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

Seattle-Tacoma · ECMWF IFS HRES · lead day 5

KSEA · ifs_hres · lead 5

Target day = initialization date + 5 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
tmax00Zbilinear30d18 1 QC4.59 [3.31, 5.60]3.48-3.24 [-5.03, -0.64]5.50 [3.79, 6.43]11% [0%, 29%]22%33%+0.16+0.322026-08-06 → 2026-08-30
tmax00Zbilinear90d18 1 QC4.59 [3.17, 5.64]3.48-3.24 [-5.04, -0.47]5.50 [3.55, 6.43]11% [0%, 30%]22%33%+0.16+0.322026-08-06 → 2026-08-30
tmax00Zbilinear365d18 1 QC4.59 [3.16, 5.71]3.48-3.24 [-5.15, -0.31]5.50 [3.58, 6.48]11% [0%, 30%]22%33%+0.16+0.322026-08-06 → 2026-08-30
tmax00Zbilinearall18 1 QC4.59 [3.19, 5.70]3.48-3.24 [-5.32, -0.34]5.50 [3.56, 6.55]11% [0%, 29%]22%33%+0.16+0.322026-08-06 → 2026-08-30
tmax00Znearest30d18 1 QC4.83 [3.46, 5.84]3.47-3.62 [-5.37, -0.98]5.79 [3.93, 6.86]6% [0%, 14%]17%28%+0.11+0.322026-08-06 → 2026-08-30
tmax00Znearest90d18 1 QC4.83 [3.35, 5.81]3.47-3.62 [-5.38, -0.81]5.79 [3.73, 6.79]6% [0%, 15%]17%28%+0.11+0.322026-08-06 → 2026-08-30
tmax00Znearest365d18 1 QC4.83 [3.27, 5.97]3.47-3.62 [-5.51, -0.66]5.79 [3.72, 6.87]6% [0%, 14%]17%28%+0.11+0.322026-08-06 → 2026-08-30
tmax00Znearestall18 1 QC4.83 [3.35, 5.95]3.47-3.62 [-5.73, -0.68]5.79 [3.75, 6.90]6% [0%, 15%]17%28%+0.11+0.322026-08-06 → 2026-08-30
tmax12Zbilinear30d20 1 QC3.63 [2.69, 4.27]3.22-1.69 [-3.54, 1.41]4.52 [3.17, 5.38]15% [0%, 28%]30%40%+0.27+0.322026-08-06 → 2026-08-30
tmax12Zbilinear90d20 1 QC3.63 [2.50, 4.27]3.22-1.69 [-3.57, 2.26]4.52 [2.92, 5.29]15% [0%, 29%]30%40%+0.27+0.322026-08-06 → 2026-08-30
tmax12Zbilinear365d20 1 QC3.63 [2.43, 4.33]3.22-1.69 [-3.79, 2.39]4.52 [2.78, 5.34]15% [0%, 29%]30%40%+0.27+0.322026-08-06 → 2026-08-30
tmax12Zbilinearall20 1 QC3.63 [2.43, 4.27]3.22-1.69 [-3.82, 2.20]4.52 [2.73, 5.36]15% [0%, 29%]30%40%+0.27+0.322026-08-06 → 2026-08-30
tmax12Znearest30d20 1 QC3.73 [2.63, 4.41]3.15-2.06 [-3.85, 0.93]4.62 [3.08, 5.58]20% [5%, 42%]25%35%+0.25+0.332026-08-06 → 2026-08-30
tmax12Znearest90d20 1 QC3.73 [2.43, 4.42]3.15-2.06 [-3.83, 1.81]4.62 [2.94, 5.48]20% [0%, 46%]25%35%+0.25+0.332026-08-06 → 2026-08-30
tmax12Znearest365d20 1 QC3.73 [2.41, 4.48]3.15-2.06 [-4.03, 1.94]4.62 [2.92, 5.54]20% [0%, 50%]25%35%+0.25+0.332026-08-06 → 2026-08-30
tmax12Znearestall20 1 QC3.73 [2.35, 4.41]3.15-2.06 [-4.08, 1.73]4.62 [2.78, 5.58]20% [0%, 50%]25%35%+0.25+0.332026-08-06 → 2026-08-30
tmin00Zbilinear30d18 1 QC1.46 [0.87, 2.65]1.41+0.98 [0.20, 2.38]1.91 [1.15, 2.90]50% [18%, 67%]72%83%+0.27+0.292026-08-06 → 2026-08-30
tmin00Zbilinear90d18 1 QC1.46 [0.82, 2.82]1.41+0.98 [0.03, 2.77]1.91 [1.07, 3.01]50% [0%, 68%]72%83%+0.27+0.292026-08-06 → 2026-08-30
tmin00Zbilinear365d18 1 QC1.46 [0.80, 2.83]1.41+0.98 [0.02, 2.77]1.91 [1.04, 3.02]50% [0%, 68%]72%83%+0.27+0.292026-08-06 → 2026-08-30
tmin00Zbilinearall18 1 QC1.46 [0.80, 2.77]1.41+0.98 [-0.05, 2.77]1.91 [1.04, 3.01]50% [0%, 67%]72%83%+0.27+0.292026-08-06 → 2026-08-30
tmin00Znearest30d18 1 QC1.75 [1.06, 3.14]1.43+1.56 [0.76, 3.08]2.31 [1.34, 3.52]39% [13%, 55%]61%78%+0.12+0.282026-08-06 → 2026-08-30
tmin00Znearest90d18 1 QC1.75 [0.96, 3.57]1.43+1.56 [0.52, 3.57]2.31 [1.21, 3.67]39% [0%, 56%]61%78%+0.12+0.282026-08-06 → 2026-08-30
tmin00Znearest365d18 1 QC1.75 [0.95, 3.57]1.43+1.56 [0.56, 3.57]2.31 [1.11, 3.63]39% [0%, 56%]61%78%+0.12+0.282026-08-06 → 2026-08-30
tmin00Znearestall18 1 QC1.75 [0.99, 3.57]1.43+1.56 [0.50, 3.57]2.31 [1.15, 3.62]39% [0%, 53%]61%78%+0.12+0.282026-08-06 → 2026-08-30
tmin12Zbilinear30d20 1 QC1.80 [1.05, 2.87]1.46+1.35 [0.44, 2.64]2.33 [1.40, 3.26]30% [7%, 48%]65%85%+0.08+0.252026-08-06 → 2026-08-30
tmin12Zbilinear90d20 1 QC1.80 [1.06, 3.25]1.46+1.35 [0.27, 3.03]2.33 [1.42, 3.55]30% [0%, 50%]65%85%+0.08+0.252026-08-06 → 2026-08-30
tmin12Zbilinear365d20 1 QC1.80 [1.01, 3.27]1.46+1.35 [0.21, 3.06]2.33 [1.29, 3.48]30% [0%, 52%]65%85%+0.08+0.252026-08-06 → 2026-08-30
tmin12Zbilinearall20 1 QC1.80 [0.90, 3.06]1.46+1.35 [0.21, 2.93]2.33 [1.19, 3.45]30% [0%, 54%]65%85%+0.08+0.252026-08-06 → 2026-08-30
tmin12Znearest30d20 1 QC2.09 [1.25, 3.37]1.60+1.75 [0.71, 3.23]2.71 [1.62, 3.83]35% [7%, 59%]55%80%-0.07+0.182026-08-06 → 2026-08-30
tmin12Znearest90d20 1 QC2.09 [1.23, 3.73]1.60+1.75 [0.49, 3.66]2.71 [1.60, 4.16]35% [0%, 59%]55%80%-0.07+0.182026-08-06 → 2026-08-30
tmin12Znearest365d20 1 QC2.09 [1.17, 3.70]1.60+1.75 [0.43, 3.70]2.71 [1.44, 4.10]35% [0%, 62%]55%80%-0.07+0.182026-08-06 → 2026-08-30
tmin12Znearestall20 1 QC2.09 [1.08, 3.68]1.60+1.75 [0.43, 3.56]2.71 [1.36, 4.04]35% [0%, 63%]55%80%-0.07+0.182026-08-06 → 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 5, 00Z bilinear tmax+20+100-10-202026-08-06: -3.88 °F2026-08-12: -2.8 °F2026-08-13: -1.35 °F2026-08-14: +5.15 °F2026-08-16: +4.32 °F2026-08-17: -6.61 °F2026-08-19: -6.76 °F2026-08-20: -9.93 °F2026-08-21: -1.82 °F2026-08-22: -4.01 °F2026-08-23: -3.05 °F2026-08-24: -4.05 °F2026-08-25: -12.18 °F2026-08-26: -6.71 °F2026-08-27: -0.12 °F2026-08-28: -0.84 °F2026-08-29: -6.4 °F2026-08-30: +2.65 °F2026-08-062026-08-30°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 (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+2.65
2026-08-29-6.40
2026-08-28-0.84
2026-08-27-0.12
2026-08-26-6.71
2026-08-25-12.18
2026-08-24-4.05
2026-08-23-3.05
2026-08-22-4.01
2026-08-21-1.82
2026-08-20-9.93
2026-08-19-6.76
2026-08-18—
2026-08-17-6.61
2026-08-16+4.32
2026-08-15—
2026-08-14+5.15
2026-08-13-1.35
2026-08-12-2.80
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06-3.88

