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

Minneapolis-St Paul · ECMWF AIFS Single · lead day 8

KMSP · aifs_single · lead 8

Target day = initialization date + 8 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
tmax00Zbilinear30d22 1 QC6.48 [4.84, 8.15]4.05-5.57 [-8.07, -3.09]7.44 [5.70, 8.88]0% [0%, 0%]14%27%-1.01-0.272026-08-09 → 2026-08-30
tmax00Zbilinear90d22 1 QC6.48 [4.73, 8.14]4.05-5.57 [-8.04, -3.00]7.44 [5.47, 8.86]0% [0%, 0%]14%27%-1.01-0.272026-08-09 → 2026-08-30
tmax00Zbilinear365d22 1 QC6.48 [4.75, 8.33]4.05-5.57 [-8.29, -3.03]7.44 [5.53, 9.01]0% [0%, 0%]14%27%-1.01-0.272026-08-09 → 2026-08-30
tmax00Zbilinearall22 1 QC6.48 [4.60, 8.37]4.05-5.57 [-8.37, -2.98]7.44 [5.35, 9.07]0% [0%, 0%]14%27%-1.01-0.272026-08-09 → 2026-08-30
tmax00Znearest30d22 1 QC6.43 [4.84, 8.05]3.99-5.55 [-7.99, -3.14]7.38 [5.69, 8.77]0% [0%, 0%]18%27%-0.99-0.252026-08-09 → 2026-08-30
tmax00Znearest90d22 1 QC6.43 [4.73, 8.00]3.99-5.55 [-7.95, -3.05]7.38 [5.50, 8.74]0% [0%, 0%]18%27%-0.99-0.252026-08-09 → 2026-08-30
tmax00Znearest365d22 1 QC6.43 [4.75, 8.20]3.99-5.55 [-8.19, -3.05]7.38 [5.57, 8.89]0% [0%, 0%]18%27%-0.99-0.252026-08-09 → 2026-08-30
tmax00Znearestall22 1 QC6.43 [4.60, 8.26]3.99-5.55 [-8.26, -2.98]7.38 [5.37, 8.96]0% [0%, 0%]18%27%-0.99-0.252026-08-09 → 2026-08-30
tmax12Zbilinear30d22 1 QC7.11 [5.65, 8.93]3.29-7.07 [-8.91, -5.62]8.08 [6.68, 9.64]14% [4%, 22%]14%14%-1.20-0.032026-08-09 → 2026-08-30
tmax12Zbilinear90d22 1 QC7.11 [5.69, 9.31]3.29-7.07 [-9.29, -5.64]8.08 [6.68, 9.93]14% [0%, 22%]14%14%-1.20-0.032026-08-09 → 2026-08-30
tmax12Zbilinear365d22 1 QC7.11 [5.52, 9.21]3.29-7.07 [-9.21, -5.47]8.08 [6.51, 9.93]14% [0%, 23%]14%14%-1.20-0.032026-08-09 → 2026-08-30
tmax12Zbilinearall22 1 QC7.11 [5.43, 9.38]3.29-7.07 [-9.38, -5.39]8.08 [6.51, 9.93]14% [0%, 23%]14%14%-1.20-0.032026-08-09 → 2026-08-30
tmax12Znearest30d22 1 QC7.09 [5.66, 8.86]3.24-7.05 [-8.86, -5.62]8.04 [6.67, 9.56]14% [4%, 22%]14%14%-1.20-0.012026-08-09 → 2026-08-30
tmax12Znearest90d22 1 QC7.09 [5.67, 9.23]3.24-7.05 [-9.20, -5.65]8.04 [6.68, 9.85]14% [0%, 22%]14%14%-1.20-0.012026-08-09 → 2026-08-30
tmax12Znearest365d22 1 QC7.09 [5.52, 9.14]3.24-7.05 [-9.12, -5.48]8.04 [6.48, 9.85]14% [0%, 23%]14%14%-1.20-0.012026-08-09 → 2026-08-30
tmax12Znearestall22 1 QC7.09 [5.43, 9.28]3.24-7.05 [-9.28, -5.39]8.04 [6.49, 9.84]14% [0%, 23%]14%14%-1.20-0.012026-08-09 → 2026-08-30
tmin00Zbilinear30d22 1 QC4.69 [3.67, 6.09]3.42-2.76 [-5.66, -0.43]5.21 [3.88, 6.60]5% [0%, 13%]5%23%+0.17+0.402026-08-09 → 2026-08-30
tmin00Zbilinear90d22 1 QC4.69 [3.48, 6.54]3.42-2.76 [-6.54, -0.45]5.21 [3.51, 6.79]5% [0%, 14%]5%23%+0.17+0.402026-08-09 → 2026-08-30
tmin00Zbilinear365d22 1 QC4.69 [3.45, 6.57]3.42-2.76 [-6.55, -0.30]5.21 [3.50, 6.93]5% [0%, 14%]5%23%+0.17+0.402026-08-09 → 2026-08-30
tmin00Zbilinearall22 1 QC4.69 [3.41, 6.55]3.42-2.76 [-6.54, -0.23]5.21 [3.46, 6.96]5% [0%, 14%]5%23%+0.17+0.402026-08-09 → 2026-08-30
tmin00Znearest30d22 1 QC4.78 [3.65, 6.27]3.36-2.96 [-5.88, -0.61]5.30 [3.90, 6.78]0% [0%, 0%]14%23%+0.15+0.412026-08-09 → 2026-08-30
tmin00Znearest90d22 1 QC4.78 [3.48, 6.79]3.36-2.96 [-6.79, -0.61]5.30 [3.52, 7.00]0% [0%, 0%]14%23%+0.15+0.412026-08-09 → 2026-08-30
tmin00Znearest365d22 1 QC4.78 [3.47, 6.80]3.36-2.96 [-6.79, -0.48]5.30 [3.52, 7.14]0% [0%, 0%]14%23%+0.15+0.412026-08-09 → 2026-08-30
