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 2

KAUS · graphcast_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, 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
tmax00Zbilinear30d26 1 QC7.38 [6.87, 7.83]1.03-7.38 [-7.83, -6.87]7.49 [6.97, 7.91]0% [0%, 0%]0%0%-3.26+0.402026-08-03 → 2026-08-30
tmax00Zbilinear90d26 1 QC7.38 [6.80, 7.87]1.03-7.38 [-7.87, -6.80]7.49 [6.88, 7.95]0% [0%, 0%]0%0%-3.26+0.402026-08-03 → 2026-08-30
tmax00Zbilinear365d32 1 QC7.62 [7.01, 8.36]1.19-7.62 [-8.36, -7.01]7.77 [7.13, 8.54]0% [0%, 0%]0%0%-1.90+0.542026-01-03 → 2026-08-30
tmax00Zbilinearall32 1 QC7.62 [7.00, 8.27]1.19-7.62 [-8.27, -7.00]7.77 [7.11, 8.45]0% [0%, 0%]0%0%-1.90+0.542026-01-03 → 2026-08-30
tmax00Znearest30d26 1 QC7.28 [6.82, 7.70]1.03-7.28 [-7.70, -6.82]7.39 [6.92, 7.80]0% [0%, 0%]0%0%-3.21+0.412026-08-03 → 2026-08-30
tmax00Znearest90d26 1 QC7.28 [6.76, 7.75]1.03-7.28 [-7.75, -6.76]7.39 [6.85, 7.83]0% [0%, 0%]0%0%-3.21+0.412026-08-03 → 2026-08-30
tmax00Znearest365d32 1 QC7.56 [6.94, 8.34]1.20-7.56 [-8.34, -6.94]7.71 [7.06, 8.54]0% [0%, 0%]0%0%-1.88+0.542026-01-03 → 2026-08-30
tmax00Znearestall32 1 QC7.56 [6.94, 8.25]1.20-7.56 [-8.25, -6.94]7.71 [7.06, 8.44]0% [0%, 0%]0%0%-1.88+0.542026-01-03 → 2026-08-30
tmax12Zbilinear30d26 1 QC8.36 [7.90, 8.94]1.12-8.36 [-8.94, -7.90]8.47 [7.99, 9.06]0% [0%, 0%]0%0%-3.83+0.352026-08-03 → 2026-08-30
tmax12Zbilinear90d26 1 QC8.36 [7.87, 9.02]1.12-8.36 [-9.02, -7.87]8.47 [7.95, 9.13]0% [0%, 0%]0%0%-3.83+0.352026-08-03 → 2026-08-30
tmax12Zbilinear365d31 1 QC8.54 [8.00, 9.32]1.26-8.54 [-9.32, -8.00]8.67 [8.09, 9.45]0% [0%, 0%]0%0%-2.31+0.512026-01-03 → 2026-08-30
tmax12Zbilinearall31 1 QC8.54 [7.96, 9.30]1.26-8.54 [-9.30, -7.96]8.67 [8.06, 9.45]0% [0%, 0%]0%0%-2.31+0.512026-01-03 → 2026-08-30
tmax12Znearest30d26 1 QC8.26 [7.81, 8.87]1.12-8.26 [-8.87, -7.81]8.38 [7.90, 9.01]0% [0%, 0%]0%0%-3.77+0.352026-08-03 → 2026-08-30
tmax12Znearest90d26 1 QC8.26 [7.78, 8.91]1.12-8.26 [-8.91, -7.78]8.38 [7.89, 9.05]0% [0%, 0%]0%0%-3.77+0.352026-08-03 → 2026-08-30
tmax12Znearest365d31 1 QC8.46 [7.91, 9.30]1.29-8.46 [-9.30, -7.91]8.61 [8.02, 9.46]0% [0%, 0%]0%0%-2.28+0.492026-01-03 → 2026-08-30
tmax12Znearestall31 1 QC8.46 [7.88, 9.29]1.29-8.46 [-9.29, -7.88]8.61 [7.98, 9.45]0% [0%, 0%]0%0%-2.28+0.492026-01-03 → 2026-08-30
tmin00Zbilinear30d26 1 QC4.37 [3.36, 5.15]1.86+4.30 [3.30, 5.11]4.88 [4.01, 5.52]12% [0%, 23%]12%23%-0.35+0.432026-08-03 → 2026-08-30
tmin00Zbilinear90d26 1 QC4.37 [3.36, 5.29]1.86+4.30 [3.27, 5.21]4.88 [3.99, 5.62]12% [0%, 25%]12%23%-0.35+0.432026-08-03 → 2026-08-30
tmin00Zbilinear365d32 1 QC5.47 [3.77, 7.99]2.76+5.41 [3.71, 7.96]6.49 [4.42, 9.07]9% [0%, 20%]9%22%-0.16+0.422026-01-03 → 2026-08-30
tmin00Zbilinearall32 1 QC5.47 [3.84, 7.87]2.76+5.41 [3.74, 7.85]6.49 [4.48, 8.97]9% [0%, 21%]9%22%-0.16+0.422026-01-03 → 2026-08-30
tmin00Znearest30d26 1 QC4.37 [3.32, 5.18]1.84+4.29 [3.25, 5.15]4.88 [3.99, 5.55]8% [0%, 20%]12%23%-0.35+0.432026-08-03 → 2026-08-30
tmin00Znearest90d26 1 QC4.37 [3.31, 5.31]1.84+4.29 [3.22, 5.22]4.88 [3.95, 5.67]8% [0%, 20%]12%23%-0.35+0.432026-08-03 → 2026-08-30
tmin00Znearest365d32 1 QC5.42 [3.75, 7.86]2.73+5.36 [3.66, 7.82]6.41 [4.39, 8.92]6% [0%, 18%]9%22%-0.15+0.432026-01-03 → 2026-08-30
tmin00Znearestall32 1 QC5.42 [3.80, 7.77]2.73+5.36 [3.70, 7.74]6.41 [4.45, 8.80]6% [0%, 18%]9%22%-0.15+0.432026-01-03 → 2026-08-30
tmin12Zbilinear30d26 1 QC3.71 [2.85, 4.32]1.61+3.59 [2.74, 4.23]4.12 [3.41, 4.61]8% [0%, 20%]19%38%-0.15+0.502026-08-03 → 2026-08-30
tmin12Zbilinear90d26 1 QC3.71 [2.85, 4.35]1.61+3.59 [2.68, 4.28]4.12 [3.36, 4.63]8% [0%, 20%]19%38%-0.15+0.502026-08-03 → 2026-08-30
tmin12Zbilinear365d31 1 QC4.77 [3.22, 7.39]2.58+4.67 [3.08, 7.36]5.85 [3.73, 8.69]6% [0%, 19%]19%35%-0.06+0.432026-01-03 → 2026-08-30
tmin12Zbilinearall31 1 QC4.77 [3.25, 7.25]2.58+4.67 [3.12, 7.13]5.85 [3.73, 8.57]6% [0%, 18%]19%35%-0.06+0.432026-01-03 → 2026-08-30
tmin12Znearest30d26 1 QC3.69 [2.79, 4.33]1.61+3.56 [2.66, 4.25]4.10 [3.36, 4.62]8% [0%, 20%]19%42%-0.14+0.502026-08-03 → 2026-08-30
tmin12Znearest90d26 1 QC3.69 [2.80, 4.38]1.61+3.56 [2.61, 4.29]4.10 [3.33, 4.64]8% [0%, 20%]19%42%-0.14+0.502026-08-03 → 2026-08-30
tmin12Znearest365d31 1 QC4.71 [3.15, 7.27]2.55+4.60 [3.02, 7.20]5.76 [3.69, 8.52]6% [0%, 19%]19%39%-0.05+0.442026-01-03 → 2026-08-30
tmin12Znearestall31 1 QC4.71 [3.20, 7.13]2.55+4.60 [3.07, 7.03]5.76 [3.70, 8.38]6% [0%, 18%]19%39%-0.05+0.442026-01-03 → 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 2, 00Z bilinear tmax+20+100-10-202026-08-03: -7.73 °F2026-08-04: -8.27 °F2026-08-05: -5.09 °F2026-08-06: -5.93 °F2026-08-07: -6.33 °F2026-08-08: -6.11 °F2026-08-09: -7.84 °F2026-08-10: -7.04 °F2026-08-11: -7.49 °F2026-08-12: -7.83 °F2026-08-13: -7.97 °F2026-08-14: -5.58 °F2026-08-15: -10.01 °F2026-08-16: -6.72 °F2026-08-17: -8.45 °F2026-08-18: -7.89 °F2026-08-19: -6.75 °F2026-08-20: -7.59 °F2026-08-21: -8.41 °F2026-08-22: -10.06 °F2026-08-23: -7.69 °F2026-08-24: -7.01 °F2026-08-25: -6.4 °F2026-08-26: -4.81 °F2026-08-27: -8.4 °F2026-08-30: -8.46 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-8.46
2026-08-29—
2026-08-28—
2026-08-27-8.40
2026-08-26-4.81
2026-08-25-6.40
2026-08-24-7.01
2026-08-23-7.69
2026-08-22-10.06
2026-08-21-8.41
2026-08-20-7.59
2026-08-19-6.75
2026-08-18-7.89
2026-08-17-8.45
2026-08-16-6.72
2026-08-15-10.01
2026-08-14-5.58
2026-08-13-7.97
2026-08-12-7.83
2026-08-11-7.49
2026-08-10-7.04
2026-08-09-7.84
2026-08-08-6.11
2026-08-07-6.33
2026-08-06-5.93
2026-08-05-5.09
2026-08-04-8.27
2026-08-03-7.73

