EZTip - Area Forecast Discussions in EZWxBrief

The Airport Wx view in EZWxBrief provides access to the most recent area forecast discussion (AFD) for each airport located in the conterminous U.S. To visit the Airport Wx view, find the Airport Wx selection from the main menu bar (or from the hamburger menu on portable devices) on any EZWxBrief page as shown below. This will prompt you to enter the FAA or ICAO airport identifier of interest. Alternatively, you can press the Airports button from the Dashboard located below the Recent Airports collection. This will open up the Airport Wx view for most recent airport visited.

Once the airport has been selected, then press press the Airport Wx sitemap dropdown menu located below the main menu bar to list the options for the airport. This includes a selection for Discussion.

Just to clear up any initial confusion, the area forecast discussion is not a discussion describing the aviation area forecast (FA) that was issued by meteorologists at the Aviation Weather Center (AWC). The FA for the conterminous U.S. was retired back in October 2017. Instead, the AFD is a product issued by forecasters located at each of the local Weather Forecast Offices (WFOs) that are scattered throughout the U.S. as shown by the colored map below. The same forecaster at the WFO that issues the TAFs for their county warning area (CWA) is also responsible, in part, for issuing the corresponding AFD. The CWA is “area” they are discussing. Shown below are the boundaries of the CWAs for the conterminous U.S. As a result, an AFD is not available for any airport that is outside of the U.S.

In EZWxBrief, you can show the CWA boundaries on the Map. To display the CWA boundaries, press the Base Map button from the Map menu. This will bring up the Base Maps menu. Select the County Warning Areas option from one of the eight base maps available. Note that the U.S. States and County Warning Areas base maps are mutually exclusive. Selecting one will deselect the other.

The AFD is not a two-way conversation. Instead, it is a vehicle where the forecaster can document their technical reasoning behind the forecast they will be issuing and also describe the current and future weather patterns. In other words, it’s a way for a pilot to know what the forecaster is thinking about the current trends in the forecast. Also, this is the method the forecaster can use to quantify their uncertainty. It allows them to let the reader know what could go wrong or how alternate scenarios may play out.

While there have been thousands of errant terminal forecasts, there are very few discussions that didn’t somehow confront the potential of a busted forecast before it happened. If you are not reading the AFDs and only looking at the TAFs, you are potentially missing out on half the forecast guidance.

The good news is that AFDs are written in a plain English format. The bad news is that there’s a lot of meteorological jargon used throughout the discussion. This is because the AFD is designed as a forecaster-to-forecaster memorandum so it might be quite technical at times. Be prepared for dozens of terms that may be unfamiliar. If you are still a bit perplexed after reading an AFD, visit https://forecast.weather.gov/glossary.php which may help unravel some of the mystery of the jargon used.

Unlike a TAF that has a standard coded format required under NWS directives, forecasters do not have strict guidelines to follow when issuing an AFD. This means the AFD issued by a forecaster at the Greenville-Spartanburg, South Carolina WFO like the one pictured above, will not necessarily have the same format and organization as the one issued by a forecaster at the Flagstaff, Arizona WFO. It’s not total chaos though; you will notice a similar look and feel from region to region. Forecasters are free to write whatever they want (in a professional tone, of course) in as few or as many words as they care to offer.

Over the last few decades reading thousands of forecast discussions, it is fair to say there are some excellent ones and some mediocre ones. Unfortunately, some forecasters treat the AFD as an afterthought while other forecasters spend the time and draft a comprehensive analysis. This often depends on how busy the forecaster is at the time. When there’s significant weather impacting the CWA, don’t expect too many details. That's usually because they are focused on issuing warnings for the severe weather given that the AFD carries less weight.

Lastly, every AFD has a section dedicated to aviation. This section, like the one shown above in EZWxBrief, is specifically created to address the most recent TAFs issued by the WFO that fall within their county warning area. This is generally written using jargon or terms familiar to pilots. While some of the discussions are fairly short, the forecaster will often quantify their uncertainty here. For example, in the aviation section below issued by the Greenville-Spartanburg WFO in Greer, South Carolina, it’s clear that thunderstorms are expected across the area, but it’s not certain if they will impact the Charlotte Douglas (KCLT) terminal area. So the forecaster is adding a placeholder for showers in the vicinity (VCSH) in the KCLT TAF to cover the convective threat. In most cases, the AFD may also provide an aviation outlook beyond the typical 24- or 30-hour forecast period.