FAA Tactical Weather Forecasting In The United States National Airspace Bill Dupree Marilyn Wolfson Rick Johnson, Jr. Bob Boldi Evelyn Mann Kim Theriault Calden Carol Wilson Paul Bieringer Brian Martin Haig Iskenderian

Aviation Delay Problem Aviation Weather Delays US Air Traffic Density Forecast Requirements $200 M CIWS 2B/yr total delays See Jim Evans talk Reduce Delay Increase Capacity Keep routes open longer Anticipate reroutes Reduce ground delay Improve approach management Situational awareness Improve Safety Increase airport capacity to meet projected demand Make air traffic flow over land & sea more efficient Increase or improve airspace capacity in the 8 major metro areas & corridors that most affect total system delay Increase on-time performance of scheduled carriers Improved flight during severe en-route wx conditions Improved flight during unfavorable airport wx Reduce commercial airline fatal accident rate Reduce the number of fatal accidents in GA Reduce cabin injuries caused by turbulence Accurate Wx and Forecasts Current Rapid Update (2-5min) High-resolution (1km) Reliable

Motivation for Precip Forecast (Terminal Delays) 04:00 Z 03:30- 5:10 Z 10:30-12:10am Local Time forecasts claimed line would remain North of Airport. 22 planes missed sort 2 million/plane 44 million in losses Here is a snapshot of the wx and the Memphis tracon at 11PM. The red tracks are arrivals and the black tracks are either fly-overs or tracks that we’re not sure of. As you can see the wx is still to the north of the runways and the planes are landing successfully. Unfortunately, this is a snapshot at midnight and as you can see the wx is just about on the runways and there are microbursts and gustfronts associated with the convection. Now I’ll roll the movie and let it loop twice. As you can see right after midnight most of the planes that were trying to land couldn’t and had to divert to southern airports because they were low on gas. Even if the refueled and tried to go around the line and land from the north they would have missed the package sort. Unfortunately this episode cost the parcel carrier millions of $ since they had to deliver all the next day packages for free. Memphis, TN 15 July 1997 Vertical Integrated Liquid Water (VIL)

Motivation for Echo Tops Forecast (En Route Delays) VIL (levels) Echo Tops (kft) Flights Shown: All flights at or above 4.9 km (16,000 ft)

Overview Problem 0-2 Hour Weather Forecast System Research Efforts Evolution of Forecast System Forecast Components Forecast Products Performance Research Efforts

Evolution of the Forecast System 1998: 1-hr Forecast in ITWS 1999: Growth/Decay Tracker Patent 2002: 2-hr Forecast (Multi-scale Tracking & Weather Classification) 2003: Growth/Decay Trending 2003: Winter Forecast 2005: Echo Tops Forecast 2005: Satellite/Precip Loop 1998 1999 2000 2001 2002 2003 2004 2005 Integrated Terminal Weather System (ITWS) Corridor Integrated Weather System (CIWS) New York Orlando Memphis Dallas NEXRAD ASR-9 Radars Canadian Radars

Weather Classification NEXRAD Precipitation (VIL) Weather Classification 9 July 2003 17:17 Z Line Storms Small Cells Large Cells Stratiform Rain Multi-scale Tracking Forecast Engine

Multi-scale Tracking Technology Weather Classification Envelope Envelope Vectors VIL 9 July 2003 Weather Classification Image 13 x 69 km Multi-scale Tracking Vectors Cell Cell Vectors 13 km

Growth and Decay Trends Difference Images (Each Advected to Analysis Time) Trend Images VIL & Echo Top Images Prior Image Current Image Growth/Decay Boundary Growth Apply match template kernels to each pixel VIL

Generation of 2-hr Forecast Weather Classification Multi-scale Tracking Growth & Decay Trends Boundary Growth Echo Top Cap VIL Forecasts Thunderstorm Evolution Models Echo Top Forecasts

VIL Forecast Verification 60min (25 June – 1 July 2005) Hit Miss False Alarm Loop twice: One week of data not just an isolated case. Point out how good performance. How it cycles from 16-17Z. Coupling of Miss and FA for airmass. Still useful for air traffic. Note Convective Initiation: ETF even better performance.

Overview Problem 0-2 Hour Weather Forecast System Research Efforts

Convective Initiation Forecasting (Front and Wind Boundary Locations) DATA SOURCES Doppler Radar Surface Sensors Model Winds Surface Wind Analysis System Temporal Integration Filters Automated Front/Boundary Detections “Low Altitude wind shear” Space Time Mesoscale Analysis System (STMAS). Currently uses the largest analysis domain Utilizes largest surface observational database (no radar data) 5 km horizontal resolution only at the surface 15 minute update rate, ~45 minute product latency Corridor Boundary Layer Wind Analysis System (CBOUND) Utilizes Doppler radar and surface observations 1 km horizontal resolution, ~250 m vertical resolution in BL 5 minute update rate and 5 minute product latency New convection often develops in areas where fronts and wind boundaries are present

Automated Front Detection 20 April 2005 (10-5 sec-1) Data from NOAA FSL: Space Time Mesoscale Analysis System (STMAS)

Summary Demonstrating 0-2 hr forecasts of VIL and Echo Tops Covers busiest air traffic sectors of US Performance is consistently excellent User feedback has been crucial in system development High benefits now being realized Convective initiation forecasts still needed Promising new techniques for automated boundary detection Displayed: 8 ARTCC, 6 TRACONS, Command center, major airline carriers.

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