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

Seattle-Tacoma · Pangu-Weather (IFS init) · lead day 1

KSEA · pangu_ifs · 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, PANG_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
tmax00Zbilinear30d2 1 QC3.06 [1.67, 4.45]1.39-3.06 [-4.45, -1.67]3.36 [1.67, 4.45]0% [0%, 0%]50%50%-1.04-1.782026-08-29 → 2026-08-30
tmax00Zbilinear90d2 1 QC3.06 [1.67, 4.45]1.39-3.06 [-4.45, -1.67]3.36 [1.67, 4.45]0% [0%, 0%]50%50%-1.04-1.782026-08-29 → 2026-08-30
tmax00Zbilinear365d2 1 QC3.06 [1.67, 4.45]1.39-3.06 [-4.45, -1.67]3.36 [1.67, 4.45]0% [0%, 0%]50%50%-1.04-1.782026-08-29 → 2026-08-30
tmax00Zbilinearall2 1 QC3.06 [1.67, 4.45]1.39-3.06 [-4.45, -1.67]3.36 [1.67, 4.45]0% [0%, 0%]50%50%-1.04-1.782026-08-29 → 2026-08-30
tmax00Znearest30d2 1 QC3.07 [1.64, 4.50]1.43-3.07 [-4.50, -1.64]3.39 [1.64, 4.50]0% [0%, 0%]50%50%-1.05-1.872026-08-29 → 2026-08-30
tmax00Znearest90d2 1 QC3.07 [1.64, 4.50]1.43-3.07 [-4.50, -1.64]3.39 [1.64, 4.50]0% [0%, 0%]50%50%-1.05-1.872026-08-29 → 2026-08-30
tmax00Znearest365d2 1 QC3.07 [1.64, 4.50]1.43-3.07 [-4.50, -1.64]3.39 [1.64, 4.50]0% [0%, 0%]50%50%-1.05-1.872026-08-29 → 2026-08-30
tmax00Znearestall2 1 QC3.07 [1.64, 4.50]1.43-3.07 [-4.50, -1.64]3.39 [1.64, 4.50]0% [0%, 0%]50%50%-1.05-1.872026-08-29 → 2026-08-30
tmax12Zbilinear30d2 1 QC2.74 [1.42, 4.06]1.32-2.74 [-4.06, -1.42]3.04 [1.42, 4.06]0% [0%, 0%]50%50%-0.83-1.642026-08-29 → 2026-08-30
tmax12Zbilinear90d2 1 QC2.74 [1.42, 4.06]1.32-2.74 [-4.06, -1.42]3.04 [1.42, 4.06]0% [0%, 0%]50%50%-0.83-1.642026-08-29 → 2026-08-30
tmax12Zbilinear365d2 1 QC2.74 [1.42, 4.06]1.32-2.74 [-4.06, -1.42]3.04 [1.42, 4.06]0% [0%, 0%]50%50%-0.83-1.642026-08-29 → 2026-08-30
tmax12Zbilinearall2 1 QC2.74 [1.42, 4.06]1.32-2.74 [-4.06, -1.42]3.04 [1.42, 4.06]0% [0%, 0%]50%50%-0.83-1.642026-08-29 → 2026-08-30
tmax12Znearest30d2 1 QC2.97 [1.54, 4.40]1.43-2.97 [-4.40, -1.54]3.30 [1.54, 4.40]0% [0%, 0%]50%50%-0.98-1.862026-08-29 → 2026-08-30
tmax12Znearest90d2 1 QC2.97 [1.54, 4.40]1.43-2.97 [-4.40, -1.54]3.30 [1.54, 4.40]0% [0%, 0%]50%50%-0.98-1.862026-08-29 → 2026-08-30
tmax12Znearest365d2 1 QC2.97 [1.54, 4.40]1.43-2.97 [-4.40, -1.54]3.30 [1.54, 4.40]0% [0%, 0%]50%50%-0.98-1.862026-08-29 → 2026-08-30
tmax12Znearestall2 1 QC2.97 [1.54, 4.40]1.43-2.97 [-4.40, -1.54]3.30 [1.54, 4.40]0% [0%, 0%]50%50%-0.98-1.862026-08-29 → 2026-08-30
tmin00Zbilinear30d2 1 QC1.59 [0.27, 2.91]1.59+1.32 [-0.27, 2.91]2.07 [0.27, 2.91]50% [0%, 100%]50%100%-0.59-0.592026-08-29 → 2026-08-30
tmin00Zbilinear90d2 1 QC1.59 [0.27, 2.91]1.59+1.32 [-0.27, 2.91]2.07 [0.27, 2.91]50% [0%, 100%]50%100%-0.59-0.592026-08-29 → 2026-08-30
tmin00Zbilinear365d2 1 QC1.59 [0.27, 2.91]1.59+1.32 [-0.27, 2.91]2.07 [0.27, 2.91]50% [0%, 100%]50%100%-0.59-0.592026-08-29 → 2026-08-30
tmin00Zbilinearall2 1 QC1.59 [0.27, 2.91]1.59+1.32 [-0.27, 2.91]2.07 [0.27, 2.91]50% [0%, 100%]50%100%-0.59-0.592026-08-29 → 2026-08-30
tmin00Znearest30d2 1 QC1.71 [0.18, 3.25]1.54+1.71 [0.18, 3.25]2.30 [0.18, 3.25]50% [0%, 100%]50%50%-0.71-0.542026-08-29 → 2026-08-30
tmin00Znearest90d2 1 QC1.71 [0.18, 3.25]1.54+1.71 [0.18, 3.25]2.30 [0.18, 3.25]50% [0%, 100%]50%50%-0.71-0.542026-08-29 → 2026-08-30
tmin00Znearest365d2 1 QC1.71 [0.18, 3.25]1.54+1.71 [0.18, 3.25]2.30 [0.18, 3.25]50% [0%, 100%]50%50%-0.71-0.542026-08-29 → 2026-08-30
tmin00Znearestall2 1 QC1.71 [0.18, 3.25]1.54+1.71 [0.18, 3.25]2.30 [0.18, 3.25]50% [0%, 100%]50%50%-0.71-0.542026-08-29 → 2026-08-30
tmin12Zbilinear30d2 1 QC1.94 [0.67, 3.20]1.94+1.27 [-0.67, 3.20]2.31 [0.67, 3.20]50% [0%, 100%]50%50%-0.94-0.942026-08-29 → 2026-08-30
tmin12Zbilinear90d2 1 QC1.94 [0.67, 3.20]1.94+1.27 [-0.67, 3.20]2.31 [0.67, 3.20]50% [0%, 100%]50%50%-0.94-0.942026-08-29 → 2026-08-30
tmin12Zbilinear365d2 1 QC1.94 [0.67, 3.20]1.94+1.27 [-0.67, 3.20]2.31 [0.67, 3.20]50% [0%, 100%]50%50%-0.94-0.942026-08-29 → 2026-08-30
tmin12Zbilinearall2 1 QC1.94 [0.67, 3.20]1.94+1.27 [-0.67, 3.20]2.31 [0.67, 3.20]50% [0%, 100%]50%50%-0.94-0.942026-08-29 → 2026-08-30
tmin12Znearest30d2 1 QC1.94 [0.37, 3.52]1.94+1.58 [-0.37, 3.52]2.50 [0.37, 3.52]50% [0%, 100%]50%50%-0.94-0.942026-08-29 → 2026-08-30
tmin12Znearest90d2 1 QC1.94 [0.37, 3.52]1.94+1.58 [-0.37, 3.52]2.50 [0.37, 3.52]50% [0%, 100%]50%50%-0.94-0.942026-08-29 → 2026-08-30
tmin12Znearest365d2 1 QC1.94 [0.37, 3.52]1.94+1.58 [-0.37, 3.52]2.50 [0.37, 3.52]50% [0%, 100%]50%50%-0.94-0.942026-08-29 → 2026-08-30
tmin12Znearestall2 1 QC1.94 [0.37, 3.52]1.94+1.58 [-0.37, 3.52]2.50 [0.37, 3.52]50% [0%, 100%]50%50%-0.94-0.942026-08-29 → 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 Pangu-Weather (IFS init) at KSEA, lead day 1, 00Z bilinear tmax+5+2.50-2.5-52026-08-29: -4.45 °F2026-08-30: -1.67 °F2026-08-292026-08-30°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 (2 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.67
2026-08-29-4.45

