Screening · Bias correction · January initialization · FMAM and its months

Screening · January initialization · FMAM and its months

✓ = screening pass within the method (Holm across its targets); ✓✓ = also passes with Holm across all methods and targets (national aggregate only). A pass is screening evidence, not an adoption decision. Bold: the operational method. Skill is against the CHIRPS training climatology (0 = no better than climatology).

Region for the result tables

All Ethiopia (national aggregate)

FMAM season at a glance — All Ethiopia
MethodAmount CRPSS 1993–2016Amount CRPSS 2017–2025Tercile RPSS (no blend) 1993–2016Tercile RPSS (no blend) 2017–2025Mean bias (mm)MAE (mm)CorrelationSpread–errorReliability indexMembers ≤ 1 mm
Raw ECMWF (no correction)-0.696-0.803-0.465-0.760-86.1105.70.240.480.790.0%
Linear Scaling+0.019+0.020+0.035+0.004+0.067.90.111.160.140.0%
Mean-Variance Scaling (operational)+0.025+0.016+0.034+0.009-0.067.80.070.980.050.0%
Variance Scaling (unbounded)+0.025+0.015+0.035+0.008-0.067.80.070.990.040.0%
Square-root-space Mean-Variance Scaling+0.025+0.018+0.035+0.013-0.067.80.070.980.040.0%
Power Transformation+0.024+0.017+0.034+0.014-0.067.80.070.990.050.0%
Delta Change+0.029+0.010+0.031-0.010+0.067.90.111.040.040.0%
Local Intensity Scaling+0.020+0.020+0.036+0.004+0.067.80.111.160.130.0%
Empirical Quantile Mapping+0.011+0.005+0.023-0.004-0.068.00.060.980.050.0%
Gamma Quantile Mapping+0.025+0.019+0.035+0.015+0.067.80.070.970.050.0%
Detrended Quantile Mapping+0.013+0.004+0.024-0.009+0.268.10.100.990.050.0%
Quantile Delta Mapping+0.013+0.001+0.023-0.013+1.267.90.111.020.070.0%
Scaled Distribution Mapping+0.009-0.012+0.019-0.019-5.567.40.110.910.160.7%
CDF-transform+0.013+0.003+0.023-0.013+0.468.00.111.000.040.0%
MVS with all-zero guard (variant)+0.025+0.016+0.034+0.009-0.067.80.070.980.050.0%
Amount skill (CRPSS) by target, leave-one-year-out 1993–2016
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)-0.370-0.372-0.287-0.238-0.696
Linear Scaling-0.084-0.083-0.030+0.004+0.019
Mean-Variance Scaling (operational)+0.070-0.044-0.016+0.007+0.025
Variance Scaling (unbounded)+0.076 ✓-0.040 ✓-0.016+0.007+0.025
Square-root-space Mean-Variance Scaling+0.110 ✓-0.019 ✓-0.014+0.011+0.025
Power Transformation+0.064-0.020-0.017+0.012+0.024
Delta Change+0.051-0.062-0.021+0.010+0.029
Local Intensity Scaling-0.049-0.076-0.029+0.004+0.020
Empirical Quantile Mapping+0.099-0.028-0.026+0.000+0.011
Gamma Quantile Mapping+0.084-0.021 ✓-0.014+0.011+0.025
Detrended Quantile Mapping+0.033-0.074-0.037-0.004+0.013
Quantile Delta Mapping+0.082-0.084-0.046-0.000+0.013
Scaled Distribution Mapping-0.111-0.101-0.050-0.007+0.009
CDF-transform-0.085-0.085-0.041-0.001+0.013
MVS with all-zero guard (variant)+0.070-0.044-0.016+0.007+0.025
Tercile skill (RPSS of smoothed counts, no blend) by target, 1993–2016
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)-0.298-0.325-0.248-0.208-0.465
Linear Scaling-0.050-0.055-0.026+0.028+0.035
Mean-Variance Scaling (operational)-0.093-0.111-0.027+0.026+0.034
Variance Scaling (unbounded)-0.083-0.104 ✓-0.022+0.026+0.035
Square-root-space Mean-Variance Scaling+0.077 ✓✓-0.012 ✓✓-0.021+0.034+0.035
Power Transformation+0.055 ✓✓-0.024 ✓✓-0.027+0.034+0.034
Delta Change+0.002-0.096-0.034+0.024+0.031
Local Intensity Scaling-0.057-0.054-0.026+0.028+0.036
Empirical Quantile Mapping+0.082 ✓✓-0.025 ✓-0.035+0.022+0.023
Gamma Quantile Mapping+0.036 ✓✓-0.035 ✓✓-0.022+0.034+0.035
Detrended Quantile Mapping-0.000-0.092-0.054+0.017+0.024
Quantile Delta Mapping+0.069-0.075-0.067+0.020+0.023
Scaled Distribution Mapping-0.122-0.150-0.070+0.011+0.019
CDF-transform-0.064-0.087-0.059+0.020+0.023
MVS with all-zero guard (variant)-0.093-0.111-0.027+0.026+0.034
More scores by target: test years, fair CRPS, bias, correlation, spread, reliability, coverage
Amount skill (CRPSS), fit 1993–2016, scored 2017–2025
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)-0.628-0.414-0.356-0.391-0.803
Linear Scaling-0.259-0.028-0.022-0.019+0.020
Mean-Variance Scaling (operational)+0.000+0.005-0.006-0.007+0.016
Variance Scaling (unbounded)+0.003+0.009-0.005-0.009+0.015
Square-root-space Mean-Variance Scaling+0.015+0.030-0.000-0.012+0.018
Power Transformation-0.032+0.030+0.002-0.004+0.017
Delta Change-0.086+0.011-0.005-0.001+0.010
Local Intensity Scaling-0.218-0.024-0.021-0.019+0.020
Empirical Quantile Mapping+0.012+0.023-0.011-0.019+0.005
Gamma Quantile Mapping+0.010+0.029+0.002-0.015+0.019
Detrended Quantile Mapping-0.110+0.018-0.020-0.019+0.004
Quantile Delta Mapping-0.054+0.016-0.025-0.019+0.001
Scaled Distribution Mapping-0.265-0.037-0.039-0.023-0.012
CDF-transform-0.232+0.016-0.025-0.021+0.003
MVS with all-zero guard (variant)+0.000+0.005-0.006-0.007+0.016
Amount skill with the fair CRPS (diagnostic), 1993–2016
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)-0.404-0.406-0.311-0.261-0.740
Linear Scaling-0.070-0.075-0.029+0.002+0.022
Mean-Variance Scaling (operational)+0.063-0.055-0.023+0.001+0.020
Variance Scaling (unbounded)+0.069 ✓-0.050 ✓-0.022+0.002+0.021
Square-root-space Mean-Variance Scaling+0.109 ✓-0.025 ✓✓-0.019+0.008+0.021
Power Transformation+0.064-0.025-0.022+0.007 ✓+0.020
Delta Change+0.053-0.064-0.022+0.010+0.030
Local Intensity Scaling-0.040-0.069-0.028+0.002+0.022
Empirical Quantile Mapping+0.096-0.035-0.033-0.005+0.005
Gamma Quantile Mapping+0.079-0.027 ✓-0.019+0.007+0.020
Detrended Quantile Mapping+0.029-0.082-0.044-0.009+0.008
Quantile Delta Mapping+0.082-0.091-0.053-0.005+0.009
Scaled Distribution Mapping-0.129-0.117-0.061-0.017-0.000
