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

Denver Intl · NCEP GFS · lead day 7

KDEN · gfs · lead 7

Target day = initialization date + 7 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, gfs-0p25, 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
tmax00Zbilinear30d23 1 QC6.35 [4.06, 8.39]6.39-4.20 [-6.60, -1.60]8.94 [5.44, 11.20]22% [9%, 33%]35%43%+0.23+0.212026-08-08 → 2026-08-30
tmax00Zbilinear90d23 1 QC6.35 [3.67, 8.49]6.39-4.20 [-6.59, -1.22]8.94 [4.71, 11.22]22% [8%, 35%]35%43%+0.23+0.212026-08-08 → 2026-08-30
tmax00Zbilinear365d23 1 QC6.35 [3.78, 8.58]6.39-4.20 [-6.87, -1.02]8.94 [4.77, 11.39]22% [7%, 36%]35%43%+0.23+0.212026-08-08 → 2026-08-30
tmax00Zbilinearall23 1 QC6.35 [3.85, 8.47]6.39-4.20 [-6.58, -0.86]8.94 [4.85, 11.12]22% [0%, 35%]35%43%+0.23+0.212026-08-08 → 2026-08-30
tmax00Znearest30d23 1 QC6.53 [4.47, 8.36]6.15-4.23 [-6.74, -1.66]8.73 [5.56, 10.90]13% [0%, 24%]30%39%+0.21+0.242026-08-08 → 2026-08-30
tmax00Znearest90d23 1 QC6.53 [4.07, 8.53]6.15-4.23 [-6.65, -1.29]8.73 [4.97, 10.87]13% [0%, 24%]30%39%+0.21+0.242026-08-08 → 2026-08-30
tmax00Znearest365d23 1 QC6.53 [4.16, 8.62]6.15-4.23 [-7.01, -1.00]8.73 [4.97, 11.03]13% [0%, 25%]30%39%+0.21+0.242026-08-08 → 2026-08-30
tmax00Znearestall23 1 QC6.53 [4.11, 8.50]6.15-4.23 [-6.77, -0.96]8.73 [4.96, 10.86]13% [0%, 25%]30%39%+0.21+0.242026-08-08 → 2026-08-30
tmax12Zbilinear30d23 1 QC3.31 [2.55, 3.96]3.05-1.87 [-2.95, -0.45]4.37 [3.56, 4.97]22% [0%, 46%]39%61%+0.60+0.622026-08-08 → 2026-08-30
tmax12Zbilinear90d23 1 QC3.31 [2.57, 3.95]3.05-1.87 [-2.98, -0.17]4.37 [3.43, 5.01]22% [0%, 45%]39%61%+0.60+0.622026-08-08 → 2026-08-30
tmax12Zbilinear365d23 1 QC3.31 [2.54, 3.99]3.05-1.87 [-3.09, -0.06]4.37 [3.44, 5.06]22% [0%, 47%]39%61%+0.60+0.622026-08-08 → 2026-08-30
tmax12Zbilinearall23 1 QC3.31 [2.50, 4.03]3.05-1.87 [-3.03, -0.16]4.37 [3.43, 5.05]22% [0%, 48%]39%61%+0.60+0.622026-08-08 → 2026-08-30
tmax12Znearest30d23 1 QC3.31 [2.51, 4.01]3.20-1.93 [-2.95, -0.56]4.43 [3.61, 5.03]30% [8%, 53%]39%61%+0.60+0.602026-08-08 → 2026-08-30
tmax12Znearest90d23 1 QC3.31 [2.51, 3.98]3.20-1.93 [-3.03, -0.39]4.43 [3.52, 5.06]30% [0%, 52%]39%61%+0.60+0.602026-08-08 → 2026-08-30
tmax12Znearest365d23 1 QC3.31 [2.45, 4.06]3.20-1.93 [-3.13, -0.27]4.43 [3.55, 5.08]30% [0%, 55%]39%61%+0.60+0.602026-08-08 → 2026-08-30
tmax12Znearestall23 1 QC3.31 [2.45, 4.13]3.20-1.93 [-3.06, -0.35]4.43 [3.50, 5.07]30% [0%, 55%]39%61%+0.60+0.602026-08-08 → 2026-08-30
tmin00Zbilinear30d23 1 QC5.36 [3.98, 6.60]2.98+4.37 [2.10, 6.44]5.83 [4.43, 6.87]4% [0%, 17%]4%17%+0.04+0.472026-08-08 → 2026-08-30
tmin00Zbilinear90d23 1 QC5.36 [3.44, 6.80]2.98+4.37 [1.43, 6.75]5.83 [3.73, 7.01]4% [0%, 22%]4%17%+0.04+0.472026-08-08 → 2026-08-30
