Wednesday, June 25, 2014

GFA Challenge

The GFA is a series of aviation weather maps showing what weather is forecast to affect aviation in a given region in the next twelve hours or so. It shows the centres of high and low pressure regions, the fronts, low visibility, clouds and precipitation, and dangerous weather, including icing and turbulence on a separate page. GFA stands for graphical area forecast (yes, the letters are in the wrong order). It replaced the FA (area forecast) about 15 years ago.

The GFA depicts provincial borders and has little circles for locations that have TAFs. (A TAF is forecast that covers the immediate area of an aerodrome). What takes some people a while to realize is that when you mouse over the little circle on the online GFA, text pops up to tell you the name of the place.  It would be cooler if you could click on said text to see the latest TAF and METAR (which officially doesn't stand for anything), but I'll take what I can get.

I like to think of it as a little geography quiz. Pull up the GFA page, click on one of the regions, then choose any time. I recommend you pick one of the icing, turbulence  and freezing level charts from the right column, because the left column clouds and weather charts can get so busy that you can't see the towns at all.  Now try to name all the cities and towns represented by the circles, before you mouse over and see if you're right.

Sometimes one of the little circles doesn't show anything when you mouse over. I think it's usually when it's very close to a weather depiction.  Some of the circles represent closed aerodromes where there is no observation or forecast, like Edmonton City Centre. They don't recode the GFA when they close an aerodrome, so it's a history quiz as well as a geography quiz.

6 comments:

Cedar Glen said...

Would you really want a regional forecast called 'GAF?' In some forms of our language, a gaf (or gaff?) represents a major screw up. While many/most weather forecasts are gaffs, I can understand why the providers changed the acronym. For the immediate area at moments before take-off the best weather report is LOTFW. Do I need to translate that? Sadly, LOTFW does not do you much good at your destination, until you actually get there. While I no longer fly, I still live or die by the weather. Over time, one learns to interpret the broad forecasts and apply them to micro climates. In my location, the forecast weather (other than temperature) usually occurs 4-6 hours after predicted; the micro-climate predictions are +/- worthless. Do you consider the primary target and adjust for time? --At least when you remain in a specific area? That too can be a stretch, but LOTFW is accurate.

Aviatrix said...

It sort of stands for Graphical FA, and FA was the old designation for the area forecast.

Aviatrix said...

And my job doesn't take place in microclimes. It zooms from place to place, so a GFA is what I need.

World'sMostAnxiousPerson said...

I'd always assumed that the letters were in the wrong order because it was some kind of French thing.
That's my go to answer for everything in Canada :)

Aviatrix said...

It probably is in the wrong order for French as well. Typical Canadian compromise.

Michael5000 said...

Mmmmm, little geography quiz...