CDF-transform-0.095-0.093-0.047-0.007+0.008
MVS with all-zero guard (variant)+0.063-0.055-0.023+0.001+0.020
Tercile skill (RPSS, no blend), fit 1993–2016, scored 2017–2025
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)-0.889-0.417-0.361-0.414-0.760
Linear Scaling-0.467-0.063-0.043-0.055+0.004
Mean-Variance Scaling (operational)-0.116-0.067-0.029-0.025+0.009
Variance Scaling (unbounded)-0.099-0.058-0.028-0.027+0.008
Square-root-space Mean-Variance Scaling-0.031+0.017-0.018-0.038+0.013
Power Transformation-0.063+0.011-0.009-0.020+0.014
Delta Change-0.300-0.001-0.024-0.016-0.010
Local Intensity Scaling-0.471-0.056-0.044-0.056+0.004
Empirical Quantile Mapping-0.092+0.003-0.025-0.035-0.004
Gamma Quantile Mapping-0.039+0.017-0.013-0.031+0.015
Detrended Quantile Mapping-0.347-0.005-0.044-0.035-0.009
Quantile Delta Mapping-0.195-0.022-0.050-0.039-0.013
Scaled Distribution Mapping-0.599-0.100-0.067-0.052-0.019
CDF-transform-0.387-0.027-0.058-0.047-0.013
MVS with all-zero guard (variant)-0.116-0.067-0.029-0.025+0.009
Ensemble-mean bias (mm), 1993–2016
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)-8.7-25.9-28.8-22.6-86.1
Linear Scaling+0.1+0.2+0.1+0.0+0.0
Mean-Variance Scaling (operational)+0.0+0.1+0.0+0.0-0.0
Variance Scaling (unbounded)+0.0+0.1+0.0+0.0-0.0
Square-root-space Mean-Variance Scaling+0.0+0.1+0.0+0.0-0.0
Power Transformation-0.0+0.0+0.0+0.0-0.0
Delta Change+0.1+0.2+0.1+0.0+0.0
Local Intensity Scaling-0.7-0.2-0.0+0.0+0.0
Empirical Quantile Mapping-0.1+0.0+0.0+0.0-0.0
Gamma Quantile Mapping-0.1-0.0+0.1-0.0+0.0
Detrended Quantile Mapping+0.5+0.9+0.3+0.3+0.2
Quantile Delta Mapping+1.1+2.1+1.1+0.6+1.2
Scaled Distribution Mapping-5.4-7.4-4.9-4.0-5.5
CDF-transform+2.3+2.0+0.8+0.5+0.4
MVS with all-zero guard (variant)+0.0+0.1+0.0+0.0-0.0
Correlation of the ensemble mean with CHIRPS over years, 1993–2016
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)+0.29+0.02+0.07+0.18+0.24
Linear Scaling+0.21-0.09-0.11+0.01+0.11
Mean-Variance Scaling (operational)+0.14-0.15-0.14-0.00+0.07
Variance Scaling (unbounded)+0.12-0.15-0.14-0.00+0.07
Square-root-space Mean-Variance Scaling+0.17-0.12-0.13+0.01+0.07
Power Transformation+0.20-0.11-0.14+0.01+0.07
Delta Change+0.20-0.09-0.11+0.01+0.11
Local Intensity Scaling+0.20-0.09-0.11+0.01+0.11
Empirical Quantile Mapping+0.16-0.12-0.14-0.00+0.06
Gamma Quantile Mapping+0.13-0.13-0.14+0.01+0.07
Detrended Quantile Mapping+0.22-0.07-0.10+0.02+0.10
Quantile Delta Mapping+0.19-0.07-0.10+0.02+0.11
Scaled Distribution Mapping+0.22-0.06-0.11+0.01+0.11
CDF-transform+0.25-0.06-0.09+0.03+0.11
MVS with all-zero guard (variant)+0.14-0.15-0.14-0.00+0.07
Spread–error ratio, 1993–2016 (1 = spread matches the error)
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)0.610.550.640.660.48
Linear Scaling1.911.441.171.051.16
Mean-Variance Scaling (operational)1.020.930.950.960.98
Variance Scaling (unbounded)1.050.950.960.970.99
Square-root-space Mean-Variance Scaling1.061.000.991.010.98
Power Transformation1.040.960.960.970.99
Delta Change1.260.990.991.011.04
Local Intensity Scaling1.741.411.161.051.16
Empirical Quantile Mapping1.030.950.960.970.98
Gamma Quantile Mapping0.950.980.981.020.97
Detrended Quantile Mapping1.120.950.960.970.99
Quantile Delta Mapping1.220.980.991.001.02
Scaled Distribution Mapping0.870.810.860.870.91
CDF-transform1.070.990.980.961.00
MVS with all-zero guard (variant)1.020.930.950.960.98
Rank-histogram reliability index, 1993–2016 (0 = flat)
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)0.960.630.460.440.79
Linear Scaling0.740.330.140.090.14
Mean-Variance Scaling (operational)0.520.450.180.160.05
Variance Scaling (unbounded)0.570.440.170.150.04
Square-root-space Mean-Variance Scaling0.140.100.090.110.04
Power Transformation0.320.140.060.080.05
Delta Change0.450.120.050.030.04
Local Intensity Scaling0.710.320.140.080.13
Empirical Quantile Mapping0.150.070.060.040.05
Gamma Quantile Mapping0.350.150.070.070.05
Detrended Quantile Mapping0.450.110.070.030.05
Quantile Delta Mapping0.260.090.080.040.07
Scaled Distribution Mapping0.780.280.130.120.16
CDF-transform0.600.160.080.050.04
MVS with all-zero guard (variant)0.520.450.180.160.05
Score coverage, mean per year, 1993–2016 (share of the region’s area)
TargetAmount cellsAmount areaProbability cellsProbability area
Feb1484100%126385%
Mar1484100%146399%
Apr1484100%1484100%
May1484100%1484100%
FMAM1484100%1484100%
Dry months: shares of totals at exactly 0 mm and at ≤ 1 mm, CHIRPS and corrected
Area-weighted mean share over cells, pooled leave-one-year-out 1993–2025
Exactly 0 mm≤ 1 mm
Feb: CHIRPS0.2%12.9%
Raw ECMWF (no correction)12.2%50.0%
Linear Scaling12.2%40.7%
Mean-Variance Scaling (operational)2.7%13.4%
Variance Scaling (unbounded)1.5%12.6%
Square-root-space Mean-Variance Scaling0.5%13.4%
Power Transformation12.2%21.1%
Delta Change0.2%16.1%
Local Intensity Scaling19.8%19.8%
Empirical Quantile Mapping12.9%13.0%
Gamma Quantile Mapping11.3%14.9%
Detrended Quantile Mapping12.7%17.1%
Quantile Delta Mapping12.9%13.9%
Scaled Distribution Mapping43.3%50.7%
CDF-transform0.2%16.0%
MVS with all-zero guard (variant)2.7%13.4%
Mar: CHIRPS0.7%5.1%
Raw ECMWF (no correction)2.2%20.1%
Linear Scaling2.2%14.5%
Mean-Variance Scaling (operational)1.3%3.0%
Variance Scaling (unbounded)0.6%3.0%
Square-root-space Mean-Variance Scaling0.4%5.1%
Power Transformation2.2%7.3%
Delta Change0.7%6.1%
Local Intensity Scaling6.5%6.5%
Empirical Quantile Mapping5.1%5.1%
Gamma Quantile Mapping5.1%7.4%
Detrended Quantile Mapping4.8%6.2%
Quantile Delta Mapping5.1%5.5%
Scaled Distribution Mapping21.9%22.3%
CDF-transform0.4%5.9%
