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

New Orleans Intl · NCEP GFS · lead day 9

KMSY · 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 QC4.48 [3.25, 5.37]1.84-4.41 [-5.35, -3.17]4.95 [3.81, 5.70]14% [0%, 32%]14%24%-0.36+0.452026-08-10 → 2026-08-30
tmax00Zbilinear90d21 1 QC4.48 [2.92, 5.46]1.84-4.41 [-5.43, -2.92]4.95 [3.39, 5.75]14% [0%, 33%]14%24%-0.36+0.452026-08-10 → 2026-08-30
tmax00Zbilinear365d21 1 QC4.48 [2.85, 5.45]1.84-4.41 [-5.35, -2.81]4.95 [3.33, 5.74]14% [0%, 37%]14%24%-0.36+0.452026-08-10 → 2026-08-30
tmax00Zbilinearall21 1 QC4.48 [2.83, 5.60]1.84-4.41 [-5.60, -2.83]4.95 [3.31, 5.85]14% [0%, 38%]14%24%-0.36+0.452026-08-10 → 2026-08-30
tmax00Znearest30d21 1 QC4.63 [3.39, 5.53]1.83-4.58 [-5.53, -3.38]5.09 [3.99, 5.83]10% [0%, 17%]14%19%-0.41+0.452026-08-10 → 2026-08-30
tmax00Znearest90d21 1 QC4.63 [3.20, 5.61]1.83-4.58 [-5.58, -3.20]5.09 [3.60, 5.89]10% [0%, 17%]14%19%-0.41+0.452026-08-10 → 2026-08-30
tmax00Znearest365d21 1 QC4.63 [3.04, 5.57]1.83-4.58 [-5.49, -3.01]5.09 [3.55, 5.87]10% [0%, 17%]14%19%-0.41+0.452026-08-10 → 2026-08-30
tmax00Znearestall21 1 QC4.63 [3.05, 5.76]1.83-4.58 [-5.76, -3.05]5.09 [3.51, 5.99]10% [0%, 17%]14%19%-0.41+0.452026-08-10 → 2026-08-30
tmax12Zbilinear30d21 1 QC4.52 [3.29, 5.32]1.89-4.26 [-5.32, -2.53]4.93 [3.72, 5.65]0% [0%, 0%]10%29%-0.38+0.432026-08-10 → 2026-08-30
tmax12Zbilinear90d21 1 QC4.52 [2.81, 5.38]1.89-4.26 [-5.37, -1.92]4.93 [3.13, 5.68]0% [0%, 0%]10%29%-0.38+0.432026-08-10 → 2026-08-30
tmax12Zbilinear365d21 1 QC4.52 [2.78, 5.48]1.89-4.26 [-5.48, -1.93]4.93 [3.11, 5.78]0% [0%, 0%]10%29%-0.38+0.432026-08-10 → 2026-08-30
tmax12Zbilinearall21 1 QC4.52 [2.58, 5.36]1.89-4.26 [-5.35, -1.77]4.93 [2.89, 5.68]0% [0%, 0%]10%29%-0.38+0.432026-08-10 → 2026-08-30
tmax12Znearest30d21 1 QC4.67 [3.42, 5.48]1.90-4.42 [-5.48, -2.72]5.07 [3.86, 5.80]0% [0%, 0%]10%29%-0.42+0.432026-08-10 → 2026-08-30
tmax12Znearest90d21 1 QC4.67 [2.93, 5.52]1.90-4.42 [-5.52, -2.12]5.07 [3.24, 5.83]0% [0%, 0%]10%29%-0.42+0.432026-08-10 → 2026-08-30
tmax12Znearest365d21 1 QC4.67 [2.93, 5.61]1.90-4.42 [-5.61, -2.15]5.07 [3.24, 5.93]0% [0%, 0%]10%29%-0.42+0.432026-08-10 → 2026-08-30
tmax12Znearestall21 1 QC4.67 [2.74, 5.51]1.90-4.42 [-5.51, -1.99]5.07 [3.02, 5.83]0% [0%, 0%]10%29%-0.42+0.432026-08-10 → 2026-08-30
tmin00Zbilinear30d21 1 QC2.11 [1.44, 2.86]1.93+0.86 [0.06, 1.59]2.78 [1.86, 3.70]29% [14%, 42%]62%71%+0.24+0.302026-08-10 → 2026-08-30
tmin00Zbilinear90d21 1 QC2.11 [1.42, 2.99]1.93+0.86 [0.01, 1.55]2.78 [1.80, 3.83]29% [10%, 42%]62%71%+0.24+0.302026-08-10 → 2026-08-30
tmin00Zbilinear365d21 1 QC2.11 [1.36, 3.03]1.93+0.86 [0.01, 1.63]2.78 [1.71, 3.86]29% [8%, 43%]62%71%+0.24+0.302026-08-10 → 2026-08-30
tmin00Zbilinearall21 1 QC2.11 [1.40, 3.03]1.93+0.86 [-0.05, 1.63]2.78 [1.79, 3.86]29% [7%, 43%]62%71%+0.24+0.302026-08-10 → 2026-08-30
tmin00Znearest30d21 1 QC2.13 [1.47, 2.89]1.93+0.89 [0.09, 1.63]2.80 [1.87, 3.72]29% [14%, 42%]62%71%+0.23+0.302026-08-10 → 2026-08-30
tmin00Znearest90d21 1 QC2.13 [1.43, 3.00]1.93+0.89 [0.05, 1.60]2.80 [1.81, 3.84]29% [10%, 42%]62%71%+0.23+0.302026-08-10 → 2026-08-30
tmin00Znearest365d21 1 QC2.13 [1.38, 3.04]1.93+0.89 [0.05, 1.68]2.80 [1.73, 3.88]29% [8%, 43%]62%71%+0.23+0.302026-08-10 → 2026-08-30
