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

Denver Intl · ECMWF AIFS Single · lead day 8

KDEN · aifs_single · lead 8

Target day = initialization date + 8 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
tmax00Zbilinear30d22 1 QC4.94 [2.75, 6.86]3.99-4.61 [-6.66, -2.11]6.80 [3.38, 8.77]18% [4%, 33%]27%55%+0.36+0.462026-08-09 → 2026-08-30
tmax00Zbilinear90d22 1 QC4.94 [2.42, 6.98]3.99-4.61 [-6.76, -1.65]6.80 [2.82, 8.85]18% [0%, 33%]27%55%+0.36+0.462026-08-09 → 2026-08-30
tmax00Zbilinear365d22 1 QC4.94 [2.52, 7.18]3.99-4.61 [-7.04, -1.68]6.80 [2.91, 9.21]18% [0%, 33%]27%55%+0.36+0.462026-08-09 → 2026-08-30
tmax00Zbilinearall22 1 QC4.94 [2.38, 7.18]3.99-4.61 [-7.02, -1.42]6.80 [2.75, 9.21]18% [0%, 35%]27%55%+0.36+0.462026-08-09 → 2026-08-30
tmax00Znearest30d22 1 QC4.95 [2.77, 6.92]3.97-4.65 [-6.69, -2.15]6.83 [3.37, 8.83]18% [4%, 33%]32%55%+0.36+0.462026-08-09 → 2026-08-30
tmax00Znearest90d22 1 QC4.95 [2.45, 7.00]3.97-4.65 [-6.78, -1.67]6.83 [2.87, 8.88]18% [0%, 33%]32%55%+0.36+0.462026-08-09 → 2026-08-30
tmax00Znearest365d22 1 QC4.95 [2.55, 7.22]3.97-4.65 [-7.07, -1.71]6.83 [2.95, 9.27]18% [0%, 33%]32%55%+0.36+0.462026-08-09 → 2026-08-30
tmax00Znearestall22 1 QC4.95 [2.40, 7.24]3.97-4.65 [-7.07, -1.46]6.83 [2.78, 9.27]18% [0%, 35%]32%55%+0.36+0.462026-08-09 → 2026-08-30
tmax12Zbilinear30d22 1 QC6.78 [4.01, 9.42]4.78-6.17 [-9.07, -2.96]8.59 [4.62, 11.39]5% [0%, 12%]14%32%+0.12+0.352026-08-09 → 2026-08-30
tmax12Zbilinear90d22 1 QC6.78 [3.74, 9.45]4.78-6.17 [-9.01, -2.52]8.59 [4.38, 11.48]5% [0%, 12%]14%32%+0.12+0.352026-08-09 → 2026-08-30
tmax12Zbilinear365d22 1 QC6.78 [3.74, 9.73]4.78-6.17 [-9.46, -2.66]8.59 [4.28, 11.64]5% [0%, 14%]14%32%+0.12+0.352026-08-09 → 2026-08-30
tmax12Zbilinearall22 1 QC6.78 [3.74, 9.64]4.78-6.17 [-9.36, -2.42]8.59 [4.30, 11.68]5% [0%, 14%]14%32%+0.12+0.352026-08-09 → 2026-08-30
tmax12Znearest30d22 1 QC6.78 [4.05, 9.38]4.74-6.20 [-9.12, -2.98]8.63 [4.53, 11.53]9% [0%, 20%]14%27%+0.12+0.362026-08-09 → 2026-08-30
tmax12Znearest90d22 1 QC6.78 [3.78, 9.46]4.74-6.20 [-9.11, -2.54]8.63 [4.27, 11.61]9% [0%, 22%]14%27%+0.12+0.362026-08-09 → 2026-08-30
tmax12Znearest365d22 1 QC6.78 [3.83, 9.77]4.74-6.20 [-9.61, -2.67]8.63 [4.29, 11.81]9% [0%, 23%]14%27%+0.12+0.362026-08-09 → 2026-08-30
tmax12Znearestall22 1 QC6.78 [3.78, 9.70]4.74-6.20 [-9.44, -2.38]8.63 [4.25, 11.85]9% [0%, 24%]14%27%+0.12+0.362026-08-09 → 2026-08-30
tmin00Zbilinear30d22 1 QC3.42 [2.52, 4.88]3.43+0.90 [-1.61, 4.02]4.15 [3.17, 5.33]23% [0%, 38%]36%45%+0.41+0.412026-08-09 → 2026-08-30
tmin00Zbilinear90d22 1 QC3.42 [2.50, 5.29]3.43+0.90 [-2.15, 5.25]4.15 [3.03, 5.53]23% [0%, 38%]36%45%+0.41+0.412026-08-09 → 2026-08-30
tmin00Zbilinear365d22 1 QC3.42 [2.50, 5.30]3.43+0.90 [-2.24, 5.24]4.15 [2.97, 5.67]23% [0%, 38%]36%45%+0.41+0.412026-08-09 → 2026-08-30
tmin00Zbilinearall22 1 QC3.42 [2.43, 5.72]3.43+0.90 [-2.24, 5.72]4.15 [3.00, 5.92]23% [0%, 40%]36%45%+0.41+0.412026-08-09 → 2026-08-30
tmin00Znearest30d22 1 QC3.44 [2.54, 4.81]3.45+0.91 [-1.58, 4.05]4.14 [3.16, 5.30]18% [0%, 28%]36%50%+0.40+0.402026-08-09 → 2026-08-30
tmin00Znearest90d22 1 QC3.44 [2.46, 5.27]3.45+0.91 [-2.18, 5.22]4.14 [2.99, 5.48]18% [0%, 29%]36%50%+0.40+0.402026-08-09 → 2026-08-30
tmin00Znearest365d22 1 QC3.44 [2.47, 5.27]3.45+0.91 [-2.20, 5.20]4.14 [2.88, 5.62]18% [0%, 29%]36%50%+0.40+0.402026-08-09 → 2026-08-30
