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CastCheck methodology v0.2 · data through 2026-08-30

Washington Reagan · ECMWF AIFS Single · lead day 5

KDCA · aifs_single · lead 5

Target day = initialization date + 5 days. This page is a permanent link: the numbers change as history accumulates, the address and the methodology version do not.

Scores use the latest model version segment, aifs-single-gpid5, starting 2026-08-01 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 1 carry a QC flag on the observation.

JSON for this page CSV of the daily errors Cite this page

Every number for this combination

All four windows × both initializations × both interpolations × both variables. Errors are computed in °C and shown in °F; CI is a 95 % moving-block bootstrap interval. MAE debiased and skill, debiased remove the constant offset of the window first, so a station that the model always reads a degree too warm is not scored as if it had no skill — compare the two skill columns to see how much of the error is a fixed offset. n QC next to n counts days whose observation carries a QC flag.

VariableInitMethod Windown MAE °F MAE debiased Bias °F RMSE °F ±1 °F±2 °F±3 °F Skill Skill, debiased Period
tmax00Zbilinear30d25 1 QC3.54 [2.22, 4.69]2.56-2.33 [-3.94, -0.82]4.21 [2.56, 5.43]8% [0%, 19%]28%48%+0.27+0.472026-08-06 → 2026-08-30
tmax00Zbilinear90d25 1 QC3.54 [2.06, 4.87]2.56-2.33 [-4.21, -0.48]4.21 [2.33, 5.60]8% [0%, 21%]28%48%+0.27+0.472026-08-06 → 2026-08-30
tmax00Zbilinear365d25 1 QC3.54 [2.07, 4.98]2.56-2.33 [-4.51, -0.52]4.21 [2.33, 5.72]8% [0%, 20%]28%48%+0.27+0.472026-08-06 → 2026-08-30
tmax00Zbilinearall25 1 QC3.54 [2.06, 4.94]2.56-2.33 [-4.10, -0.49]4.21 [2.32, 5.70]8% [0%, 22%]28%48%+0.27+0.472026-08-06 → 2026-08-30
tmax00Znearest30d25 1 QC3.41 [2.21, 4.49]2.57-2.09 [-3.72, -0.58]4.07 [2.51, 5.25]8% [0%, 19%]24%44%+0.30+0.472026-08-06 → 2026-08-30
tmax00Znearest90d25 1 QC3.41 [2.07, 4.69]2.57-2.09 [-3.94, -0.30]4.07 [2.37, 5.46]8% [0%, 21%]24%44%+0.30+0.472026-08-06 → 2026-08-30
tmax00Znearest365d25 1 QC3.41 [2.09, 4.78]2.57-2.09 [-4.36, -0.31]4.07 [2.37, 5.53]8% [0%, 20%]24%44%+0.30+0.472026-08-06 → 2026-08-30
tmax00Znearestall25 1 QC3.41 [2.07, 4.79]2.57-2.09 [-3.89, -0.28]4.07 [2.37, 5.54]8% [0%, 22%]24%44%+0.30+0.472026-08-06 → 2026-08-30
tmax12Zbilinear30d24 1 QC3.03 [2.26, 3.67]2.11-2.42 [-3.34, -1.51]3.48 [2.82, 3.99]17% [10%, 27%]33%46%+0.38+0.572026-08-06 → 2026-08-30
tmax12Zbilinear90d24 1 QC3.03 [1.99, 3.80]2.11-2.42 [-3.43, -1.28]3.48 [2.44, 4.08]17% [9%, 30%]33%46%+0.38+0.572026-08-06 → 2026-08-30
tmax12Zbilinear365d24 1 QC3.03 [2.03, 3.79]2.11-2.42 [-3.54, -1.26]3.48 [2.43, 4.08]17% [8%, 29%]33%46%+0.38+0.572026-08-06 → 2026-08-30
tmax12Zbilinearall24 1 QC3.03 [1.97, 3.74]2.11-2.42 [-3.47, -1.28]3.48 [2.53, 4.04]17% [10%, 31%]33%46%+0.38+0.572026-08-06 → 2026-08-30
