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

Washington Reagan · ECMWF AIFS Single · lead day 3

KDCA · aifs_single · lead 3

Target day = initialization date + 3 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
tmax00Zbilinear30d27 1 QC3.02 [2.16, 3.81]2.24-2.09 [-3.31, -0.79]3.52 [2.66, 4.22]7% [0%, 17%]33%48%+0.26+0.452026-08-04 → 2026-08-30
tmax00Zbilinear90d27 1 QC3.02 [2.05, 3.89]2.24-2.09 [-3.47, -0.76]3.52 [2.45, 4.26]7% [0%, 17%]33%48%+0.26+0.452026-08-04 → 2026-08-30
tmax00Zbilinear365d27 1 QC3.02 [1.99, 3.90]2.24-2.09 [-3.53, -0.57]3.52 [2.38, 4.28]7% [0%, 17%]33%48%+0.26+0.452026-08-04 → 2026-08-30
tmax00Zbilinearall27 1 QC3.02 [2.03, 3.87]2.24-2.09 [-3.53, -0.60]3.52 [2.43, 4.26]7% [0%, 17%]33%48%+0.26+0.452026-08-04 → 2026-08-30
tmax00Znearest30d27 1 QC2.93 [2.10, 3.69]2.25-1.90 [-3.16, -0.56]3.43 [2.56, 4.10]15% [0%, 33%]33%56%+0.28+0.452026-08-04 → 2026-08-30
tmax00Znearest90d27 1 QC2.93 [1.99, 3.76]2.25-1.90 [-3.34, -0.53]3.43 [2.39, 4.16]15% [0%, 36%]33%56%+0.28+0.452026-08-04 → 2026-08-30
tmax00Znearest365d27 1 QC2.93 [1.92, 3.78]2.25-1.90 [-3.40, -0.34]3.43 [2.33, 4.19]15% [0%, 36%]33%56%+0.28+0.452026-08-04 → 2026-08-30
tmax00Znearestall27 1 QC2.93 [1.97, 3.75]2.25-1.90 [-3.39, -0.37]3.43 [2.37, 4.15]15% [0%, 36%]33%56%+0.28+0.452026-08-04 → 2026-08-30
tmax12Zbilinear30d27 1 QC2.50 [1.67, 3.29]1.77-2.17 [-3.22, -1.03]3.02 [2.10, 3.72]19% [11%, 26%]48%63%+0.39+0.572026-08-04 → 2026-08-30
tmax12Zbilinear90d27 1 QC2.50 [1.66, 3.34]1.77-2.17 [-3.28, -0.99]3.02 [2.06, 3.78]19% [11%, 27%]48%63%+0.39+0.572026-08-04 → 2026-08-30
tmax12Zbilinear365d27 1 QC2.50 [1.49, 3.39]1.77-2.17 [-3.36, -0.81]3.02 [1.92, 3.82]19% [11%, 28%]48%63%+0.39+0.572026-08-04 → 2026-08-30
tmax12Zbilinearall27 1 QC2.50 [1.59, 3.40]1.77-2.17 [-3.40, -0.88]3.02 [2.02, 3.80]19% [11%, 28%]48%63%+0.39+0.572026-08-04 → 2026-08-30
tmax12Znearest30d27 1 QC2.43 [1.69, 3.13]1.81-1.97 [-3.07, -0.76]2.91 [2.04, 3.56]19% [11%, 26%]48%63%+0.40+0.562026-08-04 → 2026-08-30
tmax12Znearest90d27 1 QC2.43 [1.65, 3.19]1.81-1.97 [-3.14, -0.74]2.91 [2.00, 3.63]19% [11%, 27%]48%63%+0.40+0.562026-08-04 → 2026-08-30
tmax12Znearest365d27 1 QC2.43 [1.55, 3.22]1.81-1.97 [-3.21, -0.58]2.91 [1.87, 3.66]19% [11%, 28%]48%63%+0.40+0.562026-08-04 → 2026-08-30
tmax12Znearestall27 1 QC2.43 [1.60, 3.28]1.81-1.97 [-3.26, -0.65]2.91 [1.93, 3.66]19% [11%, 28%]48%63%+0.40+0.562026-08-04 → 2026-08-30
tmin00Zbilinear30d27 1 QC2.00 [1.59, 2.35]2.05+0.45 [-0.78, 1.48]2.56 [1.98, 2.97]33% [23%, 43%]56%74%+0.36+0.342026-08-04 → 2026-08-30
tmin00Zbilinear90d27 1 QC2.00 [1.55, 2.35]2.05+0.45 [-1.02, 1.61]2.56 [1.88, 2.97]33% [23%, 44%]56%74%+0.36+0.342026-08-04 → 2026-08-30
tmin00Zbilinear365d27 1 QC2.00 [1.50, 2.36]2.05+0.45 [-1.30, 1.62]2.56 [1.85, 2.98]33% [23%, 44%]56%74%+0.36+0.342026-08-04 → 2026-08-30
tmin00Zbilinearall27 1 QC2.00 [1.46, 2.37]2.05+0.45 [-1.10, 1.63]2.56 [1.78, 3.01]33% [22%, 44%]56%74%+0.36+0.342026-08-04 → 2026-08-30
tmin00Znearest30d27 1 QC2.05 [1.63, 2.44]2.04+0.73 [-0.50, 1.77]2.62 [1.93, 3.09]37% [26%, 47%]48%78%+0.34+0.352026-08-04 → 2026-08-30
tmin00Znearest90d27 1 QC2.05 [1.54, 2.45]2.04+0.73 [-0.75, 1.90]2.62 [1.84, 3.10]37% [25%, 48%]48%78%+0.34+0.352026-08-04 → 2026-08-30
tmin00Znearest365d27 1 QC2.05 [1.52, 2.45]2.04+0.73 [-1.02, 1.92]2.62 [1.80, 3.12]37% [25%, 49%]48%78%+0.34+0.352026-08-04 → 2026-08-30
tmin00Znearestall27 1 QC2.05 [1.50, 2.47]2.04+0.73 [-0.82, 1.93]2.62 [1.78, 3.12]37% [25%, 50%]48%78%+0.34+0.352026-08-04 → 2026-08-30
tmin12Zbilinear30d27 1 QC2.01 [1.70, 2.34]2.04+0.53 [-0.64, 1.55]2.45 [1.99, 2.81]22% [9%, 33%]59%74%+0.35+0.352026-08-04 → 2026-08-30
tmin12Zbilinear90d27 1 QC2.01 [1.68, 2.34]2.04+0.53 [-0.83, 1.64]2.45 [1.93, 2.81]22% [5%, 32%]59%74%+0.35+0.352026-08-04 → 2026-08-30
tmin12Zbilinear365d27 1 QC2.01 [1.60, 2.35]2.04+0.53 [-0.97, 1.74]2.45 [1.86, 2.82]22% [5%, 32%]59%74%+0.35+0.352026-08-04 → 2026-08-30
tmin12Zbilinearall27 1 QC2.01 [1.62, 2.33]2.04+0.53 [-0.94, 1.65]2.45 [1.84, 2.81]22% [0%, 33%]59%74%+0.35+0.352026-08-04 → 2026-08-30
tmin12Znearest30d27 1 QC2.06 [1.66, 2.44]2.02+0.81 [-0.36, 1.83]2.52 [1.95, 2.93]26% [11%, 39%]56%78%+0.34+0.352026-08-04 → 2026-08-30
tmin12Znearest90d27 1 QC2.06 [1.62, 2.45]2.02+0.81 [-0.55, 1.94]2.52 [1.89, 2.95]26% [6%, 37%]56%78%+0.34+0.352026-08-04 → 2026-08-30
tmin12Znearest365d27 1 QC2.06 [1.57, 2.44]2.02+0.81 [-0.72, 2.03]2.52 [1.82, 2.95]26% [7%, 38%]56%78%+0.34+0.352026-08-04 → 2026-08-30
tmin12Znearestall27 1 QC2.06 [1.58, 2.44]2.02+0.81 [-0.69, 1.95]2.52 [1.82, 2.94]26% [0%, 38%]56%78%+0.34+0.352026-08-04 → 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 3, 00Z bilinear tmax+10+50-5-102026-08-04: -3.13 °F2026-08-05: -4.68 °F2026-08-06: +0.13 °F2026-08-07: -2.82 °F2026-08-08: -1.13 °F2026-08-09: -1.23 °F2026-08-10: +1.11 °F2026-08-11: +2.65 °F2026-08-12: -1.35 °F2026-08-13: -0.26 °F2026-08-14: +2.17 °F2026-08-15: -3.14 °F2026-08-16: +4.44 °F2026-08-17: -5.94 °F2026-08-18: -3.3 °F2026-08-19: -3.13 °F2026-08-20: -6.25 °F2026-08-21: -1.73 °F2026-08-22: +2.09 °F2026-08-23: -3.93 °F2026-08-24: -4.55 °F2026-08-25: -3.45 °F2026-08-26: -2 °F2026-08-27: -7.95 °F2026-08-28: -4.21 °F2026-08-29: -1.77 °F2026-08-30: -3.02 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.02
2026-08-29-1.77
2026-08-28-4.21
2026-08-27-7.95
2026-08-26-2.00
2026-08-25-3.45
2026-08-24-4.55
2026-08-23-3.93
2026-08-22+2.09
2026-08-21-1.73
2026-08-20-6.25
2026-08-19-3.13
2026-08-18-3.30
2026-08-17-5.94
2026-08-16+4.44
2026-08-15-3.14
2026-08-14+2.17
2026-08-13-0.26
2026-08-12-1.35
2026-08-11+2.65
2026-08-10+1.11
2026-08-09-1.23
2026-08-08-1.13
2026-08-07-2.82
2026-08-06+0.13
2026-08-05-4.68
2026-08-04-3.13

