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

Washington Reagan · ECMWF AIFS Single · lead day 1

KDCA · aifs_single · lead 1

Target day = initialization date + 1 day. 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
tmax00Zbilinear30d29 1 QC2.39 [1.32, 3.41]1.78-2.14 [-3.39, -0.85]3.12 [1.96, 4.15]34% [10%, 66%]45%69%+0.33+0.502026-08-02 → 2026-08-30
tmax00Zbilinear90d29 1 QC2.39 [1.30, 3.56]1.78-2.14 [-3.54, -0.85]3.12 [1.93, 4.21]34% [6%, 64%]45%69%+0.33+0.502026-08-02 → 2026-08-30
tmax00Zbilinear365d29 1 QC2.39 [1.20, 3.60]1.78-2.14 [-3.60, -0.73]3.12 [1.84, 4.22]34% [7%, 67%]45%69%+0.33+0.502026-08-02 → 2026-08-30
tmax00Zbilinearall29 1 QC2.39 [1.23, 3.57]1.78-2.14 [-3.57, -0.73]3.12 [1.83, 4.25]34% [7%, 68%]45%69%+0.33+0.502026-08-02 → 2026-08-30
tmax00Znearest30d29 1 QC2.33 [1.41, 3.25]1.84-1.94 [-3.22, -0.57]3.01 [1.91, 3.99]31% [10%, 57%]48%72%+0.35+0.492026-08-02 → 2026-08-30
tmax00Znearest90d29 1 QC2.33 [1.39, 3.40]1.84-1.94 [-3.36, -0.57]3.01 [1.88, 4.04]31% [6%, 55%]48%72%+0.35+0.492026-08-02 → 2026-08-30
tmax00Znearest365d29 1 QC2.33 [1.31, 3.42]1.84-1.94 [-3.41, -0.45]3.01 [1.79, 4.07]31% [7%, 58%]48%72%+0.35+0.492026-08-02 → 2026-08-30
tmax00Znearestall29 1 QC2.33 [1.33, 3.38]1.84-1.94 [-3.38, -0.46]3.01 [1.80, 4.08]31% [7%, 58%]48%72%+0.35+0.492026-08-02 → 2026-08-30
tmax12Zbilinear30d29 1 QC2.11 [1.31, 2.88]1.66-1.76 [-2.86, -0.56]2.65 [1.81, 3.32]28% [4%, 54%]59%69%+0.41+0.542026-08-02 → 2026-08-30
tmax12Zbilinear90d29 1 QC2.11 [1.27, 3.02]1.66-1.76 [-3.01, -0.53]2.65 [1.71, 3.42]28% [0%, 54%]59%69%+0.41+0.542026-08-02 → 2026-08-30
tmax12Zbilinear365d29 1 QC2.11 [1.23, 3.03]1.66-1.76 [-3.03, -0.45]2.65 [1.65, 3.43]28% [0%, 57%]59%69%+0.41+0.542026-08-02 → 2026-08-30
tmax12Zbilinearall29 1 QC2.11 [1.21, 2.95]1.66-1.76 [-2.95, -0.43]2.65 [1.63, 3.37]28% [0%, 58%]59%69%+0.41+0.542026-08-02 → 2026-08-30
tmax12Znearest30d29 1 QC2.06 [1.40, 2.70]1.68-1.54 [-2.65, -0.30]2.53 [1.76, 3.13]28% [10%, 50%]59%72%+0.43+0.532026-08-02 → 2026-08-30
tmax12Znearest90d29 1 QC2.06 [1.36, 2.86]1.68-1.54 [-2.85, -0.22]2.53 [1.69, 3.24]28% [6%, 50%]59%72%+0.43+0.532026-08-02 → 2026-08-30
tmax12Znearest365d29 1 QC2.06 [1.33, 2.83]1.68-1.54 [-2.81, -0.15]2.53 [1.62, 3.23]28% [7%, 53%]59%72%+0.43+0.532026-08-02 → 2026-08-30
tmax12Znearestall29 1 QC2.06 [1.33, 2.77]1.68-1.54 [-2.75, -0.15]2.53 [1.63, 3.20]28% [6%, 53%]59%72%+0.43+0.532026-08-02 → 2026-08-30
tmin00Zbilinear30d29 1 QC1.66 [1.32, 1.97]1.65+0.55 [-0.49, 1.46]2.15 [1.67, 2.52]38% [29%, 50%]69%86%+0.30+0.312026-08-02 → 2026-08-30
tmin00Zbilinear90d29 1 QC1.66 [1.28, 2.01]1.65+0.55 [-0.68, 1.58]2.15 [1.64, 2.55]38% [29%, 50%]69%86%+0.30+0.312026-08-02 → 2026-08-30
tmin00Zbilinear365d29 1 QC1.66 [1.26, 2.01]1.65+0.55 [-0.87, 1.58]2.15 [1.60, 2.54]38% [29%, 50%]69%86%+0.30+0.312026-08-02 → 2026-08-30
tmin00Zbilinearall29 1 QC1.66 [1.25, 2.01]1.65+0.55 [-0.73, 1.56]2.15 [1.56, 2.55]38% [29%, 50%]69%86%+0.30+0.312026-08-02 → 2026-08-30
