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

Denver Intl · ECMWF AIFS Single · lead day 3

KDEN · 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 QC3.99 [2.98, 4.98]2.44-3.59 [-4.70, -2.34]4.69 [3.52, 5.57]11% [3%, 22%]19%41%+0.47+0.682026-08-04 → 2026-08-30
tmax00Zbilinear90d27 1 QC3.99 [2.73, 4.93]2.44-3.59 [-4.76, -2.16]4.69 [3.25, 5.56]11% [0%, 25%]19%41%+0.47+0.682026-08-04 → 2026-08-30
tmax00Zbilinear365d27 1 QC3.99 [2.68, 4.99]2.44-3.59 [-4.81, -2.07]4.69 [3.25, 5.61]11% [0%, 25%]19%41%+0.47+0.682026-08-04 → 2026-08-30
tmax00Zbilinearall27 1 QC3.99 [2.59, 5.00]2.44-3.59 [-4.73, -1.79]4.69 [3.12, 5.60]11% [0%, 29%]19%41%+0.47+0.682026-08-04 → 2026-08-30
tmax00Znearest30d27 1 QC4.04 [3.06, 5.01]2.37-3.63 [-4.79, -2.35]4.71 [3.59, 5.62]7% [0%, 15%]19%41%+0.47+0.692026-08-04 → 2026-08-30
tmax00Znearest90d27 1 QC4.04 [2.86, 4.99]2.37-3.63 [-4.84, -2.18]4.71 [3.26, 5.61]7% [0%, 16%]19%41%+0.47+0.692026-08-04 → 2026-08-30
tmax00Znearest365d27 1 QC4.04 [2.82, 5.05]2.37-3.63 [-4.85, -2.05]4.71 [3.31, 5.65]7% [0%, 15%]19%41%+0.47+0.692026-08-04 → 2026-08-30
tmax00Znearestall27 1 QC4.04 [2.65, 5.09]2.37-3.63 [-4.83, -1.77]4.71 [3.14, 5.64]7% [0%, 17%]19%41%+0.47+0.692026-08-04 → 2026-08-30
tmax12Zbilinear30d27 1 QC3.86 [3.16, 4.55]2.41-3.34 [-4.33, -1.88]4.48 [3.74, 5.12]15% [7%, 23%]30%37%+0.49+0.682026-08-04 → 2026-08-30
tmax12Zbilinear90d27 1 QC3.86 [2.98, 4.59]2.41-3.34 [-4.36, -1.72]4.48 [3.54, 5.14]15% [6%, 25%]30%37%+0.49+0.682026-08-04 → 2026-08-30
tmax12Zbilinear365d27 1 QC3.86 [2.91, 4.63]2.41-3.34 [-4.42, -1.55]4.48 [3.48, 5.18]15% [6%, 27%]30%37%+0.49+0.682026-08-04 → 2026-08-30
tmax12Zbilinearall27 1 QC3.86 [2.91, 4.68]2.41-3.34 [-4.45, -1.13]4.48 [3.52, 5.18]15% [6%, 29%]30%37%+0.49+0.682026-08-04 → 2026-08-30
tmax12Znearest30d27 1 QC3.97 [3.31, 4.66]2.40-3.37 [-4.40, -1.89]4.54 [3.83, 5.17]15% [7%, 23%]22%37%+0.48+0.692026-08-04 → 2026-08-30
tmax12Znearest90d27 1 QC3.97 [3.13, 4.70]2.40-3.37 [-4.44, -1.69]4.54 [3.64, 5.21]15% [6%, 25%]22%37%+0.48+0.692026-08-04 → 2026-08-30
tmax12Znearest365d27 1 QC3.97 [3.07, 4.75]2.40-3.37 [-4.50, -1.60]4.54 [3.57, 5.27]15% [6%, 27%]22%37%+0.48+0.692026-08-04 → 2026-08-30
tmax12Znearestall27 1 QC3.97 [3.07, 4.76]2.40-3.37 [-4.57, -1.17]4.54 [3.61, 5.26]15% [6%, 29%]22%37%+0.48+0.692026-08-04 → 2026-08-30
tmin00Zbilinear30d27 1 QC3.09 [2.26, 4.46]2.51+2.30 [0.90, 4.17]4.00 [2.76, 5.75]19% [7%, 29%]41%52%+0.49+0.592026-08-04 → 2026-08-30
tmin00Zbilinear90d27 1 QC3.09 [2.29, 4.54]2.51+2.30 [0.84, 4.35]4.00 [2.81, 5.98]19% [6%, 29%]41%52%+0.49+0.592026-08-04 → 2026-08-30
tmin00Zbilinear365d27 1 QC3.09 [2.19, 4.58]2.51+2.30 [0.76, 4.31]4.00 [2.73, 5.83]19% [0%, 29%]41%52%+0.49+0.592026-08-04 → 2026-08-30
tmin00Zbilinearall27 1 QC3.09 [2.25, 4.80]2.51+2.30 [0.79, 4.55]4.00 [2.74, 6.22]19% [0%, 29%]41%52%+0.49+0.592026-08-04 → 2026-08-30
tmin00Znearest30d27 1 QC3.13 [2.33, 4.47]2.46+2.32 [0.85, 4.21]4.01 [2.79, 5.70]22% [7%, 37%]33%56%+0.48+0.592026-08-04 → 2026-08-30
tmin00Znearest90d27 1 QC3.13 [2.35, 4.54]2.46+2.32 [0.84, 4.38]4.01 [2.84, 5.94]22% [6%, 36%]33%56%+0.48+0.592026-08-04 → 2026-08-30
tmin00Znearest365d27 1 QC3.13 [2.24, 4.56]2.46+2.32 [0.74, 4.39]4.01 [2.75, 5.78]22% [0%, 38%]33%56%+0.48+0.592026-08-04 → 2026-08-30
tmin00Znearestall27 1 QC3.13 [2.29, 4.78]2.46+2.32 [0.76, 4.64]4.01 [2.77, 6.17]22% [0%, 38%]33%56%+0.48+0.592026-08-04 → 2026-08-30
