Results from Winter Storm Reconnaissance Program 2007

1. Results from Winter Storm Reconnaissance Program 2007 Yucheng SongIMSG/EMC/NCEP Zoltan TothEMC/NCEP/NWS Sharan MajumdarUniv. of Miami Mark ShirleyNCO/NCEP/NWS http://www.emc.ncep.noaa.gov/gmb/targobs Meeting of the Working Group on Space-based Lidar Winds, Monterey, CA 5-8 Feburary 2008

2. Winter Storm Damages can’t be underestimated

3. Acknowledgments • NWS field offices, HPC/NCEP and SDMs • NOAA G-IV and the USAFR C-130 flight crews • CARCAH (John Pavone) • Jack Woollen - EMC • Russ Treadon - EMC • Mark Iredell - EMC • Istvan Szunyogh – Univ. of Maryland • Craig Bishop - NRL • + others who have contributed!

4. Winter Storm Reconnaissance Program Operational since January 2001 Objective: Improve Forecasts ofSignificant Winter Weather Events Through TargetedObservations in Data Sparse Northeast Pacific Ocean Adaptive approach to collection of observational data: 1) Only Prior to SignificantWinter Weather Events of Interest 2) Only in Areas that Influence high impact event Forecasts Results: 70+% of Targeted Numerical Weather Predictions Improve 10-20% error reduction for high impact event forecasts 12-hour gain in predicting high impact events – earlier warnings possible

5. About the Winter Storm Reconnaissance (WSR 2007) Program • Took place 20 Jan – 13 March 2007 • Dropwinsonde observations taken over the NE 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 of interest • in areas that might influence forecast the most. • 31 flights, around 478 dropsondes this winter which is increased from 342 drops last year • Several communication problems from C-130s

6. About the Winter Storm Reconnaissance (WSR 2007) Program – (continued) • Evaluation methods • NCEP Global Forecast System running on T126L28 resolution • Three sets of experiments • A. GFS run with all the WSR dropsondes being assimilated • B. GFS run without WSR dropsondes data rejected on all days • C. GFS run with WSR dropsondes data rejected only on the WSR observation day (i.e. the guess files are the same as the operational) • Experiment Design - Experiment C is used for signal propagation studies, it can single out the data impact due to current dropsondes clearly without interferences from the previous dropsondes

7. Targeting methods – ETKF application example Dropsondes to be made by G-IV Storm The ETKF spotted the target area Expected error reduction propagation

8. Forecast verification(Jan 20-22,2007 A vs.C) 500mb height Sea Level Pressure Red contours show forecast improvement due to WSR dropsondes, blue contours show forecast degradation 250mb height

9. Impact of Dropsondes Surface pressure Precipitation Contours are 1000mb geopotential height, shades are differences in the fields between two experiments 500mb height 250mb height

10. Comparison of ETKF signal and NCEP signal(A vs. C) The ETKF signal The NCEPsignal

11. Valentine’s day storm2007 One of the largest winterstorms that strikes interior sections of the Northeast since 1950

12. NCEP requested two missions • A flight is requested from Honolulu along track 34 with a control time of 11/00Z Verification information is as follows: Verification time: 2007021400 Latitude: 36 Longitude: 86 Priority: HIGH Comments: East Coast winter Wx • A flight is requested from Honolulu along track 46 with a control time of 12/00Z Verification information is as follows: Verification time: 2007021412 Latitude: 38 Longitude: 77 Priority: HIGH Comments: East Coast winter wx

13. Comparison of ETKF signal and NCEP signal

14. Valentine’s day Storm • Weather event with a large societal impact • Each GFS run verified against its own analysis – 60 hr forecast • Impact on surface pressure verification • RMS error improvement: 19.7% • (2.48mb vs. 2.97mb) Surface pressure from analysis (hPa; solid contours) Forecast Improvement (hPa; shown in red) Forecast Degradation (hPa; blue)

15. Valentine’s day Storm • Weather event with a large societal impact • Each GFS run verified against its own analysis – 60 hr forecast • Impact on surface pressure verification • RMS error improvement: 19.7% • (2.48mb vs. 2.97mb) Surface pressure from analysis (hPa; solid contours) Forecast Improvement (hPa; shown in red) Forecast Degradation (hPa; blue)

