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

Trenton Mercer · ECMWF IFS HRES · lead day 8

KTTN · ifs_hres · 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, 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
tmax00Zbilinear30d17 1 QC2.67 [1.91, 3.43]2.61+1.14 [-0.84, 2.22]3.60 [2.21, 4.61]24% [9%, 33%]41%65%+0.36+0.142026-08-09 → 2026-08-30
tmax00Zbilinear90d17 1 QC2.67 [1.85, 3.47]2.61+1.14 [-1.84, 2.31]3.60 [2.16, 4.62]24% [0%, 33%]41%65%+0.36+0.142026-08-09 → 2026-08-30
tmax00Zbilinear365d17 1 QC2.67 [1.87, 3.48]2.61+1.14 [-3.05, 2.48]3.60 [2.15, 4.65]24% [0%, 33%]41%65%+0.36+0.142026-08-09 → 2026-08-30
tmax00Zbilinearall17 1 QC2.67 [1.81, 3.49]2.61+1.14 [-1.75, 2.38]3.60 [2.12, 4.58]24% [0%, 33%]41%65%+0.36+0.142026-08-09 → 2026-08-30
tmax00Znearest30d17 1 QC2.72 [1.82, 3.65]2.57+1.27 [-0.75, 2.39]3.68 [2.21, 4.77]24% [9%, 33%]35%65%+0.35+0.152026-08-09 → 2026-08-30
tmax00Znearest90d17 1 QC2.72 [1.75, 3.67]2.57+1.27 [-1.49, 2.55]3.68 [2.07, 4.79]24% [0%, 33%]35%65%+0.35+0.152026-08-09 → 2026-08-30
tmax00Znearest365d17 1 QC2.72 [1.74, 3.75]2.57+1.27 [-2.95, 2.61]3.68 [2.10, 4.80]24% [0%, 33%]35%65%+0.35+0.152026-08-09 → 2026-08-30
tmax00Znearestall17 1 QC2.72 [1.74, 3.76]2.57+1.27 [-1.59, 2.59]3.68 [2.13, 4.73]24% [0%, 33%]35%65%+0.35+0.152026-08-09 → 2026-08-30
tmax12Zbilinear30d17 1 QC3.96 [2.85, 4.99]3.97-0.12 [-1.67, 1.14]5.25 [3.25, 6.60]24% [0%, 38%]29%41%+0.05-0.312026-08-09 → 2026-08-30
tmax12Zbilinear90d17 1 QC3.96 [2.77, 5.07]3.97-0.12 [-1.87, 1.21]5.25 [3.14, 6.64]24% [0%, 38%]29%41%+0.05-0.312026-08-09 → 2026-08-30
tmax12Zbilinear365d17 1 QC3.96 [2.80, 5.07]3.97-0.12 [-3.14, 1.16]5.25 [3.14, 6.78]24% [0%, 38%]29%41%+0.05-0.312026-08-09 → 2026-08-30
tmax12Zbilinearall17 1 QC3.96 [2.80, 5.00]3.97-0.12 [-2.33, 1.14]5.25 [3.14, 6.69]24% [0%, 38%]29%41%+0.05-0.312026-08-09 → 2026-08-30
tmax12Znearest30d17 1 QC3.96 [2.79, 4.92]3.95+0.03 [-1.46, 1.36]5.21 [3.17, 6.49]18% [0%, 28%]29%47%+0.05-0.302026-08-09 → 2026-08-30
tmax12Znearest90d17 1 QC3.96 [2.69, 5.04]3.95+0.03 [-1.77, 1.40]5.21 [3.04, 6.51]18% [0%, 29%]29%47%+0.05-0.302026-08-09 → 2026-08-30
tmax12Znearest365d17 1 QC3.96 [2.72, 5.08]3.95+0.03 [-2.81, 1.36]5.21 [2.99, 6.65]18% [0%, 29%]29%47%+0.05-0.302026-08-09 → 2026-08-30
tmax12Znearestall17 1 QC3.96 [2.67, 4.97]3.95+0.03 [-2.01, 1.36]5.21 [3.04, 6.54]18% [0%, 29%]29%47%+0.05-0.302026-08-09 → 2026-08-30
tmin00Zbilinear30d17 1 QC5.98 [4.85, 6.77]2.73+5.65 [4.37, 6.74]6.60 [5.46, 7.44]6% [0%, 15%]12%24%-0.21+0.112026-08-09 → 2026-08-30
tmin00Zbilinear90d17 1 QC5.98 [4.26, 6.87]2.73+5.65 [3.89, 6.87]6.60 [4.48, 7.58]6% [0%, 16%]12%24%-0.21+0.112026-08-09 → 2026-08-30
tmin00Zbilinear365d17 1 QC5.98 [4.30, 6.88]2.73+5.65 [4.02, 6.88]6.60 [4.50, 7.63]6% [0%, 15%]12%24%-0.21+0.112026-08-09 → 2026-08-30
tmin00Zbilinearall17 1 QC5.98 [4.30, 6.82]2.73+5.65 [3.96, 6.82]6.60 [4.50, 7.63]6% [0%, 16%]12%24%-0.21+0.112026-08-09 → 2026-08-30
tmin00Znearest30d17 1 QC6.26 [5.18, 7.06]2.78+5.98 [4.73, 7.03]6.88 [5.74, 7.66]0% [0%, 0%]6%18%-0.27+0.092026-08-09 → 2026-08-30
tmin00Znearest90d17 1 QC6.26 [4.61, 7.17]2.78+5.98 [4.29, 7.16]6.88 [4.94, 7.80]0% [0%, 0%]6%18%-0.27+0.092026-08-09 → 2026-08-30
tmin00Znearest365d17 1 QC6.26 [4.78, 7.18]2.78+5.98 [4.40, 7.18]6.88 [5.04, 7.86]0% [0%, 0%]6%18%-0.27+0.092026-08-09 → 2026-08-30
