Evaluating Guidance for Planning Day 1 and Beyond

The Aviation Weather Center (AWC) does not currently produce a Day1, or longer, outlook for aviation planning.  One of the goals of this experiment was to evaluate guidance and the capability to produce a Day 1, as well as a Day 2-4 outlook for planning purposes.  What these products would look like and entail is still very much in the early stages.

The goal of the Day 1 product is to target extreme turbulence broken up into four categories; Marginal, Slight, Moderate, and High.  The Moderate and High categories would indicate areas where a SIGMET is most likely, with the greatest certainty contained in the High coverage areas.  The graphic above is an example of what this product could look like.  When it would be issued, and the audience of such a product still needs to be discussed at length.  Along with the graphic, an accompanying text product, or discussion explaining the coverage areas and reasoning may also be beneficial.

Guidance evaluated for this product included the operational "Graphical Turbulence Guidance", or the GTG, RAP GTG, and the FV3 GTG.  The operational and RAP GTG were very similar in signal, with the RAP version having hourly forecasts out to f21, which is very useful for planning in the extended period.  Noticeable differences were seen when comparing the GFS GTG and the FV3 GTG, with FV3 showing stronger signals over GFS.  An example is shown below, with FV3 in the top left and GFS on the bottom right.




The extended out, looking at Day2-4 would be focused on several phenomena that could have high impacts on flight planning.  These include snow, thunderstorms, winds, wind compression, low ceilings and visibilities, sleet/freezing rain, turbulence, and en-route icing.  This product would likely focus on weather activity affecting the core 30 airports to support NAM operations and PERTI outlooks.

 

In addition to making the outlook product, participants compared the new FV3 variables with GFS, to see if they were consistent.  Visibility in FV3 seemed to be more concentrated showing lower visibilities and less coverage when compared to the GFS.  The convective and icing fields showed similar outputs between the two models, with FV3 tending toward slightly higher intensities of icing.

When it came to creating the product, there was a difference observed in how the NAM particpant would create the forecast versus a forecaster from AWC.  The NAMs are very focused on  high impacts to the core 30 airports, and thus tended to make a quicker product with less model interrogation.  Whereas the AWC meteorologists tended to focus on all possible weather hazards regardless of specific airports providing more structured commentary and taking a longer time to produce the product overall.

The development of both products is still in the very early stages.  A lot more discussion and demonstration needs to take place before it would be looked at as a possible operational product.  However, the feedback received this week was a giant step in the forward direction to seeing how such a product would be beneficial for users at all levels.