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

Seattle-Tacoma · ECMWF IFS HRES · lead day 3

KSEA · ifs_hres · lead 3

Target day = initialization date + 3 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
tmax00Zbilinear30d22 1 QC2.83 [2.04, 3.51]2.73-0.80 [-2.40, 1.05]3.52 [2.56, 4.16]32% [17%, 45%]45%59%+0.49+0.512026-08-04 → 2026-08-30
tmax00Zbilinear90d22 1 QC2.83 [1.96, 3.52]2.73-0.80 [-2.43, 1.42]3.52 [2.44, 4.20]32% [12%, 48%]45%59%+0.49+0.512026-08-04 → 2026-08-30
tmax00Zbilinear365d22 1 QC2.83 [1.92, 3.52]2.73-0.80 [-2.49, 1.56]3.52 [2.39, 4.20]32% [12%, 50%]45%59%+0.49+0.512026-08-04 → 2026-08-30
tmax00Zbilinearall22 1 QC2.83 [1.93, 3.47]2.73-0.80 [-2.60, 1.49]3.52 [2.24, 4.13]32% [11%, 48%]45%59%+0.49+0.512026-08-04 → 2026-08-30
tmax00Znearest30d22 1 QC2.97 [2.12, 3.66]2.79-1.12 [-2.70, 0.69]3.63 [2.60, 4.33]23% [5%, 41%]41%50%+0.47+0.502026-08-04 → 2026-08-30
tmax00Znearest90d22 1 QC2.97 [1.89, 3.68]2.79-1.12 [-2.77, 1.04]3.63 [2.38, 4.35]23% [0%, 43%]41%50%+0.47+0.502026-08-04 → 2026-08-30
tmax00Znearest365d22 1 QC2.97 [1.93, 3.70]2.79-1.12 [-2.81, 1.13]3.63 [2.44, 4.37]23% [0%, 43%]41%50%+0.47+0.502026-08-04 → 2026-08-30
tmax00Znearestall22 1 QC2.97 [1.86, 3.62]2.79-1.12 [-3.02, 1.10]3.63 [2.35, 4.29]23% [0%, 43%]41%50%+0.47+0.502026-08-04 → 2026-08-30
tmax12Zbilinear30d22 1 QC2.99 [2.17, 3.67]2.77-0.77 [-2.29, 1.01]3.48 [2.45, 4.13]14% [0%, 27%]32%55%+0.46+0.502026-08-04 → 2026-08-30
tmax12Zbilinear90d22 1 QC2.99 [1.99, 3.68]2.77-0.77 [-2.31, 1.29]3.48 [2.20, 4.15]14% [0%, 28%]32%55%+0.46+0.502026-08-04 → 2026-08-30
tmax12Zbilinear365d22 1 QC2.99 [1.92, 3.70]2.77-0.77 [-2.47, 1.48]3.48 [2.11, 4.18]14% [0%, 29%]32%55%+0.46+0.502026-08-04 → 2026-08-30
tmax12Zbilinearall22 1 QC2.99 [1.98, 3.65]2.77-0.77 [-2.39, 1.35]3.48 [2.16, 4.10]14% [0%, 29%]32%55%+0.46+0.502026-08-04 → 2026-08-30
tmax12Znearest30d22 1 QC3.18 [2.29, 3.84]2.87-1.13 [-2.74, 0.69]3.64 [2.56, 4.32]9% [0%, 17%]27%50%+0.43+0.492026-08-04 → 2026-08-30
tmax12Znearest90d22 1 QC3.18 [2.13, 3.88]2.87-1.13 [-2.79, 0.99]3.64 [2.35, 4.33]9% [0%, 18%]27%50%+0.43+0.492026-08-04 → 2026-08-30
tmax12Znearest365d22 1 QC3.18 [2.10, 3.89]2.87-1.13 [-2.90, 1.18]3.64 [2.32, 4.36]9% [0%, 18%]27%50%+0.43+0.492026-08-04 → 2026-08-30
tmax12Znearestall22 1 QC3.18 [2.10, 3.82]2.87-1.13 [-2.96, 1.09]3.64 [2.32, 4.32]9% [0%, 17%]27%50%+0.43+0.492026-08-04 → 2026-08-30
tmin00Zbilinear30d22 1 QC1.67 [1.19, 2.15]1.05+1.51 [0.91, 2.04]2.03 [1.29, 2.57]27% [11%, 38%]68%86%+0.22+0.512026-08-04 → 2026-08-30
tmin00Zbilinear90d22 1 QC1.67 [1.12, 2.20]1.05+1.51 [0.71, 2.12]2.03 [1.21, 2.58]27% [0%, 38%]68%86%+0.22+0.512026-08-04 → 2026-08-30
tmin00Zbilinear365d22 1 QC1.67 [1.09, 2.22]1.05+1.51 [0.67, 2.13]2.03 [1.16, 2.63]27% [0%, 38%]68%86%+0.22+0.512026-08-04 → 2026-08-30
tmin00Zbilinearall22 1 QC1.67 [1.09, 2.25]1.05+1.51 [0.63, 2.14]2.03 [1.19, 2.62]27% [0%, 38%]68%86%+0.22+0.512026-08-04 → 2026-08-30
tmin00Znearest30d22 1 QC2.04 [1.43, 2.66]1.13+1.98 [1.30, 2.63]2.41 [1.56, 3.01]23% [8%, 36%]59%73%+0.05+0.482026-08-04 → 2026-08-30
tmin00Znearest90d22 1 QC2.04 [1.31, 2.71]1.13+1.98 [1.08, 2.71]2.41 [1.41, 3.06]23% [0%, 38%]59%73%+0.05+0.482026-08-04 → 2026-08-30
tmin00Znearest365d22 1 QC2.04 [1.28, 2.72]1.13+1.98 [1.07, 2.72]2.41 [1.38, 3.07]23% [0%, 40%]59%73%+0.05+0.482026-08-04 → 2026-08-30
tmin00Znearestall22 1 QC2.04 [1.30, 2.75]1.13+1.98 [1.04, 2.75]2.41 [1.41, 3.07]23% [0%, 40%]59%73%+0.05+0.482026-08-04 → 2026-08-30
tmin12Zbilinear30d22 1 QC1.55 [1.06, 2.06]0.94+1.45 [0.97, 1.95]1.91 [1.25, 2.41]36% [10%, 58%]73%91%+0.27+0.562026-08-04 → 2026-08-30
tmin12Zbilinear90d22 1 QC1.55 [0.99, 2.10]0.94+1.45 [0.91, 2.00]1.91 [1.20, 2.43]36% [0%, 61%]73%91%+0.27+0.562026-08-04 → 2026-08-30
tmin12Zbilinear365d22 1 QC1.55 [0.96, 2.15]0.94+1.45 [0.88, 2.00]1.91 [1.15, 2.48]36% [0%, 62%]73%91%+0.27+0.562026-08-04 → 2026-08-30
tmin12Zbilinearall22 1 QC1.55 [0.94, 2.14]0.94+1.45 [0.83, 2.00]1.91 [1.14, 2.46]36% [0%, 64%]73%91%+0.27+0.562026-08-04 → 2026-08-30
tmin12Znearest30d22 1 QC1.99 [1.36, 2.63]0.99+1.96 [1.30, 2.63]2.37 [1.53, 2.98]23% [8%, 36%]50%77%+0.07+0.542026-08-04 → 2026-08-30
tmin12Znearest90d22 1 QC1.99 [1.28, 2.68]0.99+1.96 [1.17, 2.68]2.37 [1.44, 3.00]23% [0%, 38%]50%77%+0.07+0.542026-08-04 → 2026-08-30
tmin12Znearest365d22 1 QC1.99 [1.25, 2.70]0.99+1.96 [1.15, 2.70]2.37 [1.40, 3.05]23% [0%, 39%]50%77%+0.07+0.542026-08-04 → 2026-08-30
tmin12Znearestall22 1 QC1.99 [1.23, 2.72]0.99+1.96 [1.14, 2.71]2.37 [1.41, 3.04]23% [0%, 42%]50%77%+0.07+0.542026-08-04 → 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 3, 00Z bilinear tmax+10+50-5-102026-08-04: +1.97 °F2026-08-10: +4.58 °F2026-08-11: -0.93 °F2026-08-12: -2.66 °F2026-08-13: -1.91 °F2026-08-14: +3.48 °F2026-08-15: +5.97 °F2026-08-16: +3.88 °F2026-08-17: -0.34 °F2026-08-18: -2.16 °F2026-08-19: -6.92 °F2026-08-20: -5.9 °F2026-08-21: -0.58 °F2026-08-22: -4.85 °F2026-08-23: -0.43 °F2026-08-24: -5.1 °F2026-08-25: +1.32 °F2026-08-26: +0.47 °F2026-08-27: -5.14 °F2026-08-28: +0.65 °F2026-08-29: -0.56 °F2026-08-30: -2.54 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.54
2026-08-29-0.56
2026-08-28+0.65
2026-08-27-5.14
2026-08-26+0.47
2026-08-25+1.32
2026-08-24-5.10
2026-08-23-0.43
2026-08-22-4.85
2026-08-21-0.58
2026-08-20-5.90
2026-08-19-6.92
2026-08-18-2.16
2026-08-17-0.34
2026-08-16+3.88
2026-08-15+5.97
2026-08-14+3.48
2026-08-13-1.91
2026-08-12-2.66
2026-08-11-0.93
2026-08-10+4.58
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04+1.97

