Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

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

Denver Intl · ECMWF IFS HRES · lead day 4

KDEN · ifs_hres · lead 4

Target day = initialization date + 4 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, ifs-gpid161, 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
tmax00Zbilinear30d20 1 QC4.51 [2.59, 6.29]3.79-3.77 [-5.53, -1.85]5.90 [3.37, 7.81]20% [7%, 29%]35%50%+0.31+0.422026-08-05 → 2026-08-30
tmax00Zbilinear90d20 1 QC4.51 [1.75, 6.29]3.79-3.77 [-5.55, -1.49]5.90 [1.80, 7.79]20% [5%, 29%]35%50%+0.31+0.422026-08-05 → 2026-08-30
tmax00Zbilinear365d20 1 QC4.51 [1.68, 6.44]3.79-3.77 [-5.69, -1.49]5.90 [1.79, 7.80]20% [0%, 30%]35%50%+0.31+0.422026-08-05 → 2026-08-30
tmax00Zbilinearall20 1 QC4.51 [1.50, 6.20]3.79-3.77 [-5.44, -1.48]5.90 [1.50, 7.77]20% [0%, 29%]35%50%+0.31+0.422026-08-05 → 2026-08-30
tmax00Znearest30d20 1 QC4.54 [2.56, 6.30]3.67-3.88 [-5.58, -1.88]5.83 [3.25, 7.62]15% [6%, 23%]40%45%+0.31+0.442026-08-05 → 2026-08-30
tmax00Znearest90d20 1 QC4.54 [1.99, 6.31]3.67-3.88 [-5.63, -1.36]5.83 [2.10, 7.59]15% [4%, 25%]40%45%+0.31+0.442026-08-05 → 2026-08-30
tmax00Znearest365d20 1 QC4.54 [1.78, 6.43]3.67-3.88 [-5.81, -1.36]5.83 [1.98, 7.71]15% [0%, 25%]40%45%+0.31+0.442026-08-05 → 2026-08-30
tmax00Znearestall20 1 QC4.54 [1.36, 6.18]3.67-3.88 [-5.56, -1.32]5.83 [1.36, 7.56]15% [0%, 25%]40%45%+0.31+0.442026-08-05 → 2026-08-30
tmax12Zbilinear30d21 1 QC4.95 [3.10, 6.34]3.23-4.47 [-5.91, -2.43]5.89 [3.99, 7.12]14% [0%, 27%]19%38%+0.29+0.542026-08-05 → 2026-08-30
tmax12Zbilinear90d21 1 QC4.95 [2.32, 6.33]3.23-4.47 [-5.91, -1.66]5.89 [2.90, 7.13]14% [0%, 29%]19%38%+0.29+0.542026-08-05 → 2026-08-30
tmax12Zbilinear365d21 1 QC4.95 [2.29, 6.46]3.23-4.47 [-6.04, -1.66]5.89 [2.37, 7.24]14% [0%, 29%]19%38%+0.29+0.542026-08-05 → 2026-08-30
tmax12Zbilinearall21 1 QC4.95 [2.01, 6.37]3.23-4.47 [-6.04, -1.66]5.89 [2.01, 7.17]14% [0%, 29%]19%38%+0.29+0.542026-08-05 → 2026-08-30
tmax12Znearest30d21 1 QC5.13 [3.36, 6.51]2.96-4.75 [-6.28, -2.71]6.05 [4.08, 7.37]14% [0%, 27%]19%29%+0.26+0.582026-08-05 → 2026-08-30
tmax12Znearest90d21 1 QC5.13 [2.83, 6.52]2.96-4.75 [-6.32, -2.22]6.05 [3.19, 7.40]14% [0%, 29%]19%29%+0.26+0.582026-08-05 → 2026-08-30
tmax12Znearest365d21 1 QC5.13 [2.65, 6.65]2.96-4.75 [-6.44, -2.36]6.05 [3.13, 7.52]14% [0%, 29%]19%29%+0.26+0.582026-08-05 → 2026-08-30
tmax12Znearestall21 1 QC5.13 [2.65, 6.65]2.96-4.75 [-6.43, -1.88]6.05 [2.65, 7.46]14% [0%, 29%]19%29%+0.26+0.582026-08-05 → 2026-08-30
tmin00Zbilinear30d20 1 QC3.33 [1.96, 6.71]2.42+2.89 [1.43, 6.46]4.74 [2.37, 8.86]5% [0%, 13%]45%55%+0.22+0.452026-08-05 → 2026-08-30
tmin00Zbilinear90d20 1 QC3.33 [2.01, 8.69]2.42+2.89 [1.40, 8.34]4.74 [2.37, 10.87]5% [0%, 13%]45%55%+0.22+0.452026-08-05 → 2026-08-30
tmin00Zbilinear365d20 1 QC3.33 [1.90, 7.87]2.42+2.89 [1.36, 7.30]4.74 [2.25, 10.03]5% [0%, 14%]45%55%+0.22+0.452026-08-05 → 2026-08-30
tmin00Zbilinearall20 1 QC3.33 [1.95, 8.47]2.42+2.89 [1.42, 8.47]4.74 [2.33, 10.20]5% [0%, 14%]45%55%+0.22+0.452026-08-05 → 2026-08-30
tmin00Znearest30d20 1 QC3.20 [1.83, 6.73]2.52+2.66 [1.15, 6.36]4.64 [2.22, 8.80]15% [0%, 38%]50%60%+0.25+0.432026-08-05 → 2026-08-30
tmin00Znearest90d20 1 QC3.20 [1.88, 8.69]2.52+2.66 [1.13, 8.30]4.64 [2.27, 10.81]15% [0%, 38%]50%60%+0.25+0.432026-08-05 → 2026-08-30
tmin00Znearest365d20 1 QC3.20 [1.72, 7.90]2.52+2.66 [1.09, 7.28]4.64 [2.09, 9.97]15% [0%, 41%]50%60%+0.25+0.432026-08-05 → 2026-08-30
tmin00Znearestall20 1 QC3.20 [1.82, 8.54]2.52+2.66 [1.10, 8.54]4.64 [2.19, 10.17]15% [0%, 41%]50%60%+0.25+0.432026-08-05 → 2026-08-30
tmin12Zbilinear30d21 1 QC3.80 [2.47, 7.35]2.68+3.24 [1.71, 6.84]5.19 [2.83, 9.61]14% [5%, 22%]29%52%+0.19+0.442026-08-05 → 2026-08-30
tmin12Zbilinear90d21 1 QC3.80 [2.50, 9.43]2.68+3.24 [1.71, 8.50]5.19 [2.87, 11.56]14% [0%, 22%]29%52%+0.19+0.442026-08-05 → 2026-08-30
tmin12Zbilinear365d21 1 QC3.80 [2.40, 8.59]2.68+3.24 [1.65, 8.17]5.19 [2.73, 10.81]14% [0%, 22%]29%52%+0.19+0.442026-08-05 → 2026-08-30
tmin12Zbilinearall21 1 QC3.80 [2.45, 9.91]2.68+3.24 [1.71, 9.23]5.19 [2.75, 11.24]14% [0%, 22%]29%52%+0.19+0.442026-08-05 → 2026-08-30
tmin12Znearest30d21 1 QC3.70 [2.29, 7.29]2.72+3.06 [1.43, 6.61]5.09 [2.77, 9.41]19% [6%, 28%]29%48%+0.21+0.442026-08-05 → 2026-08-30
tmin12Znearest90d21 1 QC3.70 [2.32, 9.37]2.72+3.06 [1.45, 8.19]5.09 [2.78, 11.37]19% [0%, 28%]29%48%+0.21+0.442026-08-05 → 2026-08-30
tmin12Znearest365d21 1 QC3.70 [2.21, 8.20]2.72+3.06 [1.39, 7.80]5.09 [2.56, 10.60]19% [0%, 29%]29%48%+0.21+0.442026-08-05 → 2026-08-30
tmin12Znearestall21 1 QC3.70 [2.29, 9.57]2.72+3.06 [1.42, 8.90]5.09 [2.66, 10.97]19% [0%, 29%]29%48%+0.21+0.442026-08-05 → 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 IFS HRES at KDEN, lead day 4, 00Z bilinear tmax+20+100-10-202026-08-05: -1.49 °F2026-08-11: -2.05 °F2026-08-12: -2.7 °F2026-08-13: +0.54 °F2026-08-14: -8.82 °F2026-08-16: -3.86 °F2026-08-17: -9.91 °F2026-08-18: +2.34 °F2026-08-19: -15.05 °F2026-08-20: -7.24 °F2026-08-21: -8.48 °F2026-08-22: +0.68 °F2026-08-23: -5.33 °F2026-08-24: -0.96 °F2026-08-25: +1.9 °F2026-08-26: -4.14 °F2026-08-27: -6.02 °F2026-08-28: -6.7 °F2026-08-29: +0.41 °F2026-08-30: +1.5 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+1.50
2026-08-29+0.41
2026-08-28-6.70
2026-08-27-6.02
2026-08-26-4.14
2026-08-25+1.90
2026-08-24-0.96
2026-08-23-5.33
2026-08-22+0.68
2026-08-21-8.48
2026-08-20-7.24
2026-08-19-15.05
2026-08-18+2.34
2026-08-17-9.91
2026-08-16-3.86
2026-08-15—
2026-08-14-8.82
2026-08-13+0.54
2026-08-12-2.70
2026-08-11-2.05
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05-1.49

