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

Minneapolis-St Paul · NCEP GFS · lead day 9

KMSP · gfs · 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, 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
tmax00Zbilinear30d21 1 QC6.39 [4.96, 8.09]6.05-2.92 [-7.04, 0.75]8.16 [6.57, 9.55]19% [8%, 32%]29%33%-1.31-1.192026-08-10 → 2026-08-30
tmax00Zbilinear90d21 1 QC6.39 [4.73, 8.11]6.05-2.92 [-7.76, 0.98]8.16 [6.11, 9.69]19% [7%, 33%]29%33%-1.31-1.192026-08-10 → 2026-08-30
tmax00Zbilinear365d21 1 QC6.39 [4.76, 8.30]6.05-2.92 [-7.76, 1.40]8.16 [6.10, 9.82]19% [5%, 33%]29%33%-1.31-1.192026-08-10 → 2026-08-30
tmax00Zbilinearall21 1 QC6.39 [4.75, 8.30]6.05-2.92 [-7.76, 1.47]8.16 [6.09, 9.68]19% [7%, 33%]29%33%-1.31-1.192026-08-10 → 2026-08-30
tmax00Znearest30d21 1 QC5.96 [4.67, 7.42]5.78-2.32 [-6.06, 1.14]7.61 [6.29, 8.70]19% [5%, 32%]33%33%-1.16-1.092026-08-10 → 2026-08-30
tmax00Znearest90d21 1 QC5.96 [4.49, 7.45]5.78-2.32 [-6.65, 1.38]7.61 [5.89, 8.68]19% [0%, 34%]33%33%-1.16-1.092026-08-10 → 2026-08-30
tmax00Znearest365d21 1 QC5.96 [4.51, 7.66]5.78-2.32 [-6.63, 1.71]7.61 [5.85, 8.89]19% [0%, 33%]33%33%-1.16-1.092026-08-10 → 2026-08-30
tmax00Znearestall21 1 QC5.96 [4.44, 7.59]5.78-2.32 [-6.72, 1.75]7.61 [5.82, 8.77]19% [0%, 33%]33%33%-1.16-1.092026-08-10 → 2026-08-30
tmax12Zbilinear30d21 1 QC4.70 [2.88, 6.48]4.73-1.70 [-4.71, 1.22]6.41 [4.27, 8.28]19% [0%, 42%]38%38%-0.70-0.712026-08-10 → 2026-08-30
tmax12Zbilinear90d21 1 QC4.70 [2.94, 6.57]4.73-1.70 [-5.40, 1.55]6.41 [4.26, 8.41]19% [0%, 43%]38%38%-0.70-0.712026-08-10 → 2026-08-30
tmax12Zbilinear365d21 1 QC4.70 [2.68, 6.59]4.73-1.70 [-5.11, 1.67]6.41 [3.86, 8.36]19% [0%, 43%]38%38%-0.70-0.712026-08-10 → 2026-08-30
tmax12Zbilinearall21 1 QC4.70 [2.68, 6.57]4.73-1.70 [-5.34, 1.81]6.41 [3.80, 8.38]19% [0%, 44%]38%38%-0.70-0.712026-08-10 → 2026-08-30
tmax12Znearest30d21 1 QC4.35 [2.79, 5.81]4.39-1.18 [-4.18, 1.67]6.02 [4.07, 7.73]19% [5%, 36%]38%48%-0.58-0.592026-08-10 → 2026-08-30
tmax12Znearest90d21 1 QC4.35 [2.77, 5.94]4.39-1.18 [-4.99, 1.87]6.02 [3.99, 7.83]19% [0%, 38%]38%48%-0.58-0.592026-08-10 → 2026-08-30
tmax12Znearest365d21 1 QC4.35 [2.57, 6.00]4.39-1.18 [-4.57, 2.16]6.02 [3.79, 7.83]19% [0%, 40%]38%48%-0.58-0.592026-08-10 → 2026-08-30
tmax12Znearestall21 1 QC4.35 [2.46, 6.02]4.39-1.18 [-4.56, 2.14]6.02 [3.41, 7.84]19% [0%, 42%]38%48%-0.58-0.592026-08-10 → 2026-08-30
tmin00Zbilinear30d21 1 QC6.63 [5.10, 8.00]5.83-2.56 [-7.33, 2.19]8.02 [6.01, 9.14]5% [0%, 13%]5%29%-0.28-0.102026-08-10 → 2026-08-30
tmin00Zbilinear90d21 1 QC6.63 [4.58, 8.14]5.83-2.56 [-8.02, 2.57]8.02 [5.42, 9.07]5% [0%, 13%]5%29%-0.28-0.102026-08-10 → 2026-08-30
tmin00Zbilinear365d21 1 QC6.63 [4.74, 8.04]5.83-2.56 [-7.85, 2.91]8.02 [5.42, 9.00]5% [0%, 14%]5%29%-0.28-0.102026-08-10 → 2026-08-30
tmin00Zbilinearall21 1 QC6.63 [4.48, 8.13]5.83-2.56 [-8.04, 2.87]8.02 [5.10, 9.08]5% [0%, 14%]5%29%-0.28-0.102026-08-10 → 2026-08-30
tmin00Znearest30d21 1 QC6.22 [4.54, 7.71]5.72-1.90 [-6.97, 2.72]7.74 [5.44, 9.04]5% [0%, 13%]10%38%-0.20-0.082026-08-10 → 2026-08-30
tmin00Znearest90d21 1 QC6.22 [3.95, 7.79]5.72-1.90 [-7.79, 3.24]7.74 [4.44, 8.84]5% [0%, 13%]10%38%-0.20-0.082026-08-10 → 2026-08-30
tmin00Znearest365d21 1 QC6.22 [3.79, 7.72]5.72-1.90 [-7.70, 3.50]7.74 [4.31, 8.79]5% [0%, 14%]10%38%-0.20-0.082026-08-10 → 2026-08-30