tmin12Zbilinear30d27 1 QC3.02 [2.20, 4.38]2.37+2.33 [0.88, 4.08]3.82 [2.69, 5.35]22% [11%, 33%]41%52%+0.50+0.612026-08-04 → 2026-08-30
tmin12Zbilinear90d27 1 QC3.02 [2.23, 4.46]2.37+2.33 [0.90, 4.30]3.82 [2.73, 5.59]22% [11%, 33%]41%52%+0.50+0.612026-08-04 → 2026-08-30
tmin12Zbilinear365d27 1 QC3.02 [2.14, 4.44]2.37+2.33 [0.78, 4.37]3.82 [2.62, 5.45]22% [10%, 35%]41%52%+0.50+0.612026-08-04 → 2026-08-30
tmin12Zbilinearall27 1 QC3.02 [2.20, 4.74]2.37+2.33 [0.80, 4.57]3.82 [2.68, 5.79]22% [10%, 33%]41%52%+0.50+0.612026-08-04 → 2026-08-30
tmin12Znearest30d27 1 QC3.06 [2.28, 4.36]2.35+2.34 [0.85, 4.10]3.81 [2.75, 5.28]22% [11%, 33%]33%56%+0.49+0.612026-08-04 → 2026-08-30
tmin12Znearest90d27 1 QC3.06 [2.33, 4.44]2.35+2.34 [0.88, 4.27]3.81 [2.77, 5.54]22% [11%, 33%]33%56%+0.49+0.612026-08-04 → 2026-08-30
tmin12Znearest365d27 1 QC3.06 [2.23, 4.32]2.35+2.34 [0.75, 4.28]3.81 [2.67, 5.39]22% [10%, 35%]33%56%+0.49+0.612026-08-04 → 2026-08-30
tmin12Znearestall27 1 QC3.06 [2.28, 4.71]2.35+2.34 [0.70, 4.54]3.81 [2.73, 5.72]22% [10%, 33%]33%56%+0.49+0.612026-08-04 → 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 KDEN, lead day 3, 00Z bilinear tmax+10+50-5-102026-08-04: +2.18 °F2026-08-05: -5.18 °F2026-08-06: -3.28 °F2026-08-07: -0.09 °F2026-08-08: -2.28 °F2026-08-09: -1.07 °F2026-08-10: -3.7 °F2026-08-11: -5.96 °F2026-08-12: -7.14 °F2026-08-13: -9.01 °F2026-08-14: -7.93 °F2026-08-15: -4.22 °F2026-08-16: -2.37 °F2026-08-17: -4.01 °F2026-08-18: +2.54 °F2026-08-19: -4.92 °F2026-08-20: -1.22 °F2026-08-21: -9.25 °F2026-08-22: -4.51 °F2026-08-23: -5.72 °F2026-08-24: -2.46 °F2026-08-25: +0.68 °F2026-08-26: -4.84 °F2026-08-27: -6.31 °F2026-08-28: -4.06 °F2026-08-29: -2.06 °F2026-08-30: -0.72 °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
2026-08-30-0.72
2026-08-29-2.06
2026-08-28-4.06
2026-08-27-6.31
2026-08-26-4.84
2026-08-25+0.68
2026-08-24-2.46
2026-08-23-5.72
2026-08-22-4.51
2026-08-21-9.25
2026-08-20-1.22
2026-08-19-4.92
2026-08-18+2.54
2026-08-17-4.01
2026-08-16-2.37
2026-08-15-4.22
2026-08-14-7.93
2026-08-13-9.01
2026-08-12-7.14
2026-08-11-5.96
2026-08-10-3.70
2026-08-09-1.07
2026-08-08-2.28
2026-08-07-0.09
2026-08-06-3.28
2026-08-05-5.18
2026-08-04+2.18

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KDEN, lead day 3-10 to -9 °F: 2 days-9 to -8 °F: 0 days-8 to -7 °F: 2 days-7 to -6 °F: 1 day-6 to -5 °F: 3 days-5 to -4 °F: 6 days-4 to -3 °F: 2 days-3 to -2 °F: 4 days-2 to -1 °F: 2 days-1 to 0 °F: 2 days0 to 1 °F: 1 day1 to 2 °F: 0 days2 to 3 °F: 2 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| 4.01 · P90 |e| 7.45 °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
-10.00-9.002
-9.00-8.000
-8.00-7.002
-7.00-6.001
-6.00-5.003
-5.00-4.006
-4.00-3.002
-3.00-2.004
-2.00-1.002
-1.00+0.002
+0.00+1.001
+1.00+2.000
+2.00+3.002
+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
2026-08273.99 -3.59

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 +0.00 [-1.86, 1.18] no
GraphCast (IFS init) 25 -2.40 [-3.27, -1.67] yes
ECMWF IFS HRES 22 -0.11 [-2.01, 1.31] no
Persistence (baseline) 27 -3.60 [-9.47, -0.97] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDEN (Denver Intl), 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/KDEN/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