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

Seattle-Tacoma · Pangu-Weather (IFS init) · lead day 2

KSEA · pangu_ifs · lead 2

Target day = initialization date + 2 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, 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
tmax00Zbilinear30d1 1 QC2.28 [2.28, 2.28]0.00-2.28 [-2.28, -2.28]2.28 [2.28, 2.28]0% [0%, 0%]0%100%+0.24—2026-08-30 → 2026-08-30
tmax00Zbilinear90d1 1 QC2.28 [2.28, 2.28]0.00-2.28 [-2.28, -2.28]2.28 [2.28, 2.28]0% [0%, 0%]0%100%+0.24—2026-08-30 → 2026-08-30
tmax00Zbilinear365d1 1 QC2.28 [2.28, 2.28]0.00-2.28 [-2.28, -2.28]2.28 [2.28, 2.28]0% [0%, 0%]0%100%+0.24—2026-08-30 → 2026-08-30
tmax00Zbilinearall1 1 QC2.28 [2.28, 2.28]0.00-2.28 [-2.28, -2.28]2.28 [2.28, 2.28]0% [0%, 0%]0%100%+0.24—2026-08-30 → 2026-08-30
tmax00Znearest30d1 1 QC2.32 [2.32, 2.32]0.00-2.32 [-2.32, -2.32]2.32 [2.32, 2.32]0% [0%, 0%]0%100%+0.23—2026-08-30 → 2026-08-30
tmax00Znearest90d1 1 QC2.32 [2.32, 2.32]0.00-2.32 [-2.32, -2.32]2.32 [2.32, 2.32]0% [0%, 0%]0%100%+0.23—2026-08-30 → 2026-08-30
tmax00Znearest365d1 1 QC2.32 [2.32, 2.32]0.00-2.32 [-2.32, -2.32]2.32 [2.32, 2.32]0% [0%, 0%]0%100%+0.23—2026-08-30 → 2026-08-30
tmax00Znearestall1 1 QC2.32 [2.32, 2.32]0.00-2.32 [-2.32, -2.32]2.32 [2.32, 2.32]0% [0%, 0%]0%100%+0.23—2026-08-30 → 2026-08-30
tmax12Zbilinear30d1 1 QC1.27 [1.27, 1.27]0.00-1.27 [-1.27, -1.27]1.27 [1.27, 1.27]0% [0%, 0%]100%100%+0.58—2026-08-30 → 2026-08-30
tmax12Zbilinear90d1 1 QC1.27 [1.27, 1.27]0.00-1.27 [-1.27, -1.27]1.27 [1.27, 1.27]0% [0%, 0%]100%100%+0.58—2026-08-30 → 2026-08-30
tmax12Zbilinear365d1 1 QC1.27 [1.27, 1.27]0.00-1.27 [-1.27, -1.27]1.27 [1.27, 1.27]0% [0%, 0%]100%100%+0.58—2026-08-30 → 2026-08-30
tmax12Zbilinearall1 1 QC1.27 [1.27, 1.27]0.00-1.27 [-1.27, -1.27]1.27 [1.27, 1.27]0% [0%, 0%]100%100%+0.58—2026-08-30 → 2026-08-30
tmax12Znearest30d1 1 QC1.31 [1.31, 1.31]0.00-1.31 [-1.31, -1.31]1.31 [1.31, 1.31]0% [0%, 0%]100%100%+0.56—2026-08-30 → 2026-08-30
tmax12Znearest90d1 1 QC1.31 [1.31, 1.31]0.00-1.31 [-1.31, -1.31]1.31 [1.31, 1.31]0% [0%, 0%]100%100%+0.56—2026-08-30 → 2026-08-30
tmax12Znearest365d1 1 QC1.31 [1.31, 1.31]0.00-1.31 [-1.31, -1.31]1.31 [1.31, 1.31]0% [0%, 0%]100%100%+0.56—2026-08-30 → 2026-08-30
tmax12Znearestall1 1 QC1.31 [1.31, 1.31]0.00-1.31 [-1.31, -1.31]1.31 [1.31, 1.31]0% [0%, 0%]100%100%+0.56—2026-08-30 → 2026-08-30
tmin00Zbilinear30d1 1 QC0.35 [0.35, 0.35]0.00+0.35 [0.35, 0.35]0.35 [0.35, 0.35]100% [100%, 100%]100%100%+0.82—2026-08-30 → 2026-08-30
tmin00Zbilinear90d1 1 QC0.35 [0.35, 0.35]0.00+0.35 [0.35, 0.35]0.35 [0.35, 0.35]100% [100%, 100%]100%100%+0.82—2026-08-30 → 2026-08-30
tmin00Zbilinear365d1 1 QC0.35 [0.35, 0.35]0.00+0.35 [0.35, 0.35]0.35 [0.35, 0.35]100% [100%, 100%]100%100%+0.82—2026-08-30 → 2026-08-30
tmin00Zbilinearall1 1 QC0.35 [0.35, 0.35]0.00+0.35 [0.35, 0.35]0.35 [0.35, 0.35]100% [100%, 100%]100%100%+0.82—2026-08-30 → 2026-08-30
tmin00Znearest30d1 1 QC0.73 [0.73, 0.73]0.00+0.73 [0.73, 0.73]0.73 [0.73, 0.73]100% [100%, 100%]100%100%+0.63—2026-08-30 → 2026-08-30
tmin00Znearest90d1 1 QC0.73 [0.73, 0.73]0.00+0.73 [0.73, 0.73]0.73 [0.73, 0.73]100% [100%, 100%]100%100%+0.63—2026-08-30 → 2026-08-30
tmin00Znearest365d1 1 QC0.73 [0.73, 0.73]0.00+0.73 [0.73, 0.73]0.73 [0.73, 0.73]100% [100%, 100%]100%100%+0.63—2026-08-30 → 2026-08-30
tmin00Znearestall1 1 QC0.73 [0.73, 0.73]0.00+0.73 [0.73, 0.73]0.73 [0.73, 0.73]100% [100%, 100%]100%100%+0.63—2026-08-30 → 2026-08-30
tmin12Zbilinear30d1 1 QC1.22 [1.22, 1.22]0.00+1.22 [1.22, 1.22]1.22 [1.22, 1.22]0% [0%, 0%]100%100%+0.39—2026-08-30 → 2026-08-30
tmin12Zbilinear90d1 1 QC1.22 [1.22, 1.22]0.00+1.22 [1.22, 1.22]1.22 [1.22, 1.22]0% [0%, 0%]100%100%+0.39—2026-08-30 → 2026-08-30
tmin12Zbilinear365d1 1 QC1.22 [1.22, 1.22]0.00+1.22 [1.22, 1.22]1.22 [1.22, 1.22]0% [0%, 0%]100%100%+0.39—2026-08-30 → 2026-08-30
tmin12Zbilinearall1 1 QC1.22 [1.22, 1.22]0.00+1.22 [1.22, 1.22]1.22 [1.22, 1.22]0% [0%, 0%]100%100%+0.39—2026-08-30 → 2026-08-30
tmin12Znearest30d1 1 QC1.77 [1.77, 1.77]0.00+1.77 [1.77, 1.77]1.77 [1.77, 1.77]0% [0%, 0%]100%100%+0.12—2026-08-30 → 2026-08-30
tmin12Znearest90d1 1 QC1.77 [1.77, 1.77]0.00+1.77 [1.77, 1.77]1.77 [1.77, 1.77]0% [0%, 0%]100%100%+0.12—2026-08-30 → 2026-08-30
tmin12Znearest365d1 1 QC1.77 [1.77, 1.77]0.00+1.77 [1.77, 1.77]1.77 [1.77, 1.77]0% [0%, 0%]100%100%+0.12—2026-08-30 → 2026-08-30
tmin12Znearestall1 1 QC1.77 [1.77, 1.77]0.00+1.77 [1.77, 1.77]1.77 [1.77, 1.77]0% [0%, 0%]100%100%+0.12—2026-08-30 → 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 2, 00Z bilinear tmax+2.5+1.20-1.2-2.52026-08-30: -2.28 °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
2026-08-30-2.28

