FAA Flight Instructor Airplane (FIA)Weather and Weather ServicesHard
A pilot reviewing a 24-hour Surface Prognostic Chart notices a scalloped line with H's and L's along with frontal symbols positioned differently than the current surface analysis chart. What is the primary purpose of this chart?
- ATo display current observed surface weather conditions only
- BTo provide a graphical depiction of current PIREPs and AIRMETs
- CTo depict forecast positions of pressure systems and fronts at a specified future time
- DTo show upper-level wind patterns at the jet stream level
Show answer & explanationAnswer & explanation
Correct answer: C. To depict forecast positions of pressure systems and fronts at a specified future time
Prognostic (prog) charts are forecast products showing where meteorologists expect pressure systems, fronts, and associated weather to be located at specified valid times (e.g., 12, 24, 36, or 48 hours in the future), unlike the surface analysis chart, which shows current observed conditions.
Why the other options are wrong
- A. Current observed conditions are shown on the Surface Analysis Chart, not a prog chart.
- B. PIREPs and AIRMETs are separate text/graphic products, not part of the surface prog chart.
- D. Upper-level jet stream winds are depicted on constant pressure charts, not surface prog charts.
Surface Prognostic (Prog) Chart
A forecast chart depicting the anticipated positions of high and low pressure systems, fronts, and associated precipitation at specified valid times in the future, used to anticipate changing weather along a route.
- Forecast product, unlike the analysis chart which shows current conditions
- Valid times commonly 12, 24, 36, and 48 hours ahead
- Shows forecast fronts, pressure centers, and precipitation areas
Memory trick: Prog chart = a crystal ball for tomorrow's fronts