1. Products and Forecasts - Examples and experiences Yuejian Zhu and Hong Guan Ensemble Team EMC/NCEP/NWS/NOAA Presents for NWP Forecast Training Class March 31, 2015, Fuzhou, Fujian, China

2. Background NDGD – National Digit Guidance Database Guidance's are produced from NWP output, post process and et al. NDFD – National Digit Forecast Database Forecasts are issued from WFO forecasters based on all different guidance Coverage and resolution – CONUS – 2.5km – Alaska – 3km – Hawaii – 2.5km – Puerto Rico – 2.5km – Guam – 2.5km

3. US NWS NDFD forecast elements and projections (2014)

4. High Impact Weather and Extreme Forecast

5. Hurricane Katrina (2005)

6. Early prediction: Friday – August 26 NHC’s prediction ECMWF ensemble forecast: Strike probability from Friday – August 26 0-120 hours 120km radius

7. Typhoon Morakot (2009)

8. Courtesy of Bill Kuo

10. 10 Resolution makes difference for Typhoon Morakot Ini: 2009080600 T126 ensemble T190 ensemble Ini: 2009080700 T126 ensemble T190 ensemble Most models do not make right forecasts

11. Typhoon Megi (2010) 2010101512 2010101612 20101017122010101812 1.NCEP 2.CMC 3.ECMWF 4.3-ENS

12. Derecho (2012)

13. Date(s) June 29–30, 2012 Duration ~18 hours (10:00 AM-4:00 AM) Track length ~800 Miles Peak wind gust 91 mph (Fort Wayne, Indiana) Largest hail 2.75 Inches (Bismarck, Illinois) Fatalities 28 fatalities Damage $2.9 billion[1] Areas affected United States Midwest, United States Mid-Atlantic A moderate risk area was issued by the SPC for the areas downstream of the derecho. It was later expanded eastward. Derecho (2012)

14. Sandy Case Study for NEXT GEFS Period: 10/22 – 10/28/2012 Named: 10/23/2012 Yuejian Zhu EMC/NCEP September 15 2014 Acknolegements: Dingchen Hou, Xiaqiong Zhou and Jiayi Peng

15. 00UTC 20121022 (8 days) Opr: T254L42 (55km) Opr: T254L42 (55km) Para: T574L64 (33km) Para: T574L64 (33km) 06UTC Thick blue: ensemble mean Bimodality? Red arrow means good forecast

16. 12UTC 20121022 (7.5 days) Opr: T254L42 (55km) Opr: T254L42 (55km) Para: T574L64 (33km) Para: T574L64 (33km) 18UTC Thick blue: ensemble mean Bimodality?

17. Opr: T254L42 (55km) Opr: T254L42 (55km) Para: T574L64 (33km) Para: T574L64 (33km) 20121026 (4 days) 00UTC 06UTC

18. Opr: T254L42 (55km) Opr: T254L42 (55km) Para: T574L64 (33km) Para: T574L64 (33km) 20121028 (2 days) 00UTC 06UTC

19. Short Summary for Sandy case Higher resolution and new model improve the forecast skill for most lead-time, especially for longer lead-time (day 7-8). Higher resolution and new model have excellent predictability around 8-days Bimodality of forecast tracks is clearly for early lead- time – around 30-32N Very good forecasts for short lead-time (less than 4- 5 days) of both production and parallel Problem/concern: – Forecast inconsistency from cycle to cycle since initial condition changes, especially for Oct. 23 - 24

20. March 6 2013 – winter storm “Saturn” Heavy, wet late season snowstorm likely to paste D.C., Mid-Atlantic Wednesday Tuesday night to Wednesday night for potential of at least 5 inches of snow for entire region* From 11:47 AM Update: 1:55PM

21. FEDERAL OFFICES in the Washington, DC, area are CLOSED. Emergency and telework-ready employees (employees with approved individual telework agreements) required to work must follow their agency’s policies, including their approved individual telework agreement All Howard County public schools and offices are closed today, Wednesday, March 6, 2013. All evening activities in schools, both school-sponsored and community-sponsored, are canceled. This includes high school athletic practices and games.

22. Review of 2015 NE Blizzard 01/26 12UTC – 01/27 12UTC 2015 Yuejian Zhu EMC/NCEP/NWS Jan. 27 2015 Acknowledgements: Hong Guan, Yan Luo and Xiaxiong Zhou ESRL’s EFI maps

23. WFO forecast (48 hours accumulation)

24. CCPA 24 hours accumulation (mm) ENDING 12 UTC 20150127 ENDING 12 UTC 20150128

26. Ensemble Forecast - Uncertainty Small and large uncertainty. 1 day (large uncertainty) = 4 days (control) = 10-13 days (small uncertainty) Toth and Zhu (2001)

34. Ensemble Based Probabilistic Quantitative Precipitation Forecast (PQPF) Valid: 2015012612 – 2015012712 Amount 24hr >25.4mm (1 inch) PROD PARA Initial Time 2015012400 2015012500 2015012600 NCEP GEFS PROD/PARA Forecast difference NCEP GEFS PROD/PARA Forecast difference

35. Ensemble Based Probabilistic Quantitative Precipitation Forecast (PQPF) Valid: 2015012612 – 2015012712 Amount 24hr >25.4mm (1 inch) Initial Time 2015012100 2015012300 2015012200 PROD ECMWF PARA

36. Ensemble Based Probabilistic Quantitative Precipitation Forecast (PQPF) Valid: 2015012612 – 2015012712 Amount 24hr >25.4mm (1 inch) PROD PARA Initial Time 2015012400 2015012500 2015012600 ECMWF Here is the difference EC’s ensemble predicted 50%+ chance for 1 inch prcip over NY city Here is the difference EC’s ensemble predicted 50%+ chance for 1 inch prcip over NY city

37. NCEP GEFS failed on Oct. 3-4 2014 First fail – 18UTC Oct. 3 rd 2014 – Friday – No product for GEFS, SREF, Wave and NAEFS Second fail – 12UTC Oct. 4 th 2014 – Saturday – Delayed 3hrs for all products and downstream Where is the problem? – Failed on first integration time step Point to short wave radiation – In fact, the problem is longwave radiation code secdiff(j) = a0(j) + a1(j) * exp( a2(j)*pwvcm) < 0.0 It was never happened before – Protect – cost? Morning of Oct. 10 th 2014 – Friday – Announced we found a problem

38. The art of good forecasting 经验预报 Meteorologist 最好的预报 Modified NWP forecast A A2A2 持续性预报 Persistence 最好的数值预报 World Best NWP