MVS with all-zero guard (variant)1.3%3.0%
Apr: CHIRPS0.2%1.3%
Raw ECMWF (no correction)0.3%3.6%
Linear Scaling0.3%2.4%
Mean-Variance Scaling (operational)0.2%0.3%
Variance Scaling (unbounded)0.2%0.3%
Square-root-space Mean-Variance Scaling0.0%0.5%
Power Transformation0.3%0.7%
Delta Change0.2%1.4%
Local Intensity Scaling1.4%1.4%
Empirical Quantile Mapping1.3%1.4%
Gamma Quantile Mapping1.3%1.5%
Detrended Quantile Mapping1.3%1.4%
Quantile Delta Mapping1.4%1.6%
Scaled Distribution Mapping4.9%4.9%
CDF-transform0.1%1.2%
MVS with all-zero guard (variant)0.2%0.3%
May: CHIRPS0.5%1.3%
Raw ECMWF (no correction)0.2%2.4%
Linear Scaling0.2%1.5%
Mean-Variance Scaling (operational)0.2%0.2%
Variance Scaling (unbounded)0.2%0.3%
Square-root-space Mean-Variance Scaling0.0%0.3%
Power Transformation0.2%0.3%
Delta Change0.5%1.3%
Local Intensity Scaling1.3%1.3%
Empirical Quantile Mapping1.3%1.3%
Gamma Quantile Mapping1.2%1.4%
Detrended Quantile Mapping1.2%1.3%
Quantile Delta Mapping1.3%1.3%
Scaled Distribution Mapping3.6%3.7%
CDF-transform0.2%1.1%
MVS with all-zero guard (variant)0.2%0.2%
FMAM: CHIRPS0.0%0.0%
Raw ECMWF (no correction)0.0%0.0%
Linear Scaling0.0%0.0%
Mean-Variance Scaling (operational)0.0%0.0%
Variance Scaling (unbounded)0.0%0.0%
Square-root-space Mean-Variance Scaling0.0%0.0%
Power Transformation0.0%0.0%
Delta Change0.0%0.0%
Local Intensity Scaling0.0%0.0%
Empirical Quantile Mapping0.0%0.0%
Gamma Quantile Mapping0.0%0.0%
Detrended Quantile Mapping0.0%0.0%
Quantile Delta Mapping0.0%0.0%
Scaled Distribution Mapping0.7%0.7%
CDF-transform0.0%0.0%
MVS with all-zero guard (variant)0.0%0.0%
Distribution of the corrected members (mean, spread, 10th and 90th percentiles)
Mean of the corrected members / CHIRPS (area-weighted median of cell ratios, 1993–2025; 1 = same)
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)0.430.470.670.700.63
Linear Scaling1.001.001.001.001.00
Mean-Variance Scaling (operational)1.001.001.001.001.00
Variance Scaling (unbounded)1.001.001.001.001.00
Square-root-space Mean-Variance Scaling1.001.001.001.001.00
Power Transformation1.001.001.001.001.00
Delta Change1.001.001.001.001.00
Local Intensity Scaling0.961.001.001.001.00
Empirical Quantile Mapping1.001.001.001.001.00
Gamma Quantile Mapping0.991.001.001.001.00
Detrended Quantile Mapping1.021.011.001.001.00
Quantile Delta Mapping1.061.031.011.011.00
Scaled Distribution Mapping0.590.820.950.960.98
CDF-transform1.131.031.011.011.00
MVS with all-zero guard (variant)1.001.001.001.001.00
Standard deviation of the corrected members / CHIRPS (area-weighted median of cell ratios, 1993–2025; 1 = same)
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)0.920.690.820.790.70
Linear Scaling2.011.541.221.161.12
Mean-Variance Scaling (operational)1.011.011.001.001.00
Variance Scaling (unbounded)1.011.011.001.001.00
Square-root-space Mean-Variance Scaling1.051.061.021.030.99
Power Transformation1.001.001.001.001.00
Delta Change1.331.121.051.041.05
Local Intensity Scaling1.731.471.221.161.12
Empirical Quantile Mapping0.991.001.001.001.00
Gamma Quantile Mapping0.901.021.011.030.98
Detrended Quantile Mapping1.271.091.021.021.01
Quantile Delta Mapping1.341.131.041.041.03
Scaled Distribution Mapping0.950.920.920.920.92
CDF-transform1.411.141.051.041.04
MVS with all-zero guard (variant)1.011.011.001.001.00
10th percentile of the corrected members / CHIRPS (area-weighted median of cell ratios, 1993–2025; 1 = same)
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)0.010.090.470.630.54
Linear Scaling0.030.210.690.900.87
Mean-Variance Scaling (operational)1.181.541.061.060.97
Variance Scaling (unbounded)1.211.491.051.050.96
Square-root-space Mean-Variance Scaling0.890.980.971.000.96
Power Transformation0.360.730.921.000.94
Delta Change0.530.850.920.930.95
Local Intensity Scaling0.160.300.680.880.87
Empirical Quantile Mapping0.990.960.940.950.98
Gamma Quantile Mapping0.680.900.950.980.96
Detrended Quantile Mapping0.520.860.920.940.96
Quantile Delta Mapping0.880.860.910.940.97
Scaled Distribution Mapping0.000.000.910.960.98
CDF-transform0.480.830.920.960.96
MVS with all-zero guard (variant)1.181.541.061.060.97
90th percentile of the corrected members / CHIRPS (area-weighted median of cell ratios, 1993–2025; 1 = same)
MethodFebMarAprMayFMAM
Raw ECMWF (no correction)0.590.560.750.750.66
Linear Scaling1.341.231.111.091.05
Mean-Variance Scaling (operational)0.940.981.011.021.00
Variance Scaling (unbounded)0.930.981.021.021.01
Square-root-space Mean-Variance Scaling1.051.021.031.041.00
Power Transformation1.111.021.021.021.00
Delta Change1.131.061.041.031.03
Local Intensity Scaling1.201.201.111.091.05
Empirical Quantile Mapping1.041.051.031.021.02
Gamma Quantile Mapping0.971.001.031.041.00
Detrended Quantile Mapping1.141.071.031.031.02
Quantile Delta Mapping1.141.081.041.031.02
Scaled Distribution Mapping0.710.880.960.960.97
CDF-transform1.301.091.041.031.02
MVS with all-zero guard (variant)0.940.981.011.021.00

Screening statistics

Every method, target and score (within-method and family-wide Holm)

Screening rule (docs/36 rule applied as a screen): a method passes for a target and score if, on the leave-one-year-out 1993-2016 per-year scores, its mean improvement over mvs has a one-sided sign-flip p-value below 0.05 after Holm adjustment, and its mean score over 2017-2025 (fits on 1993-2016) is not worse. 'screen_pass': Holm across the 5 targets of one method. 'screen_pass_family': Holm across every method and target of the benchmark for that score. A screening pass is not an operational adoption decision (see the confirmation run).

