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

Denver Intl · ECMWF AIFS Single · lead day 6

KDEN · aifs_single · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d24 1 QC5.58 [3.59, 7.14]3.27-5.35 [-6.84, -3.46]6.81 [4.33, 8.41]12% [0%, 31%]17%25%+0.26+0.562026-08-07 → 2026-08-30
tmax00Zbilinear90d24 1 QC5.58 [3.20, 7.21]3.27-5.35 [-6.91, -3.05]6.81 [3.72, 8.41]12% [0%, 36%]17%25%+0.26+0.562026-08-07 → 2026-08-30
tmax00Zbilinear365d24 1 QC5.58 [3.24, 7.40]3.27-5.35 [-7.07, -3.09]6.81 [3.67, 8.56]12% [0%, 34%]17%25%+0.26+0.562026-08-07 → 2026-08-30
tmax00Zbilinearall24 1 QC5.58 [3.17, 7.36]3.27-5.35 [-6.92, -3.03]6.81 [3.58, 8.44]12% [0%, 33%]17%25%+0.26+0.562026-08-07 → 2026-08-30
tmax00Znearest30d24 1 QC5.62 [3.63, 7.21]3.18-5.45 [-6.90, -3.57]6.85 [4.41, 8.46]12% [0%, 31%]17%21%+0.25+0.582026-08-07 → 2026-08-30
tmax00Znearest90d24 1 QC5.62 [3.22, 7.25]3.18-5.45 [-6.98, -3.19]6.85 [3.79, 8.43]12% [0%, 36%]17%21%+0.25+0.582026-08-07 → 2026-08-30
tmax00Znearest365d24 1 QC5.62 [3.33, 7.43]3.18-5.45 [-7.15, -3.29]6.85 [3.79, 8.66]12% [0%, 34%]17%21%+0.25+0.582026-08-07 → 2026-08-30
tmax00Znearestall24 1 QC5.62 [3.22, 7.37]3.18-5.45 [-7.02, -3.18]6.85 [3.66, 8.52]12% [0%, 33%]17%21%+0.25+0.582026-08-07 → 2026-08-30
tmax12Zbilinear30d24 1 QC5.15 [4.00, 6.50]2.78-5.15 [-6.50, -4.00]6.10 [4.64, 7.44]8% [0%, 15%]17%33%+0.31+0.632026-08-07 → 2026-08-30
tmax12Zbilinear90d24 1 QC5.15 [3.74, 6.53]2.78-5.15 [-6.52, -3.73]6.10 [4.32, 7.50]8% [0%, 14%]17%33%+0.31+0.632026-08-07 → 2026-08-30
tmax12Zbilinear365d24 1 QC5.15 [3.75, 6.76]2.78-5.15 [-6.76, -3.73]6.10 [4.50, 7.62]8% [0%, 14%]17%33%+0.31+0.632026-08-07 → 2026-08-30
tmax12Zbilinearall24 1 QC5.15 [3.74, 6.69]2.78-5.15 [-6.68, -3.74]6.10 [4.42, 7.61]8% [0%, 14%]17%33%+0.31+0.632026-08-07 → 2026-08-30
tmax12Znearest30d24 1 QC5.20 [4.03, 6.58]2.75-5.17 [-6.57, -4.00]6.12 [4.68, 7.48]8% [0%, 15%]21%33%+0.31+0.632026-08-07 → 2026-08-30
tmax12Znearest90d24 1 QC5.20 [3.80, 6.58]2.75-5.17 [-6.58, -3.80]6.12 [4.35, 7.52]8% [0%, 14%]21%33%+0.31+0.632026-08-07 → 2026-08-30
tmax12Znearest365d24 1 QC5.20 [3.83, 6.84]2.75-5.17 [-6.82, -3.80]6.12 [4.54, 7.65]8% [0%, 14%]21%33%+0.31+0.632026-08-07 → 2026-08-30
tmax12Znearestall24 1 QC5.20 [3.82, 6.76]2.75-5.17 [-6.73, -3.80]6.12 [4.47, 7.64]8% [0%, 14%]21%33%+0.31+0.632026-08-07 → 2026-08-30
tmin00Zbilinear30d24 1 QC2.82 [1.91, 3.63]2.56+1.70 [0.50, 3.05]3.40 [2.57, 4.04]25% [8%, 45%]38%54%+0.49+0.542026-08-07 → 2026-08-30
tmin00Zbilinear90d24 1 QC2.82 [1.70, 3.70]2.56+1.70 [0.33, 3.19]3.40 [2.34, 4.12]25% [7%, 50%]38%54%+0.49+0.542026-08-07 → 2026-08-30
tmin00Zbilinear365d24 1 QC2.82 [1.71, 3.84]2.56+1.70 [0.25, 3.50]3.40 [2.32, 4.17]25% [0%, 47%]38%54%+0.49+0.542026-08-07 → 2026-08-30
tmin00Zbilinearall24 1 QC2.82 [1.70, 3.70]2.56+1.70 [0.27, 3.49]3.40 [2.32, 4.12]25% [0%, 50%]38%54%+0.49+0.542026-08-07 → 2026-08-30
tmin00Znearest30d24 1 QC2.89 [1.96, 3.71]2.58+1.73 [0.46, 3.09]3.46 [2.59, 4.13]17% [0%, 37%]38%54%+0.47+0.532026-08-07 → 2026-08-30
tmin00Znearest90d24 1 QC2.89 [1.78, 3.80]2.58+1.73 [0.29, 3.31]3.46 [2.38, 4.23]17% [0%, 43%]38%54%+0.47+0.532026-08-07 → 2026-08-30
tmin00Znearest365d24 1 QC2.89 [1.77, 3.94]2.58+1.73 [0.17, 3.48]3.46 [2.35, 4.26]17% [0%, 42%]38%54%+0.47+0.532026-08-07 → 2026-08-30
tmin00Znearestall24 1 QC2.89 [1.75, 3.83]2.58+1.73 [0.21, 3.46]3.46 [2.36, 4.22]17% [0%, 43%]38%54%+0.47+0.532026-08-07 → 2026-08-30
tmin12Zbilinear30d24 1 QC2.32 [1.66, 2.96]2.00+1.55 [0.43, 2.60]2.84 [2.18, 3.38]33% [13%, 56%]46%62%+0.58+0.642026-08-07 → 2026-08-30
tmin12Zbilinear90d24 1 QC2.32 [1.52, 3.02]2.00+1.55 [0.18, 2.75]2.84 [2.07, 3.44]33% [12%, 60%]46%62%+0.58+0.642026-08-07 → 2026-08-30
tmin12Zbilinear365d24 1 QC2.32 [1.46, 3.12]2.00+1.55 [0.14, 2.81]2.84 [2.04, 3.47]33% [11%, 60%]46%62%+0.58+0.642026-08-07 → 2026-08-30
tmin12Zbilinearall24 1 QC2.32 [1.51, 3.12]2.00+1.55 [0.16, 2.81]2.84 [2.07, 3.48]33% [11%, 62%]46%62%+0.58+0.642026-08-07 → 2026-08-30
tmin12Znearest30d24 1 QC2.43 [1.77, 3.07]2.06+1.57 [0.36, 2.68]2.93 [2.22, 3.53]29% [5%, 55%]33%62%+0.56+0.632026-08-07 → 2026-08-30
tmin12Znearest90d24 1 QC2.43 [1.61, 3.13]2.06+1.57 [0.09, 2.87]2.93 [2.09, 3.60]29% [0%, 60%]33%62%+0.56+0.632026-08-07 → 2026-08-30
tmin12Znearest365d24 1 QC2.43 [1.57, 3.22]2.06+1.57 [0.16, 2.91]2.93 [2.07, 3.62]29% [0%, 60%]33%62%+0.56+0.632026-08-07 → 2026-08-30
tmin12Znearestall24 1 QC2.43 [1.61, 3.20]2.06+1.57 [0.09, 2.88]2.93 [2.12, 3.63]29% [0%, 62%]33%62%+0.56+0.632026-08-07 → 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 6, 00Z bilinear tmax+20+100-10-202026-08-07: +0.34 °F2026-08-08: -2.78 °F2026-08-09: -0.33 °F2026-08-10: -10.52 °F2026-08-11: -8.67 °F2026-08-12: -7.9 °F2026-08-13: -3.17 °F2026-08-14: -13.69 °F2026-08-15: -4.35 °F2026-08-16: +1.94 °F2026-08-17: -5.03 °F2026-08-18: -15.76 °F2026-08-19: -8.02 °F2026-08-20: -4.86 °F2026-08-21: -9.71 °F2026-08-22: -6.18 °F2026-08-23: -6.93 °F2026-08-24: -4.28 °F2026-08-25: +0.44 °F2026-08-26: -2.44 °F2026-08-27: -3.71 °F2026-08-28: -5.35 °F2026-08-29: -3.41 °F2026-08-30: -4.02 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.02
2026-08-29-3.41
2026-08-28-5.35
2026-08-27-3.71
2026-08-26-2.44
2026-08-25+0.44
2026-08-24-4.28
2026-08-23-6.93
2026-08-22-6.18
2026-08-21-9.71
2026-08-20-4.86
2026-08-19-8.02
2026-08-18-15.76
2026-08-17-5.03
2026-08-16+1.94
2026-08-15-4.35
2026-08-14-13.69
2026-08-13-3.17
2026-08-12-7.90
2026-08-11-8.67
2026-08-10-10.52
2026-08-09-0.33
2026-08-08-2.78
2026-08-07+0.34