tmin00Znearestall17 1 QC6.26 [4.78, 7.14]2.78+5.98 [4.31, 7.14]6.88 [5.05, 7.86]0% [0%, 0%]6%18%-0.27+0.092026-08-09 → 2026-08-30
tmin12Zbilinear30d17 1 QC5.95 [4.69, 7.40]2.87+5.41 [3.91, 7.32]6.70 [5.28, 8.14]6% [0%, 17%]12%24%-0.20+0.062026-08-09 → 2026-08-30
tmin12Zbilinear90d17 1 QC5.95 [4.57, 7.80]2.87+5.41 [3.70, 7.80]6.70 [5.10, 8.47]6% [0%, 16%]12%24%-0.20+0.062026-08-09 → 2026-08-30
tmin12Zbilinear365d17 1 QC5.95 [4.50, 8.03]2.87+5.41 [3.68, 8.03]6.70 [5.03, 8.48]6% [0%, 17%]12%24%-0.20+0.062026-08-09 → 2026-08-30
tmin12Zbilinearall17 1 QC5.95 [4.52, 8.00]2.87+5.41 [3.69, 8.00]6.70 [5.09, 8.61]6% [0%, 17%]12%24%-0.20+0.062026-08-09 → 2026-08-30
tmin12Znearest30d17 1 QC6.18 [5.00, 7.60]2.99+5.65 [4.21, 7.51]6.94 [5.56, 8.37]6% [0%, 17%]6%24%-0.25+0.032026-08-09 → 2026-08-30
tmin12Znearest90d17 1 QC6.18 [4.90, 8.01]2.99+5.65 [4.01, 8.01]6.94 [5.37, 8.69]6% [0%, 16%]6%24%-0.25+0.032026-08-09 → 2026-08-30
tmin12Znearest365d17 1 QC6.18 [4.77, 8.22]2.99+5.65 [3.97, 8.22]6.94 [5.33, 8.72]6% [0%, 17%]6%24%-0.25+0.032026-08-09 → 2026-08-30
tmin12Znearestall17 1 QC6.18 [4.82, 8.20]2.99+5.65 [3.98, 8.20]6.94 [5.41, 8.87]6% [0%, 17%]6%24%-0.25+0.032026-08-09 → 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 IFS HRES at KTTN, lead day 8, 00Z bilinear tmax+20+100-10-202026-08-09: -3.05 °F2026-08-15: +1.8 °F2026-08-16: -0.5 °F2026-08-17: +3.27 °F2026-08-18: -2.43 °F2026-08-19: +2.82 °F2026-08-20: +10.99 °F2026-08-21: -0.13 °F2026-08-22: +2.42 °F2026-08-23: +1.61 °F2026-08-24: -0.78 °F2026-08-25: +1.9 °F2026-08-26: +3.18 °F2026-08-27: -0.11 °F2026-08-28: -2.09 °F2026-08-29: +4.43 °F2026-08-30: -3.9 °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
2026-08-30-3.90
2026-08-29+4.43
2026-08-28-2.09
2026-08-27-0.11
2026-08-26+3.18
2026-08-25+1.90
2026-08-24-0.78
2026-08-23+1.61
2026-08-22+2.42
2026-08-21-0.13
2026-08-20+10.99
2026-08-19+2.82
2026-08-18-2.43
2026-08-17+3.27
2026-08-16-0.50
2026-08-15+1.80
2026-08-14—
2026-08-13—
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09-3.05

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KTTN, lead day 8-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 0 days-10 to -8 °F: 0 days-8 to -6 °F: 0 days-6 to -4 °F: 0 days-4 to -2 °F: 4 days-2 to 0 °F: 4 days0 to 2 °F: 3 days2 to 4 °F: 4 days4 to 6 °F: 1 day6 to 8 °F: 0 days8 to 10 °F: 0 days10 to 12 °F: 1 day12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 2.42 · P90 |e| 4.11 °F-200+20 °Fn = 17 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
-16.00-14.000
-14.00-12.000
-12.00-10.000
-10.00-8.000
-8.00-6.000
-6.00-4.000
-4.00-2.004
-2.00+0.004
+0.00+2.003
+2.00+4.004
+4.00+6.001
+6.00+8.000
+8.00+10.000
+10.00+12.001
+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
2026-08172.67 +1.14

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17

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 17 +0.76 [-0.16, 1.74] no
NCEP GFS 17 -1.92 [-3.33, -0.32] yes
GraphCast (IFS init) 17 -1.06 [-1.75, -0.51] yes
Persistence (baseline) 17 -1.50 [-3.84, 1.05] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KTTN (Trenton Mercer), model ifs_hres, 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/KTTN/model/ifs_hres/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