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

Austin Bergstrom · GraphCast (IFS init) · lead day 7

KAUS · graphcast_ifs · lead 7

Target day = initialization date + 7 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, GRAP_v100, starting 2026-01-01 — 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
tmax00Zbilinear30d23 1 QC7.34 [5.64, 8.87]2.14-7.34 [-8.87, -5.64]7.75 [5.97, 9.14]0% [0%, 0%]0%0%-2.13+0.032026-08-08 → 2026-08-30
tmax00Zbilinear90d23 1 QC7.34 [5.35, 8.98]2.14-7.34 [-8.98, -5.35]7.75 [5.74, 9.21]0% [0%, 0%]0%0%-2.13+0.032026-08-08 → 2026-08-30
tmax00Zbilinear365d29 1 QC7.05 [5.45, 8.61]2.29-7.05 [-8.61, -5.45]7.56 [5.97, 8.93]3% [0%, 12%]3%3%-0.49+0.572026-01-08 → 2026-08-30
tmax00Zbilinearall29 1 QC7.05 [5.54, 8.63]2.29-7.05 [-8.63, -5.54]7.56 [6.03, 8.93]3% [0%, 13%]3%3%-0.49+0.572026-01-08 → 2026-08-30
tmax00Znearest30d23 1 QC7.32 [5.64, 8.81]2.10-7.32 [-8.81, -5.64]7.72 [5.98, 9.06]0% [0%, 0%]0%0%-2.12+0.042026-08-08 → 2026-08-30
tmax00Znearest90d23 1 QC7.32 [5.37, 8.91]2.10-7.32 [-8.91, -5.37]7.72 [5.74, 9.13]0% [0%, 0%]0%0%-2.12+0.042026-08-08 → 2026-08-30
tmax00Znearest365d29 1 QC7.05 [5.48, 8.56]2.25-7.05 [-8.56, -5.48]7.53 [6.00, 8.86]3% [0%, 12%]3%3%-0.49+0.582026-01-08 → 2026-08-30
tmax00Znearestall29 1 QC7.05 [5.58, 8.59]2.25-7.05 [-8.59, -5.58]7.53 [6.08, 8.88]3% [0%, 13%]3%3%-0.49+0.582026-01-08 → 2026-08-30
tmax12Zbilinear30d23 1 QC7.55 [5.88, 9.03]1.88-7.55 [-9.03, -5.88]7.89 [6.12, 9.20]0% [0%, 0%]0%0%-2.22+0.142026-08-08 → 2026-08-30
tmax12Zbilinear90d23 1 QC7.55 [5.52, 9.14]1.88-7.55 [-9.14, -5.52]7.89 [5.71, 9.30]0% [0%, 0%]0%0%-2.22+0.142026-08-08 → 2026-08-30
tmax12Zbilinear365d28 1 QC7.15 [5.33, 8.83]2.56-7.15 [-8.83, -5.33]7.89 [6.17, 9.23]7% [0%, 25%]7%11%-0.76+0.432026-01-08 → 2026-08-30
tmax12Zbilinearall28 1 QC7.15 [5.34, 8.83]2.56-7.15 [-8.83, -5.34]7.89 [6.27, 9.30]7% [0%, 29%]7%11%-0.76+0.432026-01-08 → 2026-08-30
tmax12Znearest30d23 1 QC7.58 [5.91, 9.03]1.87-7.58 [-9.03, -5.91]7.91 [6.15, 9.20]0% [0%, 0%]0%0%-2.23+0.152026-08-08 → 2026-08-30
tmax12Znearest90d23 1 QC7.58 [5.57, 9.14]1.87-7.58 [-9.14, -5.57]7.91 [5.75, 9.30]0% [0%, 0%]0%0%-2.23+0.152026-08-08 → 2026-08-30
tmax12Znearest365d28 1 QC7.19 [5.37, 8.86]2.58-7.19 [-8.86, -5.37]7.93 [6.20, 9.24]7% [0%, 25%]7%11%-0.77+0.422026-01-08 → 2026-08-30
tmax12Znearestall28 1 QC7.19 [5.41, 8.86]2.58-7.19 [-8.86, -5.41]7.93 [6.33, 9.33]7% [0%, 29%]7%11%-0.77+0.422026-01-08 → 2026-08-30
tmin00Zbilinear30d23 1 QC4.93 [4.05, 5.76]1.46+4.93 [4.05, 5.76]5.28 [4.57, 5.95]0% [0%, 0%]9%17%-0.47+0.562026-08-08 → 2026-08-30
tmin00Zbilinear90d23 1 QC4.93 [3.98, 5.90]1.46+4.93 [3.98, 5.90]5.28 [4.51, 6.02]0% [0%, 0%]9%17%-0.47+0.562026-08-08 → 2026-08-30
tmin00Zbilinear365d29 1 QC4.59 [3.45, 5.62]2.30+4.19 [2.36, 5.61]5.13 [4.30, 5.84]7% [0%, 23%]17%24%+0.01+0.502026-01-08 → 2026-08-30
tmin00Zbilinearall29 1 QC4.59 [3.53, 5.54]2.30+4.19 [2.25, 5.53]5.13 [4.33, 5.79]7% [0%, 25%]17%24%+0.01+0.502026-01-08 → 2026-08-30
tmin00Znearest30d23 1 QC4.84 [3.93, 5.67]1.46+4.84 [3.93, 5.67]5.20 [4.49, 5.86]4% [0%, 12%]13%17%-0.44+0.562026-08-08 → 2026-08-30
tmin00Znearest90d23 1 QC4.84 [3.86, 5.81]1.46+4.84 [3.86, 5.81]5.20 [4.41, 5.94]4% [0%, 12%]13%17%-0.44+0.562026-08-08 → 2026-08-30
tmin00Znearest365d29 1 QC4.50 [3.42, 5.51]2.30+4.06 [2.18, 5.50]5.02 [4.19, 5.72]10% [0%, 25%]21%24%+0.03+0.502026-01-08 → 2026-08-30
tmin00Znearestall29 1 QC4.50 [3.47, 5.45]2.30+4.06 [2.05, 5.44]5.02 [4.22, 5.68]10% [0%, 27%]21%24%+0.03+0.502026-01-08 → 2026-08-30
tmin12Zbilinear30d23 1 QC4.62 [3.74, 5.55]1.49+4.62 [3.74, 5.55]5.00 [4.30, 5.74]4% [0%, 12%]9%26%-0.38+0.552026-08-08 → 2026-08-30
tmin12Zbilinear90d23 1 QC4.62 [3.71, 5.78]1.49+4.62 [3.71, 5.78]5.00 [4.29, 5.89]4% [0%, 12%]9%26%-0.38+0.552026-08-08 → 2026-08-30
tmin12Zbilinear365d28 1 QC4.64 [3.80, 5.56]1.74+4.64 [3.80, 5.56]5.22 [4.38, 6.17]7% [0%, 18%]11%29%+0.02+0.632026-01-08 → 2026-08-30
tmin12Zbilinearall28 1 QC4.64 [3.78, 5.48]1.74+4.64 [3.78, 5.48]5.22 [4.35, 6.18]7% [0%, 17%]11%29%+0.02+0.632026-01-08 → 2026-08-30
tmin12Znearest30d23 1 QC4.50 [3.59, 5.44]1.50+4.50 [3.59, 5.44]4.90 [4.18, 5.63]4% [0%, 12%]13%26%-0.34+0.552026-08-08 → 2026-08-30
tmin12Znearest90d23 1 QC4.50 [3.57, 5.66]1.50+4.50 [3.57, 5.66]4.90 [4.17, 5.78]4% [0%, 12%]13%26%-0.34+0.552026-08-08 → 2026-08-30
tmin12Znearest365d28 1 QC4.49 [3.64, 5.39]1.73+4.49 [3.64, 5.39]5.08 [4.27, 5.97]7% [0%, 18%]18%29%+0.05+0.632026-01-08 → 2026-08-30
tmin12Znearestall28 1 QC4.49 [3.63, 5.33]1.73+4.49 [3.63, 5.33]5.08 [4.25, 5.97]7% [0%, 17%]18%29%+0.05+0.632026-01-08 → 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 GraphCast (IFS init) at KAUS, lead day 7, 00Z bilinear tmax+20+100-10-202026-08-08: -3.55 °F2026-08-09: -9.09 °F2026-08-10: -3.65 °F2026-08-11: -4.96 °F2026-08-12: -4.31 °F2026-08-13: -5.12 °F2026-08-14: -3.51 °F2026-08-15: -8.81 °F2026-08-16: -8.02 °F2026-08-17: -10.11 °F2026-08-18: -9.37 °F2026-08-19: -8.08 °F2026-08-20: -7.74 °F2026-08-21: -8.51 °F2026-08-22: -12.11 °F2026-08-23: -11.09 °F2026-08-24: -10.81 °F2026-08-25: -8.92 °F2026-08-26: -6.25 °F2026-08-27: -7.07 °F2026-08-28: -5.49 °F2026-08-29: -6.52 °F2026-08-30: -5.79 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-5.79
2026-08-29-6.52
2026-08-28-5.49
2026-08-27-7.07
2026-08-26-6.25
2026-08-25-8.92
2026-08-24-10.81
2026-08-23-11.09
2026-08-22-12.11
2026-08-21-8.51
2026-08-20-7.74
2026-08-19-8.08
2026-08-18-9.37
2026-08-17-10.11
2026-08-16-8.02
2026-08-15-8.81
2026-08-14-3.51
2026-08-13-5.12
2026-08-12-4.31
2026-08-11-4.96
2026-08-10-3.65
2026-08-09-9.09
2026-08-08-3.55