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSEA, lead day 5-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 1 day-8 to -6 °F: 4 days-6 to -4 °F: 2 days-4 to -2 °F: 3 days-2 to 0 °F: 4 days0 to 2 °F: 0 days2 to 4 °F: 1 day4 to 6 °F: 2 days6 to 8 °F: 0 days8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 4.03 · P90 |e| 7.71 °F-200+20 °Fn = 18 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
-14.00-12.001
-12.00-10.000
-10.00-8.001
-8.00-6.004
-6.00-4.002
-4.00-2.003
-2.00+0.004
+0.00+2.000
+2.00+4.001
+4.00+6.002
+6.00+8.000
+8.00+10.000
+10.00+12.000
+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
2026-08184.59 -3.24

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-06 → 2026-08-30 18
ECMWF IFS HRES2026-08-06 → 2026-08-30 18
ECMWF IFS HRES2026-08-06 → 2026-08-30 20
ECMWF IFS HRES2026-08-06 → 2026-08-30 20

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 18 -1.24 [-2.43, -0.15] yes
NCEP GFS 18 +0.95 [-2.37, 3.38] no
GraphCast (IFS init) 18 -1.77 [-4.11, -0.57] yes
Persistence (baseline) 18 -0.85 [-8.75, 1.10] no

Cite this page

ShortCastCheck, KSEA ifs_hres lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSEA/model/ifs_hres/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSEA (Seattle-Tacoma), model ifs_hres, lead day 5. 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/5/

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