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

Minneapolis-St Paul · GraphCast (IFS init) · lead day 9

KMSP · graphcast_ifs · lead 9

Target day = initialization date + 9 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
tmax00Zbilinear30d21 1 QC6.44 [4.39, 9.25]4.63-5.66 [-9.16, -2.70]7.86 [5.51, 10.17]14% [3%, 25%]24%29%-1.33-0.682026-08-10 → 2026-08-30
tmax00Zbilinear90d21 1 QC6.44 [4.14, 9.57]4.63-5.66 [-9.57, -2.35]7.86 [5.06, 10.52]14% [0%, 25%]24%29%-1.33-0.682026-08-10 → 2026-08-30
tmax00Zbilinear365d27 1 QC6.90 [4.61, 9.48]4.51-6.29 [-9.46, -3.23]8.34 [5.96, 10.51]15% [3%, 25%]22%26%-0.50+0.012026-01-10 → 2026-08-30
tmax00Zbilinearall27 1 QC6.90 [4.76, 9.68]4.51-6.29 [-9.68, -3.24]8.34 [6.10, 10.57]15% [3%, 25%]22%26%-0.50+0.012026-01-10 → 2026-08-30
tmax00Znearest30d21 1 QC6.44 [4.40, 9.24]4.61-5.66 [-9.16, -2.67]7.85 [5.49, 10.14]14% [3%, 25%]24%29%-1.33-0.672026-08-10 → 2026-08-30
tmax00Znearest90d21 1 QC6.44 [4.17, 9.55]4.61-5.66 [-9.55, -2.34]7.85 [5.05, 10.50]14% [0%, 25%]24%29%-1.33-0.672026-08-10 → 2026-08-30
tmax00Znearest365d27 1 QC6.90 [4.62, 9.49]4.52-6.29 [-9.44, -3.22]8.35 [5.95, 10.58]15% [3%, 25%]22%26%-0.50+0.012026-01-10 → 2026-08-30
tmax00Znearestall27 1 QC6.90 [4.74, 9.71]4.52-6.29 [-9.71, -3.20]8.35 [6.06, 10.61]15% [3%, 25%]22%26%-0.50+0.012026-01-10 → 2026-08-30
tmax12Zbilinear30d21 1 QC7.00 [5.28, 9.53]4.06-5.94 [-9.52, -3.02]7.84 [6.02, 9.92]5% [0%, 14%]10%10%-1.53-0.472026-08-10 → 2026-08-30
tmax12Zbilinear90d21 1 QC7.00 [5.10, 10.17]4.06-5.94 [-10.17, -2.76]7.84 [5.81, 10.48]5% [0%, 14%]10%10%-1.53-0.472026-08-10 → 2026-08-30
tmax12Zbilinear365d26 1 QC6.95 [5.18, 9.35]4.15-5.93 [-9.31, -3.04]7.84 [5.93, 9.81]4% [0%, 12%]8%15%-0.47+0.102026-01-10 → 2026-08-30
tmax12Zbilinearall26 1 QC6.95 [5.20, 9.04]4.15-5.93 [-8.84, -3.04]7.84 [6.05, 9.63]4% [0%, 12%]8%15%-0.47+0.102026-01-10 → 2026-08-30
tmax12Znearest30d21 1 QC6.99 [5.25, 9.56]4.11-5.91 [-9.56, -2.95]7.87 [6.07, 9.97]5% [0%, 14%]10%19%-1.53-0.492026-08-10 → 2026-08-30
tmax12Znearest90d21 1 QC6.99 [5.11, 10.24]4.11-5.91 [-10.24, -2.68]7.87 [5.82, 10.54]5% [0%, 14%]10%19%-1.53-0.492026-08-10 → 2026-08-30
tmax12Znearest365d26 1 QC6.93 [5.15, 9.36]4.18-5.91 [-9.34, -2.98]7.84 [5.90, 9.83]4% [0%, 12%]12%23%-0.47+0.102026-01-10 → 2026-08-30
tmax12Znearestall26 1 QC6.93 [5.21, 9.03]4.18-5.91 [-8.88, -2.97]7.84 [6.07, 9.62]4% [0%, 12%]12%23%-0.47+0.102026-01-10 → 2026-08-30
tmin00Zbilinear30d21 1 QC5.95 [4.67, 7.39]5.85-1.25 [-6.10, 2.78]7.48 [5.87, 8.90]14% [0%, 29%]14%33%-0.15-0.102026-08-10 → 2026-08-30
tmin00Zbilinear90d21 1 QC5.95 [4.56, 7.50]5.85-1.25 [-6.74, 3.24]7.48 [5.55, 9.23]14% [0%, 29%]14%33%-0.15-0.102026-08-10 → 2026-08-30
tmin00Zbilinear365d27 1 QC6.12 [4.91, 7.43]6.05-1.30 [-5.68, 2.50]7.46 [6.09, 8.63]15% [0%, 26%]15%30%+0.13+0.132026-01-10 → 2026-08-30
tmin00Zbilinearall27 1 QC6.12 [5.05, 7.29]6.05-1.30 [-5.22, 2.69]7.46 [6.27, 8.66]15% [0%, 26%]15%30%+0.13+0.132026-01-10 → 2026-08-30
tmin00Znearest30d21 1 QC5.94 [4.63, 7.42]5.84-1.35 [-6.21, 2.64]7.49 [5.89, 8.91]14% [0%, 29%]14%33%-0.15-0.102026-08-10 → 2026-08-30
tmin00Znearest90d21 1 QC5.94 [4.51, 7.55]5.84-1.35 [-6.88, 3.12]7.49 [5.53, 9.22]14% [0%, 29%]14%33%-0.15-0.102026-08-10 → 2026-08-30
tmin00Znearest365d27 1 QC6.11 [4.87, 7.43]6.03-1.41 [-5.79, 2.40]7.45 [6.05, 8.62]15% [0%, 26%]15%30%+0.13+0.132026-01-10 → 2026-08-30
tmin00Znearestall27 1 QC6.11 [5.04, 7.28]6.03-1.41 [-5.33, 2.59]7.45 [6.28, 8.68]15% [0%, 26%]15%30%+0.13+0.132026-01-10 → 2026-08-30
tmin12Zbilinear30d21 1 QC6.08 [4.27, 8.10]5.88-1.58 [-7.33, 3.08]7.50 [5.62, 9.03]10% [0%, 27%]19%38%-0.17-0.112026-08-10 → 2026-08-30
tmin12Zbilinear90d21 1 QC6.08 [4.12, 8.40]5.88-1.58 [-8.25, 3.41]7.50 [5.25, 9.15]10% [0%, 29%]19%38%-0.17-0.112026-08-10 → 2026-08-30
tmin12Zbilinear365d26 1 QC6.18 [4.37, 8.07]6.06-1.88 [-7.29, 2.78]7.65 [5.70, 9.09]12% [0%, 27%]19%35%+0.07+0.052026-01-10 → 2026-08-30
tmin12Zbilinearall26 1 QC6.18 [4.47, 7.90]6.06-1.88 [-6.65, 2.66]7.65 [5.92, 9.00]12% [0%, 27%]19%35%+0.07+0.052026-01-10 → 2026-08-30
tmin12Znearest30d21 1 QC6.10 [4.28, 8.15]5.86-1.67 [-7.43, 2.98]7.53 [5.62, 9.09]10% [0%, 27%]19%33%-0.18-0.102026-08-10 → 2026-08-30
tmin12Znearest90d21 1 QC6.10 [4.13, 8.48]5.86-1.67 [-8.37, 3.29]7.53 [5.25, 9.24]10% [0%, 29%]19%33%-0.18-0.102026-08-10 → 2026-08-30
tmin12Znearest365d26 1 QC6.17 [4.34, 8.10]6.04-1.98 [-7.36, 2.67]7.66 [5.70, 9.17]12% [0%, 27%]19%31%+0.07+0.052026-01-10 → 2026-08-30
tmin12Znearestall26 1 QC6.17 [4.46, 7.94]6.04-1.98 [-6.77, 2.58]7.66 [5.91, 9.05]12% [0%, 27%]19%31%+0.07+0.052026-01-10 → 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 KMSP, lead day 9, 00Z bilinear tmax+20+100-10-202026-08-10: -8.39 °F2026-08-11: -9.72 °F2026-08-12: -15.11 °F2026-08-13: -1.61 °F2026-08-14: -10.1 °F2026-08-15: -12.46 °F2026-08-16: -6.73 °F2026-08-17: -8.39 °F2026-08-18: -0.52 °F2026-08-19: -3.55 °F2026-08-20: -1.46 °F2026-08-21: -7.69 °F2026-08-22: +2.26 °F2026-08-23: +5.26 °F2026-08-24: -0 °F2026-08-25: -6.52 °F2026-08-26: -3.4 °F2026-08-27: -5.65 °F2026-08-28: +0.71 °F2026-08-29: -14.38 °F2026-08-30: -11.37 °F2026-08-102026-08-30°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 (21 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-11.37
2026-08-29-14.38
2026-08-28+0.71
2026-08-27-5.65
2026-08-26-3.40
2026-08-25-6.52
2026-08-24-0.00
2026-08-23+5.26
2026-08-22+2.26
2026-08-21-7.69
2026-08-20-1.46
2026-08-19-3.55
2026-08-18-0.52
2026-08-17-8.39
2026-08-16-6.73
2026-08-15-12.46
2026-08-14-10.10
2026-08-13-1.61
2026-08-12-15.11
2026-08-11-9.72
2026-08-10-8.39