tmax12Znearest30d24 1 QC2.90 [2.16, 3.51]2.14-2.18 [-3.14, -1.24]3.35 [2.73, 3.84]17% [4%, 33%]33%58%+0.40+0.562026-08-06 → 2026-08-30
tmax12Znearest90d24 1 QC2.90 [1.96, 3.62]2.14-2.18 [-3.25, -1.04]3.35 [2.45, 3.95]17% [0%, 36%]33%58%+0.40+0.562026-08-06 → 2026-08-30
tmax12Znearest365d24 1 QC2.90 [1.97, 3.64]2.14-2.18 [-3.43, -1.01]3.35 [2.47, 3.95]17% [0%, 36%]33%58%+0.40+0.562026-08-06 → 2026-08-30
tmax12Znearestall24 1 QC2.90 [1.92, 3.60]2.14-2.18 [-3.32, -1.03]3.35 [2.48, 3.91]17% [0%, 36%]33%58%+0.40+0.562026-08-06 → 2026-08-30
tmin00Zbilinear30d25 1 QC2.86 [2.41, 3.28]2.89+0.42 [-1.26, 2.03]3.37 [2.72, 3.82]16% [6%, 25%]40%56%+0.28+0.272026-08-06 → 2026-08-30
tmin00Zbilinear90d25 1 QC2.86 [2.33, 3.31]2.89+0.42 [-1.63, 2.28]3.37 [2.57, 3.86]16% [5%, 25%]40%56%+0.28+0.272026-08-06 → 2026-08-30
tmin00Zbilinear365d25 1 QC2.86 [2.28, 3.34]2.89+0.42 [-1.84, 2.32]3.37 [2.48, 3.86]16% [0%, 27%]40%56%+0.28+0.272026-08-06 → 2026-08-30
tmin00Zbilinearall25 1 QC2.86 [2.24, 3.34]2.89+0.42 [-1.79, 2.34]3.37 [2.54, 3.90]16% [0%, 25%]40%56%+0.28+0.272026-08-06 → 2026-08-30
tmin00Znearest30d25 1 QC2.83 [2.29, 3.34]2.87+0.72 [-0.97, 2.31]3.41 [2.63, 3.95]20% [7%, 32%]44%56%+0.29+0.282026-08-06 → 2026-08-30
tmin00Znearest90d25 1 QC2.83 [2.15, 3.39]2.87+0.72 [-1.33, 2.56]3.41 [2.45, 3.98]20% [6%, 32%]44%56%+0.29+0.282026-08-06 → 2026-08-30
tmin00Znearest365d25 1 QC2.83 [2.10, 3.46]2.87+0.72 [-1.51, 2.60]3.41 [2.33, 4.01]20% [0%, 33%]44%56%+0.29+0.282026-08-06 → 2026-08-30
tmin00Znearestall25 1 QC2.83 [2.10, 3.45]2.87+0.72 [-1.50, 2.60]3.41 [2.40, 4.03]20% [0%, 32%]44%56%+0.29+0.282026-08-06 → 2026-08-30
tmin12Zbilinear30d24 1 QC2.58 [2.09, 3.01]2.57-0.07 [-1.56, 1.42]3.15 [2.48, 3.63]25% [16%, 35%]42%67%+0.35+0.352026-08-06 → 2026-08-30
tmin12Zbilinear90d24 1 QC2.58 [2.01, 3.03]2.57-0.07 [-1.78, 1.70]3.15 [2.37, 3.64]25% [16%, 33%]42%67%+0.35+0.352026-08-06 → 2026-08-30
tmin12Zbilinear365d24 1 QC2.58 [1.99, 3.07]2.57-0.07 [-1.87, 1.75]3.15 [2.32, 3.69]25% [14%, 33%]42%67%+0.35+0.352026-08-06 → 2026-08-30
tmin12Zbilinearall24 1 QC2.58 [2.02, 3.04]2.57-0.07 [-1.88, 1.72]3.15 [2.32, 3.65]25% [14%, 34%]42%67%+0.35+0.352026-08-06 → 2026-08-30
tmin12Znearest30d24 1 QC2.57 [2.13, 3.01]2.57+0.22 [-1.26, 1.70]3.13 [2.47, 3.64]17% [5%, 26%]42%67%+0.35+0.362026-08-06 → 2026-08-30
tmin12Znearest90d24 1 QC2.57 [2.09, 3.03]2.57+0.22 [-1.47, 1.98]3.13 [2.36, 3.67]17% [0%, 28%]42%67%+0.35+0.362026-08-06 → 2026-08-30
tmin12Znearest365d24 1 QC2.57 [2.06, 3.07]2.57+0.22 [-1.54, 2.04]3.13 [2.33, 3.71]17% [0%, 29%]42%67%+0.35+0.362026-08-06 → 2026-08-30
tmin12Znearestall24 1 QC2.57 [2.06, 3.03]2.57+0.22 [-1.56, 2.01]3.13 [2.36, 3.65]17% [0%, 29%]42%67%+0.35+0.362026-08-06 → 2026-08-30

+ model too warm · − model too cold · bias interval includes zero · ★ lowest MAE · = not distinguishable from the leader · ▼ significantly worse · n < 30 greyed and unranked · CI is a 95 % moving-block bootstrap interval.

