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 3

KMSY · gfs · lead 3

Target day = initialization date + 3 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
tmax00Zbilinear30d27 1 QC3.78 [2.99, 4.67]1.53-3.78 [-4.67, -2.98]4.25 [3.44, 5.08]4% [0%, 10%]15%33%-0.70+0.322026-08-04 → 2026-08-30
tmax00Zbilinear90d27 1 QC3.78 [2.93, 4.86]1.53-3.78 [-4.86, -2.92]4.25 [3.29, 5.24]4% [0%, 10%]15%33%-0.70+0.322026-08-04 → 2026-08-30
tmax00Zbilinear365d27 1 QC3.78 [2.87, 5.03]1.53-3.78 [-5.03, -2.86]4.25 [3.34, 5.33]4% [0%, 11%]15%33%-0.70+0.322026-08-04 → 2026-08-30
tmax00Zbilinearall27 1 QC3.78 [2.84, 4.87]1.53-3.78 [-4.87, -2.83]4.25 [3.26, 5.19]4% [0%, 11%]15%33%-0.70+0.322026-08-04 → 2026-08-30
tmax00Znearest30d27 1 QC3.91 [3.12, 4.79]1.57-3.91 [-4.79, -3.12]4.39 [3.57, 5.20]4% [0%, 10%]15%30%-0.76+0.302026-08-04 → 2026-08-30
tmax00Znearest90d27 1 QC3.91 [3.05, 4.98]1.57-3.91 [-4.98, -3.05]4.39 [3.42, 5.36]4% [0%, 10%]15%30%-0.76+0.302026-08-04 → 2026-08-30
tmax00Znearest365d27 1 QC3.91 [2.98, 5.13]1.57-3.91 [-5.13, -2.98]4.39 [3.48, 5.46]4% [0%, 11%]15%30%-0.76+0.302026-08-04 → 2026-08-30
tmax00Znearestall27 1 QC3.91 [2.96, 4.98]1.57-3.91 [-4.98, -2.96]4.39 [3.40, 5.31]4% [0%, 11%]15%30%-0.76+0.302026-08-04 → 2026-08-30
tmax12Zbilinear30d27 1 QC4.10 [3.24, 5.08]1.39-4.10 [-5.08, -3.24]4.49 [3.67, 5.34]4% [0%, 10%]19%22%-0.85+0.382026-08-04 → 2026-08-30
tmax12Zbilinear90d27 1 QC4.10 [3.14, 5.27]1.39-4.10 [-5.27, -3.14]4.49 [3.59, 5.49]4% [0%, 10%]19%22%-0.85+0.382026-08-04 → 2026-08-30
tmax12Zbilinear365d27 1 QC4.10 [3.06, 5.48]1.39-4.10 [-5.48, -3.06]4.49 [3.57, 5.69]4% [0%, 11%]19%22%-0.85+0.382026-08-04 → 2026-08-30
tmax12Zbilinearall27 1 QC4.10 [3.10, 5.31]1.39-4.10 [-5.31, -3.10]4.49 [3.53, 5.53]4% [0%, 11%]19%22%-0.85+0.382026-08-04 → 2026-08-30
tmax12Znearest30d27 1 QC4.18 [3.33, 5.13]1.38-4.18 [-5.13, -3.33]4.57 [3.75, 5.41]4% [0%, 10%]19%22%-0.88+0.392026-08-04 → 2026-08-30
tmax12Znearest90d27 1 QC4.18 [3.23, 5.31]1.38-4.18 [-5.31, -3.23]4.57 [3.67, 5.56]4% [0%, 10%]19%22%-0.88+0.392026-08-04 → 2026-08-30
tmax12Znearest365d27 1 QC4.18 [3.15, 5.53]1.38-4.18 [-5.53, -3.15]4.57 [3.66, 5.75]4% [0%, 11%]19%22%-0.88+0.392026-08-04 → 2026-08-30
tmax12Znearestall27 1 QC4.18 [3.18, 5.37]1.38-4.18 [-5.37, -3.18]4.57 [3.62, 5.57]4% [0%, 11%]19%22%-0.88+0.392026-08-04 → 2026-08-30
tmin00Zbilinear30d27 1 QC1.70 [1.17, 2.30]1.40+1.00 [0.16, 1.73]2.13 [1.40, 2.81]33% [21%, 47%]67%85%+0.21+0.352026-08-04 → 2026-08-30
tmin00Zbilinear90d27 1 QC1.70 [1.19, 2.45]1.40+1.00 [-0.01, 1.81]2.13 [1.41, 2.93]33% [20%, 47%]67%85%+0.21+0.352026-08-04 → 2026-08-30
tmin00Zbilinear365d27 1 QC1.70 [1.09, 2.59]1.40+1.00 [-0.08, 1.80]2.13 [1.28, 3.09]33% [18%, 50%]67%85%+0.21+0.352026-08-04 → 2026-08-30
tmin00Zbilinearall27 1 QC1.70 [1.14, 2.50]1.40+1.00 [-0.01, 1.83]2.13 [1.34, 3.03]33% [19%, 50%]67%85%+0.21+0.352026-08-04 → 2026-08-30
tmin00Znearest30d27 1 QC1.73 [1.20, 2.33]1.41+1.04 [0.20, 1.79]2.15 [1.43, 2.83]33% [21%, 47%]67%85%+0.19+0.352026-08-04 → 2026-08-30
tmin00Znearest90d27 1 QC1.73 [1.21, 2.48]1.41+1.04 [0.03, 1.86]2.15 [1.43, 2.95]33% [20%, 47%]67%85%+0.19+0.352026-08-04 → 2026-08-30
tmin00Znearest365d27 1 QC1.73 [1.11, 2.62]1.41+1.04 [-0.04, 1.85]2.15 [1.30, 3.10]33% [18%, 50%]67%85%+0.19+0.352026-08-04 → 2026-08-30
tmin00Znearestall27 1 QC1.73 [1.16, 2.53]1.41+1.04 [0.04, 1.88]2.15 [1.37, 3.04]33% [19%, 50%]67%85%+0.19+0.352026-08-04 → 2026-08-30
tmin12Zbilinear30d27 1 QC1.67 [1.15, 2.21]1.49+1.15 [0.38, 1.82]2.10 [1.53, 2.59]41% [28%, 54%]56%78%+0.22+0.312026-08-04 → 2026-08-30
tmin12Zbilinear90d27 1 QC1.67 [1.18, 2.28]1.49+1.15 [0.26, 1.83]2.10 [1.56, 2.67]41% [29%, 54%]56%78%+0.22+0.312026-08-04 → 2026-08-30
tmin12Zbilinear365d27 1 QC1.67 [1.11, 2.29]1.49+1.15 [0.14, 1.90]2.10 [1.44, 2.69]41% [27%, 57%]56%78%+0.22+0.312026-08-04 → 2026-08-30
tmin12Zbilinearall27 1 QC1.67 [1.16, 2.33]1.49+1.15 [0.20, 1.97]2.10 [1.51, 2.72]41% [28%, 56%]56%78%+0.22+0.312026-08-04 → 2026-08-30
tmin12Znearest30d27 1 QC1.70 [1.18, 2.24]1.50+1.19 [0.42, 1.87]2.13 [1.56, 2.62]41% [28%, 54%]56%78%+0.21+0.312026-08-04 → 2026-08-30
tmin12Znearest90d27 1 QC1.70 [1.20, 2.30]1.50+1.19 [0.30, 1.88]2.13 [1.58, 2.69]41% [29%, 54%]56%78%+0.21+0.312026-08-04 → 2026-08-30
tmin12Znearest365d27 1 QC1.70 [1.13, 2.32]1.50+1.19 [0.19, 1.95]2.13 [1.47, 2.73]41% [27%, 57%]56%78%+0.21+0.312026-08-04 → 2026-08-30
tmin12Znearestall27 1 QC1.70 [1.18, 2.36]1.50+1.19 [0.23, 2.03]2.13 [1.54, 2.75]41% [28%, 56%]56%78%+0.21+0.312026-08-04 → 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 3, 00Z bilinear tmax+10+50-5-102026-08-04: -5.28 °F2026-08-05: -3.01 °F2026-08-06: -3.43 °F2026-08-07: -3.68 °F2026-08-08: -3.4 °F2026-08-09: -2.72 °F2026-08-10: -1.58 °F2026-08-11: -1.22 °F2026-08-12: +0.06 °F2026-08-13: -2.7 °F2026-08-14: -3.36 °F2026-08-15: -6.89 °F2026-08-16: -7.09 °F2026-08-17: -2.07 °F2026-08-18: -1.42 °F2026-08-19: -2.08 °F2026-08-20: -4.24 °F2026-08-21: -3.59 °F2026-08-22: -3.43 °F2026-08-23: -5.97 °F2026-08-24: -5.37 °F2026-08-25: -4.58 °F2026-08-26: -2.54 °F2026-08-27: -3.87 °F2026-08-28: -7.78 °F2026-08-29: -7.36 °F2026-08-30: -3.43 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.43
2026-08-29-7.36
2026-08-28-7.78
2026-08-27-3.87
2026-08-26-2.54
2026-08-25-4.58
2026-08-24-5.37
2026-08-23-5.97
2026-08-22-3.43
2026-08-21-3.59
2026-08-20-4.24
2026-08-19-2.08
2026-08-18-1.42
2026-08-17-2.07
2026-08-16-7.09
2026-08-15-6.89
2026-08-14-3.36
2026-08-13-2.70
2026-08-12+0.06
2026-08-11-1.22
2026-08-10-1.58
2026-08-09-2.72
2026-08-08-3.40
2026-08-07-3.68
2026-08-06-3.43
2026-08-05-3.01
2026-08-04-5.28