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSEA, lead day 3-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 3 days-5 to -4 °F: 1 day-4 to -3 °F: 0 days-3 to -2 °F: 3 days-2 to -1 °F: 1 day-1 to 0 °F: 5 days0 to 1 °F: 2 days1 to 2 °F: 2 days2 to 3 °F: 0 days3 to 4 °F: 2 days4 to 5 °F: 1 day5 to 6 °F: 1 day6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2.35 · P90 |e| 5.83 °F-100+10 °Fn = 22 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
-10.00-9.000
-9.00-8.000
-8.00-7.000
-7.00-6.001
-6.00-5.003
-5.00-4.001
-4.00-3.000
-3.00-2.003
-2.00-1.001
-1.00+0.005
+0.00+1.002
+1.00+2.002
+2.00+3.000
+3.00+4.002
+4.00+5.001
+5.00+6.001
+6.00+7.000
+7.00+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08222.83 -0.80

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22

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 22 -2.50 [-3.96, -0.06] yes
NCEP GFS 22 -1.82 [-3.23, -0.61] yes
GraphCast (IFS init) 20 -2.05 [-3.07, -0.38] yes
Persistence (baseline) 22 -2.76 [-5.56, -1.47] yes

Cite this page

ShortCastCheck, KSEA ifs_hres lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSEA/model/ifs_hres/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSEA (Seattle-Tacoma), model ifs_hres, lead day 3. 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/3/

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