1. Ensemble-4DWX update: focus on calibration and verification
Tom Hopson, Josh Hacker, Jason Knievel, Yubao Liu, Gregory Roux, Wanli Wu
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

2. Reminder of status in April 2009
Running WRF V
Had just finished running E-4DWX for ATC during Dec 2008 and Jan 2009, then returned configuration to DPG
Configured and ran E-4DWX for supporting UT Division of Air Quality
Improved MYJ and YSU PBL height diagnosis and PBL mixing
Added new graphics and improve post-processing flexibility (installation for GMOD and plotting historical case archive) and computing parallelisms
Fully automated calibration just being tested
Calibrated variables: 2-m T
Aberdine
Myj eta ; ysu korean scheme
Gmod - global model on demand (nsap)
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

3. Progress since April 2009 (1 of 2)
Improved scripting to manage the computational resources
Increased stations from 26 to 34 (regional)
Calibration hindcast increased from roughly 600 to over 1000 points
Increased hindcast size allows calibration of 2 additional lead-times (36hr, 42hr)
Included new skill measure for ensemble skill-spread relationship
Corrected over-dispersion of calibration process
Calibrated variables: 2-m T, 2-m Td (new)
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

4. Progress since April 2009 (2 of 2)
Examined results from CAD study at ATC (earlier talk)
Using performance of ensemble members to optimize DPG’s single-model configuration
Submitted proposal for brief paper in BAMS but was rejected. Have not decide whether to revise and resubmit
Continuing to work on scientific paper for MWR
Downtime of HPC (recent):
May 13-20, Agami4 failure
June 16-18, SGI node
July 11-19, power outage caused Agami4 failure
July 29 - August 4, Agami4 failure
Cad - clear air damming study
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

5. Calibration and verification
Ensemble calibration to correct predicted distribution
Calibration is needed for users capable of decision making with probabilistic guidance. Will be needed for foreseeable future
Verification of different ensemble characteristics is easily completed when performing calibration
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

6. Calibration: review and recap
“bias”
obs
Forecast
PDF
Probability
Probability
Forecast
PDF
obs
“spread” or “dispersion”
calibration
Temperature [K]
Temperature [K]
Calibration (and verification) is now fully-automated
Utilizes “persistence” if available
34 sites in and near DPG
Full calibration for all sites ~ 1X per week for each weather variable
Using lookup tables ~ every hour (8 hrs, was 1hr)
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

7. 3-hr dewpoint time series
Station DPG S01
Before Calibration
After Calibration
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

8. 42-hr dewpoint time series
Station DPG S01
Before Calibration
After Calibration
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

9. PDFs: raw vs. calibrated
Blue is “raw” ensemble
Black is calibrated ensemble
Red is the observed value
Notice: significant change in both “bias” and dispersion of final PDF
(also notice PDF asymmetries)
obs
ATEC-4DWX IPR, Aug

10. Troubled rank histograms
Counts
Counts
Ensemble #
Ensemble #
ATEC-4DWX IPR, Aug

11. 3-hr dewpoint rank histograms
Station DPG S01
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

12. 42-hr dewpoint rank histograms
Station DPG S01
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

13. RMSE of ensemble members
Station DPG S01
3hr Lead-time
42hr Lead-time
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

14. Significant calibration regressors
Station DPG S01
3hr Lead-time
42hr Lead-time
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug

15. Future plans
Refine lookup table process to decrease computation time (required as calibration data size continues to increase and new weather variables are added)
Implement for a) wind speed, b) wind direction, c) precipitation, d) surface pressure
Diagnose most informative model set to use operationally
Develop scheme for model points without surface observations over whole model domain
National Security Applications Program Research Applications Laboratory
ATEC-4DWX IPR, Aug