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

Seattle-Tacoma · ECMWF IFS HRES · lead day 8

KSEA · 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 QC6.14 [2.88, 8.32]5.88-2.65 [-5.50, 2.81]7.12 [3.88, 8.83]18% [0%, 36%]24%29%-0.08-0.012026-08-09 → 2026-08-30
tmax00Zbilinear90d17 1 QC6.14 [1.90, 8.33]5.88-2.65 [-5.40, 3.57]7.12 [1.90, 8.95]18% [0%, 40%]24%29%-0.08-0.012026-08-09 → 2026-08-30
tmax00Zbilinear365d17 1 QC6.14 [1.90, 8.48]5.88-2.65 [-5.80, 3.73]7.12 [1.90, 9.03]18% [0%, 40%]24%29%-0.08-0.012026-08-09 → 2026-08-30
tmax00Zbilinearall17 1 QC6.14 [1.90, 8.71]5.88-2.65 [-6.08, 3.11]7.12 [1.90, 9.22]18% [0%, 40%]24%29%-0.08-0.012026-08-09 → 2026-08-30
tmax00Znearest30d17 1 QC6.14 [2.84, 8.21]5.90-2.82 [-5.65, 2.67]7.16 [3.93, 8.76]18% [0%, 36%]24%29%-0.08-0.022026-08-09 → 2026-08-30
tmax00Znearest90d17 1 QC6.14 [2.00, 8.28]5.90-2.82 [-5.57, 3.48]7.16 [2.00, 8.88]18% [0%, 40%]24%29%-0.08-0.022026-08-09 → 2026-08-30
tmax00Znearest365d17 1 QC6.14 [2.00, 8.40]5.90-2.82 [-5.99, 3.66]7.16 [2.00, 8.89]18% [0%, 40%]24%29%-0.08-0.022026-08-09 → 2026-08-30
tmax00Znearestall17 1 QC6.14 [2.00, 8.57]5.90-2.82 [-6.22, 2.95]7.16 [2.00, 9.09]18% [0%, 40%]24%29%-0.08-0.022026-08-09 → 2026-08-30
tmax12Zbilinear30d17 1 QC3.76 [2.03, 4.83]3.58-1.38 [-3.55, 2.36]4.41 [2.50, 5.36]12% [0%, 35%]18%41%+0.34+0.382026-08-09 → 2026-08-30
tmax12Zbilinear90d17 1 QC3.76 [1.76, 4.91]3.58-1.38 [-3.52, 2.60]4.41 [1.97, 5.41]12% [0%, 40%]18%41%+0.34+0.382026-08-09 → 2026-08-30
tmax12Zbilinear365d17 1 QC3.76 [1.87, 4.97]3.58-1.38 [-3.80, 2.74]4.41 [2.16, 5.48]12% [0%, 39%]18%41%+0.34+0.382026-08-09 → 2026-08-30
tmax12Zbilinearall17 1 QC3.76 [1.76, 4.98]3.58-1.38 [-3.93, 2.95]4.41 [2.01, 5.45]12% [0%, 40%]18%41%+0.34+0.382026-08-09 → 2026-08-30
tmax12Znearest30d17 1 QC3.83 [1.91, 4.94]3.59-1.65 [-3.79, 2.09]4.52 [2.60, 5.39]12% [0%, 35%]35%41%+0.33+0.382026-08-09 → 2026-08-30
tmax12Znearest90d17 1 QC3.83 [1.51, 4.99]3.59-1.65 [-3.76, 2.27]4.52 [1.61, 5.49]12% [0%, 40%]35%41%+0.33+0.382026-08-09 → 2026-08-30
tmax12Znearest365d17 1 QC3.83 [1.60, 5.06]3.59-1.65 [-3.98, 2.43]4.52 [1.80, 5.52]12% [0%, 39%]35%41%+0.33+0.382026-08-09 → 2026-08-30
tmax12Znearestall17 1 QC3.83 [1.51, 5.05]3.59-1.65 [-4.19, 2.48]4.52 [1.57, 5.52]12% [0%, 40%]35%41%+0.33+0.382026-08-09 → 2026-08-30
tmin00Zbilinear30d17 1 QC2.35 [1.50, 3.65]2.38+1.01 [-0.54, 3.54]2.99 [2.09, 4.02]35% [0%, 56%]41%59%+0.00-0.002026-08-09 → 2026-08-30
tmin00Zbilinear90d17 1 QC2.35 [1.45, 3.73]2.38+1.01 [-0.58, 3.73]2.99 [2.01, 4.08]35% [0%, 57%]41%59%+0.00-0.002026-08-09 → 2026-08-30
tmin00Zbilinear365d17 1 QC2.35 [1.42, 3.87]2.38+1.01 [-0.63, 3.84]2.99 [2.03, 4.23]35% [0%, 57%]41%59%+0.00-0.002026-08-09 → 2026-08-30
tmin00Zbilinearall17 1 QC2.35 [1.42, 3.85]2.38+1.01 [-0.75, 3.84]2.99 [1.97, 4.16]35% [0%, 57%]41%59%+0.00-0.002026-08-09 → 2026-08-30
tmin00Znearest30d17 1 QC2.53 [1.46, 4.30]2.34+1.62 [0.06, 4.22]3.17 [1.88, 4.60]29% [0%, 45%]35%65%-0.07+0.012026-08-09 → 2026-08-30
tmin00Znearest90d17 1 QC2.53 [1.41, 4.47]2.34+1.62 [0.02, 4.47]3.17 [1.86, 4.71]29% [0%, 47%]35%65%-0.07+0.012026-08-09 → 2026-08-30