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KAUS, lead day 7-20 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: 3 days-10 to -8 °F: 10 days-8 to -6 °F: 4 days-6 to -4 °F: 7 days-4 to -2 °F: 3 days-2 to 0 °F: 1 day0 to 2 °F: 0 days2 to 4 °F: 0 days4 to 6 °F: 0 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| 7.74 · P90 |e| 10.25 °F-200+20 °Fn = 29 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
-12.00-10.003
-10.00-8.0010
-8.00-6.004
-6.00-4.007
-4.00-2.003
-2.00+0.001
+0.00+2.000
+2.00+4.000
+4.00+6.000
+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
2026-08237.34 -7.34
2026-0165.94 -5.94

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-08 → 2026-08-30 29
GraphCast (IFS init)2026-01-08 → 2026-08-30 29
GraphCast (IFS init)2026-01-08 → 2026-08-30 28
GraphCast (IFS init)2026-01-08 → 2026-08-30 28

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 23 +2.52 [-0.07, 3.77] no
NCEP GFS 23 +4.57 [2.45, 5.97] yes
ECMWF IFS HRES 18 +3.89 [2.24, 4.81] yes
Persistence (baseline) 23 +5.00 [2.63, 6.72] yes

Cite this page

ShortCastCheck, KAUS graphcast_ifs lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KAUS/model/graphcast_ifs/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KAUS (Austin Bergstrom), model graphcast_ifs, lead day 7. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KAUS/model/graphcast_ifs/lead/7/

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