1. Weather Forecast Guidance and Impact on NAS Management
Friends and Partners of Aviation Weather Summer 2016 Meeting
Weather Forecast Guidance and Impact on NAS Management
August 3, 2016
Jim Enders and Kevin Johnston
FAA
Air Traffic Organization

2. Introduction
NAS management is moving toward “Plan - Execute – Review – Train – Improve” (PERTI)
Successful NAS management depends on understanding the probability of weather following the forecast, as well as the ability to rapidly adapt when weather doesn’t follow the forecast
This briefing contrasts two similar weather days in the NAS, and the NAS management challenges associated with forecast differences
How can we be more efficient on days when forecast uncertainty is high and/or weather does not follow forecasts?
Plan for weather following the forecast
Tactical adjustments to Plan if weather doesn’t follow forecast

3. Audience Participation – Forecast Analysis
6-hour CCFP (issued at 13Z) -Valid for 19Z
Shown for two different days
What traffic management initiatives would you expect to see for each day?
GDP, AFP, GS, TRANSCON routes, CDRs?
Day 1
Day 2

4. NAS Management

5. NAS Management When Convective Weather Does Not Follow Forecast…
When Convective Weather Follows Forecast…
Plan
Communicate
Execute
Monitor
Re-Plan
Re-Communicate
Re-Execute
Plan
Communicate
Execute
Monitor
Decreased system predictability
Decreased efficiency-Increased workload
Operation more reactive – “churn”

6. Complexity of Decision Making

7. Complexity of Decision Making
A number of convective forecasts exist for FAA to review and determine mitigation strategies
Collaborative Convective Forecast Product (CCFP)
Target Time: 2-hour, 4-hour, 6-hour, and 8-hour forecasts
Collaborative, human generated product in 2014; auto generated in and 2016
Uses percent coverage and confidence thresholds to graphically represent areas of expected convective occurrence (pseudo- probabilistic forecast product)

8. Complexity of Decision Making
Collaborative Storm Prediction for Aviation (CoSPA)
Target Time: 0-8 hour forecasts
Deterministic forecast of precipitation and echo tops by showing storm locations, growth/decay, motion and scale

9. Complexity of Decision Making
Collaborative Aviation Weather Statement (CAWS)
Target Time: Ideally 4- hour lead time to impact
Experimental 2014; CAWS considered for strategic planning in 2015 and 2016
Collaborative product identifying areas of convection that will result in an impact (and/or action to be taken) to FAA operations

10. Operational Challenges 7/18/15

11. Operational Challenges for Saturday 7/18/15
Morning convection in NE (ZNY, Northern ZDC, and Eastern ZOB) underforecast by CCFP
Broad area of low confidence, sparse coverage for NE in afternoon; by 21Z thunderstorms developed along PA/NY border however most ZNY and ZDC clear of convection
1100Z
1900Z
Underforecast AM convection in NE
Overforecast PM convection in NE
1300Z
2100Z

12. Morning Underforecast and Resulting TMIs for 7/18/15
6-hour auto-CCFP and 6-hour HRRR Echo Tops valid 11Z
Indicates morning initiatives due to unexpected convective constraint
Morning underforecast impacted afternoon planning and actions
NCWD 11Z Observed Weather

13. 11Z Forecast Guidance (for 17Z) and Ops Plan for 7/18/15
Note LGA Runway Closure
6-hour auto-CCFP and 6-hour HRRR Echo Tops valid 17Z
NCWD 17Z Observed Weather
6-hour forecast (issuance 11Z) valid 17Z
Forecast: HRRR and CCFP in agreement indicating very little convection for ZNY, ZOB, or ZBW; some in ZDC
Observation: Most of ZNY, ZOB, ZBW and ZDC free of convection
1150Z SPT, valid 12Z or later
AFPs and GDPs/GSs for NY terminals not considered in Plan

14. 13Z Forecast Guidance (for 19Z) and Ops Plan for 7/18/15
6-hour auto-CCFP and 6-hour HRRR Echo Tops valid 19Z
AFPs inserted into plan after 17Z
NCWD 19Z Observed Weather
19Z Analysis
Forecast: HRRR indicating very little convection for ZNY, ZOB, or ZBW; Low confidence, sparse coverage CCFP in ZNY, ZBW, ZDC
Observation: Most of ZNY, ZOB, ZBW and northern ZDC free of convection

15. 14Z-15Z Forecast Guidance (for 21Z) 7/18/15
6-hour auto-CCFP and 6-hour HRRR Echo Tops valid 21Z
CAWS006 (issued 1438Z)
Valid 17Z to 00Z
Programs valid 1800Z to 0159Z
Likely forecast guidance during this time period drove decision to issue AFPs
NCWD 21Z Observed Weather
21Z Analysis
Forecast: HRRR indicating “scattered” convection in ZNY, ZDC; Low confidence, sparse coverage CCFP
Observation: “Scattered” convection in northern ZNY, eastern ZOB, and southern ZDC

