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

Seattle-Tacoma · Aurora (GFS init) · lead day 1

KSEA · aurora_gfs · lead 1

Target day = initialization date + 1 day. 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, AURO_v100, starting 2026-08-28 — 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
tmax00Zbilinear30d1 1 QC4.50 [4.50, 4.50]0.00-4.50 [-4.50, -4.50]4.50 [4.50, 4.50]0% [0%, 0%]0%0%-3.50—2026-08-30 → 2026-08-30
tmax00Zbilinear90d1 1 QC4.50 [4.50, 4.50]0.00-4.50 [-4.50, -4.50]4.50 [4.50, 4.50]0% [0%, 0%]0%0%-3.50—2026-08-30 → 2026-08-30
tmax00Zbilinear365d1 1 QC4.50 [4.50, 4.50]0.00-4.50 [-4.50, -4.50]4.50 [4.50, 4.50]0% [0%, 0%]0%0%-3.50—2026-08-30 → 2026-08-30
tmax00Zbilinearall1 1 QC4.50 [4.50, 4.50]0.00-4.50 [-4.50, -4.50]4.50 [4.50, 4.50]0% [0%, 0%]0%0%-3.50—2026-08-30 → 2026-08-30
tmax00Znearest30d1 1 QC4.47 [4.47, 4.47]0.00-4.47 [-4.47, -4.47]4.47 [4.47, 4.47]0% [0%, 0%]0%0%-3.47—2026-08-30 → 2026-08-30
tmax00Znearest90d1 1 QC4.47 [4.47, 4.47]0.00-4.47 [-4.47, -4.47]4.47 [4.47, 4.47]0% [0%, 0%]0%0%-3.47—2026-08-30 → 2026-08-30
tmax00Znearest365d1 1 QC4.47 [4.47, 4.47]0.00-4.47 [-4.47, -4.47]4.47 [4.47, 4.47]0% [0%, 0%]0%0%-3.47—2026-08-30 → 2026-08-30
tmax00Znearestall1 1 QC4.47 [4.47, 4.47]0.00-4.47 [-4.47, -4.47]4.47 [4.47, 4.47]0% [0%, 0%]0%0%-3.47—2026-08-30 → 2026-08-30
tmax12Zbilinear30d2 1 QC6.50 [4.68, 8.31]1.81-6.50 [-8.31, -4.68]6.74 [4.68, 8.31]0% [0%, 0%]0%0%-3.33-2.622026-08-29 → 2026-08-30
tmax12Zbilinear90d2 1 QC6.50 [4.68, 8.31]1.81-6.50 [-8.31, -4.68]6.74 [4.68, 8.31]0% [0%, 0%]0%0%-3.33-2.622026-08-29 → 2026-08-30
tmax12Zbilinear365d2 1 QC6.50 [4.68, 8.31]1.81-6.50 [-8.31, -4.68]6.74 [4.68, 8.31]0% [0%, 0%]0%0%-3.33-2.622026-08-29 → 2026-08-30
tmax12Zbilinearall2 1 QC6.50 [4.68, 8.31]1.81-6.50 [-8.31, -4.68]6.74 [4.68, 8.31]0% [0%, 0%]0%0%-3.33-2.622026-08-29 → 2026-08-30
tmax12Znearest30d2 1 QC6.39 [4.61, 8.16]1.77-6.39 [-8.16, -4.61]6.63 [4.61, 8.16]0% [0%, 0%]0%0%-3.26-2.552026-08-29 → 2026-08-30
tmax12Znearest90d2 1 QC6.39 [4.61, 8.16]1.77-6.39 [-8.16, -4.61]6.63 [4.61, 8.16]0% [0%, 0%]0%0%-3.26-2.552026-08-29 → 2026-08-30
tmax12Znearest365d2 1 QC6.39 [4.61, 8.16]1.77-6.39 [-8.16, -4.61]6.63 [4.61, 8.16]0% [0%, 0%]0%0%-3.26-2.552026-08-29 → 2026-08-30
tmax12Znearestall2 1 QC6.39 [4.61, 8.16]1.77-6.39 [-8.16, -4.61]6.63 [4.61, 8.16]0% [0%, 0%]0%0%-3.26-2.552026-08-29 → 2026-08-30
tmin00Zbilinear30d1 1 QC0.38 [0.38, 0.38]0.00+0.38 [0.38, 0.38]0.38 [0.38, 0.38]100% [100%, 100%]100%100%——2026-08-30 → 2026-08-30
tmin00Zbilinear90d1 1 QC0.38 [0.38, 0.38]0.00+0.38 [0.38, 0.38]0.38 [0.38, 0.38]100% [100%, 100%]100%100%——2026-08-30 → 2026-08-30
tmin00Zbilinear365d1 1 QC0.38 [0.38, 0.38]0.00+0.38 [0.38, 0.38]0.38 [0.38, 0.38]100% [100%, 100%]100%100%——2026-08-30 → 2026-08-30
tmin00Zbilinearall1 1 QC0.38 [0.38, 0.38]0.00+0.38 [0.38, 0.38]0.38 [0.38, 0.38]100% [100%, 100%]100%100%——2026-08-30 → 2026-08-30
tmin00Znearest30d1 1 QC0.39 [0.39, 0.39]0.00+0.39 [0.39, 0.39]0.39 [0.39, 0.39]100% [100%, 100%]100%100%——2026-08-30 → 2026-08-30
tmin00Znearest90d1 1 QC0.39 [0.39, 0.39]0.00+0.39 [0.39, 0.39]0.39 [0.39, 0.39]100% [100%, 100%]100%100%——2026-08-30 → 2026-08-30
tmin00Znearest365d1 1 QC0.39 [0.39, 0.39]0.00+0.39 [0.39, 0.39]0.39 [0.39, 0.39]100% [100%, 100%]100%100%——2026-08-30 → 2026-08-30
tmin00Znearestall1 1 QC0.39 [0.39, 0.39]0.00+0.39 [0.39, 0.39]0.39 [0.39, 0.39]100% [100%, 100%]100%100%——2026-08-30 → 2026-08-30
tmin12Zbilinear30d2 1 QC0.90 [0.10, 1.70]0.90+0.80 [-0.10, 1.70]1.20 [0.10, 1.70]50% [0%, 100%]100%100%+0.10+0.102026-08-29 → 2026-08-30
tmin12Zbilinear90d2 1 QC0.90 [0.10, 1.70]0.90+0.80 [-0.10, 1.70]1.20 [0.10, 1.70]50% [0%, 100%]100%100%+0.10+0.102026-08-29 → 2026-08-30
tmin12Zbilinear365d2 1 QC0.90 [0.10, 1.70]0.90+0.80 [-0.10, 1.70]1.20 [0.10, 1.70]50% [0%, 100%]100%100%+0.10+0.102026-08-29 → 2026-08-30
tmin12Zbilinearall2 1 QC0.90 [0.10, 1.70]0.90+0.80 [-0.10, 1.70]1.20 [0.10, 1.70]50% [0%, 100%]100%100%+0.10+0.102026-08-29 → 2026-08-30
tmin12Znearest30d2 1 QC0.88 [0.03, 1.72]0.88+0.85 [-0.03, 1.72]1.22 [0.03, 1.72]50% [0%, 100%]100%100%+0.12+0.122026-08-29 → 2026-08-30
tmin12Znearest90d2 1 QC0.88 [0.03, 1.72]0.88+0.85 [-0.03, 1.72]1.22 [0.03, 1.72]50% [0%, 100%]100%100%+0.12+0.122026-08-29 → 2026-08-30
tmin12Znearest365d2 1 QC0.88 [0.03, 1.72]0.88+0.85 [-0.03, 1.72]1.22 [0.03, 1.72]50% [0%, 100%]100%100%+0.12+0.122026-08-29 → 2026-08-30
tmin12Znearestall2 1 QC0.88 [0.03, 1.72]0.88+0.85 [-0.03, 1.72]1.22 [0.03, 1.72]50% [0%, 100%]100%100%+0.12+0.122026-08-29 → 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 Aurora (GFS init) at KSEA, lead day 1, 00Z bilinear tmax+5+2.50-2.5-52026-08-30: -4.5 °F2026-08-30°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 (1 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.50

