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

Seattle-Tacoma · ECMWF IFS HRES · lead day 6

KSEA · ifs_hres · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d19 1 QC4.75 [2.22, 6.27]4.53-2.30 [-5.06, 1.11]6.13 [2.99, 7.54]16% [0%, 33%]37%42%-0.04+0.022026-08-07 → 2026-08-30
tmax00Zbilinear90d19 1 QC4.75 [1.63, 6.43]4.53-2.30 [-5.38, 1.48]6.13 [1.79, 7.67]16% [0%, 38%]37%42%-0.04+0.022026-08-07 → 2026-08-30
tmax00Zbilinear365d19 1 QC4.75 [1.71, 6.44]4.53-2.30 [-5.52, 1.71]6.13 [1.79, 7.68]16% [0%, 37%]37%42%-0.04+0.022026-08-07 → 2026-08-30
tmax00Zbilinearall19 1 QC4.75 [1.76, 6.45]4.53-2.30 [-5.47, 1.71]6.13 [1.79, 7.71]16% [0%, 34%]37%42%-0.04+0.022026-08-07 → 2026-08-30
tmax00Znearest30d19 1 QC4.87 [2.37, 6.40]4.55-2.66 [-5.41, 0.68]6.26 [3.25, 7.66]21% [7%, 36%]32%37%-0.06+0.022026-08-07 → 2026-08-30
tmax00Znearest90d19 1 QC4.87 [1.78, 6.61]4.55-2.66 [-5.71, 1.03]6.26 [2.13, 7.84]21% [0%, 40%]32%37%-0.06+0.022026-08-07 → 2026-08-30
tmax00Znearest365d19 1 QC4.87 [1.91, 6.57]4.55-2.66 [-5.89, 1.27]6.26 [2.13, 7.84]21% [0%, 38%]32%37%-0.06+0.022026-08-07 → 2026-08-30
tmax00Znearestall19 1 QC4.87 [1.89, 6.61]4.55-2.66 [-5.79, 1.23]6.26 [2.13, 7.88]21% [0%, 38%]32%37%-0.06+0.022026-08-07 → 2026-08-30
tmax12Zbilinear30d19 1 QC4.56 [3.21, 5.54]4.04-2.07 [-4.63, 2.19]5.39 [3.80, 6.34]16% [7%, 25%]26%26%+0.00+0.122026-08-07 → 2026-08-30
tmax12Zbilinear90d19 1 QC4.56 [2.83, 5.53]4.04-2.07 [-4.68, 2.82]5.39 [3.37, 6.35]16% [0%, 25%]26%26%+0.00+0.122026-08-07 → 2026-08-30
tmax12Zbilinear365d19 1 QC4.56 [2.81, 5.71]4.04-2.07 [-4.74, 3.19]5.39 [3.42, 6.53]16% [0%, 27%]26%26%+0.00+0.122026-08-07 → 2026-08-30
tmax12Zbilinearall19 1 QC4.56 [2.81, 5.59]4.04-2.07 [-4.87, 3.23]5.39 [3.40, 6.38]16% [0%, 25%]26%26%+0.00+0.122026-08-07 → 2026-08-30
tmax12Znearest30d19 1 QC4.64 [3.52, 5.55]3.94-2.41 [-4.96, 1.73]5.49 [4.10, 6.42]16% [0%, 29%]26%26%-0.01+0.152026-08-07 → 2026-08-30
tmax12Znearest90d19 1 QC4.64 [3.27, 5.59]3.94-2.41 [-4.93, 2.36]5.49 [3.81, 6.45]16% [0%, 31%]26%26%-0.01+0.152026-08-07 → 2026-08-30
tmax12Znearest365d19 1 QC4.64 [3.19, 5.72]3.94-2.41 [-4.96, 2.71]5.49 [3.79, 6.56]16% [0%, 33%]26%26%-0.01+0.152026-08-07 → 2026-08-30
tmax12Znearestall19 1 QC4.64 [3.17, 5.61]3.94-2.41 [-5.13, 2.79]5.49 [3.78, 6.49]16% [0%, 33%]26%26%-0.01+0.152026-08-07 → 2026-08-30
tmin00Zbilinear30d19 1 QC2.16 [1.21, 3.46]2.09+1.23 [-0.39, 3.38]3.07 [1.73, 4.24]42% [11%, 64%]63%74%-0.02+0.022026-08-07 → 2026-08-30
tmin00Zbilinear90d19 1 QC2.16 [1.22, 3.59]2.09+1.23 [-0.57, 3.56]3.07 [1.75, 4.39]42% [0%, 64%]63%74%-0.02+0.022026-08-07 → 2026-08-30
tmin00Zbilinear365d19 1 QC2.16 [1.16, 3.59]2.09+1.23 [-0.61, 3.54]3.07 [1.66, 4.44]42% [0%, 68%]63%74%-0.02+0.022026-08-07 → 2026-08-30
tmin00Zbilinearall19 1 QC2.16 [1.12, 3.59]2.09+1.23 [-0.64, 3.55]3.07 [1.60, 4.46]42% [0%, 71%]63%74%-0.02+0.022026-08-07 → 2026-08-30
tmin00Znearest30d19 1 QC2.39 [1.31, 4.02]2.15+1.65 [-0.04, 3.97]3.30 [1.80, 4.68]37% [0%, 67%]58%68%-0.14-0.002026-08-07 → 2026-08-30
tmin00Znearest90d19 1 QC2.39 [1.29, 4.16]2.15+1.65 [-0.25, 4.16]3.30 [1.75, 4.83]37% [0%, 67%]58%68%-0.14-0.002026-08-07 → 2026-08-30
tmin00Znearest365d19 1 QC2.39 [1.22, 4.16]2.15+1.65 [-0.28, 4.13]3.30 [1.73, 4.87]37% [0%, 69%]58%68%-0.14-0.002026-08-07 → 2026-08-30
