The National Weather Service (NWS) has fielded an experimental aviation weather product for many Alaska communities that lack a Terminal Area Forecast (TAF).  It represents the latest step in helping pilots anticipate local weather conditions before they fly. The Alaska Aviation Guidance (AAG) product takes the current conditions and applies a model to predict how conditions will change over the next six hours.

A state-wide display of the 61 airports where the AAG product is available, color coded for the predicted weather category (VFR, MVFR, IFR, LIFR).

 What does this mean for Alaska?
Today NWS only issues 39 TAFs for airports across the state—an area one fifth the size of the continental US.  Adding this new experimental product that covers 61 additional airports greatly increases a pilot’s ability to anticipate weather in the immediate vicinity of those locations.  An overall display of the state includes a graphic depiction, color coded for the major flight conditions categories (VFR, marginal VFR, IFR and low IFR), providing a synoptic awareness of conditions over larger areas.

What’s different?
Unlike a TAF, that covers a twenty-four-hour period, these forecasts only project conditions for the next six hours. They are updated each hour, however, to give a fresh look ahead—while TAFs are only routinely updated four times a day.  The product describes the elements pilots most care about; ceiling, visibility, wind and weather.  If conditions are expected to be stable during the next six hours, a single set of elements will be provided, however if change is expected, the guidance will break the time into finer segments. The results are also displayed in an easy to read decoded fashion.

A sample forecast, broken down into time blocks when conditions are expected to change.

Pilots should be aware of some limitations.  This product is completely automated, with no oversight or input from a human forecaster.  And while it covers the key elements we most care about, it does not forecast conditions such as localized convective activity, blowing snow or smoke during fire season.

How can pilots use the product?
Unlike the TAF, which is the staple for IFR operations, the AAG is intended for VFR use only.  On March 25th,  FAA Flight Standards released an InFO sheet that describes how it may be used for flights conducted under different operating regulations, with some limitations.  NWS also cautions us that this is not monitored on a 24 hour basis and may experience outages. AAG should be used in conjunction with all other weather forecasts (such as SIGMETs, AIRMET, Area Forecasts, etc) to best inform pilots of the expected weather conditions.

Where do I find it?
The AAG is an online product found at: https://www.weather.gov/arh/aag. Users will also find an FAQ with additional information, a link to the FAA InFO document and to a user survey.  Please use this product as you fly this summer. The experimental period currently runs to October 16. What happens after that may be influenced by your feedback!

More on Alaska weather developments
On April 8th, the National Weather Service organized a webinar which featured information from the FAA describing plans to deploy a Visual Weather Observing System in Alaska, on a test basis.  To learn more about this project, slated to start this summer, check out the Alaska Aviation Weather Update Webinar.