Ground Lesson: Weather
It’s never great when you’re scheduled to fly and the METAR prints “OVC 010” and doesn’t change when you get to the airport despite the forecasts (that’s overcast skies at 1000 feet, which is no good when you’re a student pilot flying VFR). Fittingly, we did a ground lesson on weather instead.
I learned about Synopses, area forecasts, TAFs, AIRMETs, SIGMETs, pireps, MOS, and a litany of weather abbreviations.
I also learned about weather systems and the explanation for why San Francisco is so cold and foggy. The reasoning goes something like this: warm air rises and denser colder air tends to move in to take its place. Especially in summer, the inland Central Valley heats up a fair amount relative to the coastal waters (which are quite cold as they tend to flow down from the arctic). This draws in a mass of cold air from the ocean, but it typically is blocked by the coastal range of hills that extends up and down the west coast. The bay inlet that the Golden Gate Bridge spans is the only sea level break in the hill range for hundreds of miles in either direction, so the cold air and mist pours in through that opening and swamps the city in its trademark summer foggy coldness. When the temperature imbalance is too much, the mist can roll over the hills, but that’s relatively rare and explains why the peninsula can be so sunny when San Francisco is not.
3:03pm 
