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 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. 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. 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 OutIn OffOn Tower TRACON ARTCC Tower ATCSCC Air Traffic Flow Chart 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 TFM applies Ground Delay Programs (GDPs) and Ground Stops (GS) to mitigate reduced capacity at terminals MIT’s, (Miles-in-Trail) MIT’s, (Miles-in-Trail) APREQs APREQs or other departure restrictions restrictions Example: GDP for ORD and EWR on 7/27/2006

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

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

9. Decision Support Tools: En-Route cont. CIWS Echo-Tops FCAA02 is 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. 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 FCA002 AFP

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, Location and 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 Then, a planned re-route into the weather, ouch If the forecast indicated here

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

15. July 27, 2006 Accuracy 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) 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. July 27, 2006 Consistency Consistency Valid 21z;Valid 21z; issued at 15z, 17z, 19zissued 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 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 15z Issued 17z Issued 19z

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 Midway ORD Arrivals – Maroon ORD Departures – Pink MDW Arrivals - Olive MDW Departures – Blue DTW Arrivals – Turquoise DTW - Green