tmin00Znearestall22 1 QC3.44 [2.44, 5.70]3.45+0.91 [-2.18, 5.70]4.14 [2.98, 5.89]18% [0%, 29%]36%50%+0.40+0.402026-08-09 → 2026-08-30
tmin12Zbilinear30d22 1 QC2.86 [2.47, 3.35]2.79+0.99 [-0.87, 2.71]3.32 [2.89, 3.75]18% [0%, 29%]27%55%+0.50+0.522026-08-09 → 2026-08-30
tmin12Zbilinear90d22 1 QC2.86 [2.44, 3.43]2.79+0.99 [-1.17, 3.06]3.32 [2.82, 3.80]18% [0%, 29%]27%55%+0.50+0.522026-08-09 → 2026-08-30
tmin12Zbilinear365d22 1 QC2.86 [2.48, 3.41]2.79+0.99 [-1.21, 3.07]3.32 [2.85, 3.86]18% [0%, 29%]27%55%+0.50+0.522026-08-09 → 2026-08-30
tmin12Zbilinearall22 1 QC2.86 [2.43, 3.35]2.79+0.99 [-1.31, 3.13]3.32 [2.81, 3.76]18% [0%, 29%]27%55%+0.50+0.522026-08-09 → 2026-08-30
tmin12Znearest30d22 1 QC2.96 [2.56, 3.43]2.87+1.02 [-0.86, 2.79]3.41 [2.95, 3.88]14% [0%, 24%]27%50%+0.49+0.502026-08-09 → 2026-08-30
tmin12Znearest90d22 1 QC2.96 [2.52, 3.53]2.87+1.02 [-1.10, 3.17]3.41 [2.85, 3.95]14% [0%, 25%]27%50%+0.49+0.502026-08-09 → 2026-08-30
tmin12Znearest365d22 1 QC2.96 [2.58, 3.53]2.87+1.02 [-1.20, 3.15]3.41 [2.88, 3.98]14% [0%, 25%]27%50%+0.49+0.502026-08-09 → 2026-08-30
tmin12Znearestall22 1 QC2.96 [2.51, 3.49]2.87+1.02 [-1.21, 3.24]3.41 [2.86, 3.88]14% [0%, 26%]27%50%+0.49+0.502026-08-09 → 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 8, 00Z bilinear tmax+20+100-10-202026-08-09: -3.39 °F2026-08-10: -1.11 °F2026-08-11: -6.35 °F2026-08-12: -17.66 °F2026-08-13: +0.75 °F2026-08-14: -12.03 °F2026-08-15: -9.33 °F2026-08-16: -2.71 °F2026-08-17: -9.26 °F2026-08-18: -3.67 °F2026-08-19: -2.49 °F2026-08-20: -2.94 °F2026-08-21: -14.37 °F2026-08-22: +0.47 °F2026-08-23: -2.61 °F2026-08-24: -6.88 °F2026-08-25: -0.65 °F2026-08-26: +0.6 °F2026-08-27: -2.52 °F2026-08-28: -4.87 °F2026-08-29: -2.17 °F2026-08-30: +1.77 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+1.77
2026-08-29-2.17
2026-08-28-4.87
2026-08-27-2.52
2026-08-26+0.60
2026-08-25-0.65
2026-08-24-6.88
2026-08-23-2.61
2026-08-22+0.47
2026-08-21-14.37
2026-08-20-2.94
2026-08-19-2.49
2026-08-18-3.67
2026-08-17-9.26
2026-08-16-2.71
2026-08-15-9.33
2026-08-14-12.03
2026-08-13+0.75
2026-08-12-17.66
2026-08-11-6.35
2026-08-10-1.11
2026-08-09-3.39

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KDEN, lead day 8-20 to -18 °F: 0 days-18 to -16 °F: 1 day-16 to -14 °F: 1 day-14 to -12 °F: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 2 days-8 to -6 °F: 2 days-6 to -4 °F: 1 day-4 to -2 °F: 8 days-2 to 0 °F: 2 days0 to 2 °F: 4 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| 2.83 · P90 |e| 11.76 °F-200+20 °Fn = 22 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
-18.00-16.001
-16.00-14.001
-14.00-12.001
-12.00-10.000
-10.00-8.002
-8.00-6.002
-6.00-4.001
-4.00-2.008
-2.00+0.002
+0.00+2.004
+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
2026-08224.94 -4.61

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22

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 22 -0.39 [-1.97, 1.40] no
GraphCast (IFS init) 22 -4.54 [-6.72, -2.04] yes
ECMWF IFS HRES 17 -1.87 [-4.28, -0.33] yes
Persistence (baseline) 22 -2.75 [-3.79, -1.68] yes

Cite this page

ShortCastCheck, KDEN aifs_single lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDEN/model/aifs_single/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDEN (Denver Intl), model aifs_single, lead day 8. 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/8/

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