1. MIT Lincoln Laboratory Evans benefits ARAM1 jee 6/4/2015 Assessment of Aviation Delay Reduction Benefits for Nowcasts and Short Term Forecasts James Evans and Mike Robinson Weather Sensing Group MIT Lincoln Laboratory

2. Evans benefits ARAM2 jee 6/4/2015 Outline Motivation –Quantification of user benefits for nowcasts and short term forecasts is increasingly important in time of government austerity and increased commercial applications –Aviation is a particularly important application since it has key elements needed for practical use of these forecasts Real time communications Ability to react to weather Users can be trained Urgent current need Causality of delays Key elements of nowcast/short term forecast usage Assessing delay reduction for a contemporary system Suggestions for nowcast/short term forecast developers

3. MIT Lincoln Laboratory Evans benefits ARAM3 jee 6/4/2015 What is Generating the US Delays: NAS Network Constraints Paradigm A: Insufficient adverse weather capacity at airports Paradigm B: Convective storms impact the network by reducing the capacity of jet routes, en route sectors and terminals. Bad delay days invariably involve en route and terminal demand > effective capacity… ability to reroute is a key factor in delay magnitude Assessing benefits by comparing delays is very difficult due to differences in weather severity and demand 1 2 3 4 5 Airport

4. MIT Lincoln Laboratory Evans benefits ARAM4 jee 6/4/2015 CIWS Benefits Approach Multi-day “Blitz” observations of product usage Detailed Case Study Modeling Observations during “Blitz” Events Cases identified in Daily feedback Frequency of convective weather at various ATC facilities Individual Delay Savings Events ‘Annualized’ CIWS Delay Reduction Benefits # of improved ATC decisions Average Benefit (for each ATC decision) ZAU ZID ZOB ZBW ZNY ZDC C90 N90 SCC ARTCC TRACON ATCSCC FedEx Airline User Facilities Visited in 2003

5. MIT Lincoln Laboratory Evans benefits ARAM5 jee 6/4/2015 Coordination for Decisions Davison and Hansman, ATC Quarterly 2002

6. MIT Lincoln Laboratory Evans benefits ARAM6 jee 6/4/2015 CIWS Domain Delay Benefits in 2003 3. 6. Unquantifiable with 2003 Assessment Approach 439 311 276 69 52 953 756749 196 194 183 157 110 14 1289 3314 Estimate of Annual Benefit Occurrences Quantifiable Benefit Annual benefit 11,702 hours delay reduction ($43.8 M) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Annual benefit 28,383 hours delay reduction ($108.7 M) 3500 3000 2500 2000 1500 1000 500 0 1Situational awareness 2Inter facility coordination 3Routes open longer 4Improved Arrival Transition Area (ATA) management 5Reduce workload 6Proactive reroutes 7Directing pathfinders 8More SWAP departures 9Shorter/fewer ground steps 10Directing traffic through gaps 11Improved safety 12Close route proactively 13Optimize runway usage 14Avoid ground stop 15Reduced MIT restrictions 16Improved use of Ground Delay Program (GDP)

7. MIT Lincoln Laboratory Evans benefits ARAM7 jee 6/4/2015 The Weather Delay Statistics Challenge Although many nowcasts/short term forecasts have been introduced since 1998, reducing delays has been difficult due to other changes in the NAS

8. MIT Lincoln Laboratory Evans benefits ARAM8 jee 6/4/2015 Benefits Assessment Suggestions Use intensive user facility observations during adverse weather before forecast deployment to better understand the user decision “system” and, establish baseline –May need to modify forecast content to address key user issues Intensive user facility observations after forecast deployment plus detailed analysis to 1.Obtain initial quantitative results, and 2. focus aviation delay statistical analysis Look in detail at flight tracks and wide area sensor (e.g., weather radar) data as opposed to relying only on surface observation reports (METARs) to characterize convective weather impacts Be prepared to acquire an in depth understanding of the operations of the aviation system if you must carry out delay (and, possibly safety) analyses

9. MIT Lincoln Laboratory Evans benefits ARAM9 jee 6/4/2015 Summary Weather continues to dominate overall US delays and, convective weather causes large unexpected delays that are particularly disruptive to the system customers Policy changes make it critical to assess whether the aviation system is managing weather impacts better Assessment of performance is challenging –Convective weather events are not repeatable –Many other factors (traffic management system, procedures, and/or demand) impact delay User feedback plus detailed observations and data analysis have shown very high benefits for nowcasts and short term forecasts Development of reliable delay statistics based approaches will be a topic of research for a number of years