Screening statistics, CRPS (method minus Mean-Variance Scaling; negative favours the method)
MethodTargetΔ CRPS 1993–2016 (mm)95% intervalYears betterp (one-sided)Holm p (method)Holm p (all 60)Δ 2017–2025Screening
Linear ScalingFeb+1.06+0.48 to +1.576/240.99921.00001.0000+1.87—
Linear ScalingMar+0.78-0.38 to +1.778/240.90971.00001.0000+0.77—
Linear ScalingApr+0.38-0.21 to +0.927/240.89551.00001.0000+0.49—
Linear ScalingMay+0.09-0.38 to +0.517/240.64681.00001.0000+0.31—
Linear ScalingFMAM+0.27-0.58 to +1.087/240.72811.00001.0000-0.23—
Variance Scaling (unbounded)Feb-0.04-0.06 to -0.0219/240.00280.01390.1637-0.02✓
Variance Scaling (unbounded)Mar-0.07-0.12 to -0.0219/240.00370.01490.2158-0.10✓
Variance Scaling (unbounded)Apr-0.02-0.07 to +0.0313/240.23310.69921.0000-0.01—
Variance Scaling (unbounded)May+0.00-0.03 to +0.0310/240.53190.84801.0000+0.04—
Variance Scaling (unbounded)FMAM-0.01-0.07 to +0.0511/240.42400.84801.0000+0.05—
Square-root-space Mean-Variance ScalingFeb-0.28-0.46 to -0.0917/240.00450.01790.2545-0.11✓
Square-root-space Mean-Variance ScalingMar-0.49-0.82 to -0.1915/240.00150.00760.0918-0.58✓
Square-root-space Mean-Variance ScalingApr-0.08-0.23 to +0.0617/240.14400.30551.0000-0.17—
Square-root-space Mean-Variance ScalingMay-0.13-0.32 to +0.0513/240.10180.30551.0000+0.14—
Square-root-space Mean-Variance ScalingFMAM-0.04-0.12 to +0.0511/240.21970.30551.0000-0.14—
Power TransformationFeb+0.04-0.29 to +0.3810/240.59781.00001.0000+0.23—
Power TransformationMar-0.48-0.94 to -0.0313/240.02610.10421.0000-0.58—
Power TransformationApr+0.00-0.20 to +0.2214/240.50651.00001.0000-0.25—
Power TransformationMay-0.15-0.28 to -0.0216/240.01790.08950.9850-0.09—
Power TransformationFMAM+0.03-0.17 to +0.228/240.62421.00001.0000-0.04—
Delta ChangeFeb+0.14-0.33 to +0.6311/240.70231.00001.0000+0.63—
Delta ChangeMar+0.36-0.47 to +1.199/240.78941.00001.0000-0.14—
Delta ChangeApr+0.12-0.29 to +0.5410/240.70861.00001.0000-0.01—
Delta ChangeMay-0.08-0.42 to +0.2511/240.32291.00001.0000-0.15—
Delta ChangeFMAM-0.21-0.98 to +0.5712/240.30901.00001.0000+0.34—
Local Intensity ScalingFeb+0.82+0.33 to +1.276/240.99831.00001.0000+1.58—
Local Intensity ScalingMar+0.64-0.49 to +1.617/240.86991.00001.0000+0.68—
Local Intensity ScalingApr+0.35-0.23 to +0.867/240.87781.00001.0000+0.47—
Local Intensity ScalingMay+0.09-0.37 to +0.507/240.64451.00001.0000+0.30—
Local Intensity ScalingFMAM+0.24-0.59 to +1.057/240.71171.00001.0000-0.24—
Empirical Quantile MappingFeb-0.20-0.41 to +0.0114/240.04210.21051.0000-0.08—
Empirical Quantile MappingMar-0.33-0.73 to +0.0613/240.06320.25291.0000-0.43—
Empirical Quantile MappingApr+0.28+0.05 to +0.517/240.98681.00001.0000+0.17—
Empirical Quantile MappingMay+0.20-0.05 to +0.4610/240.92871.00001.0000+0.30—
Empirical Quantile MappingFMAM+0.71+0.50 to +0.912/241.00001.00001.0000+0.64—
Gamma Quantile MappingFeb-0.09-0.26 to +0.0813/240.15070.60291.0000-0.07—
Gamma Quantile MappingMar-0.45-0.78 to -0.1415/240.00450.02250.2545-0.56✓
Gamma Quantile MappingApr-0.08-0.23 to +0.0816/240.18140.60291.0000-0.23—
Gamma Quantile MappingMay-0.10-0.32 to +0.1010/240.17060.60291.0000+0.20—
Gamma Quantile MappingFMAM-0.01-0.13 to +0.1210/240.46810.60291.0000-0.16—
Detrended Quantile MappingFeb+0.26-0.46 to +1.0210/240.73701.00001.0000+0.80—
Detrended Quantile MappingMar+0.61-0.45 to +1.838/240.82651.00001.0000-0.32—
Detrended Quantile MappingApr+0.59+0.18 to +1.0911/240.99321.00001.0000+0.43—
Detrended Quantile MappingMay+0.32-0.09 to +0.717/240.92491.00001.0000+0.31—
Detrended Quantile MappingFMAM+0.60+0.02 to +1.176/240.97061.00001.0000+0.73—
Quantile Delta MappingFeb-0.08-0.92 to +0.8112/240.43201.00001.0000+0.39—
Quantile Delta MappingMar+0.80-0.53 to +2.298/240.83771.00001.0000-0.25—
Quantile Delta MappingApr+0.85+0.19 to +1.679/240.98831.00001.0000+0.58—
Quantile Delta MappingMay+0.22-0.22 to +0.667/240.81641.00001.0000+0.29—
Quantile Delta MappingFMAM+0.57-0.09 to +1.195/240.94381.00001.0000+0.90—
Scaled Distribution MappingFeb+1.24+0.77 to +1.734/241.00001.00001.0000+1.92—
Scaled Distribution MappingMar+1.14-0.15 to +2.286/240.95681.00001.0000+0.98—
Scaled Distribution MappingApr+0.96+0.33 to +1.563/240.99751.00001.0000+1.01—
Scaled Distribution MappingMay+0.41-0.02 to +0.817/240.96491.00001.0000+0.41—
Scaled Distribution MappingFMAM+0.80+0.13 to +1.496/240.98111.00001.0000+1.67—
CDF-transformFeb+1.07-0.32 to +2.568/240.91141.00001.0000+1.68—
CDF-transformMar+0.83-0.44 to +2.387/240.84651.00001.0000-0.27—
CDF-transformApr+0.69+0.16 to +1.349/240.99051.00001.0000+0.59—
CDF-transformMay+0.24-0.18 to +0.657/240.85751.00001.0000+0.35—
CDF-transformFMAM+0.58-0.09 to +1.216/240.94611.00001.0000+0.77—
MVS with all-zero guard (variant)Feb+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
MVS with all-zero guard (variant)Mar+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
MVS with all-zero guard (variant)Apr+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
MVS with all-zero guard (variant)May+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
MVS with all-zero guard (variant)FMAM+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
Screening statistics, fair CRPS (method minus Mean-Variance Scaling; negative favours the method)
MethodTargetΔ fair CRPS 1993–2016 (mm)95% intervalYears betterp (one-sided)Holm p (method)Holm p (all 60)Δ 2017–2025Screening
Linear ScalingFeb+0.87+0.28 to +1.386/240.99681.00001.0000+1.78—
Linear ScalingMar+0.40-0.76 to +1.398/240.75181.00001.0000+0.58—
Linear ScalingApr+0.15-0.45 to +0.689/240.68371.00001.0000+0.38—