tmin00Znearest30d29 1 QC1.69 [1.26, 2.09]1.67+0.84 [-0.22, 1.76]2.26 [1.67, 2.70]45% [31%, 61%]66%83%+0.29+0.302026-08-02 → 2026-08-30
tmin00Znearest90d29 1 QC1.69 [1.20, 2.13]1.67+0.84 [-0.42, 1.89]2.26 [1.60, 2.74]45% [29%, 62%]66%83%+0.29+0.302026-08-02 → 2026-08-30
tmin00Znearest365d29 1 QC1.69 [1.12, 2.13]1.67+0.84 [-0.60, 1.88]2.26 [1.55, 2.73]45% [29%, 65%]66%83%+0.29+0.302026-08-02 → 2026-08-30
tmin00Znearestall29 1 QC1.69 [1.18, 2.15]1.67+0.84 [-0.46, 1.87]2.26 [1.58, 2.74]45% [29%, 64%]66%83%+0.29+0.302026-08-02 → 2026-08-30
tmin12Zbilinear30d29 1 QC1.47 [1.14, 1.82]1.43+0.46 [-0.42, 1.26]2.02 [1.52, 2.42]52% [36%, 63%]79%86%+0.38+0.402026-08-02 → 2026-08-30
tmin12Zbilinear90d29 1 QC1.47 [1.08, 1.85]1.43+0.46 [-0.68, 1.38]2.02 [1.44, 2.45]52% [33%, 64%]79%86%+0.38+0.402026-08-02 → 2026-08-30
tmin12Zbilinear365d29 1 QC1.47 [1.08, 1.88]1.43+0.46 [-0.82, 1.38]2.02 [1.42, 2.44]52% [30%, 65%]79%86%+0.38+0.402026-08-02 → 2026-08-30
tmin12Zbilinearall29 1 QC1.47 [1.06, 1.85]1.43+0.46 [-0.76, 1.34]2.02 [1.40, 2.45]52% [33%, 67%]79%86%+0.38+0.402026-08-02 → 2026-08-30
tmin12Znearest30d29 1 QC1.56 [1.24, 1.93]1.45+0.74 [-0.16, 1.56]2.12 [1.57, 2.57]45% [30%, 57%]69%90%+0.34+0.392026-08-02 → 2026-08-30
tmin12Znearest90d29 1 QC1.56 [1.17, 1.95]1.45+0.74 [-0.41, 1.67]2.12 [1.52, 2.59]45% [28%, 58%]69%90%+0.34+0.392026-08-02 → 2026-08-30
tmin12Znearest365d29 1 QC1.56 [1.17, 1.95]1.45+0.74 [-0.56, 1.70]2.12 [1.45, 2.59]45% [27%, 60%]69%90%+0.34+0.392026-08-02 → 2026-08-30
tmin12Znearestall29 1 QC1.56 [1.18, 1.94]1.45+0.74 [-0.53, 1.66]2.12 [1.47, 2.58]45% [27%, 61%]69%90%+0.34+0.392026-08-02 → 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 1, 00Z bilinear tmax+10+50-5-102026-08-02: -2.27 °F2026-08-03: -4.13 °F2026-08-04: -2.17 °F2026-08-05: -4.14 °F2026-08-06: +1.05 °F2026-08-07: +0.09 °F2026-08-08: -0.54 °F2026-08-09: +0.33 °F2026-08-10: -0.04 °F2026-08-11: +0.63 °F2026-08-12: +0.41 °F2026-08-13: +0.76 °F2026-08-14: +0.23 °F2026-08-15: -2.96 °F2026-08-16: -4.49 °F2026-08-17: -3.85 °F2026-08-18: -0.91 °F2026-08-19: -2.31 °F2026-08-20: -8.97 °F2026-08-21: -5.38 °F2026-08-22: -1.62 °F2026-08-23: -3.8 °F2026-08-24: -2.3 °F2026-08-25: -3.01 °F2026-08-26: -0.58 °F2026-08-27: -1.97 °F2026-08-28: -5.21 °F2026-08-29: -2.93 °F2026-08-30: -2.08 °F2026-08-022026-08-30°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 (29 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.08
2026-08-29-2.93
2026-08-28-5.21
2026-08-27-1.97
2026-08-26-0.58
2026-08-25-3.01
2026-08-24-2.30
2026-08-23-3.80
2026-08-22-1.62
2026-08-21-5.38
2026-08-20-8.97
2026-08-19-2.31
2026-08-18-0.91
2026-08-17-3.85
2026-08-16-4.49
2026-08-15-2.96
2026-08-14+0.23
2026-08-13+0.76
2026-08-12+0.41
2026-08-11+0.63
2026-08-10-0.04
2026-08-09+0.33
2026-08-08-0.54
2026-08-07+0.09
2026-08-06+1.05
2026-08-05-4.14
2026-08-04-2.17
2026-08-03-4.13
2026-08-02-2.27