Daily error, last 90 days

Daily forecast minus observed error in °F for ECMWF AIFS Single at KDCA, lead day 5, 00Z bilinear tmax+20+100-10-202026-08-06: +0.47 °F2026-08-07: +1.37 °F2026-08-08: -3.66 °F2026-08-09: -3.05 °F2026-08-10: +1.39 °F2026-08-11: +2.79 °F2026-08-12: -1.69 °F2026-08-13: -0.77 °F2026-08-14: +1.82 °F2026-08-15: -4.18 °F2026-08-16: -1.78 °F2026-08-17: -3.82 °F2026-08-18: -4.41 °F2026-08-19: -4.23 °F2026-08-20: -5.37 °F2026-08-21: -2.17 °F2026-08-22: +7.36 °F2026-08-23: -4.11 °F2026-08-24: -2.89 °F2026-08-25: -4.99 °F2026-08-26: -2.92 °F2026-08-27: -11.49 °F2026-08-28: -5.24 °F2026-08-29: -3.95 °F2026-08-30: -2.66 °F2026-08-062026-08-30°F, forecast − observed
Forecast − observed, °F, 00Z bilinear daily maximum. The dashed line is zero; the thick line is a centred 7-day mean, drawn only where the whole window is present. Gaps are days with no score, never interpolation. Hover a point for its date and value.
The same series as a table (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.66
2026-08-29-3.95
2026-08-28-5.24
2026-08-27-11.49
2026-08-26-2.92
2026-08-25-4.99
2026-08-24-2.89
2026-08-23-4.11
2026-08-22+7.36
2026-08-21-2.17
2026-08-20-5.37
2026-08-19-4.23
2026-08-18-4.41
2026-08-17-3.82
2026-08-16-1.78
2026-08-15-4.18
2026-08-14+1.82
2026-08-13-0.77
2026-08-12-1.69
2026-08-11+2.79
2026-08-10+1.39
2026-08-09-3.05
2026-08-08-3.66
2026-08-07+1.37
2026-08-06+0.47

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KDCA, lead day 5-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 0 days-8 to -6 °F: 0 days-6 to -4 °F: 7 days-4 to -2 °F: 8 days-2 to 0 °F: 3 days0 to 2 °F: 4 days2 to 4 °F: 1 day4 to 6 °F: 0 days6 to 8 °F: 1 day8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 3.05 · P90 |e| 5.32 °F-200+20 °Fn = 25 days
All scored days for 00Z bilinear daily maximum, 20 equal bins. The dashed marks are the 50th and 90th percentiles of the absolute error, mirrored on both sides. Hover a bar for its bin and count.
Bin counts as a table
From °FTo °FDays
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.000
-12.00-10.001
-10.00-8.000
-8.00-6.000
-6.00-4.007
-4.00-2.008
-2.00+0.003
+0.00+2.004
+2.00+4.001
+4.00+6.000
+6.00+8.001
+8.00+10.000
+10.00+12.000
+12.00+14.000
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08253.54 -2.33

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-06 → 2026-08-30 25
ECMWF AIFS Single2026-08-06 → 2026-08-30 25
ECMWF AIFS Single2026-08-06 → 2026-08-30 24
ECMWF AIFS Single2026-08-06 → 2026-08-30 24

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF AIFS Single has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
NCEP GFS 25 -0.79 [-1.71, -0.06] yes
GraphCast (IFS init) 25 -1.24 [-1.78, -0.84] yes
ECMWF IFS HRES 18 +0.14 [-1.42, 1.52] no
Persistence (baseline) 25 -1.30 [-2.61, 0.33] no

Cite this page

ShortCastCheck, KDCA aifs_single lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDCA/model/aifs_single/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDCA (Washington Reagan), model aifs_single, lead day 5. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KDCA/model/aifs_single/lead/5/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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