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KMSY, lead day 3-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 3 days-7 to -6 °F: 1 day-6 to -5 °F: 3 days-5 to -4 °F: 2 days-4 to -3 °F: 9 days-3 to -2 °F: 5 days-2 to -1 °F: 3 days-1 to 0 °F: 0 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| 3.43 · P90 |e| 6.97 °F-100+10 °Fn = 27 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
-9.00-8.000
-8.00-7.003
-7.00-6.001
-6.00-5.003
-5.00-4.002
-4.00-3.009
-3.00-2.005
-2.00-1.003
-1.00+0.000
+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
2026-08273.78 -3.78

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-04 → 2026-08-30 27
NCEP GFS2026-08-04 → 2026-08-30 27
NCEP GFS2026-08-04 → 2026-08-30 27
NCEP GFS2026-08-04 → 2026-08-30 27

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 27 -0.84 [-1.78, 0.30] no
GraphCast (IFS init) 25 -1.56 [-2.50, -0.41] yes
ECMWF IFS HRES 22 -0.89 [-2.56, 0.26] no
Persistence (baseline) 27 +1.56 [-0.35, 3.02] no

Cite this page

ShortCastCheck, KMSY gfs lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KMSY/model/gfs/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KMSY (New Orleans Intl), model gfs, lead day 3. 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/3/

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