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KDCA, lead day 3-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 1 day-6 to -5 °F: 1 day-5 to -4 °F: 3 days-4 to -3 °F: 7 days-3 to -2 °F: 1 day-2 to -1 °F: 6 days-1 to 0 °F: 1 day0 to 1 °F: 1 day1 to 2 °F: 1 day2 to 3 °F: 3 days3 to 4 °F: 0 days4 to 5 °F: 1 day5 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| 3.02 · P90 |e| 5.19 °F-100+10 °Fn = 27 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
-8.00-7.001
-7.00-6.001
-6.00-5.001
-5.00-4.003
-4.00-3.007
-3.00-2.001
-2.00-1.006
-1.00+0.001
+0.00+1.001
+1.00+2.001
+2.00+3.003
+3.00+4.000
+4.00+5.001
+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
2026-08273.02 -2.09

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27

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 27 -0.56 [-2.35, 0.73] no
GraphCast (IFS init) 25 -1.78 [-2.72, -1.09] yes
ECMWF IFS HRES 22 -0.65 [-1.78, 0.97] no
Persistence (baseline) 27 -1.05 [-2.02, 0.36] no

Cite this page

ShortCastCheck, KDCA aifs_single lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDCA/model/aifs_single/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDCA (Washington Reagan), model aifs_single, lead day 3. 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/3/

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

JSON CSV all scores methodology v0.2 licence