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 · NCEP GFS · lead day 8

KMSP · gfs · 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, gfs-0p25, 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 QC7.09 [5.80, 8.81]6.63-2.37 [-6.51, 1.86]8.45 [6.85, 10.32]9% [0%, 22%]14%23%-1.20-1.072026-08-09 → 2026-08-30
tmax00Zbilinear90d22 1 QC7.09 [5.81, 9.14]6.63-2.37 [-6.46, 2.77]8.45 [6.76, 10.82]9% [0%, 23%]14%23%-1.20-1.072026-08-09 → 2026-08-30
tmax00Zbilinear365d22 1 QC7.09 [5.72, 9.14]6.63-2.37 [-6.96, 2.76]8.45 [6.66, 10.73]9% [0%, 25%]14%23%-1.20-1.072026-08-09 → 2026-08-30
tmax00Zbilinearall22 1 QC7.09 [5.81, 9.08]6.63-2.37 [-7.30, 3.39]8.45 [6.80, 10.74]9% [0%, 25%]14%23%-1.20-1.072026-08-09 → 2026-08-30
tmax00Znearest30d22 1 QC6.98 [5.87, 8.47]6.79-2.00 [-6.10, 1.96]8.32 [6.98, 9.96]9% [0%, 18%]14%23%-1.16-1.122026-08-09 → 2026-08-30
tmax00Znearest90d22 1 QC6.98 [5.90, 8.85]6.79-2.00 [-6.02, 2.89]8.32 [6.97, 10.30]9% [0%, 19%]14%23%-1.16-1.122026-08-09 → 2026-08-30
tmax00Znearest365d22 1 QC6.98 [5.81, 8.83]6.79-2.00 [-6.44, 2.77]8.32 [6.90, 10.30]9% [0%, 18%]14%23%-1.16-1.122026-08-09 → 2026-08-30
tmax00Znearestall22 1 QC6.98 [5.86, 9.07]6.79-2.00 [-7.03, 3.54]8.32 [7.02, 10.30]9% [0%, 19%]14%23%-1.16-1.122026-08-09 → 2026-08-30
tmax12Zbilinear30d22 1 QC6.22 [4.17, 8.06]6.60-2.55 [-5.65, 0.39]7.98 [5.56, 9.58]23% [10%, 36%]27%32%-0.93-1.062026-08-09 → 2026-08-30
tmax12Zbilinear90d22 1 QC6.22 [3.73, 8.54]6.60-2.55 [-7.11, 0.77]7.98 [4.66, 9.83]23% [7%, 38%]27%32%-0.93-1.062026-08-09 → 2026-08-30
tmax12Zbilinear365d22 1 QC6.22 [3.58, 8.61]6.60-2.55 [-6.50, 1.03]7.98 [4.69, 9.84]23% [6%, 38%]27%32%-0.93-1.062026-08-09 → 2026-08-30
tmax12Zbilinearall22 1 QC6.22 [3.09, 8.57]6.60-2.55 [-6.54, 1.36]7.98 [3.92, 9.84]23% [7%, 40%]27%32%-0.93-1.062026-08-09 → 2026-08-30
tmax12Znearest30d22 1 QC5.98 [4.01, 7.69]6.36-2.33 [-5.42, 0.37]7.67 [5.39, 9.27]23% [10%, 36%]27%32%-0.85-0.992026-08-09 → 2026-08-30
tmax12Znearest90d22 1 QC5.98 [3.58, 8.13]6.36-2.33 [-6.82, 0.87]7.67 [4.57, 9.38]23% [7%, 38%]27%32%-0.85-0.992026-08-09 → 2026-08-30
tmax12Znearest365d22 1 QC5.98 [3.46, 8.21]6.36-2.33 [-6.23, 1.03]7.67 [4.57, 9.44]23% [6%, 38%]27%32%-0.85-0.992026-08-09 → 2026-08-30
tmax12Znearestall22 1 QC5.98 [2.84, 8.25]6.36-2.33 [-6.17, 1.35]7.67 [3.79, 9.43]23% [7%, 40%]27%32%-0.85-0.992026-08-09 → 2026-08-30
tmin00Zbilinear30d22 1 QC7.11 [5.28, 8.34]6.73-1.90 [-7.01, 3.05]8.29 [6.28, 9.47]9% [0%, 20%]18%23%-0.26-0.192026-08-09 → 2026-08-30
tmin00Zbilinear90d22 1 QC7.11 [4.67, 8.44]6.73-1.90 [-7.33, 3.79]8.29 [5.66, 9.59]9% [0%, 21%]18%23%-0.26-0.192026-08-09 → 2026-08-30
tmin00Zbilinear365d22 1 QC7.11 [4.84, 8.32]6.73-1.90 [-7.72, 4.02]8.29 [5.53, 9.55]9% [0%, 23%]18%23%-0.26-0.192026-08-09 → 2026-08-30
tmin00Zbilinearall22 1 QC7.11 [4.93, 8.47]6.73-1.90 [-7.49, 3.86]8.29 [5.35, 9.61]9% [0%, 21%]18%23%-0.26-0.192026-08-09 → 2026-08-30
tmin00Znearest30d22 1 QC6.99 [5.09, 8.28]6.86-0.95 [-6.16, 4.07]8.21 [6.12, 9.37]5% [0%, 18%]23%23%-0.24-0.212026-08-09 → 2026-08-30
tmin00Znearest90d22 1 QC6.99 [4.54, 8.39]6.86-0.95 [-6.36, 4.85]8.21 [5.60, 9.41]5% [0%, 22%]23%23%-0.24-0.212026-08-09 → 2026-08-30
tmin00Znearest365d22 1 QC6.99 [4.67, 8.37]6.86-0.95 [-6.80, 5.00]8.21 [5.59, 9.47]5% [0%, 20%]23%23%-0.24-0.212026-08-09 → 2026-08-30
