together. When I do my own preflight briefings, my decisions are largely driven by what’s happening at that synoptic level.

Lastly, read, read, and read some more. Focus mostly on the weather guidance and less on weather theory. These are the specific weather products mentioned earlier. Weather theory is something you can tackle at a later time. The FAA’s Aviation Weather Handbook is a great start. You can download a PDF document for free from the agency website and add this to your online library. This was issued in 2022 to consolidate the weather information from six FAA advisory circulars (ACs) into one source document. My book, Pilot Weather: From Solo to the Airlines, was published in 2018 and is written for pilots at all experience levels in their journey to learn more about weather.

If you fly enough, you will eventually find yourself in challenging weather. The goal of any preflight weather briefing is to limit your exposure to adverse conditions, and that takes resources and time. Once you’ve mastered the weather guidance, then giving Flight Service a call at 1-800-WXBRIEF will allow you to sound like a true professional.

Yes, I eventually did earn that doctorate, but I am really happy that I took the step over 25 years ago to learn to fly. One guarantee with weather: You can never learn enough. I am still learning today.

This column first appeared in the March 2024/Issue 946 of FLYING’s print edition.

The post How to Wrap Your Head Around Weather appeared first on FLYING Magazine.

“No one enjoys flying through turbulence, whether you’re piloting a single-engine piston or riding in the back of a jet,” said Henrik Hansen, ForeFlight’s chief technology officer.

ForeFlight says the additional feature within the mobile app displays the measured intensity of turbulence at multiple altitudes, making it easy for pilots to find the smoothest altitude along their flight path. ForeFlight Mobile automatically uploads the reports once it establishes an internet connection after the flight or instantly if connectivity is maintained during flight, according to officials.

Turbulence reports are depicted as colored markers on the Maps tab: Gray signifies smooth air, while yellow, orange, and dark orange represent increasing levels of turbulence, ranging from light to severe.

While pilots traditionally rely on weather forecasts and PIREPs for route planning, ForeFlight says its Reported Turbulence method offers distinct advantages, including enhanced accuracy and objective reporting.

ForeFlight estimates its Reported Turbulence layer offers 50 times more turbulence reports than manual PIREPs, per Sporty’s IPAD Pilot News.

Reported Turbulence is available as two add-ons for Pro Plus subscribers. Reported Turbulence (Low) offers access to turbulence reports up to 14,000 feet, whereas Reported Turbulence (All) provides access to reports across all altitudes.

Editor’s Note: This article first appeared on AVweb.

The post ForeFlight Introduces Reported Turbulence Map appeared first on FLYING Magazine.