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

Washington Reagan · ECMWF AIFS Single · lead day 0

KDCA · aifs_single · lead 0

Target day = initialization date + 0 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
tmax00Zbilinear30d30 1 QC2.17 [1.44, 2.92]1.60-1.87 [-2.83, -0.86]2.71 [2.00, 3.39]27% [3%, 53%]53%73%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d30 1 QC2.17 [1.40, 2.99]1.60-1.87 [-2.94, -0.80]2.71 [1.93, 3.43]27% [0%, 59%]53%73%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d30 1 QC2.17 [1.34, 3.00]1.60-1.87 [-2.98, -0.74]2.71 [1.84, 3.45]27% [0%, 58%]53%73%——2026-08-01 → 2026-08-30
tmax00Zbilinearall30 1 QC2.17 [1.36, 3.05]1.60-1.87 [-3.05, -0.76]2.71 [1.86, 3.49]27% [0%, 59%]53%73%——2026-08-01 → 2026-08-30
tmax00Znearest30d30 1 QC2.11 [1.43, 2.77]1.65-1.63 [-2.63, -0.58]2.58 [1.90, 3.19]20% [3%, 37%]57%77%——2026-08-01 → 2026-08-30
tmax00Znearest90d30 1 QC2.11 [1.42, 2.86]1.65-1.63 [-2.77, -0.44]2.58 [1.88, 3.24]20% [0%, 39%]57%77%——2026-08-01 → 2026-08-30
tmax00Znearest365d30 1 QC2.11 [1.35, 2.85]1.65-1.63 [-2.81, -0.43]2.58 [1.78, 3.23]20% [0%, 42%]57%77%——2026-08-01 → 2026-08-30
tmax00Znearestall30 1 QC2.11 [1.39, 2.88]1.65-1.63 [-2.88, -0.43]2.58 [1.82, 3.27]20% [0%, 42%]57%77%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d30 1 QC1.36 [1.09, 1.61]1.34+0.33 [-0.46, 1.07]1.94 [1.53, 2.28]60% [47%, 70%]77%87%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d30 1 QC1.36 [1.05, 1.73]1.34+0.33 [-0.72, 1.17]1.94 [1.44, 2.38]60% [40%, 72%]77%87%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d30 1 QC1.36 [1.03, 1.78]1.34+0.33 [-0.95, 1.18]1.94 [1.42, 2.38]60% [36%, 72%]77%87%——2026-08-01 → 2026-08-30
tmin00Zbilinearall30 1 QC1.36 [1.03, 1.72]1.34+0.33 [-0.81, 1.14]1.94 [1.41, 2.34]60% [41%, 72%]77%87%——2026-08-01 → 2026-08-30
tmin00Znearest30d30 1 QC1.46 [1.16, 1.75]1.38+0.59 [-0.21, 1.35]2.03 [1.55, 2.42]57% [47%, 67%]73%87%——2026-08-01 → 2026-08-30
tmin00Znearest90d30 1 QC1.46 [1.14, 1.85]1.38+0.59 [-0.50, 1.45]2.03 [1.51, 2.50]57% [45%, 67%]73%87%——2026-08-01 → 2026-08-30
tmin00Znearest365d30 1 QC1.46 [1.10, 1.86]1.38+0.59 [-0.70, 1.46]2.03 [1.46, 2.51]57% [44%, 68%]73%87%——2026-08-01 → 2026-08-30
tmin00Znearestall30 1 QC1.46 [1.09, 1.81]1.38+0.59 [-0.58, 1.43]2.03 [1.42, 2.45]57% [44%, 68%]73%87%——2026-08-01 → 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 0, 00Z bilinear tmax+10+50-5-102026-08-01: -0.62 °F2026-08-02: +0.55 °F2026-08-03: -2.84 °F2026-08-04: -0.95 °F2026-08-05: -4.93 °F2026-08-06: +2.1 °F2026-08-07: -0.09 °F2026-08-08: -0.35 °F2026-08-09: +0.01 °F2026-08-10: +0.83 °F2026-08-11: -2.35 °F2026-08-12: -0.25 °F2026-08-13: +1.03 °F2026-08-14: -1.28 °F2026-08-15: -1.21 °F2026-08-16: -4.62 °F2026-08-17: -3.7 °F2026-08-18: -1.35 °F2026-08-19: -1.38 °F2026-08-20: -6.67 °F2026-08-21: -4.38 °F2026-08-22: -1.95 °F2026-08-23: -3.03 °F2026-08-24: -2.83 °F2026-08-25: -2.69 °F2026-08-26: -1.12 °F2026-08-27: -1.98 °F2026-08-28: -4.33 °F2026-08-29: -3.19 °F2026-08-30: -2.61 °F2026-08-012026-08-30°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 (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.61
2026-08-29-3.19
2026-08-28-4.33
2026-08-27-1.98
2026-08-26-1.12
2026-08-25-2.69
2026-08-24-2.83
2026-08-23-3.03
2026-08-22-1.95
2026-08-21-4.38
2026-08-20-6.67
2026-08-19-1.38
2026-08-18-1.35
2026-08-17-3.70
2026-08-16-4.62
2026-08-15-1.21
2026-08-14-1.28
2026-08-13+1.03
2026-08-12-0.25
2026-08-11-2.35
2026-08-10+0.83
2026-08-09+0.01
2026-08-08-0.35
2026-08-07-0.09
2026-08-06+2.10
2026-08-05-4.93
2026-08-04-0.95
2026-08-03-2.84
2026-08-02+0.55
2026-08-01-0.62

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KDCA, lead day 0-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 0 days-5 to -4 °F: 4 days-4 to -3 °F: 3 days-3 to -2 °F: 5 days-2 to -1 °F: 7 days-1 to 0 °F: 5 days0 to 1 °F: 3 days1 to 2 °F: 1 day2 to 3 °F: 1 day3 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| 1.96 · P90 |e| 4.41 °F-100+10 °Fn = 30 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
-9.00-8.000
-8.00-7.000
-7.00-6.001
-6.00-5.000
-5.00-4.004
-4.00-3.003
-3.00-2.005
-2.00-1.007
-1.00+0.005
+0.00+1.003
+1.00+2.001
+2.00+3.001
+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
2026-08302.17 -1.87

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-01 → 2026-08-30 30
ECMWF AIFS Single2026-08-01 → 2026-08-30 30

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) 2 -3.74 [-4.48, -3.00] yes
Aurora (IFS init) 3 -3.23 [-3.73, -2.83] yes
FourCastNet v2 (GFS init) 2 -1.24 [-1.87, -0.61] yes
FourCastNet v2 (IFS init) 3 -2.33 [-4.00, -1.45] yes
NCEP GFS 30 -0.15 [-1.46, 0.95] no
GraphCast (GFS init) 2 -3.04 [-3.56, -2.52] yes
GraphCast (IFS init) 28 -2.42 [-2.79, -2.11] yes
ECMWF IFS HRES 24 -0.69 [-0.99, -0.05] yes
Pangu-Weather (GFS init) 2 +0.69 [-0.44, 1.81] no
Pangu-Weather (IFS init) 3 +0.58 [-0.65, 1.20] no

Cite this page

ShortCastCheck, KDCA aifs_single lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDCA/model/aifs_single/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDCA (Washington Reagan), model aifs_single, lead day 0. 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/0/

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

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