tmin00Znearestall22 1 QC4.78 [3.41, 6.79]3.36-2.96 [-6.79, -0.41]5.30 [3.49, 7.18]0% [0%, 0%]14%23%+0.15+0.412026-08-09 → 2026-08-30
tmin12Zbilinear30d22 1 QC5.71 [4.08, 7.71]3.48-4.63 [-7.63, -1.95]6.59 [4.72, 8.39]5% [0%, 12%]14%14%-0.01+0.392026-08-09 → 2026-08-30
tmin12Zbilinear90d22 1 QC5.71 [4.02, 8.18]3.48-4.63 [-8.16, -1.84]6.59 [4.46, 8.51]5% [0%, 12%]14%14%-0.01+0.392026-08-09 → 2026-08-30
tmin12Zbilinear365d22 1 QC5.71 [3.71, 8.23]3.48-4.63 [-8.23, -1.69]6.59 [3.96, 8.61]5% [0%, 14%]14%14%-0.01+0.392026-08-09 → 2026-08-30
tmin12Zbilinearall22 1 QC5.71 [3.91, 7.96]3.48-4.63 [-7.96, -1.73]6.59 [4.28, 8.51]5% [0%, 14%]14%14%-0.01+0.392026-08-09 → 2026-08-30
tmin12Znearest30d22 1 QC5.82 [4.14, 7.90]3.49-4.82 [-7.86, -2.12]6.71 [4.79, 8.53]5% [0%, 12%]14%14%-0.03+0.382026-08-09 → 2026-08-30
tmin12Znearest90d22 1 QC5.82 [4.07, 8.38]3.49-4.82 [-8.35, -2.03]6.71 [4.58, 8.70]5% [0%, 12%]14%14%-0.03+0.382026-08-09 → 2026-08-30
tmin12Znearest365d22 1 QC5.82 [3.78, 8.42]3.49-4.82 [-8.42, -1.85]6.71 [4.01, 8.81]5% [0%, 14%]14%14%-0.03+0.382026-08-09 → 2026-08-30
tmin12Znearestall22 1 QC5.82 [3.96, 8.16]3.49-4.82 [-8.16, -1.93]6.71 [4.36, 8.62]5% [0%, 14%]14%14%-0.03+0.382026-08-09 → 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 8, 00Z bilinear tmax+20+100-10-202026-08-09: -5.85 °F2026-08-10: -7.61 °F2026-08-11: -8.34 °F2026-08-12: -11.86 °F2026-08-13: -1.2 °F2026-08-14: -11.86 °F2026-08-15: -10.26 °F2026-08-16: -12.11 °F2026-08-17: -7.16 °F2026-08-18: -5.3 °F2026-08-19: -2.56 °F2026-08-20: -4.91 °F2026-08-21: -12.43 °F2026-08-22: +2.42 °F2026-08-23: +5.34 °F2026-08-24: -9.03 °F2026-08-25: -1.49 °F2026-08-26: -1.12 °F2026-08-27: -4.56 °F2026-08-28: -6.41 °F2026-08-29: -8.46 °F2026-08-30: +2.3 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+2.30
2026-08-29-8.46
2026-08-28-6.41
2026-08-27-4.56
2026-08-26-1.12
2026-08-25-1.49
2026-08-24-9.03
2026-08-23+5.34
2026-08-22+2.42
2026-08-21-12.43
2026-08-20-4.91
2026-08-19-2.56
2026-08-18-5.30
2026-08-17-7.16
2026-08-16-12.11
2026-08-15-10.26
2026-08-14-11.86
2026-08-13-1.20
2026-08-12-11.86
2026-08-11-8.34
2026-08-10-7.61
2026-08-09-5.85

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KMSP, lead day 8-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 2 days-12 to -10 °F: 3 days-10 to -8 °F: 3 days-8 to -6 °F: 3 days-6 to -4 °F: 4 days-4 to -2 °F: 1 day-2 to 0 °F: 3 days0 to 2 °F: 0 days2 to 4 °F: 2 days4 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| 6.13 · P90 |e| 11.86 °F-200+20 °Fn = 22 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
-14.00-12.002
-12.00-10.003
-10.00-8.003
-8.00-6.003
-6.00-4.004
-4.00-2.001
-2.00+0.003
+0.00+2.000
+2.00+4.002
+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
2026-08226.48 -5.57

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22
ECMWF AIFS Single2026-08-09 → 2026-08-30 22

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 22 -0.61 [-2.14, 0.70] no
GraphCast (IFS init) 22 +0.17 [-2.03, 2.07] no
ECMWF IFS HRES 17 +0.96 [-1.33, 2.85] no
Persistence (baseline) 22 +3.25 [1.53, 5.30] yes

Cite this page

ShortCastCheck, KMSP aifs_single lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KMSP/model/aifs_single/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KMSP (Minneapolis-St Paul), model aifs_single, lead day 8. 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/8/

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