Codes Employed

The components of the end-to-end forecast system used in the QNSE Sensitivity Test included:

    • WRF Preprocessing System (WPS) (v3.1.1)

    • WRF-ARW model (tag from the WRF Repository, based on v3.1.1        with a considerable number of updates)

    • WRF Post Processor (WPP) (v3.1)

    • Model Evaluation Tools (MET) (v3.0.1) *Includes PB2NC error       described here

    • NCAR Command Language (NCL) for graphics generation

    • Statistical programming language, R, to compute confidence        intervals

Domain Configuration

    • A contiguous U.S. (CONUS) domain with 15-km grid spacing was employed for this test covering complex terrain, plains and coastal regions spanning from the Gulf of Mexico, north to Central Canada in order to capture diverse regional effects for worldwide comparability.

Click thumbnail for larger image.

    • 403 x 302 gridpoints, for a total of 121,706 horizontal gridpoints

    • 56 vertical levels (57 sigma entries); model top at 10 hPa

    • Lambert-Conformal map projection

Sample Namelists

    • namelist.wps

    • namelist.input based on the AFWA Operational Configuration

    • namelist.input with QNSE replacement for PBL and surface layer

AFWA Reference Configuration

Microphysics:	WRF Single-Moment 5 Scheme
Radiation (LW/SW):	RRTM/Dudhia
Surface Layer:	Monin-Obukhov Similarity Theory
Land Surface:	Noah
PBL:	Yonsei University Scheme
Convection:	Kain-Fritsch Scheme

    • Sample namelist.input

QNSE-replacement Configuration

Microphysics:	WRF Single-Moment 5 Scheme
Radiation (LW/SW):	RRTM/Dudhia
Surface Layer:	QNSE
Land Surface:	Noah
PBL:	QNSE
Convection:	Kain-Fritsch Scheme

    • Sample namelist.input

Other run-time settings

    • Long timestep = 90 s; Acoustic step = 4
    • Calls to the boundary layer and microphysics parameterization        were made every time step
    • Calls to the cumulus parameterization were made every 5        minutes
    • Calls to radiation were made every 30 minutes

The end-to-end system for this test did not include a data assimilation component.

Initial and Boundary Conditions

    • Initial conditions (ICs) and Lateral Boundary Conditions
       (LBCs): 0.5 x 0.5 degree Global Forecast System (GFS) model

    • Lower Boundary Conditions (LoBCs): Agricultural
       Meteorological Model (AGRMET) System output

    • SST Initialization: Fleet Numerical Meteorology and        Oceanography Center (FNMOC) daily, real-time sea surface        temperature (SST) product

Cases Run

• Forecast Dates: 2 June 2008 - 31 May 2009

• Initializations: Every 36 hours, including both 00 and 12 UTC

• Forecast Length: 48 hours; output files generated every 3 hours

00 UTC Initializations
June 2008: 4, 7, 10, 13, 16, 19, 22, 25, 28
July 2008: 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31
August 2008: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30
September 2008: 2, 5, 8, 11, 14, 17, 20, 23, 26, 29
October 2008: 2, 5, 8, 11, 14, 17, 20, 23, 26, 29
November 2008: 1, 4, 7, 10, 13, 16, 19, 22, 25, 28
December 2008: 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31
January 2009: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30
February 2009: 2, 5, 8, 11, 14, 17, 20, 23, 26
March 2009: 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31
April 2009: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30
May 2009: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30

12 UTC Initializations
June 2008: 2, 5, 8, 11, 14, 17, 20, 23, 26, 29
July 2008: 2, 5, 8, 11, 14, 17, 20, 23, 26, 29
August 2008: 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31
September 2008: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30
October 2008: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30
November 2008: 2, 5, 8, 11, 14, 17, 20, 23, 26, 29
December 2008: 2, 5, 8, 11, 14, 17, 20, 23, 26, 29
January 2009: 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31
February 2009: 3, 6, 9, 12, 15, 18, 21, 24, 27
March 2009: 2, 5, 8, 11, 14, 17, 20, 23, 26, 29
April 2009: 1, 4, 7, 10, 13, 16, 19, 22, 25, 28
May 2009: 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31

The tables below list the forecast initializations that failed to complete the end-to-end process due to the reasons described in the table. All incomplete forecasts were due to missing or bad input data sets, not model crashes. Given these missing data sets, the final number of forecasts run was 237 with 7 other cases missing some QPF verification.

Missing Forecasts:

Affected Case	Missing Data	Reason
2008091512	WRF Output	Bad SST Input Data
2008101512	WRF Output	Bad SST Input Data
2008101700	WRF Output	Bad SST Input Data
2008101812	WRF Output	Bad SST Input Data
2008102112	WRF Output	Missing AGRMET Input Data
2009030100	WRF Output	Missing SST Input Data
2009040112	WRF Output	Bad SST Input Data

Missing Verification:

Affected Case	Missing Data	Reason
2008062712	Incomplete 24-hr QPF verification	Missing RFC analysis
2008063012	Incomplete 24-hr QPF verification	Missing RFC analysis
2008080312	Incomplete 24-hr QPF verification	Missing RFC analysis
2008082612	Incomplete 24-hr QPF verification	Missing RFC analysis
2008090112	Incomplete 24-hr QPF verification	Missing RFC analysis
2008110100	Incomplete 3-hr QPF verification	Missing ST2 analysis
2008110212	Incomplete 3-hr QPF verification	Missing ST2 analysis

Verification

The Model Evaluation Tools (MET) package, comprised of:

    • grid-to-point comparisons - utilized for surface and upper air        model data
    • grid-to-grid comparisons - utilized for QPF

was used to generate objective verification statistics, including:

    • Bias-corrected Root Mean Square Error (BCRMSE) and Mean
       Error (Bias) for:
        • Surface: Temperature (2 m), Dew Point Temperature (2 m)            and Winds (10 m)
        • Upper Air: Temperature, Dew Point Temperature and Winds

    • Equitable Threat Score (ETS) and Frequency Bias (FBias) for:
        • 3-hr and 24-hr Precipiation Accumulation intervals

Each type of verification metric is accompanied by confidence intervals (CIs), at the 99% level, computed using a parametric method for the surface and upper air variables and a boostrapping method for precipitation.

Both configurations were run for the same cases allowing for a pair-wise difference methodology to be applied, as appropriate. The CIs on the pair-wise differences between statistics for the two configurations objectively determines whether the differences are statistically significant (SS).

To establish practical significance (PS) in order to examine SS pair-wise differences that are potentially more meaningful, the data was censored to only look at differences that were greater than the operational measurement uncertainty requirements as defined by the World Meteorological Organization (WMO). The following criteria were applied to determine PS pair-wise differences between the configurations and versions for each variable: i) temperature and dew point temperature differences greater than 0.1K, ii) wind speed differences greater than 0.5 ms-1, iii) and precipitation differences greater than 0.1 mm.

Area-averaged verification results were computed for the full domain, as well as 14 sub-domains.