Linear ScalingMay-0.01-0.49 to +0.427/240.47971.00001.0000+0.27—
Linear ScalingFMAM-0.08-0.94 to +0.748/240.43091.00001.0000-0.39—
Variance Scaling (unbounded)Feb-0.04-0.07 to -0.0219/240.00150.00610.0864-0.02✓
Variance Scaling (unbounded)Mar-0.08-0.13 to -0.0419/240.00110.00570.0676-0.10✓
Variance Scaling (unbounded)Apr-0.03-0.08 to +0.0213/240.11390.34171.0000-0.02—
Variance Scaling (unbounded)May-0.01-0.04 to +0.0212/240.27050.40021.0000+0.03—
Variance Scaling (unbounded)FMAM-0.03-0.09 to +0.0313/240.20010.40021.0000+0.04—
Square-root-space Mean-Variance ScalingFeb-0.30-0.49 to -0.1219/240.00200.00800.1123-0.12✓
Square-root-space Mean-Variance ScalingMar-0.57-0.90 to -0.2717/240.00030.00150.0186-0.62✓✓
Square-root-space Mean-Variance ScalingApr-0.13-0.28 to +0.0118/240.04540.10351.0000-0.20—
Square-root-space Mean-Variance ScalingMay-0.18-0.38 to -0.0114/240.03450.10351.0000+0.11—
Square-root-space Mean-Variance ScalingFMAM-0.05-0.13 to +0.0411/240.15000.15001.0000-0.14—
Power TransformationFeb-0.01-0.34 to +0.3210/240.47831.00001.0000+0.20—
Power TransformationMar-0.56-1.02 to -0.1014/240.01400.05620.7582-0.62—
Power TransformationApr-0.03-0.23 to +0.1914/240.38561.00001.0000-0.26—
Power TransformationMay-0.17-0.30 to -0.0418/240.00790.03960.4356-0.10✓
Power TransformationFMAM-0.00-0.20 to +0.189/240.49801.00001.0000-0.06—
Delta ChangeFeb+0.06-0.40 to +0.5413/240.59901.00001.0000+0.47—
Delta ChangeMar+0.19-0.64 to +1.0011/240.66171.00001.0000-0.61—
Delta ChangeApr-0.05-0.45 to +0.3711/240.41221.00001.0000-0.66—
Delta ChangeMay-0.25-0.60 to +0.0814/240.07720.38591.0000-0.77—
Delta ChangeFMAM-0.48-1.26 to +0.3114/240.12790.51171.0000-0.74—
Local Intensity ScalingFeb+0.67+0.19 to +1.126/240.99401.00001.0000+1.51—
Local Intensity ScalingMar+0.28-0.86 to +1.268/240.69031.00001.0000+0.50—
Local Intensity ScalingApr+0.12-0.46 to +0.649/240.65381.00001.0000+0.36—
Local Intensity ScalingMay-0.01-0.48 to +0.417/240.48511.00001.0000+0.26—
Local Intensity ScalingFMAM-0.09-0.94 to +0.718/240.41511.00001.0000-0.40—
Empirical Quantile MappingFeb-0.22-0.43 to -0.0115/240.02930.14641.0000-0.09—
Empirical Quantile MappingMar-0.39-0.80 to +0.0113/240.03900.15591.0000-0.47—
Empirical Quantile MappingApr+0.26+0.03 to +0.497/240.97991.00001.0000+0.17—
Empirical Quantile MappingMay+0.18-0.08 to +0.4510/240.90421.00001.0000+0.29—
Empirical Quantile MappingFMAM+0.71+0.51 to +0.922/241.00001.00001.0000+0.65—
Gamma Quantile MappingFeb-0.11-0.28 to +0.0713/240.11370.24911.0000-0.08—
Gamma Quantile MappingMar-0.53-0.85 to -0.2116/240.00130.00670.0774-0.60✓
Gamma Quantile MappingApr-0.12-0.27 to +0.0418/240.07690.24911.0000-0.25—
Gamma Quantile MappingMay-0.17-0.38 to +0.0313/240.06230.24911.0000+0.17—
Gamma Quantile MappingFMAM-0.00-0.13 to +0.1210/240.48080.48081.0000-0.16—
Detrended Quantile MappingFeb+0.22-0.49 to +0.9811/240.70981.00001.0000+0.79—
Detrended Quantile MappingMar+0.53-0.53 to +1.748/240.79351.00001.0000-0.35—
Detrended Quantile MappingApr+0.57+0.15 to +1.0611/240.99071.00001.0000+0.42—
Detrended Quantile MappingMay+0.29-0.12 to +0.687/240.90851.00001.0000+0.30—
Detrended Quantile MappingFMAM+0.60+0.02 to +1.167/240.96961.00001.0000+0.73—
Quantile Delta MappingFeb-0.13-0.97 to +0.7513/240.38601.00001.0000+0.37—
Quantile Delta MappingMar+0.70-0.62 to +2.198/240.80651.00001.0000-0.30—
Quantile Delta MappingApr+0.80+0.14 to +1.639/240.98261.00001.0000+0.57—
Quantile Delta MappingMay+0.17-0.27 to +0.617/240.76221.00001.0000+0.28—
Quantile Delta MappingFMAM+0.53-0.13 to +1.166/240.93351.00001.0000+0.89—
Scaled Distribution MappingFeb+1.26+0.78 to +1.754/241.00001.00001.0000+1.93—
Scaled Distribution MappingMar+1.19-0.10 to +2.336/240.96251.00001.0000+0.98—
Scaled Distribution MappingApr+1.04+0.41 to +1.653/240.99871.00001.0000+1.04—
Scaled Distribution MappingMay+0.50+0.07 to +0.917/240.98481.00001.0000+0.44—
Scaled Distribution MappingFMAM+0.98+0.30 to +1.676/240.99451.00001.0000+1.74—
CDF-transformFeb+1.03-0.34 to +2.528/240.90521.00001.0000+1.66—
CDF-transformMar+0.73-0.54 to +2.277/240.81161.00001.0000-0.31—
CDF-transformApr+0.65+0.12 to +1.309/240.98511.00001.0000+0.58—
CDF-transformMay+0.22-0.19 to +0.637/240.84361.00001.0000+0.34—
CDF-transformFMAM+0.56-0.11 to +1.196/240.93981.00001.0000+0.76—
MVS with all-zero guard (variant)Feb+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
MVS with all-zero guard (variant)Mar+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
MVS with all-zero guard (variant)Apr+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
MVS with all-zero guard (variant)May+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
MVS with all-zero guard (variant)FMAM+0.00+0.00 to +0.000/241.00001.0000— (variant)+0.00—
Screening statistics, RPS (no blend) (method minus Mean-Variance Scaling; negative favours the method)
MethodTargetΔ RPS (no blend) 1993–201695% intervalYears betterp (one-sided)Holm p (method)Holm p (all 60)Δ 2017–2025Screening
Linear ScalingFeb-0.0198-0.1116 to +0.068413/240.33611.00001.0000+0.1508—
Linear ScalingMar-0.0257-0.0693 to +0.014712/240.12900.64501.0000-0.0022—
Linear ScalingApr-0.0005-0.0104 to +0.008111/240.45791.00001.0000+0.0064—
Linear ScalingMay-0.0010-0.0114 to +0.008711/240.42201.00001.0000+0.0129—
Linear ScalingFMAM-0.0009-0.0060 to +0.003810/240.37371.00001.0000+0.0023—
Variance Scaling (unbounded)Feb-0.0045-0.0090 to +0.000016/240.03250.13001.0000-0.0074—
Variance Scaling (unbounded)Mar-0.0034-0.0056 to -0.001417/240.00170.00850.0898-0.0045✓
