Adaptive Observations at NWS

1. Adaptive Observations at NWS Lacey Holland, SAIC at EMC/NCEP/NWS Zoltan Toth, EMC/NCEP/NWS Acknowledgements: Dave Emmitt, Steve Lord, Sharan Majumdar, Jon Moskaitis, Craig Bishop http://wwwt.emc.ncep.noaa.gov/gmb/targobs/

2. Outline • WSR results • THORPEX • TOST • Future Work

3. Winter Storm Reconnaissance (WSR) • Based on collaborative research between university and gov’t agencies. EMC/NCEP/NWS established the program in 1999. • Dropwinsonde observations taken over the Pacific by aircraft operated by NOAA’s Aircraft Operations Center (G-IV) and the US Air Force Reserve (C-130s). • Observations are adaptive – collected only prior to significant winter weather events in areas that influence the forecast the most. • Results show 60-80% improvement over forecast area • Operational since January 2001

4. How WSR targeting happens… • Targets selected in areas where critical winter weather events with high forecast uncertainty may have a potentially large societal impact. • Sensitivity calculations performed using ETKF, and a decision is made (flight/no flight). • Observations are taken and used in operational analysis and forecast products by major NWP centers. • Verification is performed by comparing operational analyses/forecasts including the targeted data with analyses/forecasts excluding the targeted data.

5. 54 Predetermined Flight Tracks

6. Data Impact and Forecast Verification Flight track with initial impact Data impact Verification region with impact at 48-hrs Forecast improvement (red) and degradation (blue) Estimated forecast error variance reduction with possible flight tracks 48-hr verification

7. Results from previous years of WSR Surface Pressure RMS Error Vector Wind RMS Error From Toth et al. (1999)

8. Equitable Threat Score – WSR 2002

9. Equitable Threat Score – WSR 2003

10. WSR summary results • Overall, surface pressure, winds, and precipitation forecasts improved greatly over verification area

11. THORPEX • A WWRP/WMO 10 yr international program to accelerate improvements in short range (up to 3 days), medium range (3-7 days), and extended range (two weeks) weather forecasts • Examines observing system, data assimilation, forecast procedures, and economic application issues in their complex interactions; aims at improving forecasts for high impact weather events

12. THORPEX Observing System Test (TOST), Pacific 2003 • First of a series of Pacific and Atlantic observation tests/campaigns in support of the WWRP/USRP THORPEX Program • Measurements are complimentarily provided by the various ground-, airborne-, and space-based observing systems participating in the campaign, used as targeted input. • Winter Storm Reconnaissance (WSR) used as resource to target sensitive areas for observation over northeast Pacific (N of HI), and near the California coast

13. Pacific TOST 2003 Sensitive area at observation time Expected forecast error variance reduction and verification region Verification disk and area of expected impact Sensitivity calculations for TOST 2003 flight planning For Twin Otter (Emmitt et al.)

14. Future Work • Verify precipitation forecasts for all years of WSR; introduce new metric (storm track error) • Continue collaboration with LIDAR group (Emmitt et al.) in support of Pacific TOST or other campaigns • Test adaptive observations technique in OSSE environment, on global scales with simulated LIDAR measurements