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

Minneapolis-St Paul · ECMWF AIFS Single · lead day 4

KMSP · aifs_single · lead 4

Target day = initialization date + 4 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, aifs-single-gpid5, starting 2026-08-01 — 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 QC4.01 [3.43, 4.46]2.74-3.27 [-3.97, -2.32]4.68 [4.07, 5.09]15% [7%, 24%]27%35%+0.02+0.342026-08-05 → 2026-08-30
tmax00Zbilinear90d26 1 QC4.01 [3.32, 4.45]2.74-3.27 [-3.95, -2.14]4.68 [3.86, 5.06]15% [6%, 26%]27%35%+0.02+0.342026-08-05 → 2026-08-30
tmax00Zbilinear365d26 1 QC4.01 [3.29, 4.45]2.74-3.27 [-3.96, -2.22]4.68 [3.85, 5.08]15% [6%, 26%]27%35%+0.02+0.342026-08-05 → 2026-08-30
tmax00Zbilinearall26 1 QC4.01 [3.19, 4.48]2.74-3.27 [-3.95, -2.01]4.68 [3.75, 5.07]15% [6%, 26%]27%35%+0.02+0.342026-08-05 → 2026-08-30
tmax00Znearest30d26 1 QC4.04 [3.44, 4.50]2.75-3.23 [-4.00, -2.17]4.71 [4.07, 5.14]15% [7%, 24%]19%35%+0.02+0.332026-08-05 → 2026-08-30
tmax00Znearest90d26 1 QC4.04 [3.34, 4.48]2.75-3.23 [-4.00, -1.94]4.71 [3.85, 5.08]15% [6%, 26%]19%35%+0.02+0.332026-08-05 → 2026-08-30
tmax00Znearest365d26 1 QC4.04 [3.30, 4.51]2.75-3.23 [-4.01, -2.05]4.71 [3.79, 5.14]15% [6%, 26%]19%35%+0.02+0.332026-08-05 → 2026-08-30
tmax00Znearestall26 1 QC4.04 [3.24, 4.52]2.75-3.23 [-4.00, -1.96]4.71 [3.75, 5.10]15% [6%, 26%]19%35%+0.02+0.332026-08-05 → 2026-08-30
tmax12Zbilinear30d26 1 QC4.02 [3.40, 4.60]2.60-3.34 [-3.98, -2.52]4.62 [3.91, 5.25]12% [4%, 20%]23%38%+0.02+0.372026-08-05 → 2026-08-30
tmax12Zbilinear90d26 1 QC4.02 [3.29, 4.59]2.60-3.34 [-3.98, -2.37]4.62 [3.82, 5.22]12% [0%, 20%]23%38%+0.02+0.372026-08-05 → 2026-08-30
tmax12Zbilinear365d26 1 QC4.02 [3.38, 4.64]2.60-3.34 [-3.97, -2.47]4.62 [3.80, 5.26]12% [0%, 20%]23%38%+0.02+0.372026-08-05 → 2026-08-30
tmax12Zbilinearall26 1 QC4.02 [3.16, 4.67]2.60-3.34 [-3.99, -2.33]4.62 [3.72, 5.27]12% [0%, 20%]23%38%+0.02+0.372026-08-05 → 2026-08-30
tmax12Znearest30d26 1 QC3.99 [3.30, 4.61]2.62-3.29 [-4.01, -2.35]4.62 [3.88, 5.28]15% [5%, 27%]23%35%+0.03+0.362026-08-05 → 2026-08-30
tmax12Znearest90d26 1 QC3.99 [3.16, 4.63]2.62-3.29 [-4.01, -2.17]4.62 [3.75, 5.26]15% [5%, 29%]23%35%+0.03+0.362026-08-05 → 2026-08-30
tmax12Znearest365d26 1 QC3.99 [3.20, 4.66]2.62-3.29 [-4.00, -2.30]4.62 [3.79, 5.31]15% [0%, 29%]23%35%+0.03+0.362026-08-05 → 2026-08-30
tmax12Znearestall26 1 QC3.99 [3.09, 4.67]2.62-3.29 [-4.05, -2.17]4.62 [3.61, 5.32]15% [4%, 29%]23%35%+0.03+0.362026-08-05 → 2026-08-30
tmin00Zbilinear30d26 1 QC2.83 [2.45, 3.21]1.94-1.99 [-2.71, -1.06]3.07 [2.67, 3.43]4% [0%, 11%]35%58%+0.33+0.542026-08-05 → 2026-08-30
tmin00Zbilinear90d26 1 QC2.83 [2.39, 3.27]1.94-1.99 [-2.85, -0.97]3.07 [2.63, 3.48]4% [0%, 11%]35%58%+0.33+0.542026-08-05 → 2026-08-30
tmin00Zbilinear365d26 1 QC2.83 [2.32, 3.27]1.94-1.99 [-2.90, -0.90]3.07 [2.57, 3.48]4% [0%, 12%]35%58%+0.33+0.542026-08-05 → 2026-08-30
tmin00Zbilinearall26 1 QC2.83 [2.32, 3.33]1.94-1.99 [-2.89, -0.89]3.07 [2.55, 3.53]4% [0%, 12%]35%58%+0.33+0.542026-08-05 → 2026-08-30
tmin00Znearest30d26 1 QC2.90 [2.44, 3.34]1.92-2.17 [-2.85, -1.31]3.18 [2.73, 3.58]4% [0%, 11%]31%50%+0.31+0.542026-08-05 → 2026-08-30
tmin00Znearest90d26 1 QC2.90 [2.38, 3.43]1.92-2.17 [-3.02, -1.21]3.18 [2.66, 3.64]4% [0%, 11%]31%50%+0.31+0.542026-08-05 → 2026-08-30
tmin00Znearest365d26 1 QC2.90 [2.30, 3.40]1.92-2.17 [-3.04, -1.12]3.18 [2.62, 3.64]4% [0%, 12%]31%50%+0.31+0.542026-08-05 → 2026-08-30
tmin00Znearestall26 1 QC2.90 [2.30, 3.47]1.92-2.17 [-3.06, -1.13]3.18 [2.62, 3.69]4% [0%, 12%]31%50%+0.31+0.542026-08-05 → 2026-08-30
tmin12Zbilinear30d26 1 QC2.64 [2.07, 3.15]1.94-2.13 [-2.74, -1.36]3.06 [2.59, 3.48]19% [4%, 38%]42%54%+0.38+0.542026-08-05 → 2026-08-30
tmin12Zbilinear90d26 1 QC2.64 [2.00, 3.26]1.94-2.13 [-2.84, -1.26]3.06 [2.53, 3.55]19% [0%, 41%]42%54%+0.38+0.542026-08-05 → 2026-08-30
tmin12Zbilinear365d26 1 QC2.64 [1.97, 3.28]1.94-2.13 [-2.92, -1.24]3.06 [2.53, 3.58]19% [0%, 45%]42%54%+0.38+0.542026-08-05 → 2026-08-30
tmin12Zbilinearall26 1 QC2.64 [1.96, 3.29]1.94-2.13 [-2.94, -1.24]3.06 [2.48, 3.59]19% [0%, 44%]42%54%+0.38+0.542026-08-05 → 2026-08-30
tmin12Znearest30d26 1 QC2.73 [2.11, 3.28]1.93-2.28 [-2.89, -1.53]3.17 [2.67, 3.62]19% [4%, 38%]42%54%+0.35+0.542026-08-05 → 2026-08-30
tmin12Znearest90d26 1 QC2.73 [2.04, 3.38]1.93-2.28 [-2.98, -1.44]3.17 [2.61, 3.68]19% [0%, 41%]42%54%+0.35+0.542026-08-05 → 2026-08-30
tmin12Znearest365d26 1 QC2.73 [2.02, 3.41]1.93-2.28 [-3.07, -1.42]3.17 [2.60, 3.72]19% [0%, 45%]42%54%+0.35+0.542026-08-05 → 2026-08-30
tmin12Znearestall26 1 QC2.73 [1.99, 3.41]1.93-2.28 [-3.08, -1.44]3.17 [2.55, 3.73]19% [0%, 44%]42%54%+0.35+0.542026-08-05 → 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 ECMWF AIFS Single at KMSP, lead day 4, 00Z bilinear tmax+10+50-5-102026-08-05: -4.83 °F2026-08-06: -0.33 °F2026-08-07: +4.52 °F2026-08-08: -2.25 °F2026-08-09: -4.96 °F2026-08-10: -4.51 °F2026-08-11: -5.58 °F2026-08-12: -8.82 °F2026-08-13: +1.09 °F2026-08-14: -3.3 °F2026-08-15: +0.16 °F2026-08-16: -4.58 °F2026-08-17: -6.07 °F2026-08-18: -6.15 °F2026-08-19: -7.33 °F2026-08-20: +3.93 °F2026-08-21: -0.76 °F2026-08-22: -2.37 °F2026-08-23: -5.46 °F2026-08-24: -7.75 °F2026-08-25: -0.72 °F2026-08-26: -1.99 °F2026-08-27: -7.6 °F2026-08-28: -3.33 °F2026-08-29: -4.32 °F2026-08-30: -1.65 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.65
2026-08-29-4.32
2026-08-28-3.33
2026-08-27-7.60
2026-08-26-1.99
2026-08-25-0.72
2026-08-24-7.75
2026-08-23-5.46
2026-08-22-2.37
2026-08-21-0.76
2026-08-20+3.93
2026-08-19-7.33
2026-08-18-6.15
2026-08-17-6.07
2026-08-16-4.58
2026-08-15+0.16
2026-08-14-3.30
2026-08-13+1.09
2026-08-12-8.82
2026-08-11-5.58
2026-08-10-4.51
2026-08-09-4.96
2026-08-08-2.25
2026-08-07+4.52
2026-08-06-0.33
2026-08-05-4.83

