Aviation Prog Charts - Precipitation

[Mike McDonald]

On the aviation prog charts, areas of precipitation are outlined by solid green lines. The latest surface analysis chart, shown at the beginning of the sequence of prog charts doesn't show the areas of precipitation. http://adds.aviationweather.gov/progs/

FAA/NWS Aviation Weather Services Advisory Circular AC-0045 states: Progression analysis is accomplished by comparing charts of observed conditions to the 12-, 24-, 36-, and 48-hour progs.

It would seem that to see the progression of areas of precipitation, one would want to see it on the latest analysis chart. Does anyone know why it's not shown?

Speculation is that to see current precipitation the FAA wants pilots to refer to more current sources such as METARs.

Mike

 

[Kyle Harmon]

As far as I can tell, this is not unique to aviation. For example, the HPC's surface analysis charts all omit current precipitation. Your thinking is probably right though--current precipitation is much better depicted by radar, radar summaries, and METARs than a surface analysis. (Which is probably why most surface analysis products that do incorporate precipitation do so by overlaying radar.)

Interestingly, however, the surface analysis chart from one of the only two websites we're allowed to use as a primary source for flight decision-making (strangely, neither of which is aviationweather.gov ... at least for now) actually shows precipitation.