Variance Scaling (unbounded)Apr-0.0020-0.0043 to +0.000212/240.05620.16851.0000-0.0005—
Variance Scaling (unbounded)May-0.0002-0.0007 to +0.000311/240.27480.28281.0000+0.0005—
Variance Scaling (unbounded)FMAM-0.0006-0.0015 to +0.000312/240.14140.28281.0000+0.0005—
Square-root-space Mean-Variance ScalingFeb-0.0771-0.1090 to -0.047120/240.00000.00010.0009-0.0362✓✓
Square-root-space Mean-Variance ScalingMar-0.0448-0.0642 to -0.026719/240.00010.00020.0035-0.0379✓✓
Square-root-space Mean-Variance ScalingApr-0.0026-0.0050 to -0.000018/240.02940.08821.0000-0.0049—
Square-root-space Mean-Variance ScalingMay-0.0037-0.0091 to +0.001210/240.09210.18411.0000+0.0054—
Square-root-space Mean-Variance ScalingFMAM-0.0008-0.0027 to +0.001013/240.19670.19671.0000-0.0018—
Power TransformationFeb-0.0674-0.1032 to -0.033218/240.00030.00130.0185-0.0226✓✓
Power TransformationMar-0.0393-0.0577 to -0.020819/240.00020.00120.0137-0.0352✓✓
Power TransformationApr-0.0001-0.0066 to +0.006714/240.48700.82741.0000-0.0088—
Power TransformationMay-0.0037-0.0071 to -0.000516/240.01990.05980.9965-0.0022—
Power TransformationFMAM-0.0004-0.0037 to +0.003011/240.41370.82741.0000-0.0024—
Delta ChangeFeb-0.0431-0.1080 to +0.022615/240.11160.55801.0000+0.0791—
Delta ChangeMar-0.0068-0.0413 to +0.026813/240.35071.00001.0000-0.0298—
Delta ChangeApr+0.0031-0.0076 to +0.01379/240.71171.00001.0000-0.0022—
Delta ChangeMay+0.0010-0.0061 to +0.008114/240.60771.00001.0000-0.0040—
Delta ChangeFMAM+0.0010-0.0076 to +0.010513/240.58241.00001.0000+0.0086—
Local Intensity ScalingFeb-0.0166-0.1094 to +0.072413/240.36191.00001.0000+0.1529—
Local Intensity ScalingMar-0.0257-0.0716 to +0.016512/240.14000.69981.0000-0.0050—
Local Intensity ScalingApr-0.0006-0.0105 to +0.008011/240.45221.00001.0000+0.0066—
Local Intensity ScalingMay-0.0007-0.0112 to +0.009111/240.44761.00001.0000+0.0131—
Local Intensity ScalingFMAM-0.0009-0.0060 to +0.003610/240.36241.00001.0000+0.0021—
Empirical Quantile MappingFeb-0.0795-0.1227 to -0.037917/240.00070.00360.0386-0.0101✓✓
Empirical Quantile MappingMar-0.0391-0.0659 to -0.013517/240.00470.01890.2452-0.0316✓
Empirical Quantile MappingApr+0.0037-0.0023 to +0.00979/240.87701.00001.0000-0.0015—
Empirical Quantile MappingMay+0.0017-0.0047 to +0.00809/240.69661.00001.0000+0.0041—
Empirical Quantile MappingFMAM+0.0049+0.0014 to +0.00836/240.99241.00001.0000+0.0061—
Gamma Quantile MappingFeb-0.0587-0.0783 to -0.039521/240.00000.00000.0003-0.0331✓✓
Gamma Quantile MappingMar-0.0344-0.0532 to -0.016416/240.00070.00260.0363-0.0378✓✓
Gamma Quantile MappingApr-0.0021-0.0060 to +0.002217/240.16180.32361.0000-0.0072—
Gamma Quantile MappingMay-0.0034-0.0071 to -0.000112/240.03890.11671.0000+0.0024—
Gamma Quantile MappingFMAM-0.0007-0.0036 to +0.002413/240.33590.33591.0000-0.0027—
Detrended Quantile MappingFeb-0.0422-0.1112 to +0.026415/240.12660.63311.0000+0.0994—
Detrended Quantile MappingMar-0.0086-0.0436 to +0.025310/240.31861.00001.0000-0.0283—
Detrended Quantile MappingApr+0.0125+0.0025 to +0.02379/240.98341.00001.0000+0.0070—
Detrended Quantile MappingMay+0.0043-0.0055 to +0.013310/240.80241.00001.0000+0.0042—
Detrended Quantile MappingFMAM+0.0042-0.0038 to +0.01229/240.82851.00001.0000+0.0083—
Quantile Delta MappingFeb-0.0736-0.1341 to -0.016016/240.01210.06040.6163+0.0341—
Quantile Delta MappingMar-0.0165-0.0529 to +0.017211/240.19010.76041.0000-0.0204—
Quantile Delta MappingApr+0.0184+0.0040 to +0.03499/240.98501.00001.0000+0.0095—
Quantile Delta MappingMay+0.0029-0.0074 to +0.01238/240.70601.00001.0000+0.0057—
Quantile Delta MappingFMAM+0.0048-0.0045 to +0.01388/240.83951.00001.0000+0.0100—
Scaled Distribution MappingFeb+0.0130-0.0902 to +0.114411/240.59641.00001.0000+0.2076—
Scaled Distribution MappingMar+0.0174-0.0435 to +0.072810/240.71581.00001.0000+0.0145—
Scaled Distribution MappingApr+0.0198+0.0085 to +0.03154/240.99901.00001.0000+0.0171—
Scaled Distribution MappingMay+0.0071-0.0027 to +0.016710/240.91391.00001.0000+0.0116—
Scaled Distribution MappingFMAM+0.0065-0.0032 to +0.016610/240.88491.00001.0000+0.0128—
CDF-transformFeb-0.0134-0.0921 to +0.064113/240.37011.00001.0000+0.1167—
CDF-transformMar-0.0108-0.0431 to +0.023913/240.27631.00001.0000-0.0184—
CDF-transformApr+0.0145+0.0036 to +0.02748/240.98981.00001.0000+0.0133—
CDF-transformMay+0.0030-0.0062 to +0.01179/240.73231.00001.0000+0.0093—
CDF-transformFMAM+0.0048-0.0031 to +0.01257/240.86941.00001.0000+0.0100—
MVS with all-zero guard (variant)Feb+0.0000+0.0000 to +0.00000/241.00001.0000— (variant)+0.0000—
MVS with all-zero guard (variant)Mar+0.0000+0.0000 to +0.00000/241.00001.0000— (variant)+0.0000—
MVS with all-zero guard (variant)Apr+0.0000+0.0000 to +0.00000/241.00001.0000— (variant)+0.0000—
MVS with all-zero guard (variant)May+0.0000+0.0000 to +0.00000/241.00001.0000— (variant)+0.0000—
MVS with all-zero guard (variant)FMAM+0.0000+0.0000 to +0.00000/241.00001.0000— (variant)+0.0000—

Diagnostics

How often limits, caps and fallbacks act
How often limits, caps and fallbacks act, leave-one-year-out 1993–2016 (mean over folds)
MethodTargetActivated (share of the corrected area, or of members / cells for events)
Linear ScalingFebmean fallback: 0.6% of the area
Mean-Variance Scaling (operational)Febsd fallback: 3.9% of the area; ratio lower limit: 20.2% of the area; ratio upper limit: 9.1% of the area; clipped at zero: 2.7%
Mean-Variance Scaling (operational)Marratio lower limit: 2.5% of the area; ratio upper limit: 9.1% of the area; clipped at zero: 1.3%
