Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

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

Austin Bergstrom · GraphCast (IFS init) · lead day 5

KAUS · graphcast_ifs · 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, 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
tmax00Zbilinear30d25 1 QC7.30 [6.01, 8.56]1.75-7.30 [-8.56, -6.01]7.59 [6.12, 8.84]0% [0%, 0%]0%0%-2.51+0.182026-08-06 → 2026-08-30
tmax00Zbilinear90d25 1 QC7.30 [5.81, 8.67]1.75-7.30 [-8.67, -5.81]7.59 [5.85, 8.90]0% [0%, 0%]0%0%-2.51+0.182026-08-06 → 2026-08-30
tmax00Zbilinear365d31 1 QC7.52 [6.28, 8.84]2.12-7.52 [-8.84, -6.28]7.94 [6.54, 9.30]0% [0%, 0%]0%3%-1.06+0.442026-01-06 → 2026-08-30
tmax00Zbilinearall31 1 QC7.52 [6.36, 8.89]2.12-7.52 [-8.89, -6.36]7.94 [6.62, 9.25]0% [0%, 0%]0%3%-1.06+0.442026-01-06 → 2026-08-30
tmax00Znearest30d25 1 QC7.27 [5.95, 8.51]1.77-7.27 [-8.51, -5.95]7.56 [6.06, 8.79]0% [0%, 0%]0%0%-2.49+0.172026-08-06 → 2026-08-30
tmax00Znearest90d25 1 QC7.27 [5.71, 8.61]1.77-7.27 [-8.61, -5.71]7.56 [5.77, 8.85]0% [0%, 0%]0%0%-2.49+0.172026-08-06 → 2026-08-30
tmax00Znearest365d31 1 QC7.51 [6.27, 8.81]2.12-7.51 [-8.81, -6.27]7.92 [6.50, 9.25]0% [0%, 0%]0%3%-1.06+0.442026-01-06 → 2026-08-30
tmax00Znearestall31 1 QC7.51 [6.30, 8.83]2.12-7.51 [-8.83, -6.30]7.92 [6.60, 9.20]0% [0%, 0%]0%3%-1.06+0.442026-01-06 → 2026-08-30
tmax12Zbilinear30d25 1 QC7.70 [6.40, 8.92]1.66-7.70 [-8.92, -6.40]7.95 [6.56, 9.08]0% [0%, 0%]0%0%-2.70+0.222026-08-06 → 2026-08-30
tmax12Zbilinear90d25 1 QC7.70 [6.19, 8.98]1.66-7.70 [-8.98, -6.19]7.95 [6.28, 9.17]0% [0%, 0%]0%0%-2.70+0.222026-08-06 → 2026-08-30
tmax12Zbilinear365d30 1 QC7.58 [6.25, 8.87]1.87-7.58 [-8.87, -6.25]7.94 [6.55, 9.12]3% [0%, 12%]3%3%-1.47+0.392026-01-06 → 2026-08-30
tmax12Zbilinearall30 1 QC7.58 [6.26, 8.76]1.87-7.58 [-8.76, -6.26]7.94 [6.57, 9.07]3% [0%, 14%]3%3%-1.47+0.392026-01-06 → 2026-08-30
tmax12Znearest30d25 1 QC7.66 [6.34, 8.85]1.68-7.66 [-8.85, -6.34]7.92 [6.54, 9.02]0% [0%, 0%]0%0%-2.68+0.212026-08-06 → 2026-08-30
tmax12Znearest90d25 1 QC7.66 [6.10, 8.93]1.68-7.66 [-8.93, -6.10]7.92 [6.22, 9.11]0% [0%, 0%]0%0%-2.68+0.212026-08-06 → 2026-08-30
tmax12Znearest365d30 1 QC7.54 [6.20, 8.81]1.85-7.54 [-8.81, -6.20]7.88 [6.47, 9.06]3% [0%, 12%]3%3%-1.46+0.402026-01-06 → 2026-08-30
tmax12Znearestall30 1 QC7.54 [6.20, 8.70]1.85-7.54 [-8.70, -6.20]7.88 [6.48, 8.95]3% [0%, 14%]3%3%-1.46+0.402026-01-06 → 2026-08-30
tmin00Zbilinear30d25 1 QC4.74 [3.81, 5.70]1.70+4.74 [3.81, 5.70]5.17 [4.37, 5.94]4% [0%, 12%]4%20%-0.54+0.452026-08-06 → 2026-08-30
tmin00Zbilinear90d25 1 QC4.74 [3.76, 5.88]1.70+4.74 [3.76, 5.88]5.17 [4.28, 6.10]4% [0%, 12%]4%20%-0.54+0.452026-08-06 → 2026-08-30
tmin00Zbilinear365d31 1 QC5.16 [4.03, 6.70]2.08+5.16 [4.03, 6.70]5.82 [4.52, 7.51]6% [0%, 15%]6%19%-0.09+0.572026-01-06 → 2026-08-30
tmin00Zbilinearall31 1 QC5.16 [4.03, 6.72]2.08+5.16 [4.03, 6.72]5.82 [4.60, 7.52]6% [0%, 15%]6%19%-0.09+0.572026-01-06 → 2026-08-30
tmin00Znearest30d25 1 QC4.67 [3.71, 5.65]1.70+4.67 [3.71, 5.65]5.11 [4.29, 5.88]4% [0%, 12%]12%20%-0.52+0.452026-08-06 → 2026-08-30
tmin00Znearest90d25 1 QC4.67 [3.67, 5.81]1.70+4.67 [3.67, 5.81]5.11 [4.20, 6.04]4% [0%, 12%]12%20%-0.52+0.452026-08-06 → 2026-08-30
tmin00Znearest365d31 1 QC5.04 [3.94, 6.52]2.06+5.04 [3.94, 6.52]5.70 [4.46, 7.24]6% [0%, 15%]13%19%-0.06+0.572026-01-06 → 2026-08-30
tmin00Znearestall31 1 QC5.04 [3.94, 6.51]2.06+5.04 [3.94, 6.51]5.70 [4.53, 7.28]6% [0%, 15%]13%19%-0.06+0.572026-01-06 → 2026-08-30
