TAFs and Temps

The last release (v 3.1.7) adds GFS-LAMP forecast air temperatures and dew point spread.   Temperatures are available for just about all US airport with a TAF and many smaller US airports without TAFs but with MOS forecast.   MOS forecasts are shown if a TAF is not available and are easily identified by less saturated flight category colors.   Knowing the forecast temperatures helps understand density altitude, freezing conditions, and knowing dew point spread helps in predicting fog or mist.

Forecast Air & Dew Temp

There are 2 modes of presenting temperatures in the Circle and Bar Views.  The first shows the air temperature in larger white numbers and the smaller numbers show the differences between dew point and air temperature.  The dew point difference is only shown if it is less than 4 degrees.  To see only the dew point difference swipe (or tap in Italian mode) and only the dew point difference is shown in yellow numbers.

As I was coding this feature I wondered why this data wasn’t already in the TAF.  A reasonable explanation is  due to the structure of how TAFs are arranged.  TAF segments are written when a significant change conditions occurs and temperatures gradually change throughout the day; so it would be difficult to determine a good separation between temperatures to add a new segment.  It would not be realistic to add a new segment for every temperature change or even just when the dew point spread was within certain limits.  If temperatures were included in the existing segments, what temperature would be shown?  An average? The min/max? neither of these makes much sense.  As you can see the nature of changing temperatures doesn’t fit well within the existing TAF structure.   But temperatures are valuable information used to understand the full weather picture, or at the very least to make informed decisions of what to wear.

The method in which Wx24Pilot represents forecasts lends itself to extend the TAF data to other sources of information, in this case temperatures.  The common denominator of any and all forecasts is time.  Any forecast information only makes sense in the context of time and without time the information is useless.   The visual TAF found in Wx24Pilot allows temperatures and other pertinent information to be easily integrated.

This feature, adding temperatures to the visual TAF, marks a change in thinking about presenting aviation weather reports.  No longer is the visual TAF strictly a visual TAF, maybe a visual TAF plus.    The unique interface allows for presenting a wide variety of forecast information including altitude of freezing point, winds aloft, density altitude.  In future versions I’ll be adding other forecast information and along with that filtering to handle the data.

 

Paxton Calvanese

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