Mean-Variance Scaling (operational)Aprratio lower limit: 0.2% of the area; ratio upper limit: 6.1% of the area; clipped at zero: 0.2%
Mean-Variance Scaling (operational)Mayratio lower limit: 0.1% of the area; ratio upper limit: 6.2% of the area; clipped at zero: 0.4%
Mean-Variance Scaling (operational)FMAMratio lower limit: 0.0% of the area; ratio upper limit: 6.6% of the area; clipped at zero: 0.0%
Variance Scaling (unbounded)Febsd fallback: 3.9% of the area; clipped at zero: 1.8%
Variance Scaling (unbounded)Marclipped at zero: 0.8%
Variance Scaling (unbounded)Aprclipped at zero: 0.2%
Variance Scaling (unbounded)Mayclipped at zero: 0.5%
Variance Scaling (unbounded)FMAMclipped at zero: 0.0%
Square-root-space Mean-Variance ScalingFebratio lower limit: 23.9% of the area; clipped at zero: 0.5%
Square-root-space Mean-Variance ScalingMarratio lower limit: 0.3% of the area; ratio upper limit: 0.2% of the area; clipped at zero: 0.4%
Square-root-space Mean-Variance ScalingAprratio lower limit: 0.1% of the area; ratio upper limit: 0.1% of the area; clipped at zero: 0.1%
Square-root-space Mean-Variance ScalingMayratio lower limit: 0.0% of the area; ratio upper limit: 0.1% of the area; clipped at zero: 0.0%
Square-root-space Mean-Variance ScalingFMAMratio upper limit: 0.1% of the area
Power TransformationFebb at bound: 16.6% of the area
Delta ChangeFebmean fallback: 0.6% of the area; ratio capped: 3.3%
Delta ChangeMarratio capped: 0.1%
Local Intensity ScalingFebalways wet: 83.0% of the area; never wet: 2.8% of the area
Local Intensity ScalingMaralways wet: 88.6% of the area
Local Intensity ScalingApralways wet: 85.7% of the area
Local Intensity ScalingMayalways wet: 90.6% of the area
Local Intensity ScalingFMAMalways wet: 100.0% of the area
Empirical Quantile MappingFebmodel has dry: 100.0% of the area; obs has dry: 17.0% of the area; extrapolated: 0.2%
Empirical Quantile MappingMarmodel has dry: 97.8% of the area; obs has dry: 11.4% of the area; extrapolated: 0.2%
Empirical Quantile MappingAprmodel has dry: 60.2% of the area; obs has dry: 14.3% of the area; extrapolated: 0.2%
Empirical Quantile MappingMaymodel has dry: 23.4% of the area; obs has dry: 9.4% of the area; extrapolated: 0.3%
Empirical Quantile MappingFMAMmodel has dry: 5.8% of the area; extrapolated: 0.3%
Gamma Quantile MappingFebgamma fallback: 3.6% of the area; model has dry: 100.0% of the area; obs has dry: 17.0% of the area
Gamma Quantile MappingMargamma fallback: 0.1% of the area; model has dry: 97.8% of the area; obs has dry: 11.4% of the area
Gamma Quantile MappingAprmodel has dry: 60.2% of the area; obs has dry: 14.3% of the area
Gamma Quantile MappingMaymodel has dry: 23.4% of the area; obs has dry: 9.4% of the area
Gamma Quantile MappingFMAMmodel has dry: 5.8% of the area
Detrended Quantile MappingFebmodel has dry: 100.0% of the area; obs has dry: 17.0% of the area; ratio capped: 3.3%; extrapolated: 0.1%
Detrended Quantile MappingMarmodel has dry: 97.8% of the area; obs has dry: 11.4% of the area; ratio capped: 0.1%; extrapolated: 0.1%
Detrended Quantile MappingAprmodel has dry: 60.2% of the area; obs has dry: 14.3% of the area; extrapolated: 0.2%
Detrended Quantile MappingMaymodel has dry: 23.4% of the area; obs has dry: 9.4% of the area; extrapolated: 0.3%
Detrended Quantile MappingFMAMmodel has dry: 5.8% of the area; extrapolated: 0.3%
Quantile Delta MappingFebmodel has dry: 100.0% of the area; obs has dry: 17.0% of the area; low denominator: 49.4%; ratio capped: 0.7%
Quantile Delta MappingMarmodel has dry: 97.8% of the area; obs has dry: 11.4% of the area; low denominator: 19.9%; ratio capped: 0.2%
Quantile Delta MappingAprmodel has dry: 60.2% of the area; obs has dry: 14.3% of the area; low denominator: 3.5%; ratio capped: 0.1%
Quantile Delta MappingMaymodel has dry: 23.4% of the area; obs has dry: 9.4% of the area; low denominator: 2.3%; ratio capped: 0.0%
Quantile Delta MappingFMAMmodel has dry: 5.8% of the area
Scaled Distribution MappingFebgamma fallback: 6.3% of the area; linear scaling fallback: 17.0%
Scaled Distribution MappingMargamma fallback: 0.1% of the area; linear scaling fallback: 0.2%
CDF-transformFebmean fallback: 0.6% of the area; at forecast range edge: 0.5%
CDF-transformMarat forecast range edge: 1.0%
CDF-transformAprat forecast range edge: 2.3%
CDF-transformMayat forecast range edge: 4.9%
CDF-transformFMAMat forecast range edge: 2.3%
MVS with all-zero guard (variant)Febsd fallback: 3.9% of the area; ratio lower limit: 20.2% of the area; ratio upper limit: 9.1% of the area; clipped at zero: 2.7%
MVS with all-zero guard (variant)Marratio lower limit: 2.5% of the area; ratio upper limit: 9.1% of the area; clipped at zero: 1.3%
MVS with all-zero guard (variant)Aprratio lower limit: 0.2% of the area; ratio upper limit: 6.1% of the area; clipped at zero: 0.2%
MVS with all-zero guard (variant)Mayratio lower limit: 0.1% of the area; ratio upper limit: 6.2% of the area; clipped at zero: 0.4%
MVS with all-zero guard (variant)FMAMratio lower limit: 0.0% of the area; ratio upper limit: 6.6% of the area; clipped at zero: 0.0%
Where the amount differences come from: cells grouped by their training-year climate

Each cell is grouped by its CHIRPS totals in the fold’s training years only: every year exactly 0 mm; every year ≤ 1 mm (not all 0); some years dry and some wet; never dry. Contributions are area-weighted CRPS differences from Mean-Variance Scaling (mm; negative favours the method) and add up to the national difference. Leave-one-year-out 1993–2016, All Ethiopia.