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KMSP, lead day 4-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 3 days-7 to -6 °F: 2 days-6 to -5 °F: 2 days-5 to -4 °F: 5 days-4 to -3 °F: 2 days-3 to -2 °F: 2 days-2 to -1 °F: 2 days-1 to 0 °F: 3 days0 to 1 °F: 1 day1 to 2 °F: 1 day2 to 3 °F: 0 days3 to 4 °F: 1 day4 to 5 °F: 1 day5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 4.42 · P90 |e| 7.46 °F-100+10 °Fn = 26 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
-10.00-9.000
-9.00-8.001
-8.00-7.003
-7.00-6.002
-6.00-5.002
-5.00-4.005
-4.00-3.002
-3.00-2.002
-2.00-1.002
-1.00+0.003
+0.00+1.001
+1.00+2.001
+2.00+3.000
+3.00+4.001
+4.00+5.001
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08264.01 -3.27

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
NCEP GFS 26 +0.21 [-1.33, 1.37] no
GraphCast (IFS init) 25 -1.94 [-2.54, -1.29] yes
ECMWF IFS HRES 20 +1.34 [0.74, 1.95] yes
Persistence (baseline) 26 -0.10 [-1.82, 1.39] no

Cite this page

ShortCastCheck, KMSP aifs_single lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KMSP/model/aifs_single/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KMSP (Minneapolis-St Paul), model aifs_single, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KMSP/model/aifs_single/lead/4/

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