Weather Impacts on System Operations

1. Weather Impacts on System Operations Importance of the Forecast in TFM Planning Jim Ries Oct 19, 2006

2. Overview • Traffic Flow Management (TFM) Mission • TFM Decisions and Weather Information • Forecast - A, B, C’s • Case: July 27, 2006

3. Traffic Flow Management (TFM) Mission • The United States Traffic Management System mission is to balance Air Traffic demand with system capacity to ensure the maximum efficient utilization of the National Airspace System (NAS). • The FAA's Air Traffic Control System Command Center (ATCSCC) monitors and manages the flow of Air Traffic throughout the NAS, producing a safe, orderly, and expeditious flow of traffic while minimizing delays.

4. Air Traffic Flow Chart ARTCC TRACON TRACON Tower Tower Off On Out In ATCSCC ATCSCC • The ATCSCC monitors conditions throughout the NAS in all domains • “Weather” is the largest contributor to system delays and in the reduction of NAS resources • Comprehensive weather information is needed throughout the pre-tactical (prior to the days operation), strategic planning (2-8 hours), and tactical (0-2 hours) time periods • Weather conditions monitoring and weather forecast play a vital role Pre-Tactical …………Strategic Planning …Tactical Prior to days ops. 2-8 hours <2 hours – airborne flights

5. Decision Support Tools: Terminal/TRACON Demand/Capacity ETMS - TSD FSM Weather Info METAR TAF ITWS/RAPT (1 hour forecast)

6. Decision Support Tools: Terminal cont. • TFM applies Ground Delay Programs (GDPs) and Ground Stops (GS) to mitigate reduced capacity at terminals • MIT’s, (Miles-in-Trail) • APREQs or other departure restrictions Example: GDP for ORD and EWR on 7/27/2006

7. Current – RADAR Winds aloft TSD Decision Support Tools: En-Route • En-route weather products and forecast that are available as TFM aids • current time out to 6 hours CIWS Echo-Tops CIWS - MIT LL Up to 2 hour forecast Current – RADAR TSD CCFP (4 hour) 2, 4, 6 hour snapshot available on TSD

8. Decision Support Tools: En-Route cont. • Other products • 12-24-36 hour surface progs (AWC, WSI) • Sigwx charts • Sigmets, CWAs, MISs • CCFP chat monitoring WARP NCWF1 – TSD (1-hour forecast) • Possible TFM actions • Air Space Flow Programs (AFP’s) • MIT’s • Holding • Re-Routes

9. Decision Support Tools: En-Route cont. AFP FCAA02is defined by the northern boundary of ZDC from MRB extending southeastward. Altitude Filters: 120 – 600 Arrival Filters: ZNY & ZBW Departure Filters: None Likely weather for use: Weather close in to or moving toward the N.Y. Metro area. Weather Triggers: Intense weather that is close in or moving toward the N.Y. Metro area and is or will likely directly impact the N.Y. Metro airports. CIWS Echo-Tops FCA002 NESP Rate Guidelines Flow through ZDC: Low Weather Impact: 100 – 110 Rate/Hour Med Weather Impact 90 – 100 Rate/Hour High Weather Impact 80 – 90 Rate/Hour

10. Planning Process – Operations Plan • CCFP is the cornerstone of the planning process • Impact to air traffic and TFM decisions is significant

11. Location, Location, Locationand Timing • Just as in real estate, the location of convective weather is critical to the amount of impact and the type of TFM mitigation applied; • For example: TFM proactively moving airplanes into an area where convection unexpectedly materialized • If the forecast indicated here • Then, a planned re-route into the weather, ouch

12. Proactive SWAP • Proactive reroutes are usually implemented after collaboration on the OP. In the example above, current scattered thunderstorms along a frontal zone are forecast to increase in intensity and impact the NAS throughout the afternoon. The proactive actions include: • Canadian Route: shifts volume north of the constrained area. • ZOB Chokepoints: structure the remaining major eastbound arrival volume, allowing ATC to accommodate deviations and remaining flights. • MGM Playbook: shifts volume south of the constrained area. • During significant events, multiple playbook routes may be used in association with an FEA or FCA.

13. Proactive Outcomes • As convective activity develops, pre-established routes around areas of system impact allow ATC to accommodate user operations closer in to the weather. Eastbound Playbook routes also allow for increased availability of westbound departure routes with deviations in lieu of SWAP or CDR use. Should the system impact become more significant, westbound CDRs may be utilized to minimize departure delays. • Ground stops and other high-impact traffic management initiatives are kept to a minimum, only being necessary where unforeseen volume and complexity affects the enroute structure, or where weather impacts terminal areas unrelated to SWAP routes.

14. Forecast A, B, C’s • To apply proactive actions the forecasters need to maintain the A, B, C’s • Improve forecast skill • A: Accuracy • Correctly locating the hazard based on the forecast criteria • B: Bias (Precision) • Reducing under or over forecasting • C: Consistency • Reliability between forecast periods

15. July 27, 2006 • Accuracy • Correctly forecasting the location of convection over the Northeast corridor is significant • On this day, departure route blockage created gridlock conditions at ORD

16. July 27, 2006 • Bias (precision) • Under forecast can catch TFM off guard and the system becomes reactive • Over forecasting can lead to excessive re-routes or unnecessary restraints in the system

17. Issued 17z July 27, 2006 • Consistency • Valid 21z; • issued at 15z, 17z, 19z • TFM actions can last all day (i.e. GDP’s), radical changes can cause unrecoverable delays for the NAS customers or create costly diversions Issued 19z Issued 15z

18. July 27, 2006 Operations Plan

19. Questions? NOTE: movie of traffic and weather for ORD and ZNY for the July 27 event follows:

20. Chicago and MidwayORD Arrivals – MaroonORD Departures – PinkMDW Arrivals - OliveMDW Departures – BlueDTW Arrivals – TurquoiseDTW - Green