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KDEN, lead day 4-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 1 day-14 to -12 °F: 0 days-12 to -10 °F: 0 days-10 to -8 °F: 3 days-8 to -6 °F: 3 days-6 to -4 °F: 2 days-4 to -2 °F: 3 days-2 to 0 °F: 2 days0 to 2 °F: 5 days2 to 4 °F: 1 day4 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| 3.28 · P90 |e| 8.93 °F-200+20 °Fn = 20 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
-14.00-12.000
-12.00-10.000
-10.00-8.003
-8.00-6.003
-6.00-4.002
-4.00-2.003
-2.00+0.002
+0.00+2.005
+2.00+4.001
+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
2026-08204.51 -3.77

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 21
ECMWF IFS HRES2026-08-05 → 2026-08-30 21

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF IFS HRES has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 20 -0.26 [-2.87, 1.12] no
NCEP GFS 20 -0.65 [-3.10, 1.19] no
GraphCast (IFS init) 19 -3.05 [-5.07, -1.45] yes
Persistence (baseline) 20 -2.04 [-5.20, -0.37] yes

Cite this page

ShortCastCheck, KDEN ifs_hres lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDEN/model/ifs_hres/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDEN (Denver Intl), model ifs_hres, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KDEN/model/ifs_hres/lead/4/

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