tmin00Znearestall21 1 QC2.13 [1.41, 3.04]1.93+0.89 [-0.02, 1.68]2.80 [1.81, 3.88]29% [7%, 43%]62%71%+0.23+0.302026-08-10 → 2026-08-30
tmin12Zbilinear30d21 1 QC1.70 [1.34, 2.18]1.68+0.32 [-0.33, 0.89]2.11 [1.70, 2.54]43% [30%, 55%]52%86%+0.38+0.392026-08-10 → 2026-08-30
tmin12Zbilinear90d21 1 QC1.70 [1.28, 2.24]1.68+0.32 [-0.30, 1.02]2.11 [1.63, 2.57]43% [27%, 55%]52%86%+0.38+0.392026-08-10 → 2026-08-30
tmin12Zbilinear365d21 1 QC1.70 [1.29, 2.25]1.68+0.32 [-0.54, 0.98]2.11 [1.63, 2.57]43% [29%, 55%]52%86%+0.38+0.392026-08-10 → 2026-08-30
tmin12Zbilinearall21 1 QC1.70 [1.32, 2.31]1.68+0.32 [-0.55, 0.98]2.11 [1.67, 2.63]43% [26%, 55%]52%86%+0.38+0.392026-08-10 → 2026-08-30
tmin12Znearest30d21 1 QC1.71 [1.35, 2.19]1.68+0.36 [-0.29, 0.93]2.11 [1.70, 2.53]38% [25%, 50%]52%86%+0.38+0.392026-08-10 → 2026-08-30
tmin12Znearest90d21 1 QC1.71 [1.29, 2.25]1.68+0.36 [-0.27, 1.05]2.11 [1.65, 2.58]38% [25%, 53%]52%86%+0.38+0.392026-08-10 → 2026-08-30
tmin12Znearest365d21 1 QC1.71 [1.30, 2.25]1.68+0.36 [-0.50, 1.02]2.11 [1.65, 2.57]38% [25%, 52%]52%86%+0.38+0.392026-08-10 → 2026-08-30
tmin12Znearestall21 1 QC1.71 [1.33, 2.28]1.68+0.36 [-0.51, 1.02]2.11 [1.69, 2.62]38% [22%, 52%]52%86%+0.38+0.392026-08-10 → 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 KMSY, lead day 9, 00Z bilinear tmax+10+50-5-102026-08-10: -3.07 °F2026-08-11: -5.65 °F2026-08-12: -7.19 °F2026-08-13: -6.19 °F2026-08-14: -2.92 °F2026-08-15: -3.82 °F2026-08-16: -4.69 °F2026-08-17: -3.66 °F2026-08-18: +0.67 °F2026-08-19: -6.17 °F2026-08-20: -4.8 °F2026-08-21: -5.67 °F2026-08-22: -8.7 °F2026-08-23: -5.3 °F2026-08-24: -6.81 °F2026-08-25: -5.49 °F2026-08-26: -3.59 °F2026-08-27: -0.86 °F2026-08-28: -5.6 °F2026-08-29: -2.39 °F2026-08-30: -0.76 °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
2026-08-30-0.76
2026-08-29-2.39
2026-08-28-5.60
2026-08-27-0.86
2026-08-26-3.59
2026-08-25-5.49
2026-08-24-6.81
2026-08-23-5.30
2026-08-22-8.70
2026-08-21-5.67
2026-08-20-4.80
2026-08-19-6.17
2026-08-18+0.67
2026-08-17-3.66
2026-08-16-4.69
2026-08-15-3.82
2026-08-14-2.92
2026-08-13-6.19
2026-08-12-7.19
2026-08-11-5.65
2026-08-10-3.07

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KMSY, lead day 9-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 1 day-7 to -6 °F: 3 days-6 to -5 °F: 5 days-5 to -4 °F: 2 days-4 to -3 °F: 4 days-3 to -2 °F: 2 days-2 to -1 °F: 0 days-1 to 0 °F: 2 days0 to 1 °F: 1 day1 to 2 °F: 0 days2 to 3 °F: 0 days3 to 4 °F: 0 days4 to 5 °F: 0 days5 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| 4.8 · P90 |e| 6.81 °F-100+10 °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
-10.00-9.000
-9.00-8.001
-8.00-7.001
-7.00-6.003
-6.00-5.005
-5.00-4.002
-4.00-3.004
-3.00-2.002
-2.00-1.000
-1.00+0.002
+0.00+1.001
+1.00+2.000
+2.00+3.000
+3.00+4.000
+4.00+5.000
+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
2026-08214.48 -4.41

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 -0.36 [-1.21, 0.37] no
GraphCast (IFS init) 21 -0.68 [-2.97, 0.85] no
ECMWF IFS HRES 16 -0.30 [-3.29, 1.32] no
Persistence (baseline) 21 +1.19 [-1.51, 2.77] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KMSY (New Orleans Intl), 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/KMSY/model/gfs/lead/9/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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