Error distribution

Distribution of the signed daily error in °F for GraphCast (IFS init) at KMSP, lead day 9-20 to -18 °F: 0 days-18 to -16 °F: 1 day-16 to -14 °F: 2 days-14 to -12 °F: 1 day-12 to -10 °F: 3 days-10 to -8 °F: 4 days-8 to -6 °F: 5 days-6 to -4 °F: 1 day-4 to -2 °F: 2 days-2 to 0 °F: 5 days0 to 2 °F: 1 day2 to 4 °F: 1 day4 to 6 °F: 1 day6 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| 6.7 · P90 |e| 13.23 °F-200+20 °Fn = 27 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
-18.00-16.001
-16.00-14.002
-14.00-12.001
-12.00-10.003
-10.00-8.004
-8.00-6.005
-6.00-4.001
-4.00-2.002
-2.00+0.005
+0.00+2.001
+2.00+4.001
+4.00+6.001
+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
2026-08216.44 -5.66
2026-0168.49 -8.49

Availability

ModelScored period DaysCoverage
GraphCast (IFS init)2026-01-10 → 2026-08-30 27
GraphCast (IFS init)2026-01-10 → 2026-08-30 27
GraphCast (IFS init)2026-01-10 → 2026-08-30 26
GraphCast (IFS init)2026-01-10 → 2026-08-30 26

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 21 +0.40 [-1.04, 2.45] no
NCEP GFS 21 +0.05 [-2.06, 3.29] no
ECMWF IFS HRES 16 -0.24 [-2.05, 1.86] no
Persistence (baseline) 21 +3.68 [0.71, 7.73] yes

Cite this page

ShortCastCheck, KMSP graphcast_ifs lead 9, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KMSP/model/graphcast_ifs/lead/9/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KMSP (Minneapolis-St Paul), model graphcast_ifs, lead day 9. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KMSP/model/graphcast_ifs/lead/9/

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