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KAUS, lead day 2-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 4 days-10 to -8 °F: 7 days-8 to -6 °F: 16 days-6 to -4 °F: 5 days-4 to -2 °F: 0 days-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| 7.71 · P90 |e| 9.98 °F-200+20 °Fn = 32 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
-14.00-12.000
-12.00-10.004
-10.00-8.007
-8.00-6.0016
-6.00-4.005
-4.00-2.000
-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
2026-08267.38 -7.38
2026-0168.68 -8.68

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-03 → 2026-08-30 32
GraphCast (IFS init)2026-01-03 → 2026-08-30 32
GraphCast (IFS init)2026-01-03 → 2026-08-30 31
GraphCast (IFS init)2026-01-03 → 2026-08-30 31

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 26 +2.15 [1.17, 3.01] yes
Aurora (IFS init) 1 +1.84 [1.84, 1.84] yes
FourCastNet v2 (IFS init) 1 +4.33 [4.33, 4.33] yes
NCEP GFS 26 +5.90 [4.94, 6.71] yes
ECMWF IFS HRES 20 +3.25 [2.44, 4.16] yes
Pangu-Weather (IFS init) 1 +2.12 [2.12, 2.12] yes
Persistence (baseline) 26 +5.65 [5.00, 6.14] yes

Cite this page

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

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