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

New Orleans Intl · NCEP GFS · lead day 8

KMSY · 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 QC3.48 [2.58, 4.20]2.08-3.27 [-4.14, -2.15]4.14 [3.08, 4.92]18% [10%, 29%]27%45%-0.08+0.342026-08-09 → 2026-08-30
tmax00Zbilinear90d22 1 QC3.48 [2.55, 4.27]2.08-3.27 [-4.20, -2.04]4.14 [3.06, 5.00]18% [9%, 29%]27%45%-0.08+0.342026-08-09 → 2026-08-30
tmax00Zbilinear365d22 1 QC3.48 [2.53, 4.37]2.08-3.27 [-4.28, -2.05]4.14 [3.05, 5.07]18% [8%, 29%]27%45%-0.08+0.342026-08-09 → 2026-08-30
tmax00Zbilinearall22 1 QC3.48 [2.54, 4.36]2.08-3.27 [-4.29, -2.01]4.14 [3.05, 5.07]18% [9%, 29%]27%45%-0.08+0.342026-08-09 → 2026-08-30
tmax00Znearest30d22 1 QC3.62 [2.74, 4.34]2.10-3.41 [-4.29, -2.24]4.27 [3.22, 5.07]14% [0%, 27%]27%41%-0.12+0.332026-08-09 → 2026-08-30
tmax00Znearest90d22 1 QC3.62 [2.70, 4.44]2.10-3.41 [-4.37, -2.16]4.27 [3.19, 5.12]14% [0%, 29%]27%41%-0.12+0.332026-08-09 → 2026-08-30
tmax00Znearest365d22 1 QC3.62 [2.67, 4.51]2.10-3.41 [-4.44, -2.19]4.27 [3.21, 5.21]14% [0%, 29%]27%41%-0.12+0.332026-08-09 → 2026-08-30
tmax00Znearestall22 1 QC3.62 [2.68, 4.51]2.10-3.41 [-4.47, -2.13]4.27 [3.19, 5.21]14% [0%, 29%]27%41%-0.12+0.332026-08-09 → 2026-08-30
tmax12Zbilinear30d22 1 QC4.48 [3.26, 5.41]2.23-4.36 [-5.32, -3.06]5.27 [3.97, 6.32]5% [0%, 13%]23%36%-0.39+0.292026-08-09 → 2026-08-30
tmax12Zbilinear90d22 1 QC4.48 [3.20, 5.52]2.23-4.36 [-5.44, -3.00]5.27 [3.94, 6.43]5% [0%, 14%]23%36%-0.39+0.292026-08-09 → 2026-08-30
tmax12Zbilinear365d22 1 QC4.48 [3.15, 5.64]2.23-4.36 [-5.58, -2.97]5.27 [3.92, 6.60]5% [0%, 14%]23%36%-0.39+0.292026-08-09 → 2026-08-30
tmax12Zbilinearall22 1 QC4.48 [3.19, 5.64]2.23-4.36 [-5.59, -2.93]5.27 [3.94, 6.60]5% [0%, 14%]23%36%-0.39+0.292026-08-09 → 2026-08-30
tmax12Znearest30d22 1 QC4.62 [3.39, 5.52]2.26-4.50 [-5.41, -3.18]5.38 [4.11, 6.39]5% [0%, 13%]23%36%-0.43+0.282026-08-09 → 2026-08-30
tmax12Znearest90d22 1 QC4.62 [3.32, 5.61]2.26-4.50 [-5.56, -3.11]5.38 [4.06, 6.50]5% [0%, 14%]23%36%-0.43+0.282026-08-09 → 2026-08-30
tmax12Znearest365d22 1 QC4.62 [3.27, 5.76]2.26-4.50 [-5.62, -3.08]5.38 [4.05, 6.63]5% [0%, 14%]23%36%-0.43+0.282026-08-09 → 2026-08-30
tmax12Znearestall22 1 QC4.62 [3.31, 5.71]2.26-4.50 [-5.67, -3.02]5.38 [4.03, 6.63]5% [0%, 14%]23%36%-0.43+0.282026-08-09 → 2026-08-30
tmin00Zbilinear30d22 1 QC2.14 [1.52, 3.00]1.90+0.94 [-0.05, 1.79]2.68 [1.87, 3.56]27% [6%, 46%]55%77%+0.20+0.292026-08-09 → 2026-08-30
tmin00Zbilinear90d22 1 QC2.14 [1.44, 3.14]1.90+0.94 [-0.06, 1.81]2.68 [1.65, 3.66]27% [0%, 44%]55%77%+0.20+0.292026-08-09 → 2026-08-30
tmin00Zbilinear365d22 1 QC2.14 [1.43, 3.18]1.90+0.94 [-0.23, 1.81]2.68 [1.71, 3.70]27% [0%, 46%]55%77%+0.20+0.292026-08-09 → 2026-08-30
tmin00Zbilinearall22 1 QC2.14 [1.46, 3.23]1.90+0.94 [-0.28, 1.80]2.68 [1.75, 3.73]27% [0%, 46%]55%77%+0.20+0.292026-08-09 → 2026-08-30
tmin00Znearest30d22 1 QC2.16 [1.53, 3.03]1.91+0.98 [-0.01, 1.83]2.70 [1.87, 3.58]27% [6%, 46%]55%77%+0.19+0.282026-08-09 → 2026-08-30
tmin00Znearest90d22 1 QC2.16 [1.44, 3.17]1.91+0.98 [-0.02, 1.84]2.70 [1.66, 3.69]27% [0%, 44%]55%77%+0.19+0.282026-08-09 → 2026-08-30
tmin00Znearest365d22 1 QC2.16 [1.44, 3.20]1.91+0.98 [-0.19, 1.86]2.70 [1.73, 3.72]27% [0%, 46%]55%77%+0.19+0.282026-08-09 → 2026-08-30
