Friday, August 23, 2019

Evaluating Extended Range Convection Products

AWT participants had the opportunity to look at new extended range convective forecast products this week with the goal of exploring various ways of depicting hazard information to support strategic planning for the next day and beyond. Evaluations included examining both automated and user generated forecast products.

Participants generated convective coverage forecasts over 6 hr windows (09-15z, 15-21z, 21-03z, 03-09z) during the Day 2 period. These forecasts depict areas of high confidence in convective coverage areas in the same manner as current standard TCF forecasts, communicating threat areas for strategic planning to focus on for the Day 2 period. Participants have provided positive feedback for these forecast products, indicating that they have potential to provide useful information for planning at extended ranges. During the week, emphasis has been placed on the importance of consistent forecast messaging between a Day 2 and a Day 1 product.

Participant generated convective coverage forecast graphic

In terms of automated guidance, participants evaluated two automated products currently produced at the Aviation Weather Center (AWC) for extended range convection. Comparisons were made between the Extended Convective Forecast Product (ECFP), which shows convective probabilities over a 6 hour window, and the Extended Traffic Flow Management Convective Forecast (eTCF), which displays a convective coverage forecast at 2 hour snapshots. Participants have found that the eTCF provided more useful guidance in the Day 2 period compared to the ECFP, as the inclusion of convection allowing model (CAM) guidance in the eTCF allows for greater detail in the evolution and timing of convection.

Comparison of operational and variant eTCF forecasts (upper left, upper right, lower left) with observations (lower right)

Additionally, participants evaluated two experimental variants of the operational eTCF, which is created through a blend of models which include convection parameterization and CAM guidance. Both variants were comprised of a blend of solely CAM guidance and have performed better than the operational eTCF in both subjective and objective evaluations. The improved performance of the variants can be attributed to the ability of the CAM guidance to better forecast the evolution and timing of convective processes. Based on these results, a potential upgrade to the operational eTCF will be explored in the near future.    

Thursday, August 22, 2019

AWDE Services Gathering GA Pilot Feedback

In addition to having members of the Aviation Weather Demonstration and Evaluation (AWDE) Services team in house at the AWT providing support during the week, they were also in full experimental mode at the FAA WJHTC in Atlantic City.  They conducted user evaluations, with general aviation pilot participants, to provide feedback concerning the new capabilities incorporated into the HEMS and GFA products.  Pilots attended the lab both in person and via Webex to provide their valuable feedback.
Overall, participants gave positive feedback concerning the new capabilities such as the expanded coverage and resolution over the expanded areas, the Map Options dialog, and additional MESONET observations.  The additional capabilities and information will help inform critical decision making.

The AWT also welcomed a few pilots that participated in one-on-one interviews with AWDE personnel.  AWDE staff asked them questions about the usability of the tools, how the new capabilities added value and what changes or requests they had for the tools in general.  Overall the pilots were pleased with the current products and proposed upgrades, but expressed the need for more user-friendly capabilities.  This includes making the products easier to navigate on a mobile device as well as the addition of contextual help on the tools.  Having capabilities and weather information explained in a way that users can clearly understand is extremely important as AWC continues to evolve their products to serve the greater aviation community.

Wednesday, August 21, 2019

Evaluating 3D Cloud Guidance

One of the focus areas for this year's experiment is evaluating three-dimensional cloud model guidance.  Participants are assessing current post-processing algorithms of cloud layers and the added benefits of experimental visualization capabilities.  In order to complete the evaluation and carefully assess the different guidance products available, the participants have been tasked with creating a detailed text forecast for five specific hours: 15Z, 18Z, 0Z, 9Z, and 12Z the next day.

In order to get a better visualization of the 3D cloud information, AWT developed a web interface that allows for better interrogation of the data.  The web interface displays the post-processed gridded output from various model guidance options including three cloud bases and corresponding sky coverage for each forecast hour from the the latest several model runs, as well as the model derived ceiling and visibility.  In addition to the single layer look at the information, the tool allows for creating point-and-click TAFs as well as cross-sections of the cloud layer information along a path.

Along with the descriptive cloud forecasts, the participants will be answering questions about the performance of the various guidance products, any notable strengths or weaknesses, and any biases identified as well.  The various guidance products available include experimental versions of the HRRR and RAP models, the NAM and NAM Nest, and the HIRES ARW, MEM2, and the NMMB.  The experimental 3D RTMA is also available for use as a cloud layer analysis for verification purposes. 

After day one, it was clear that the cross-section ability has several advantages and could be useful for multiple users. While it may not be the primary tool used to forecast ceilings, they could prove beneficial to bolster confidence in a cloud layer occurring or in seeing a thin low cloud deck or fog.  Forecasters may not have the time to look through multiple cross sections for multiple forecast hours, however they could use it to confirm a secondary layer or get a better idea of what the model is trying to tell them in terms of the cloud development.  However, pilots may find the tool extremely useful for planning along a flight path, especially if there could be a time element added in which conditions match the time in which they expect to be flying through that region.

In terms of model performance thus far, participants have been impressed with the HRRRx cloud placement in the vertical more accurately hitting the cloud bases and coverage.  This verified well on Day 1 with the stratus off the coast of California and cloud placement in the north east associated with late afternoon convection.  Overall, so far it seems the guidance tends to agree with cloud occurrence and conditions, but differ on timing and placement.

