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In Defense of Weather Code

By Susan Parson

Reprinted with permission from FAA Safety Briefing

Like any modern aviatrix and technology buff, I have stocked my iPad and my iPhone with a full suite of aviation apps that offer everything you could possibly want in terms of weather data and nifty color graphics. And I don’t leave home without my electronic assistants. In this era and certainly in this airspace at the heart of Washington’s Special Flight Rules Area (SFRA), no gadget means no go.

But here’s where it gets weird: I am an avid fan of traditional weather code. My coterie of codeo-phobic flying friends regard my taste for raw meteorological data with the same kind of shocked aversion that I might have if they served me a plate of, say, raw steak: plenty of potential, but a tad too hard to digest.

Since today’s technology gives you the option to wave ta-ta to weather tartare, why bother mastering outmoded abbreviations that look too much like a vowel-deficient puzzle from the Wheel of Fortune game show? Here’s why I like it so much.

Code Packs a Punch

I don’t do home brew – either for beverages or approaches – but I know enough about the distillation process to think of weather code as the meteorological equivalent of spirits. An example from my home airport, KJYO, illustrates the point. First, take a look at the ADDS-generated plain language version of a recent hourly meteorological observation (METAR):

Conditions at: KJYO (LEESBURG/GODFREY, VA, US) observed 1635 UTC 15 March 2012 Temperature: 26.0°C (79°F) Dewpoint: 9.0°C (48°F) [RH = 34%] Pressure (altimeter): 30.18 inches Hg (1022.1 mb) Winds: from the WSW (240 degrees) at 6 MPH (5 knots; 2.6 m/s) Visibility: 10 or more miles (16+ km) Ceiling: at least 12,000 feet AGL Clouds: sky clear below 12,000 feet AGL Weather: automated observation with no human augmentation; there may or may not be significant weather present at this time.

Now let’s look at the raw or, as ADDS calls it, “un-decoded” version of the same hourly observation:

KJYO 151635Z AUTO 24005KT 10SM CLR 26/09 A3018 RMK AO2.

The coded METAR packs multiple lines of information into a much tighter presentation. And that leads to a second advantage that raw data has over plain English: Code is a quick read.

Code is Quick

Before you hoot me down, let me hasten to acknowledge that, yes, learning to read weather code requires an up-front intellectual investment. You do have to spend some time, and you do have to make some effort to learn the truncated terms of weather code. But consider that it’s a one-time investment. Once you’ve mastered it, you can routinely absorb weather information much more quickly than someone who is reading the same data in plain English format.

To reinforce the point, here’s one of my favorite tips about raw weather code. As illustrated by the example given earlier, the shorter the code, the better the weather. After all, it doesn’t take a lot of letters to convey calm winds and clear skies. When I see a longer weather code entry, though, I know that I’m going to have to spend more time understanding which weather hazards lurk along my route.

And finally…

Code is Cool

Ever stop to ponder why some people give their ultra-modern Smartphone’s the ultra-retro ringtone of an old-timey telephone? If retro-ringtones can be cool, I contend that retro weather code can be cool too. The nice thing is that today’s technology gives us choices for both.

Susan Parson is editor of FAA Safety Briefing. She is an active general aviation pilot and flight instructor.