tmin00Znearestall19 1 QC2.39 [1.19, 4.14]2.15+1.65 [-0.32, 4.14]3.30 [1.63, 4.88]37% [0%, 71%]58%68%-0.14-0.002026-08-07 → 2026-08-30
tmin12Zbilinear30d19 1 QC2.20 [1.23, 3.35]1.92+1.36 [-0.08, 3.20]2.86 [1.53, 4.01]32% [12%, 55%]63%79%-0.05+0.102026-08-07 → 2026-08-30
tmin12Zbilinear90d19 1 QC2.20 [1.03, 3.54]1.92+1.36 [-0.15, 3.36]2.86 [1.31, 4.18]32% [10%, 64%]63%79%-0.05+0.102026-08-07 → 2026-08-30
tmin12Zbilinear365d19 1 QC2.20 [0.99, 3.67]1.92+1.36 [-0.14, 3.51]2.86 [1.31, 4.23]32% [7%, 63%]63%79%-0.05+0.102026-08-07 → 2026-08-30
tmin12Zbilinearall19 1 QC2.20 [0.98, 3.56]1.92+1.36 [-0.22, 3.50]2.86 [1.30, 4.21]32% [8%, 67%]63%79%-0.05+0.102026-08-07 → 2026-08-30
tmin12Znearest30d19 1 QC2.44 [1.34, 3.87]1.96+1.81 [0.23, 3.80]3.16 [1.61, 4.56]21% [5%, 45%]53%68%-0.16+0.082026-08-07 → 2026-08-30
tmin12Znearest90d19 1 QC2.44 [1.11, 4.10]1.96+1.81 [0.13, 3.96]3.16 [1.22, 4.75]21% [0%, 56%]53%68%-0.16+0.082026-08-07 → 2026-08-30
tmin12Znearest365d19 1 QC2.44 [1.15, 4.21]1.96+1.81 [0.16, 4.10]3.16 [1.38, 4.82]21% [0%, 56%]53%68%-0.16+0.082026-08-07 → 2026-08-30
tmin12Znearestall19 1 QC2.44 [1.09, 4.16]1.96+1.81 [0.05, 4.16]3.16 [1.24, 4.82]21% [0%, 56%]53%68%-0.16+0.082026-08-07 → 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 KSEA, lead day 6, 00Z bilinear tmax+20+100-10-202026-08-07: -1.79 °F2026-08-13: -5.67 °F2026-08-14: +10.32 °F2026-08-15: +4.83 °F2026-08-16: +4.67 °F2026-08-17: +0.07 °F2026-08-18: -6.35 °F2026-08-19: -10.69 °F2026-08-20: -8.11 °F2026-08-21: +1.24 °F2026-08-22: -14.05 °F2026-08-23: -1.38 °F2026-08-24: -6.61 °F2026-08-25: -6.6 °F2026-08-26: -3.16 °F2026-08-27: +1.45 °F2026-08-28: +0.1 °F2026-08-29: +0.55 °F2026-08-30: -2.56 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.56
2026-08-29+0.55
2026-08-28+0.10
2026-08-27+1.45
2026-08-26-3.16
2026-08-25-6.60
2026-08-24-6.61
2026-08-23-1.38
2026-08-22-14.05
2026-08-21+1.24
2026-08-20-8.11
2026-08-19-10.69
2026-08-18-6.35
2026-08-17+0.07
2026-08-16+4.67
2026-08-15+4.83
2026-08-14+10.32
2026-08-13-5.67
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07-1.79

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSEA, lead day 6-20 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: 1 day-10 to -8 °F: 1 day-8 to -6 °F: 3 days-6 to -4 °F: 1 day-4 to -2 °F: 2 days-2 to 0 °F: 2 days0 to 2 °F: 5 days2 to 4 °F: 0 days4 to 6 °F: 2 days6 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| 4.67 · P90 |e| 10.39 °F-200+20 °Fn = 19 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
-12.00-10.001
-10.00-8.001
-8.00-6.003
-6.00-4.001
-4.00-2.002
-2.00+0.002
+0.00+2.005
+2.00+4.000
+4.00+6.002
+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
2026-08194.75 -2.30

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19
ECMWF IFS HRES2026-08-07 → 2026-08-30 19

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 19 -0.95 [-2.34, 2.30] no
NCEP GFS 19 +0.12 [-1.94, 2.41] no
GraphCast (IFS init) 19 -2.52 [-7.17, -0.47] yes
Persistence (baseline) 19 +0.17 [-8.03, 3.02] no

Cite this page

ShortCastCheck, KSEA ifs_hres lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSEA/model/ifs_hres/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSEA (Seattle-Tacoma), model ifs_hres, lead day 6. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KSEA/model/ifs_hres/lead/6/

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