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KDEN, lead day 6-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 1 day-14 to -12 °F: 1 day-12 to -10 °F: 1 day-10 to -8 °F: 3 days-8 to -6 °F: 3 days-6 to -4 °F: 6 days-4 to -2 °F: 5 days-2 to 0 °F: 1 day0 to 2 °F: 3 days2 to 4 °F: 0 days4 to 6 °F: 0 days6 to 8 °F: 0 days8 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| 4.6 · P90 |e| 10.28 °F-200+20 °Fn = 24 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
-16.00-14.001
-14.00-12.001
-12.00-10.001
-10.00-8.003
-8.00-6.003
-6.00-4.006
-4.00-2.005
-2.00+0.001
+0.00+2.003
+2.00+4.000
+4.00+6.000
+6.00+8.000
+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
2026-08245.58 -5.35

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 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 24 +1.55 [-1.07, 3.42] no
GraphCast (IFS init) 24 -2.05 [-3.48, -0.64] yes
ECMWF IFS HRES 19 +0.36 [-3.27, 1.69] no
Persistence (baseline) 24 -1.92 [-3.61, -0.15] yes

Cite this page

ShortCastCheck, KDEN aifs_single lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDEN/model/aifs_single/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDEN (Denver Intl), model aifs_single, lead day 6. 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/6/

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