tmin00Znearest365d17 1 QC2.53 [1.40, 4.56]2.34+1.62 [-0.08, 4.55]3.17 [1.84, 4.83]29% [0%, 46%]35%65%-0.07+0.012026-08-09 → 2026-08-30
tmin00Znearestall17 1 QC2.53 [1.36, 4.54]2.34+1.62 [-0.15, 4.54]3.17 [1.80, 4.76]29% [0%, 46%]35%65%-0.07+0.012026-08-09 → 2026-08-30
tmin12Zbilinear30d17 1 QC1.88 [1.42, 2.74]1.77+0.75 [-0.28, 2.37]2.31 [1.69, 3.18]35% [9%, 54%]59%82%+0.20+0.252026-08-09 → 2026-08-30
tmin12Zbilinear90d17 1 QC1.88 [1.42, 3.27]1.77+0.75 [-0.42, 3.27]2.31 [1.67, 3.63]35% [0%, 53%]59%82%+0.20+0.252026-08-09 → 2026-08-30
tmin12Zbilinear365d17 1 QC1.88 [1.42, 3.27]1.77+0.75 [-0.40, 3.27]2.31 [1.67, 3.57]35% [0%, 56%]59%82%+0.20+0.252026-08-09 → 2026-08-30
tmin12Zbilinearall17 1 QC1.88 [1.37, 3.27]1.77+0.75 [-0.56, 3.25]2.31 [1.62, 3.57]35% [0%, 57%]59%82%+0.20+0.252026-08-09 → 2026-08-30
tmin12Znearest30d17 1 QC2.05 [1.42, 3.19]1.69+1.36 [0.39, 3.04]2.50 [1.63, 3.64]29% [18%, 40%]53%82%+0.13+0.282026-08-09 → 2026-08-30
tmin12Znearest90d17 1 QC2.05 [1.34, 3.98]1.69+1.36 [0.22, 3.98]2.50 [1.55, 4.20]29% [0%, 42%]53%82%+0.13+0.282026-08-09 → 2026-08-30
tmin12Znearest365d17 1 QC2.05 [1.36, 3.98]1.69+1.36 [0.23, 3.98]2.50 [1.55, 4.20]29% [0%, 40%]53%82%+0.13+0.282026-08-09 → 2026-08-30
tmin12Znearestall17 1 QC2.05 [1.32, 3.98]1.69+1.36 [-0.01, 3.94]2.50 [1.51, 4.20]29% [8%, 44%]53%82%+0.13+0.282026-08-09 → 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 KSEA, lead day 8, 00Z bilinear tmax+20+100-10-202026-08-09: +1.9 °F2026-08-15: +10.18 °F2026-08-16: +8.75 °F2026-08-17: -11.93 °F2026-08-18: +5.17 °F2026-08-19: -10.69 °F2026-08-20: -7.26 °F2026-08-21: -7.04 °F2026-08-22: -0.92 °F2026-08-23: -6.65 °F2026-08-24: -9.04 °F2026-08-25: -8.92 °F2026-08-26: -7.46 °F2026-08-27: -4.84 °F2026-08-28: +0.81 °F2026-08-29: +0.59 °F2026-08-30: +2.25 °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+2.25
2026-08-29+0.59
2026-08-28+0.81
2026-08-27-4.84
2026-08-26-7.46
2026-08-25-8.92
2026-08-24-9.04
2026-08-23-6.65
2026-08-22-0.92
2026-08-21-7.04
2026-08-20-7.26
2026-08-19-10.69
2026-08-18+5.17
2026-08-17-11.93
2026-08-16+8.75
2026-08-15+10.18
2026-08-14—
2026-08-13—
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09+1.90

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSEA, 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: 2 days-10 to -8 °F: 2 days-8 to -6 °F: 4 days-6 to -4 °F: 1 day-4 to -2 °F: 0 days-2 to 0 °F: 1 day0 to 2 °F: 3 days2 to 4 °F: 1 day4 to 6 °F: 1 day6 to 8 °F: 0 days8 to 10 °F: 1 day10 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| 7.04 · P90 |e| 10.38 °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
-12.00-10.002
-10.00-8.002
-8.00-6.004
-6.00-4.001
-4.00-2.000
-2.00+0.001
+0.00+2.003
+2.00+4.001
+4.00+6.001
+6.00+8.000
+8.00+10.001
+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
2026-08176.14 -2.65

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 -0.64 [-2.52, 3.30] no
NCEP GFS 17 -1.20 [-3.93, 1.51] no
GraphCast (IFS init) 17 -0.52 [-2.63, 2.11] no
Persistence (baseline) 17 +0.44 [-5.74, 3.22] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSEA (Seattle-Tacoma), 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/KSEA/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