August 29, 2013

How's the Weather Up There?

By Angel MedFlight Contributor

For those of us here on the ground, checking the weather can be as simple as looking out the window, turning on the TV or checking our favorite weather app on a mobile device. Imagine though, how a pilot must prepare for weather conditions before he takes an aircraft 45,000 feet up in the sky. Pilots at Angel MedFlight Worldwide Air Ambulance are trained to handle every weather condition ensuring a safe and comfortable ride for the patient.

But what exactly goes into checking the weather before taking one of our Learjet air ambulances up? Kindle Tannery is Chief Pilot for the combined operations of Angel MedFlight and Aviation West Charters. Tannery says there are many variables a pilot looks at on a flight plan and weather decides a lot of those variables.

Once the pilot has checked the airport environment, for example runway conditions, Notices To Airmen (NOTAMS), he or she can then check weather conditions. In the summertime pilots are looking at thunderstorm threats, convective activity around the en route weather.  Tannery says, "You're checking for turbulence, cells that you want to avoid, and you'll find that all in your pre-flight planning."

Two of the most common sources pilots use to check weather are the iPad app ForeFlight and Tannery says ForeFlight gives pilots information on airports, NOTAMS, temporary flight restrictions (TFRs)  and weather.

Pilots will also look at METARs and TAFs from the National Weather Service. METAR contains hourly surface weather observations. Typically this includes the temperature, dew point, wind speed and direction plus precipitation, barometric pressure, cloud cover and heights and visibility. In case you're wondering what the acronym METAR means, it roughly translates from French as Aviation Routine Weather Report. TAF is the international standard code for terminal forecasts issued for airports.

Flight Operations Director Brandon Kearns says there are a number of factors which must be taken into account for each flight. "Rain, turbulence, headwind, thunderstorms, and even ice are just some of the phenomena which present challenges to flight crews for finding the ideal route. "
You've seen the satellite imagery and Doppler radar images on television? Pilots look at similar radar imagery and pay special attention to the colors on the maps. Kearns says the "colors are a huge thing. 

They tell you the levels of intensity on the type of precipitation. For a thunderstorm you're dealing with the greens, to the yellow, to the red and the magenta." Greens, pinks, blues and whites are often seen on maps in the winter. The colors on the map "give the pilot a really quick onceover as to what type of precipitation, where it is and the level of its intensity."

Kearns says the pilots also look at isobaric pressure lines and lifted index charts to see what the weather looks like along the route. These show the potential for severe weather such as thunderstorms and tornadic activity. "The lifted index charts measure the stability of the air and show how much moisture is in the air and what the potential is for the actual current atmospheric conditions to create a thunderstorm, " says Kearns. "And we can see even at 8 in the morning that around 2 or 3 in the afternoon it is going to be a nasty day."

During the flight pilots can often see weather systems hundreds of miles away. There is weather radar on board the aircraft which sends a signal out that bounces off the water particles  ahead and returns with a color-coded echo reading, measuring timing and intensity.

Angel MedFlight air ambulance jets have the ability to often fly above the weather. "And our pilots," says Kearns, "are operating around the clock in different parts of the world. They are very schooled on different weather patterns." This helps to ensure a high level of safety and also a comfortable ride for the patients and their family members.

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