tmin00Znearestall22 1 QC2.16 [1.48, 3.25]1.91+0.98 [-0.24, 1.83]2.70 [1.78, 3.75]27% [0%, 46%]55%77%+0.19+0.282026-08-09 → 2026-08-30
tmin12Zbilinear30d22 1 QC1.94 [1.41, 2.69]1.79+1.01 [0.26, 1.74]2.49 [1.80, 3.27]36% [23%, 48%]59%73%+0.28+0.332026-08-09 → 2026-08-30
tmin12Zbilinear90d22 1 QC1.94 [1.39, 2.81]1.79+1.01 [0.27, 1.80]2.49 [1.78, 3.33]36% [22%, 50%]59%73%+0.28+0.332026-08-09 → 2026-08-30
tmin12Zbilinear365d22 1 QC1.94 [1.38, 2.86]1.79+1.01 [0.09, 1.82]2.49 [1.77, 3.45]36% [21%, 50%]59%73%+0.28+0.332026-08-09 → 2026-08-30
tmin12Zbilinearall22 1 QC1.94 [1.39, 2.89]1.79+1.01 [0.08, 1.79]2.49 [1.79, 3.45]36% [20%, 50%]59%73%+0.28+0.332026-08-09 → 2026-08-30
tmin12Znearest30d22 1 QC1.96 [1.43, 2.71]1.80+1.04 [0.28, 1.76]2.51 [1.82, 3.28]36% [23%, 48%]59%73%+0.27+0.322026-08-09 → 2026-08-30
tmin12Znearest90d22 1 QC1.96 [1.40, 2.83]1.80+1.04 [0.30, 1.83]2.51 [1.80, 3.35]36% [22%, 50%]59%73%+0.27+0.322026-08-09 → 2026-08-30
tmin12Znearest365d22 1 QC1.96 [1.38, 2.88]1.80+1.04 [0.12, 1.86]2.51 [1.79, 3.46]36% [21%, 50%]59%73%+0.27+0.322026-08-09 → 2026-08-30
tmin12Znearestall22 1 QC1.96 [1.40, 2.90]1.80+1.04 [0.11, 1.83]2.51 [1.81, 3.46]36% [20%, 50%]59%73%+0.27+0.322026-08-09 → 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 KMSY, lead day 8, 00Z bilinear tmax+10+50-5-102026-08-09: -1.47 °F2026-08-10: -4.69 °F2026-08-11: -2.4 °F2026-08-12: -0.92 °F2026-08-13: -4.01 °F2026-08-14: -3.12 °F2026-08-15: -5.18 °F2026-08-16: -6.64 °F2026-08-17: -1.7 °F2026-08-18: -4.84 °F2026-08-19: +0.09 °F2026-08-20: -2.34 °F2026-08-21: -8.99 °F2026-08-22: -6 °F2026-08-23: -4.71 °F2026-08-24: -4.73 °F2026-08-25: -3.63 °F2026-08-26: -0.63 °F2026-08-27: +2.16 °F2026-08-28: +0.02 °F2026-08-29: -5.44 °F2026-08-30: -2.81 °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
2026-08-30-2.81
2026-08-29-5.44
2026-08-28+0.02
2026-08-27+2.16
2026-08-26-0.63
2026-08-25-3.63
2026-08-24-4.73
2026-08-23-4.71
2026-08-22-6.00
2026-08-21-8.99
2026-08-20-2.34
2026-08-19+0.09
2026-08-18-4.84
2026-08-17-1.70
2026-08-16-6.64
2026-08-15-5.18
2026-08-14-3.12
2026-08-13-4.01
2026-08-12-0.92
2026-08-11-2.40
2026-08-10-4.69
2026-08-09-1.47

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KMSY, lead day 8-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 0 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: 3 days-2 to -1 °F: 2 days-1 to 0 °F: 2 days0 to 1 °F: 2 days1 to 2 °F: 0 days2 to 3 °F: 1 day3 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| 3.37 · P90 |e| 5.95 °F-100+10 °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
-10.00-9.000
-9.00-8.001
-8.00-7.000
-7.00-6.002
-6.00-5.002
-5.00-4.005
-4.00-3.002
-3.00-2.003
-2.00-1.002
-1.00+0.002
+0.00+1.002
+1.00+2.000
+2.00+3.001
+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
2026-08223.48 -3.27

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 -1.60 [-3.24, -0.49] yes
GraphCast (IFS init) 22 -1.71 [-3.34, -0.46] yes
ECMWF IFS HRES 17 -0.35 [-2.28, 0.93] no
Persistence (baseline) 22 +0.25 [-2.21, 1.98] no

Cite this page

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

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