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

Trenton Mercer · ECMWF IFS HRES · lead day 0

KTTN · ifs_hres · lead 0

Target day = initialization date + 0 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
tmax00Zbilinear30d24 1 QC1.55 [1.20, 1.89]1.56+0.16 [-0.72, 1.02]1.84 [1.45, 2.17]33% [17%, 50%]67%92%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d24 1 QC1.55 [1.15, 1.88]1.56+0.16 [-0.77, 1.09]1.84 [1.40, 2.19]33% [14%, 50%]67%92%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d24 1 QC1.55 [1.13, 1.91]1.56+0.16 [-0.96, 1.13]1.84 [1.35, 2.19]33% [15%, 55%]67%92%——2026-08-01 → 2026-08-30
tmax00Zbilinearall24 1 QC1.55 [1.03, 1.90]1.56+0.16 [-0.83, 1.11]1.84 [1.25, 2.18]33% [16%, 58%]67%92%——2026-08-01 → 2026-08-30
tmax00Znearest30d24 1 QC1.42 [1.03, 1.85]1.45+0.15 [-0.63, 0.98]1.75 [1.26, 2.13]42% [29%, 58%]71%92%——2026-08-01 → 2026-08-30
tmax00Znearest90d24 1 QC1.42 [1.01, 1.86]1.45+0.15 [-0.78, 1.06]1.75 [1.19, 2.15]42% [26%, 63%]71%92%——2026-08-01 → 2026-08-30
tmax00Znearest365d24 1 QC1.42 [0.95, 1.89]1.45+0.15 [-0.85, 1.09]1.75 [1.11, 2.17]42% [26%, 64%]71%92%——2026-08-01 → 2026-08-30
tmax00Znearestall24 1 QC1.42 [0.88, 1.89]1.45+0.15 [-0.81, 1.07]1.75 [1.02, 2.17]42% [27%, 67%]71%92%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d24 1 QC3.69 [2.96, 4.40]1.45+3.69 [2.96, 4.40]4.07 [3.40, 4.68]8% [0%, 22%]17%42%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d24 1 QC3.69 [2.99, 4.43]1.45+3.69 [2.99, 4.43]4.07 [3.42, 4.73]8% [0%, 24%]17%42%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d24 1 QC3.69 [2.93, 4.52]1.45+3.69 [2.93, 4.52]4.07 [3.37, 4.78]8% [0%, 25%]17%42%——2026-08-01 → 2026-08-30
tmin00Zbilinearall24 1 QC3.69 [2.94, 4.51]1.45+3.69 [2.94, 4.51]4.07 [3.39, 4.81]8% [0%, 25%]17%42%——2026-08-01 → 2026-08-30
tmin00Znearest30d24 1 QC3.92 [3.20, 4.67]1.45+3.92 [3.20, 4.67]4.30 [3.55, 4.95]4% [0%, 12%]17%38%——2026-08-01 → 2026-08-30
tmin00Znearest90d24 1 QC3.92 [3.21, 4.71]1.45+3.92 [3.21, 4.71]4.30 [3.57, 5.02]4% [0%, 12%]17%38%——2026-08-01 → 2026-08-30
tmin00Znearest365d24 1 QC3.92 [3.15, 4.78]1.45+3.92 [3.15, 4.78]4.30 [3.51, 5.07]4% [0%, 12%]17%38%——2026-08-01 → 2026-08-30
tmin00Znearestall24 1 QC3.92 [3.14, 4.79]1.45+3.92 [3.14, 4.79]4.30 [3.50, 5.08]4% [0%, 12%]17%38%——2026-08-01 → 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 KTTN, lead day 0, 00Z bilinear tmax+5+2.50-2.5-52026-08-01: -0.56 °F2026-08-08: -1.3 °F2026-08-09: -1.24 °F2026-08-10: +2.46 °F2026-08-11: +2.21 °F2026-08-12: +2.26 °F2026-08-13: -0.7 °F2026-08-14: +4.27 °F2026-08-15: +2.1 °F2026-08-16: +1.27 °F2026-08-17: -1.83 °F2026-08-18: -0.4 °F2026-08-19: +0.26 °F2026-08-20: -2.77 °F2026-08-21: -1.6 °F2026-08-22: -1.95 °F2026-08-23: -0.49 °F2026-08-24: -0.59 °F2026-08-25: +1.22 °F2026-08-26: +0.91 °F2026-08-27: +2.23 °F2026-08-28: -3.13 °F2026-08-29: -0.13 °F2026-08-30: +1.21 °F2026-08-012026-08-30°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 (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+1.21
2026-08-29-0.13
2026-08-28-3.13
2026-08-27+2.23
2026-08-26+0.91
2026-08-25+1.22
2026-08-24-0.59
2026-08-23-0.49
2026-08-22-1.95
2026-08-21-1.60
2026-08-20-2.77
2026-08-19+0.26
2026-08-18-0.40
2026-08-17-1.83
2026-08-16+1.27
2026-08-15+2.10
2026-08-14+4.27
2026-08-13-0.70
2026-08-12+2.26
2026-08-11+2.21
2026-08-10+2.46
2026-08-09-1.24
2026-08-08-1.30
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03—
2026-08-02—
2026-08-01-0.56