tmin00Znearestall22 1 QC6.99 [4.67, 8.50]6.86-0.95 [-6.76, 4.74]8.21 [5.20, 9.50]5% [0%, 22%]23%23%-0.24-0.212026-08-09 → 2026-08-30
tmin12Zbilinear30d22 1 QC5.24 [3.66, 7.45]4.86-2.09 [-6.77, 1.41]6.59 [4.47, 8.75]9% [0%, 16%]27%41%+0.07+0.142026-08-09 → 2026-08-30
tmin12Zbilinear90d22 1 QC5.24 [3.46, 8.06]4.86-2.09 [-7.85, 1.61]6.59 [4.05, 9.17]9% [0%, 15%]27%41%+0.07+0.142026-08-09 → 2026-08-30
tmin12Zbilinear365d22 1 QC5.24 [3.48, 8.10]4.86-2.09 [-7.90, 1.88]6.59 [4.08, 9.10]9% [0%, 14%]27%41%+0.07+0.142026-08-09 → 2026-08-30
tmin12Zbilinearall22 1 QC5.24 [3.48, 8.12]4.86-2.09 [-8.02, 1.69]6.59 [4.05, 9.20]9% [0%, 14%]27%41%+0.07+0.142026-08-09 → 2026-08-30
tmin12Znearest30d22 1 QC5.23 [3.79, 7.34]5.10-1.31 [-6.20, 2.27]6.60 [4.55, 8.58]14% [0%, 24%]23%41%+0.07+0.102026-08-09 → 2026-08-30
tmin12Znearest90d22 1 QC5.23 [3.65, 7.70]5.10-1.31 [-7.66, 2.55]6.60 [4.31, 8.83]14% [0%, 25%]23%41%+0.07+0.102026-08-09 → 2026-08-30
tmin12Znearest365d22 1 QC5.23 [3.66, 7.67]5.10-1.31 [-7.66, 2.83]6.60 [4.34, 8.83]14% [0%, 26%]23%41%+0.07+0.102026-08-09 → 2026-08-30
tmin12Znearestall22 1 QC5.23 [3.69, 7.67]5.10-1.31 [-7.66, 2.51]6.60 [4.34, 8.82]14% [0%, 25%]23%41%+0.07+0.102026-08-09 → 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 NCEP GFS at KMSP, lead day 8, 00Z bilinear tmax+20+100-10-202026-08-09: -0.41 °F2026-08-10: +13.75 °F2026-08-11: -13.78 °F2026-08-12: -14.46 °F2026-08-13: -2.28 °F2026-08-14: -5.18 °F2026-08-15: -13.68 °F2026-08-16: -5.76 °F2026-08-17: -4.6 °F2026-08-18: -11.67 °F2026-08-19: +0.72 °F2026-08-20: +1.92 °F2026-08-21: +4.74 °F2026-08-22: +12.59 °F2026-08-23: +9.27 °F2026-08-24: +6.67 °F2026-08-25: -4.77 °F2026-08-26: -3.37 °F2026-08-27: -6.71 °F2026-08-28: +2.34 °F2026-08-29: -5.41 °F2026-08-30: -11.98 °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
2026-08-30-11.98
2026-08-29-5.41
2026-08-28+2.34
2026-08-27-6.71
2026-08-26-3.37
2026-08-25-4.77
2026-08-24+6.67
2026-08-23+9.27
2026-08-22+12.59
2026-08-21+4.74
2026-08-20+1.92
2026-08-19+0.72
2026-08-18-11.67
2026-08-17-4.60
2026-08-16-5.76
2026-08-15-13.68
2026-08-14-5.18
2026-08-13-2.28
2026-08-12-14.46
2026-08-11-13.78
2026-08-10+13.75
2026-08-09-0.41

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KMSP, lead day 8-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 1 day-14 to -12 °F: 2 days-12 to -10 °F: 2 days-10 to -8 °F: 0 days-8 to -6 °F: 1 day-6 to -4 °F: 5 days-4 to -2 °F: 2 days-2 to 0 °F: 1 day0 to 2 °F: 2 days2 to 4 °F: 1 day4 to 6 °F: 1 day6 to 8 °F: 1 day8 to 10 °F: 1 day10 to 12 °F: 0 days12 to 14 °F: 2 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 5.58 · P90 |e| 13.74 °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
-16.00-14.001
-14.00-12.002
-12.00-10.002
-10.00-8.000
-8.00-6.001
-6.00-4.005
-4.00-2.002
-2.00+0.001
+0.00+2.002
+2.00+4.001
+4.00+6.001
+6.00+8.001
+8.00+10.001
+10.00+12.000
+12.00+14.002
+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
2026-08227.09 -2.37

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 22 +0.61 [-0.70, 2.14] no
GraphCast (IFS init) 22 +0.79 [-1.14, 2.47] no
ECMWF IFS HRES 17 +1.25 [-2.72, 2.89] no
Persistence (baseline) 22 +3.87 [2.15, 6.14] yes

Cite this page

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

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