Update: Due to the government shutdown, the changes described below have been delayed, and are planned to go into effect on November 12.
The weather is still one of the most important factors we need to evaluate before each flight. Whether you fly VFR or IFR, knowing the current conditions and how they are expected to change is critical to that all important GO/NO GO decision, figuring out which route to take, and what to watch for inflight. On October 15th, the Alaska Aviation Weather Unit (AAWU) will make changes that should help you make those decisions, as you plan to fly. Here are some of the changes.
Starting in mid-October, new Area Forecasts (FA’s) will be issued three times a day—at 4:15 a.m., 12:15 p.m. and 8:15 p.m., local Alaska time. Updates will come out at 12:15 a.m., 6:15 a.m. and 6:15 p.m.—or as needed if things are changing faster than anticipated. AIRMETs will be either issued or updated using a similar schedule, the details of which may be found on the AAWU website at: aawu.arh.noaa.gov/changes/
Icing and Turbulence Graphics
In a trend which I find helpful, more information is being presented in graphic form. Starting on Oct 15, the AAWU will issue new icing and turbulence graphics, showing the forecast in three-hour time slices, as opposed to the 6 hour charts we have been using. Found under the Graphical Forecast tab on their home page, in the sample Icing Forecast product below, the user has a choice of viewing a single 12 hour summary, or on the bar immediately above the product, selecting one of the three-hour charts to see how the forecasters expect conditions to develop during the day.
Sample Icing Forecast Product summarizes over the entire 12 hour period. Users can select individual charts showing 3 hour intervals to see how conditions are expected to develop.
Another change is that the Turbulence Forecast will be split into separate low and high altitude products. Along the top, in the sample image below, the user again has the option to look at the 12 hour summary— showing the entire forecast period—or can mouse-over a progression of graphics to see how the turbulence is expected to develop during the forecast period. Note that while the products are split at Flight Level 180, if conditions span that flight level, they will be depicted on both sets of products. A little time spent examining the legend to become familiar with the new conventions will help become accustomed to these products.
Sample low altitude turbulence product, covering a 3 hour period. Users may also select the 12 hour summary chart to get the “big picture.”
A more subtle difference in the product to note: An additional turbulence category, “Isolated Moderate” is being added. Previously the products only depicted “Occasional Moderate” and “Isolated Moderate to Severe” conditions.
Table showing when both graphic and text products will be updated. Helpful if the weather is bad and you are waiting for the next forecast!
Other graphic products, such as the Surface Map and IFR/MVFR Chart won’t change, however the issuance and update times will. The AAWU has provided a table (above) summarizing the timing of both text and graphic product which provide a roadmap to the new scheme.
These are significant enhancements to the products available to Alaskan pilots, and a downloadable document summarizing them is available online that contains examples and a more complete description of the schedules and changes. If you have feedback on products, the National Weather Service would like to hear it. An easy way to reach them is to shoot an email to mailto:[email protected].
As pilots we need to remember that the accuracy of these products is influenced by the PIREPs we file, either confirming forecast conditions, or alerting forecasters when conditions are changing faster than expected. Please take time to file an extra PIREP or two as you fly.
So a modification to an old adage might be… “If you don’t like the weather you see at the moment, just wait for the new forecast.” Thanks to these changes, the new forecasts will be showing up more graphically and more frequently than before.