tmin00Znearestall21 1 QC6.22 [3.63, 7.90]5.72-1.90 [-7.87, 3.55]7.74 [4.11, 8.82]5% [0%, 14%]10%38%-0.20-0.082026-08-10 → 2026-08-30
tmin12Zbilinear30d21 1 QC6.11 [4.22, 8.11]5.71-1.97 [-7.04, 1.86]7.06 [5.07, 8.86]14% [4%, 29%]14%24%-0.18-0.072026-08-10 → 2026-08-30
tmin12Zbilinear90d21 1 QC6.11 [3.64, 8.97]5.71-1.97 [-8.65, 1.96]7.06 [4.31, 9.31]14% [0%, 29%]14%24%-0.18-0.072026-08-10 → 2026-08-30
tmin12Zbilinear365d21 1 QC6.11 [3.52, 8.72]5.71-1.97 [-8.67, 2.23]7.06 [4.19, 9.31]14% [0%, 30%]14%24%-0.18-0.072026-08-10 → 2026-08-30
tmin12Zbilinearall21 1 QC6.11 [3.03, 8.78]5.71-1.97 [-8.69, 2.21]7.06 [3.81, 9.33]14% [0%, 33%]14%24%-0.18-0.072026-08-10 → 2026-08-30
tmin12Znearest30d21 1 QC5.61 [4.30, 6.98]5.45-0.97 [-5.65, 2.66]6.48 [5.02, 7.62]10% [0%, 21%]14%24%-0.08-0.022026-08-10 → 2026-08-30
tmin12Znearest90d21 1 QC5.61 [3.90, 7.54]5.45-0.97 [-7.25, 2.78]6.48 [4.50, 7.94]10% [0%, 21%]14%24%-0.08-0.022026-08-10 → 2026-08-30
tmin12Znearest365d21 1 QC5.61 [3.76, 7.41]5.45-0.97 [-7.25, 3.05]6.48 [4.26, 7.85]10% [0%, 22%]14%24%-0.08-0.022026-08-10 → 2026-08-30
tmin12Znearestall21 1 QC5.61 [3.52, 7.51]5.45-0.97 [-7.25, 3.07]6.48 [4.07, 7.94]10% [0%, 21%]14%24%-0.08-0.022026-08-10 → 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 NCEP GFS at KMSP, lead day 9, 00Z bilinear tmax+20+100-10-202026-08-10: -14.44 °F2026-08-11: -0.89 °F2026-08-12: -8.98 °F2026-08-13: -0.84 °F2026-08-14: -13.62 °F2026-08-15: -8.45 °F2026-08-16: -5.97 °F2026-08-17: -15.58 °F2026-08-18: +4.67 °F2026-08-19: +5.15 °F2026-08-20: +6.96 °F2026-08-21: -1.87 °F2026-08-22: -0.06 °F2026-08-23: +15.54 °F2026-08-24: -3.49 °F2026-08-25: -2.34 °F2026-08-26: -11.69 °F2026-08-27: -1.57 °F2026-08-28: -0.4 °F2026-08-29: +4.07 °F2026-08-30: -7.63 °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
2026-08-30-7.63
2026-08-29+4.07
2026-08-28-0.40
2026-08-27-1.57
2026-08-26-11.69
2026-08-25-2.34
2026-08-24-3.49
2026-08-23+15.54
2026-08-22-0.06
2026-08-21-1.87
2026-08-20+6.96
2026-08-19+5.15
2026-08-18+4.67
2026-08-17-15.58
2026-08-16-5.97
2026-08-15-8.45
2026-08-14-13.62
2026-08-13-0.84
2026-08-12-8.98
2026-08-11-0.89
2026-08-10-14.44

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KMSP, lead day 9-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 2 days-14 to -12 °F: 1 day-12 to -10 °F: 1 day-10 to -8 °F: 2 days-8 to -6 °F: 1 day-6 to -4 °F: 1 day-4 to -2 °F: 2 days-2 to 0 °F: 6 days0 to 2 °F: 0 days2 to 4 °F: 0 days4 to 6 °F: 3 days6 to 8 °F: 1 day8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 1 day16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 5.15 · P90 |e| 14.44 °F-200+20 °Fn = 21 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
-16.00-14.002
-14.00-12.001
-12.00-10.001
-10.00-8.002
-8.00-6.001
-6.00-4.001
-4.00-2.002
-2.00+0.006
+0.00+2.000
+2.00+4.000
+4.00+6.003
+6.00+8.001
+8.00+10.000
+10.00+12.000
+12.00+14.000
+14.00+16.001
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08216.39 -2.92

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21

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 21 +0.35 [-2.57, 2.30] no
GraphCast (IFS init) 21 -0.05 [-3.29, 2.06] no
ECMWF IFS HRES 16 +0.70 [-2.14, 6.34] no
Persistence (baseline) 21 +3.63 [1.70, 5.88] yes

Cite this page

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

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