Feb: contributions to the CRPS difference from Mean-Variance Scaling (mm)
MethodTotal Δ CRPSall 0 mm
0.0% of area
all ≤ 1 mm
2.8% of area
mixed
14.2% of area
always wet
83.0% of area
Linear Scaling+1.060+0.000+0.001+0.019+1.041
Variance Scaling (unbounded)-0.039+0.000-0.001+0.000-0.039
Square-root-space Mean-Variance Scaling-0.275+0.000-0.001-0.009-0.265
Power Transformation+0.044+0.000+0.000+0.004+0.040
Delta Change+0.136+0.000+0.000+0.007+0.129
Local Intensity Scaling+0.821+0.000+0.003+0.021+0.797
Empirical Quantile Mapping-0.196+0.000+0.003+0.020-0.219
Gamma Quantile Mapping-0.092+0.000+0.003+0.018-0.113
Detrended Quantile Mapping+0.256+0.000+0.003+0.021+0.232
Quantile Delta Mapping-0.077+0.000+0.003+0.019-0.099
Scaled Distribution Mapping+1.245+0.000+0.001+0.027+1.217
CDF-transform+1.069+0.000+0.002+0.040+1.027
MVS with all-zero guard (variant)+0.000+0.000+0.000+0.000+0.000
Mar: contributions to the CRPS difference from Mean-Variance Scaling (mm)
MethodTotal Δ CRPSall 0 mm
0.0% of area
all ≤ 1 mm
0.0% of area
mixed
11.4% of area
always wet
88.6% of area
Linear Scaling+0.784+0.000+0.000-0.021+0.805
Variance Scaling (unbounded)-0.070+0.000+0.000+0.002-0.072
Square-root-space Mean-Variance Scaling-0.490+0.000+0.000-0.025-0.465
Power Transformation-0.485+0.000+0.000-0.023-0.462
Delta Change+0.360+0.000+0.000-0.012+0.372
Local Intensity Scaling+0.643+0.000+0.000-0.017+0.660
Empirical Quantile Mapping-0.326+0.000+0.000-0.015-0.311
Gamma Quantile Mapping-0.452+0.000+0.000-0.015-0.437
Detrended Quantile Mapping+0.611+0.000+0.000-0.003+0.614
Quantile Delta Mapping+0.797+0.000+0.000-0.007+0.804
Scaled Distribution Mapping+1.142+0.000+0.000+0.000+1.142
CDF-transform+0.828+0.000+0.000-0.004+0.832
MVS with all-zero guard (variant)+0.000+0.000+0.000+0.000+0.000
Apr: contributions to the CRPS difference from Mean-Variance Scaling (mm)
MethodTotal Δ CRPSall 0 mm
0.0% of area
all ≤ 1 mm
0.0% of area
mixed
14.3% of area
always wet
85.7% of area
Linear Scaling+0.383+0.000+0.000+0.061+0.322
Variance Scaling (unbounded)-0.018+0.000+0.000-0.008-0.010
Square-root-space Mean-Variance Scaling-0.081+0.000+0.000-0.026-0.055
Power Transformation+0.002+0.000+0.000-0.032+0.034
Delta Change+0.120+0.000+0.000-0.017+0.137
Local Intensity Scaling+0.345+0.000+0.000+0.062+0.284
Empirical Quantile Mapping+0.282+0.000+0.000-0.019+0.301
Gamma Quantile Mapping-0.076+0.000+0.000-0.041-0.035
Detrended Quantile Mapping+0.595+0.000+0.000+0.033+0.562
Quantile Delta Mapping+0.851+0.000+0.000+0.074+0.777
Scaled Distribution Mapping+0.958+0.000+0.000+0.100+0.858
CDF-transform+0.694+0.000+0.000+0.061+0.632
MVS with all-zero guard (variant)+0.000+0.000+0.000+0.000+0.000
May: contributions to the CRPS difference from Mean-Variance Scaling (mm)
MethodTotal Δ CRPSall 0 mm
0.0% of area
all ≤ 1 mm
0.0% of area
mixed
9.4% of area
always wet
90.6% of area
Linear Scaling+0.091+0.000+0.000-0.032+0.123
Variance Scaling (unbounded)+0.001+0.000+0.000-0.001+0.002
Square-root-space Mean-Variance Scaling-0.127+0.000+0.000-0.039-0.088
Power Transformation-0.146+0.000+0.000-0.055-0.091
Delta Change-0.076+0.000+0.000-0.040-0.036
Local Intensity Scaling+0.088+0.000+0.000-0.024+0.112
Empirical Quantile Mapping+0.202+0.000+0.000-0.046+0.248
Gamma Quantile Mapping-0.103+0.000+0.000-0.050-0.053
Detrended Quantile Mapping+0.316+0.000+0.000-0.035+0.352
Quantile Delta Mapping+0.215+0.000+0.000-0.039+0.254
Scaled Distribution Mapping+0.410+0.000+0.000-0.019+0.429
CDF-transform+0.239+0.000+0.000-0.037+0.276
MVS with all-zero guard (variant)+0.000+0.000+0.000+0.000+0.000
FMAM: contributions to the CRPS difference from Mean-Variance Scaling (mm)
MethodTotal Δ CRPSall 0 mm
0.0% of area
all ≤ 1 mm
0.0% of area
mixed
0.0% of area
always wet
100.0% of area
Linear Scaling+0.270+0.000+0.000+0.000+0.270
Variance Scaling (unbounded)-0.006+0.000+0.000+0.000-0.006
Square-root-space Mean-Variance Scaling-0.036+0.000+0.000+0.000-0.036
Power Transformation+0.033+0.000+0.000+0.000+0.033
Delta Change-0.205+0.000+0.000+0.000-0.205
Local Intensity Scaling+0.245+0.000+0.000+0.000+0.245
Empirical Quantile Mapping+0.708+0.000+0.000+0.000+0.708
Gamma Quantile Mapping-0.005+0.000+0.000+0.000-0.005
Detrended Quantile Mapping+0.600+0.000+0.000+0.000+0.600
Quantile Delta Mapping+0.567+0.000+0.000+0.000+0.567
Scaled Distribution Mapping+0.796+0.000+0.000+0.000+0.796
CDF-transform+0.582+0.000+0.000+0.000+0.582
MVS with all-zero guard (variant)+0.000+0.000+0.000+0.000+0.000

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