tmin12Zbilinear30d25 1 QC4.43 [3.49, 5.28]1.57+4.41 [3.42, 5.28]4.83 [4.06, 5.52]4% [0%, 12%]12%24%-0.44+0.492026-08-06 → 2026-08-30
tmin12Zbilinear90d25 1 QC4.43 [3.46, 5.45]1.57+4.41 [3.40, 5.45]4.83 [4.01, 5.65]4% [0%, 12%]12%24%-0.44+0.492026-08-06 → 2026-08-30
tmin12Zbilinear365d30 1 QC4.93 [3.73, 6.57]2.19+4.87 [3.67, 6.48]5.67 [4.29, 7.57]7% [0%, 17%]13%23%-0.08+0.532026-01-06 → 2026-08-30
tmin12Zbilinearall30 1 QC4.93 [3.69, 6.76]2.19+4.87 [3.60, 6.61]5.67 [4.31, 7.74]7% [0%, 17%]13%23%-0.08+0.532026-01-06 → 2026-08-30
tmin12Znearest30d25 1 QC4.36 [3.39, 5.20]1.58+4.33 [3.31, 5.20]4.77 [3.98, 5.44]4% [0%, 12%]12%24%-0.41+0.492026-08-06 → 2026-08-30
tmin12Znearest90d25 1 QC4.36 [3.37, 5.36]1.58+4.33 [3.29, 5.36]4.77 [3.94, 5.58]4% [0%, 12%]12%24%-0.41+0.492026-08-06 → 2026-08-30
tmin12Znearest365d30 1 QC4.81 [3.64, 6.38]2.14+4.73 [3.57, 6.27]5.52 [4.21, 7.30]7% [0%, 17%]13%23%-0.05+0.542026-01-06 → 2026-08-30
tmin12Znearestall30 1 QC4.81 [3.56, 6.50]2.14+4.73 [3.47, 6.36]5.52 [4.22, 7.43]7% [0%, 17%]13%23%-0.05+0.542026-01-06 → 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 GraphCast (IFS init) at KAUS, lead day 5, 00Z bilinear tmax+20+100-10-202026-08-06: -6.04 °F2026-08-07: -5.97 °F2026-08-08: -4.61 °F2026-08-09: -6.22 °F2026-08-10: -5.33 °F2026-08-11: -5.84 °F2026-08-12: -5.71 °F2026-08-13: -5.45 °F2026-08-14: -4.47 °F2026-08-15: -9.97 °F2026-08-16: -8.48 °F2026-08-17: -9.08 °F2026-08-18: -6.7 °F2026-08-19: -7.39 °F2026-08-20: -9.21 °F2026-08-21: -9.48 °F2026-08-22: -12.6 °F2026-08-23: -10.24 °F2026-08-24: -9.78 °F2026-08-25: -6.75 °F2026-08-26: -4.56 °F2026-08-27: -8.6 °F2026-08-28: -6.59 °F2026-08-29: -6.05 °F2026-08-30: -7.4 °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
2026-08-30-7.40
2026-08-29-6.05
2026-08-28-6.59
2026-08-27-8.60
2026-08-26-4.56
2026-08-25-6.75
2026-08-24-9.78
2026-08-23-10.24
2026-08-22-12.60
2026-08-21-9.48
2026-08-20-9.21
2026-08-19-7.39
2026-08-18-6.70
2026-08-17-9.08
2026-08-16-8.48
2026-08-15-9.97
2026-08-14-4.47
2026-08-13-5.45
2026-08-12-5.71
2026-08-11-5.84
2026-08-10-5.33
2026-08-09-6.22
2026-08-08-4.61
2026-08-07-5.97
2026-08-06-6.04

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KAUS, 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: 3 days-12 to -10 °F: 2 days-10 to -8 °F: 7 days-8 to -6 °F: 9 days-6 to -4 °F: 9 days-4 to -2 °F: 1 day-2 to 0 °F: 0 days0 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| 6.75 · P90 |e| 10.93 °F-200+20 °Fn = 31 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
-14.00-12.003
-12.00-10.002
-10.00-8.007
-8.00-6.009
-6.00-4.009
-4.00-2.001
-2.00+0.000
+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
2026-08257.30 -7.30
2026-0168.46 -8.46

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-06 → 2026-08-30 31
GraphCast (IFS init)2026-01-06 → 2026-08-30 31
GraphCast (IFS init)2026-01-06 → 2026-08-30 30
GraphCast (IFS init)2026-01-06 → 2026-08-30 30

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 25 +2.64 [0.17, 4.07] yes
NCEP GFS 25 +5.20 [2.24, 7.38] yes
ECMWF IFS HRES 18 +3.68 [1.24, 5.06] yes
Persistence (baseline) 25 +5.22 [3.57, 6.73] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KAUS (Austin Bergstrom), model graphcast_ifs, 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/KAUS/model/graphcast_ifs/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