Error distribution

Distribution of the signed daily error in °F for Aurora (GFS init) at KSEA, lead day 1-5 to -4.5 °F: 1 day-4.5 to -4 °F: 0 days-4 to -3.5 °F: 0 days-3.5 to -3 °F: 0 days-3 to -2.5 °F: 0 days-2.5 to -2 °F: 0 days-2 to -1.5 °F: 0 days-1.5 to -1 °F: 0 days-1 to -0.5 °F: 0 days-0.5 to 0 °F: 0 days0 to 0.5 °F: 0 days0.5 to 1 °F: 0 days1 to 1.5 °F: 0 days1.5 to 2 °F: 0 days2 to 2.5 °F: 0 days2.5 to 3 °F: 0 days3 to 3.5 °F: 0 days3.5 to 4 °F: 0 days4 to 4.5 °F: 0 days4.5 to 5 °F: 0 daysdashed: P50 |e| 4.5 · P90 |e| 4.5 °F-50+5 °Fn = 1 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
-5.00-4.501
-4.50-4.000
-4.00-3.500
-3.50-3.000
-3.00-2.500
-2.50-2.000
-2.00-1.500
-1.50-1.000
-1.00-0.500
-0.50+0.000
+0.00+0.500
+0.50+1.000
+1.00+1.500
+1.50+2.000
+2.00+2.500
+2.50+3.000
+3.00+3.500
+3.50+4.000
+4.00+4.500
+4.50+5.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-0814.50 -4.50

Availability

ModelScored period DaysCoverage
Aurora (GFS init)2026-08-30 → 2026-08-30 1
Aurora (GFS init)2026-08-30 → 2026-08-30 1
Aurora (GFS init)2026-08-29 → 2026-08-30 2
Aurora (GFS init)2026-08-29 → 2026-08-30 2

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means Aurora (GFS init) has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 1 +2.29 [2.29, 2.29] yes
Aurora (IFS init) 1 +3.05 [3.05, 3.05] yes
FourCastNet v2 (GFS init) 1 +2.76 [2.76, 2.76] yes
FourCastNet v2 (IFS init) 1 +4.37 [4.37, 4.37] yes
NCEP GFS 1 +4.45 [4.45, 4.45] yes
GraphCast (GFS init) 1 +0.07 [0.07, 0.07] yes
GraphCast (IFS init) 1 +1.75 [1.75, 1.75] yes
ECMWF IFS HRES 1 +2.43 [2.43, 2.43] yes
Pangu-Weather (GFS init) 1 +2.08 [2.08, 2.08] yes
Pangu-Weather (IFS init) 1 +2.83 [2.83, 2.83] yes
Persistence (baseline) 1 +3.50 [3.50, 3.50] yes

Cite this page

ShortCastCheck, KSEA aurora_gfs lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSEA/model/aurora_gfs/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSEA (Seattle-Tacoma), model aurora_gfs, lead day 1. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KSEA/model/aurora_gfs/lead/1/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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