The experimental HRRR cloud base primary indicating low ceiling moving into the Sacramento valley via the delta breeze. 

Evaluations will continue through the week with specific areas of focus being determined each morning based on impacts for that day and the next.

Tuesday, August 20, 2019

Day 1 of the 2019 AWT Summer Experiment

The 2019 AWT Summer Experiment kicked off on Monday with a full house of collaborators and stakeholders from multiple entities of the aviation weather enterprise. Participants include developers from NOAA’s Earth System Research Lab (ESRL), NWS’s Meteorological Development Lab (MDL), and NCEP’s Environmental Modeling Center (EMC); meteorologists from each NWS region including Alaska and Hawaii, Deutscher Wetterdienst (German weather agency), and Southwest Airlines; as well as stakeholders from NWS headquarters, the US Air Force 557th Weather Wing and the FAA’s Aviation Weather Research Program (AWRP).

There are three major themes that will be explored throughout the week. The first is an evaluation of new features and capabilities in the Graphical Forecasts for Aviation (GFA) and Helicopter Emergency Medical Services (HEMS) web tools.

The Graphical Forecasts for Aviation (GFA) was recently expanded operationally to include the western Atlantic, Gulf of Mexico, and Caribbean Sea in order to give end-users graphical alternatives to the current text-based Area Forecasts still issued for that region. The AWT is also demonstrating additional geographical expansions over much of the Pacific, including Hawaii, and north into Alaska where user feedback will be critical. AWC will be updating the gridded ceiling and visibility (C&V) analysis in the HEMS tool this coming spring and is seeking user feedback on this, as well as some other potential updates to the tool, during the week long experiment.

In addition to the meteorologists and developers on hand to evaluate these updated web tools, pilots will be attending the AWT in person and remotely to provide feedback to human factors experts from the FAA Aviation Weather Demonstration and Evaluation (AWDE) services group. This feedback is critical to ensuring AWC's products continue to evolve to meet the needs of the users most dependent on them.

The second area of focus for the week will be evaluating new cloud layer guidance derived from numerical model 3-D cloud information. Participants will be given the task to create a forecast for cloud evolution over an area with expected aviation impacts. They will have various visualization tools to use in order to examine the 3D cloud information including a point-and-click TAF capability and a point to point cloud cross section viewer. The goal is to have an evaluation of the guidance itself to better tailor post-processing and tooling, as well as how 3D cloud information can be used to improve aviation forecasts in the future.

Finally, AWT participants will be looking at potential extended-range convective guidance products. National traffic planning is increasingly looking at the next day and beyond to better get ahead of potential impacts before they start affecting the NAS, and determining the best path forward in how to present this information to all stakeholders involved is critical.

Stay tuned for updates throughout the week and early findings from each desk!

Thursday, August 15, 2019

Aviation Weather Testbed Summer Experiment 2019

The 2019 Aviation Weather Testbed (AWT) Summer Experiment will be held at the Aviation Weather Center (AWC) in Kansas City next week! There are three major themes that will be explored throughout the experiment: (1) an evaluation of new features and domain expansion of the Graphical Forecasts for Aviation (GFA) and the Helicopter Emergency Medical Services (HEMS) tool, (2) an evaluation of new cloud layer guidance derived from numerical model 3-D cloud information, (3) and an evaluation of extended range impact-based convective forecasting. Stay tuned for more updates and exciting details from the week.

Tuesday, September 25, 2018

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. 

Monday, September 24, 2018

No Stratus, No Problems

Another focus of the experiment this summer was looking at high-resolution ceiling and visibility (C&V) model data over the San Francisco airport (SFO).  The airport utilizes a parallel runway system that requires pilots to be able to physically see each other as they make their landing approach.  When low ceilings are present (< 3000ft), the use of parallel approaches is restricted, causing decreased arrival capacity and increased delays. 

The UK Met Office and the ESRL Global Systems Division (GSD) HRRR group both provided high-resolution nests over SFO for this experiment.  The UK Met model nest has 330m grid spacing, with the experimental HRRR nest set at 750m horizontal grid spacing. 

As luck would have it, during the week of the experiment SFO was stratus free!  So instead, participants kept busy by looking at how the various model guidance handled the clouds and other phenomena in the area within the nests.  Focus was also given to Monterrey bay some days, which is just south of SFO.  In addition to the high-resolution nests from the UK Met model and the HRRR, participants also compared with experimental versions of the LAMP and RTMA.

In the above example, the HRRR 750m nest looks to best represent the cloud structure seen in the GOES 17 imagery west of Monterrey bay.  Another example below shows how the HRRR experimental starts to clear out the cloud cover inland of the bay by 15Z, where the experimental RTMA 3-D continues to keep the clouds at 15Z, which is later verified by satellite imagery.

In addition to clouds from the models, participants also looked at winds, the NDFD sky cover and how it compared to the guidance, as well as how RTMA and LAMP interpret observations into their analysis and forecasts.  So even without stratus, valuable information on the various guidance products was gained.

Thankfully, partners at both GSD and the UK Met office have agreed to continue producing the experimental nest data for a few more weeks so that AWC researchers can continue to evaluate the data when stratus is in fact present over SFO.