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KDCA, lead day 1-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 2 days-5 to -4 °F: 3 days-4 to -3 °F: 3 days-3 to -2 °F: 7 days-2 to -1 °F: 2 days-1 to 0 °F: 4 days0 to 1 °F: 6 days1 to 2 °F: 1 day2 to 3 °F: 0 days3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2.17 · P90 |e| 4.63 °F-100+10 °Fn = 29 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
-10.00-9.000
-9.00-8.001
-8.00-7.000
-7.00-6.000
-6.00-5.002
-5.00-4.003
-4.00-3.003
-3.00-2.007
-2.00-1.002
-1.00+0.004
+0.00+1.006
+1.00+2.001
+2.00+3.000
+3.00+4.000
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08292.39 -2.14

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29

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
Aurora (GFS init) 1 -6.00 [-6.00, -6.00] yes
Aurora (IFS init) 2 -3.57 [-4.58, -2.56] yes
FourCastNet v2 (GFS init) 1 -1.55 [-1.55, -1.55] yes
FourCastNet v2 (IFS init) 2 +0.07 [-0.92, 1.05] no
NCEP GFS 29 -1.35 [-2.35, -0.16] yes
GraphCast (GFS init) 1 -3.05 [-3.05, -3.05] yes
GraphCast (IFS init) 27 -2.68 [-3.21, -2.10] yes
ECMWF IFS HRES 23 -1.13 [-2.00, -0.68] yes
Pangu-Weather (GFS init) 1 -0.44 [-0.44, -0.44] yes
Pangu-Weather (IFS init) 2 +0.55 [-0.90, 1.99] no
Persistence (baseline) 29 -1.20 [-2.42, -0.14] yes

Cite this page

ShortCastCheck, KDCA aifs_single lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDCA/model/aifs_single/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDCA (Washington Reagan), model aifs_single, lead day 1. 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/1/

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

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