Error distribution

Distribution of the signed daily error in °F for Pangu-Weather (IFS init) at KSEA, lead day 1-5 to -4.5 °F: 0 days-4.5 to -4 °F: 1 day-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: 1 day-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| 3.06 · P90 |e| 4.18 °F-50+5 °Fn = 2 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
-5.00-4.500
-4.50-4.001
-4.00-3.500
-3.50-3.000
-3.00-2.500
-2.50-2.000
-2.00-1.501
-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
2026-0823.06 -3.06

Availability

ModelScored period DaysCoverage
Pangu-Weather (IFS init)2026-08-29 → 2026-08-30 2
Pangu-Weather (IFS init)2026-08-29 → 2026-08-30 2
Pangu-Weather (IFS init)2026-08-29 → 2026-08-30 2
Pangu-Weather (IFS 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 Pangu-Weather (IFS init) has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 2 -1.26 [-1.99, -0.54] yes
Aurora (GFS init) 1 -2.83 [-2.83, -2.83] yes
Aurora (IFS init) 2 -0.85 [-1.91, 0.22] no
FourCastNet v2 (GFS init) 1 -0.07 [-0.07, -0.07] yes
FourCastNet v2 (IFS init) 2 +1.36 [1.17, 1.55] yes
NCEP GFS 2 +1.40 [1.18, 1.63] yes
GraphCast (GFS init) 1 -2.75 [-2.75, -2.75] yes
GraphCast (IFS init) 2 -1.85 [-2.63, -1.08] yes
ECMWF IFS HRES 2 +1.72 [-0.40, 3.85] no
Pangu-Weather (GFS init) 1 -0.74 [-0.74, -0.74] yes
Persistence (baseline) 2 +1.56 [0.67, 2.45] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSEA (Seattle-Tacoma), model pangu_ifs, 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/pangu_ifs/lead/1/

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