Error distribution

Distribution of the signed daily error in °F for Pangu-Weather (IFS init) at KSEA, lead day 2-2.5 to -2.25 °F: 1 day-2.25 to -2 °F: 0 days-2 to -1.75 °F: 0 days-1.75 to -1.5 °F: 0 days-1.5 to -1.25 °F: 0 days-1.25 to -1 °F: 0 days-1 to -0.75 °F: 0 days-0.75 to -0.5 °F: 0 days-0.5 to -0.25 °F: 0 days-0.25 to 0 °F: 0 days0 to 0.25 °F: 0 days0.25 to 0.5 °F: 0 days0.5 to 0.75 °F: 0 days0.75 to 1 °F: 0 days1 to 1.25 °F: 0 days1.25 to 1.5 °F: 0 days1.5 to 1.75 °F: 0 days1.75 to 2 °F: 0 days2 to 2.25 °F: 0 days2.25 to 2.5 °F: 0 daysdashed: P50 |e| 2.28 · P90 |e| 2.28 °F-2.50+2.5 °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
-2.50-2.251
-2.25-2.000
-2.00-1.750
-1.75-1.500
-1.50-1.250
-1.25-1.000
-1.00-0.750
-0.75-0.500
-0.50-0.250
-0.25+0.000
+0.00+0.250
+0.25+0.500
+0.50+0.750
+0.75+1.000
+1.00+1.250
+1.25+1.500
+1.50+1.750
+1.75+2.000
+2.00+2.250
+2.25+2.500

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-0812.28 -2.28

Availability

ModelScored period DaysCoverage
Pangu-Weather (IFS init)2026-08-30 → 2026-08-30 1
Pangu-Weather (IFS init)2026-08-30 → 2026-08-30 1
Pangu-Weather (IFS init)2026-08-30 → 2026-08-30 1
Pangu-Weather (IFS init)2026-08-30 → 2026-08-30 1

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 1 +0.27 [0.27, 0.27] yes
Aurora (IFS init) 1 -0.10 [-0.10, -0.10] yes
FourCastNet v2 (IFS init) 1 +0.75 [0.75, 0.75] yes
NCEP GFS 1 +1.26 [1.26, 1.26] yes
GraphCast (IFS init) 1 -0.80 [-0.80, -0.80] yes
ECMWF IFS HRES 1 +0.87 [0.87, 0.87] yes
Persistence (baseline) 1 -0.72 [-0.72, -0.72] yes

Cite this page

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

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

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