tmin00Zbilinear365d23 1 QC5.36 [3.46, 6.92]2.98+4.37 [1.52, 6.92]5.83 [3.74, 7.12]4% [0%, 20%]4%17%+0.04+0.472026-08-08 → 2026-08-30
tmin00Zbilinearall23 1 QC5.36 [3.51, 6.83]2.98+4.37 [1.41, 6.83]5.83 [3.78, 7.02]4% [0%, 20%]4%17%+0.04+0.472026-08-08 → 2026-08-30
tmin00Znearest30d23 1 QC5.58 [4.20, 6.84]2.84+4.73 [2.63, 6.75]6.03 [4.62, 7.09]0% [0%, 0%]9%17%+0.01+0.502026-08-08 → 2026-08-30
tmin00Znearest90d23 1 QC5.58 [3.74, 7.06]2.84+4.73 [1.99, 7.03]6.03 [4.00, 7.22]0% [0%, 0%]9%17%+0.01+0.502026-08-08 → 2026-08-30
tmin00Znearest365d23 1 QC5.58 [3.81, 7.17]2.84+4.73 [2.10, 7.17]6.03 [4.05, 7.31]0% [0%, 0%]9%17%+0.01+0.502026-08-08 → 2026-08-30
tmin00Znearestall23 1 QC5.58 [3.74, 7.08]2.84+4.73 [1.94, 7.08]6.03 [4.00, 7.20]0% [0%, 0%]9%17%+0.01+0.502026-08-08 → 2026-08-30
tmin12Zbilinear30d23 1 QC4.89 [3.52, 6.16]3.20+3.91 [1.20, 6.04]5.59 [4.20, 6.66]4% [0%, 12%]17%30%+0.13+0.432026-08-08 → 2026-08-30
tmin12Zbilinear90d23 1 QC4.89 [2.96, 6.34]3.20+3.91 [0.44, 6.33]5.59 [3.51, 6.82]4% [0%, 12%]17%30%+0.13+0.432026-08-08 → 2026-08-30
tmin12Zbilinear365d23 1 QC4.89 [2.86, 6.39]3.20+3.91 [0.48, 6.39]5.59 [3.57, 6.81]4% [0%, 14%]17%30%+0.13+0.432026-08-08 → 2026-08-30
tmin12Zbilinearall23 1 QC4.89 [2.98, 6.39]3.20+3.91 [0.27, 6.39]5.59 [3.54, 6.80]4% [0%, 14%]17%30%+0.13+0.432026-08-08 → 2026-08-30
tmin12Znearest30d23 1 QC5.11 [3.62, 6.40]2.96+4.27 [1.63, 6.36]5.73 [4.20, 6.83]4% [0%, 17%]17%17%+0.09+0.472026-08-08 → 2026-08-30
tmin12Znearest90d23 1 QC5.11 [3.10, 6.55]2.96+4.27 [1.02, 6.53]5.73 [3.51, 6.93]4% [0%, 22%]17%17%+0.09+0.472026-08-08 → 2026-08-30
tmin12Znearest365d23 1 QC5.11 [3.05, 6.63]2.96+4.27 [0.92, 6.63]5.73 [3.60, 6.95]4% [0%, 20%]17%17%+0.09+0.472026-08-08 → 2026-08-30
tmin12Znearestall23 1 QC5.11 [3.15, 6.56]2.96+4.27 [0.83, 6.56]5.73 [3.56, 6.92]4% [0%, 20%]17%17%+0.09+0.472026-08-08 → 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 NCEP GFS at KDEN, lead day 7, 00Z bilinear tmax+25+12.50-12.5-252026-08-08: -6.3 °F2026-08-09: +2.16 °F2026-08-10: -0.07 °F2026-08-11: -11.41 °F2026-08-12: -13.07 °F2026-08-13: +9.76 °F2026-08-14: -3.37 °F2026-08-15: -19.36 °F2026-08-16: -1.07 °F2026-08-17: -10.14 °F2026-08-18: +0.82 °F2026-08-19: +2.4 °F2026-08-20: -22.91 °F2026-08-21: -14.2 °F2026-08-22: +1.71 °F2026-08-23: +0.06 °F2026-08-24: -1.41 °F2026-08-25: +0.8 °F2026-08-26: -9.3 °F2026-08-27: -0.8 °F2026-08-28: -4.59 °F2026-08-29: -3.4 °F2026-08-30: +7.02 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+7.02
2026-08-29-3.40
2026-08-28-4.59
2026-08-27-0.80
2026-08-26-9.30
2026-08-25+0.80
2026-08-24-1.41
2026-08-23+0.06
2026-08-22+1.71
2026-08-21-14.20
2026-08-20-22.91
2026-08-19+2.40
2026-08-18+0.82
2026-08-17-10.14
2026-08-16-1.07
2026-08-15-19.36
2026-08-14-3.37
2026-08-13+9.76
2026-08-12-13.07
2026-08-11-11.41
2026-08-10-0.07
2026-08-09+2.16
2026-08-08-6.30