16. Valentine’s day StormImpact on precipitation (A.vs.C)

17. Forecast Verification for Wind (2007) 10-20% rms error reduction in winds RMS error reduction vs. forecast lead time

18. Forecast Verification for Temperature (2007) 10-20% rms error reduction in Temperature 60 hr forecast is equivalent to 48hr forecast RMS error reduction vs. forecast lead time

19. Breakdown for cases

20. Individual Case Comparison VR OBSDATE P T V OVERALL REGION FHOUR AK 20070120 1 1 1 1 130W ,55N 48 C 20070128 1 -1 -1 -1 97W ,33N 72 W 20070207 1 -1 -1 -1 123W ,40N 48 W 20070208 -1 1 1 1 123W ,40N 24 W 20070209 1 1 1 1 122W ,38N 24 W 20070211 1 -1 1 1 110W ,32N 48 E 20070211 1 -1 -1 -1 86W ,36N 72 W 20070212 -1 -1 -1 -1 110W ,32N 36 E 20070212 1 1 1 1 77W ,38N 60 W 20070215 1 -1 1 1 120W ,45N 24 AK 20070216 1 -1 1 1 135W ,60N 48 W 20070217 1 1 1 1 124W ,40N 36 W 20070218 1 1 1 1 117W ,40N 24 C 20070218 1 1 1 1 108W ,37N 48 C 20070218 1 1 1 1 90W ,35N 72 W 20070220 1 1 1 1 122W ,40N 60 W 20070221 1 1 1 1 122W ,40N 36 C 20070221 1 -1 -1 -1 96W ,43N 72 C 20070221 1 1 1 1 93W ,40N 96 W 20070222 1 1 1 1 120W ,37N 24 C 20070222 -1 -1 -1 -1 90W ,40N 72 E 20070222 -1 1 1 1 80W ,36N 96 W 20070223 1 1 1 1 123W ,42N 48 C 20070223 1 -1 1 1 94W ,37N 48 W 20070225 -1 1 1 1 123W ,42N 48 W 20070226 1 1 1 1 123W ,42N 24 W 20070228 1 1 1 1 122W ,43N 36 E 20070228 -1 1 1 1 86W ,35N 48 W 20070302 1 1 1 1 125W ,49N 36 AK 20070306 -1 -1 -1 -1 130W ,55N 36 E 20070308 1 1 1 1 85W ,34N 108 W 20070308 -1 1 -1 -1 124W ,46N 60 W 20070309 1 -1 1 1 124W ,45N 72 C 20070310 -1 -1 1 -1 93W ,37N 48 C 20070311 -1 1 -1 -1 96W ,32N 36 E 20070311 -1 1 -1 -1 81W ,42N 96 E 20070313 -1 1 1 1 81W ,42N 48 1 denotes positive effect 0 denotes neutral effect -1 denotes negative effect 26 OVERALL POSITIVE 0 OVERALL NEUTRAL 11 OVERALL NEGATIVE 70% improved 30% degraded OVERALL EFFECT:

21. Overall results for Surface pressure Of all cases: 25 improved 0 neutral 12 degraded

22. Overall results for Temperature Of all cases: 24 improved 0 neutral 13 degraded

23. Overall results for Vector wind Of all cases: 27 improved 0 neutral 10 degraded

24. Overall results for Humidity Of all cases: 24 improved 0 neutral 13 degraded

25. WSR Summary statistics (2004-2007) 25+22+19+26= 92 OVERALL POSITIVE CASES. 0+1+0+0 = 1 OVERALL NEUTRAL CASES. 10+7+8+11 = 36 OVERALL NEGATIVE CASES. 71.3% improved 27.9% degraded OVERALL EFFECT:

26. WSR 2008 • More ensemble members, efficient ET KF codes • No G-IV due to new instrument installation • New tracks for NOAA P-3 flying out of Portland, OR

27. Background Slides

28. Composite summary maps 139.6W 59.8N 36hrs (7 cases) - 1422km 92W 38.6N 60hrs (5 cases)- 4064km 80W 38.6N 63.5hrs (8 cases) - 5143km 122W 37.5N 49.5hrs (8 cases) - 2034km Verification Region Verification Region

29. ETKF predicted signal propagation

30. ETS 5mm 10mm 16.35 18.56 CTL 16.50 20.44 OPR Positive vs. negative cases 4:1 3:1 Precipitation verification • Precipitation verification is still in a testing stage due to the lack of station observation data in some regions.