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KTTN, lead day 0-5 to -4.5 °F: 0 days-4.5 to -4 °F: 0 days-4 to -3.5 °F: 0 days-3.5 to -3 °F: 1 day-3 to -2.5 °F: 1 day-2.5 to -2 °F: 0 days-2 to -1.5 °F: 3 days-1.5 to -1 °F: 2 days-1 to -0.5 °F: 3 days-0.5 to 0 °F: 3 days0 to 0.5 °F: 1 day0.5 to 1 °F: 1 day1 to 1.5 °F: 3 days1.5 to 2 °F: 0 days2 to 2.5 °F: 5 days2.5 to 3 °F: 0 days3 to 3.5 °F: 0 days3.5 to 4 °F: 0 days4 to 4.5 °F: 1 day4.5 to 5 °F: 0 daysdashed: P50 |e| 1.28 · P90 |e| 2.68 °F-50+5 °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
-5.00-4.500
-4.50-4.000
-4.00-3.500
-3.50-3.001
-3.00-2.501
-2.50-2.000
-2.00-1.503
-1.50-1.002
-1.00-0.503
-0.50+0.003
+0.00+0.501
+0.50+1.001
+1.00+1.503
+1.50+2.000
+2.00+2.505
+2.50+3.000
+3.00+3.500
+3.50+4.000
+4.00+4.501
+4.50+5.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08241.55 +0.16

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-01 → 2026-08-30 24
ECMWF IFS HRES2026-08-01 → 2026-08-30 24

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 24 -0.28 [-0.51, 0.07] no
Aurora (GFS init) 2 -0.95 [-1.33, -0.56] yes
Aurora (IFS init) 3 +0.53 [0.15, 1.30] yes
FourCastNet v2 (GFS init) 2 -1.93 [-2.55, -1.31] yes
FourCastNet v2 (IFS init) 3 -1.23 [-1.90, -0.70] yes
NCEP GFS 24 -0.32 [-0.93, 0.25] no
GraphCast (GFS init) 2 -1.09 [-1.41, -0.78] yes
GraphCast (IFS init) 22 +0.02 [-1.02, 0.89] no
Pangu-Weather (GFS init) 2 -1.58 [-2.71, -0.46] yes
Pangu-Weather (IFS init) 3 -0.10 [-1.68, 3.05] no

Cite this page

ShortCastCheck, KTTN ifs_hres lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KTTN/model/ifs_hres/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KTTN (Trenton Mercer), model ifs_hres, lead day 0. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KTTN/model/ifs_hres/lead/0/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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