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KDEN, lead day 7-25 to -22.5 °F: 1 day-22.5 to -20 °F: 0 days-20 to -17.5 °F: 1 day-17.5 to -15 °F: 0 days-15 to -12.5 °F: 2 days-12.5 to -10 °F: 2 days-10 to -7.5 °F: 1 day-7.5 to -5 °F: 1 day-5 to -2.5 °F: 3 days-2.5 to 0 °F: 4 days0 to 2.5 °F: 6 days2.5 to 5 °F: 0 days5 to 7.5 °F: 1 day7.5 to 10 °F: 1 day10 to 12.5 °F: 0 days12.5 to 15 °F: 0 days15 to 17.5 °F: 0 days17.5 to 20 °F: 0 days20 to 22.5 °F: 0 days22.5 to 25 °F: 0 daysdashed: P50 |e| 3.4 · P90 |e| 13.97 °F-250+25 °Fn = 23 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
-25.00-22.501
-22.50-20.000
-20.00-17.501
-17.50-15.000
-15.00-12.502
-12.50-10.002
-10.00-7.501
-7.50-5.001
-5.00-2.503
-2.50+0.004
+0.00+2.506
+2.50+5.000
+5.00+7.501
+7.50+10.001
+10.00+12.500
+12.50+15.000
+15.00+17.500
+17.50+20.000
+20.00+22.500
+22.50+25.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08236.35 -4.20

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 23 -0.30 [-1.56, 0.87] no
GraphCast (IFS init) 23 -2.27 [-4.44, -0.06] yes
ECMWF IFS HRES 18 +1.51 [-0.09, 4.24] no
Persistence (baseline) 23 -1.91 [-4.08, 0.38] no

Cite this page

ShortCastCheck, KDEN gfs lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KDEN/model/gfs/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KDEN (Denver Intl), model gfs, lead day 7. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KDEN/model/gfs/lead/7/

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