1. Center for Analysis and Prediction of Storms (CAPS) Briefing by Ming Xue, Director
CAPS is one of the 1st NSF Science and Technology Centers established in 1989.
CAPS is the pioneer of radar data assimilation and storm-scale numerical weather prediction (NWP).
CAPS leads OU’s efforts of CASA, an NSF ERC for Collaborative Adaptive Sensing of Atmosphere
CAPS is part of the Model Development and Enhancement (MDE) Product Development Team (PDT) of FAA and contributes to the operational RUC/RR and NAM model improvement.
CAPS developed and supports a complete high-resolution NWP and data assimilation system, the ARPS (Advanced Regional Prediction System).
CAPS is one of the 4 initial partners developing the community WRF model
CAPS works closely with NSSL/SPC via HWT and other joint projects.

2. 50-m Grid Forecast v.s. Observation (Movie)
Short-Range Radar Initialized Prediction of Thunderstorms, Strong Winds, Gust Fronts, Downbursts, and Tornadoes using NWP Model
50-m Grid Forecast v.s. Observation (Movie)
Movie
Forecast Low-level Reflectivity Observed Low-level Reflectivity
43 minute forecast 2

3. Tornadoes of 8-9 May 2007 10:54pm (0354Z) Minco Tornado
El Reno tornado
© Patrick Marsh
Minco tornado
10:54pm (0354Z) Minco Tornado
9:54pm (0254Z)
8:30pm (0130Z)
© KSWO TV
7:21pm (0021Z) Lawton Tornado
Lawton tornado

4. 2 hour forecast of a tornado using 88D and CASA radar data on a 400 m grid
Minco tornado
Observed tornado
Predicted tornado
Perfect timing and <10 km position error

5. Realtime high-resolution (400 m) wind analysis using obs from multiple Doppler radars and surface stations
Analysis every volume scan.
Ideal for airport-scale warning and nowcasting

6. Impact of assimilating polarimetric variables
Blue: ZhZdr Gray: ZhZdp Green: ZhKdp Pink: ZhZZK
Jung et al. (2008a,b,c MWR) 6

7. Prediction of Convective Initiation 12 June 2002 IHOP Case
3km
Starting from 18 UTC IC
6 h assimilation at 1 h intervals
Sat. obs
(Liu and Xue 2008 MWR)
2120 UTC, from I.C. at 1800 UTC 7

8. Initiation of by colliding boundaries 6-7 h into forecast
radar observation model forecast
@0100, 13 June, 2002 8

9. Initiation of New Thunderstorms from Outflow
Boundaries of Earlier Predicted Thunderstorms
5 hour forecast 9

10. Initiation of New Thunderstorms from Outflow
Boundaries of Earlier Predicted Thunderstorms
6.5 hour forecast 10

11. Initiation of New Thunderstorms from Outflow
Boundaries of Earlier Predicted Thunderstorms
6 hour forecast

12. Initiation of New Thunderstorms from Outflow
Boundaries of Earlier Predicted Thunderstorms
7 hour forecast

13. 10-minute time interval movie
Hazardous Weather Testbed Spring Experiments (10 member 4 km ensemble and 2 km high-res forecast)
10-minute time interval movie
(from 2007 experiment)

14. 21 h ensemble forecasts valid at 18Z, May 24, 2007
CN N P N P2
PH Ph PH PH PH3
OBS km forecast
Probability of Z>35 dBz

15. Example for Spring 2008 HWT Experiment Assimilating 120+ WSR-88D Radars
Initial Reflectivity Field without Radar Data With Radar Data
Movie of 4 km forecasts with and without radar data

16. Other work and comments
First ever study directly assimilating polarimetric radar data (Jung et al. 2008a,b,c, Monthly Weather Review)
Working on assimilating clear air (refractivity and winds) data important for thunderstorm initiation
Implemented a generalized cloud analysis package using NSSL mosaic reflectivity data in GSI for RR (Hu, Weygandt, Xue and Benjamin. 2007)
Working on refining and testing Z and Vr assimilation in GSI for RR and HRRR
Extensive work with Ensemble Kalman Filter data assimilation
Assimilation of radar and other high-res data key to the short-range prediction of hazardous weather important to aviation.
Ultimate goal: Explicit, thunderstorm-resolving, continuously cycled (~10 min intervals), ensemble-based probabilistic data assimilation and prediction, for strong winds, clouds and visibility, and turbulence from few minutes to several days - the FAA NextGEN goals also.