16. 19Z-23Z Forecast Guidance and Ops for 7/18/15
CAWS009 (issued 1907Z)
valid 20Z to 00Z
NCWD 22Z Observed Weather
Lack of Significant Convection by 2200Z; AFPs cancelled over 3 hours early
CAWS009 (issued 1907Z)
Valid 20Z to 00Z
South-central NY/Western PA will drift east-southeastward and approach NY terminals by 00Z
Issued to provide additional details to 19Z CCFP which was noted as having “general good depiction of convection”

17. WX-PAC Similar Event Review for 7/18/15
7/18/15 (Saturday)
8/5/14 (Tuesday)
Similar Weather Search parameters:
ZNY-centric convective weather
Primary focus on similar weather from 17Z-23Z period
From output, we selected a similar weather day with more accurate forecast

18. Traffic Comparison on 7/18/15 Versus 8/5/14
Fewer total operations for Core NY airports (EWR, JFK, LGA) on 7/18/15 vs. 8/5/14
ATADS : Airport Operations : Standard Report
Facility=EWR, JFK, LGA
Itinerant
Date
Facility
Air Carrier
Air Taxi
General Aviation
Military
Total Operations
07/18/2015
EWR
756
275 19
1,050
JFK
1,184 87 13 2
1,286
LGA
563 64 4
631
Sub-Total for 07/18/2015
2,503
426 36
2,967
08/05/2014
888
389 8
1,321
1,179
145 18
1,342
1,009
167 22
1,198
Sub-Total for 08/05/2014
3,076
701 76
3,861
Percent Difference 7/18/15 vs. 8/5/14
19% Less
39% Less
53% Less
75% Less
23% Less

19. Forecast Guidance for 7/18/15 versus 8/5/14
Afternoon Convection – NCWD and 6-hour CCFP (Auto CCFP for 7/18/15)
Weather was “similar” on both days; however, forecasts for 8/5/14 were significantly better
Forecast for 8/5/14 shows focused area of high confidence, sparse coverage
Forecast for 7/18/15 shows broad area of low confidence, sparse coverage
7/18/15 CAWS indicated high confidence of TS development between 17Z and 19Z attempting to add focus and value to CCFP
7/18/15 (Saturday)
8/5/14 (Tuesday)
1900Z
1900Z
2100Z
2100Z
CAWS006 (issued 1438Z)
Valid 17Z to 00Z
2300Z
2300Z
Note: CAWS considered for strategic planning in 2015; No experimental CAWS was issued for 8/5/2014

20. WX-PAC Similar Event Review for 7/18/15
TMI Issuance Comparison - Afternoon
7/18/15 (Saturday)
8/5/14 (Tuesday)
Multiple AFPs, GDPs, and GSs used on 7/18/15
Only a single LGA GS on 8/5/14

21. AERO 7/18/15

22. AERO 8/5/14

23. Metric Comparison
On 8/5/14 - a Tuesday with 30% more demand than 7/18/15 - the afternoon weather impact was managed with a single LGA ground stop
Overall completion rates across NY terminals slightly better on 8/5/14
Overall cancellation / diversions / go-arounds comparable day over day
Airborne holding for JFK slightly lower on 8/5/14 during afternoon hours
Less gate arrival and departure delay on 8/5/14 for EWR, JFK during afternoon hours

24. Summary/Discussion

25. Summary / Discussion
Preceding analysis was a snapshot of two days in the NAS
Contrast NAS management strategies when weather doesn’t follow forecast
Similar Weather Search was used to identify similar convective events with very different NAS management strategies
Would probabilistic weather forecasts improve planning and execution of NAS strategies?
Illustrates NAS management challenges and impacts on outcomes
How do we incorporate this kind of analysis in daily NAS planning?
This is an important consideration as we implement PERTI

26. Summary / Discussion (continued)
Building upon Similar Weather search:
Develop a capability to identify similar forecasts from historical weather data
Identify subset of days where the forecast supported effective NAS management planning
Consider actions from these days to inform planning
Also identify days where the weather did not follow the forecast; analyze tactical adjustments made and compare against NAS performance metrics

27. Summary / Discussion (concluded)
Our ability to expand the NAS Planning window depends upon the inclusion of data driven analysis:
Similar weather and similar forecast search
Probabilistic forecast information
Statistics of objective forecast verification
Historical NAS performance outcomes

28. Summary / Discussion (concluded)
Future analytic capabilities needed:
Similar forecast search methodology
Better definitions of “good” vs. “poor” NAS performance
Methodology for application of probabilistic forecast information into plans and contingencies
Ability to execute against “80% forecast”, contingency planning for remaining “20%”

29. Summary / Discussion (concluded)
Closing the NAS Management Feedback Loop:
Collaboration with stakeholders
Data that drives decision making and collaboration on resulting plans
Capture of information for post-operations analysis
Incorporation into training, leading to improved NAS performance

30. Questions/Closing

31. Customer Comments from 7/18/15