Air to Ground
Area Forecast
If you mention the San Joaquin valley, most people know it is in California, but do they know that it will be covered with a thick blanket of fog when the rest of the state boasts clear skies? You may know that the continental divide is in the Rocky Mountains, but how does it affect the weather in the region? Where is the hill country of Texas? Who cares? Meteorologists care. Those hills create a barrier to onshore winds carrying moisture inland from the gulf. In stable conditions this means low fog that can last well into the morning across a third of the state. In unstable weather they provide an initial lift factor for afternoon summer thunderstorms.
Many pilots do not bother to study the area forecasts, preferring to look primarily at METAR’s and TAF’s to determine enroute weather. All forecasts are the predictions of the development and/or movement of weather phenomena based on meteorological observations and various mathematical models. Area Forecasts give a general synopsis of atmospheric conditions affecting the flight and the macroclimactic effects this causes over various locations and terrains.
The difference is that TAF’s are like knowing that pushing the stick forward makes you descend. Area Forecasts are like knowing why you descend. Long term acquaintance with the Area Forecasts allow a deeper understanding of how a weather system moving over local terrain affects the region. One difficulty for those flying in a new area is not knowing the terrain landmarks the NWS is referring to. Attached is the map used by the NWS and ATC which delineates how area forecast data is applied. Area Forecasts also separate their forecasts by states and parts of states. Texas is split into six basic parts which are further defined by the terrain within those areas. Though Massachusetts is much smaller, the state has three distinctive weather pattern areas.
Using the attached map and looking at the area forecast a little each day will allow you to grow into a deeper understanding of how various weather phenomena will affect flight conditions in your area. You can easily find the daily area forecasts on www.aviationweather.gov.