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

Las Vegas Harry Reid · NCEP GFS · lead day 1

KLAS · gfs · lead 1

Target day = initialization date + 1 day. 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, 2 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
tmax00Zbilinear30d29 2 QC5.14 [4.46, 5.73]2.37-4.42 [-5.62, -3.07]5.61 [4.95, 6.05]10% [0%, 21%]10%17%-0.64+0.252026-08-02 → 2026-08-30
tmax00Zbilinear90d29 2 QC5.14 [4.36, 5.82]2.37-4.42 [-5.77, -3.08]5.61 [4.83, 6.05]10% [0%, 22%]10%17%-0.64+0.252026-08-02 → 2026-08-30
tmax00Zbilinear365d29 2 QC5.14 [4.43, 5.81]2.37-4.42 [-5.80, -2.94]5.61 [4.91, 6.10]10% [0%, 22%]10%17%-0.64+0.252026-08-02 → 2026-08-30
tmax00Zbilinearall29 2 QC5.14 [4.41, 5.80]2.37-4.42 [-5.77, -3.08]5.61 [4.85, 6.08]10% [0%, 21%]10%17%-0.64+0.252026-08-02 → 2026-08-30
tmax00Znearest30d29 2 QC6.55 [5.69, 7.38]2.42-6.08 [-7.32, -4.66]7.01 [6.37, 7.56]3% [0%, 10%]7%14%-1.09+0.232026-08-02 → 2026-08-30
tmax00Znearest90d29 2 QC6.55 [5.63, 7.49]2.42-6.08 [-7.46, -4.68]7.01 [6.28, 7.63]3% [0%, 10%]7%14%-1.09+0.232026-08-02 → 2026-08-30
tmax00Znearest365d29 2 QC6.55 [5.65, 7.52]2.42-6.08 [-7.52, -4.58]7.01 [6.33, 7.63]3% [0%, 11%]7%14%-1.09+0.232026-08-02 → 2026-08-30
tmax00Znearestall29 2 QC6.55 [5.59, 7.53]2.42-6.08 [-7.52, -4.69]7.01 [6.30, 7.65]3% [0%, 11%]7%14%-1.09+0.232026-08-02 → 2026-08-30
tmax12Zbilinear30d29 2 QC5.22 [4.59, 5.90]2.24-4.64 [-5.82, -3.30]5.75 [5.04, 6.37]7% [0%, 20%]14%14%-0.66+0.292026-08-02 → 2026-08-30
tmax12Zbilinear90d29 2 QC5.22 [4.50, 5.91]2.24-4.64 [-5.87, -3.29]5.75 [4.93, 6.33]7% [0%, 21%]14%14%-0.66+0.292026-08-02 → 2026-08-30
tmax12Zbilinear365d29 2 QC5.22 [4.57, 5.96]2.24-4.64 [-5.96, -3.23]5.75 [4.95, 6.35]7% [0%, 21%]14%14%-0.66+0.292026-08-02 → 2026-08-30
tmax12Zbilinearall29 2 QC5.22 [4.51, 5.93]2.24-4.64 [-5.92, -3.28]5.75 [4.88, 6.38]7% [0%, 20%]14%14%-0.66+0.292026-08-02 → 2026-08-30
tmax12Znearest30d29 2 QC6.69 [6.00, 7.32]2.33-6.30 [-7.31, -5.09]7.16 [6.60, 7.64]7% [0%, 17%]7%10%-1.13+0.262026-08-02 → 2026-08-30
tmax12Znearest90d29 2 QC6.69 [5.97, 7.38]2.33-6.30 [-7.38, -5.05]7.16 [6.50, 7.64]7% [0%, 18%]7%10%-1.13+0.262026-08-02 → 2026-08-30
tmax12Znearest365d29 2 QC6.69 [5.97, 7.45]2.33-6.30 [-7.45, -4.99]7.16 [6.58, 7.62]7% [0%, 19%]7%10%-1.13+0.262026-08-02 → 2026-08-30
tmax12Znearestall29 2 QC6.69 [5.95, 7.42]2.33-6.30 [-7.42, -5.06]7.16 [6.54, 7.64]7% [0%, 18%]7%10%-1.13+0.262026-08-02 → 2026-08-30
tmin00Zbilinear30d29 2 QC3.46 [2.60, 4.34]3.02-1.39 [-3.87, 1.41]4.16 [3.35, 4.87]10% [3%, 20%]34%48%-0.45-0.272026-08-02 → 2026-08-30
tmin00Zbilinear90d29 2 QC3.46 [2.48, 4.50]3.02-1.39 [-4.19, 1.34]4.16 [3.21, 4.92]10% [0%, 19%]34%48%-0.45-0.272026-08-02 → 2026-08-30
tmin00Zbilinear365d29 2 QC3.46 [2.36, 4.43]3.02-1.39 [-4.21, 1.73]4.16 [3.09, 4.87]10% [0%, 20%]34%48%-0.45-0.272026-08-02 → 2026-08-30
tmin00Zbilinearall29 2 QC3.46 [2.39, 4.49]3.02-1.39 [-4.41, 1.40]4.16 [3.18, 4.90]10% [0%, 20%]34%48%-0.45-0.272026-08-02 → 2026-08-30
tmin00Znearest30d29 2 QC3.50 [2.64, 4.36]2.78-1.86 [-4.10, 0.78]4.12 [3.30, 4.78]7% [0%, 14%]31%45%-0.47-0.172026-08-02 → 2026-08-30
tmin00Znearest90d29 2 QC3.50 [2.66, 4.48]2.78-1.86 [-4.40, 0.58]4.12 [3.25, 4.89]7% [0%, 14%]31%45%-0.47-0.172026-08-02 → 2026-08-30
tmin00Znearest365d29 2 QC3.50 [2.48, 4.45]2.78-1.86 [-4.39, 1.03]4.12 [3.07, 4.80]7% [0%, 14%]31%45%-0.47-0.172026-08-02 → 2026-08-30
tmin00Znearestall29 2 QC3.50 [2.63, 4.57]2.78-1.86 [-4.56, 0.68]4.12 [3.24, 4.90]7% [0%, 14%]31%45%-0.47-0.172026-08-02 → 2026-08-30
tmin12Zbilinear30d29 2 QC3.32 [2.22, 4.49]2.99-1.52 [-4.07, 1.21]3.99 [2.76, 4.93]21% [7%, 34%]31%48%-0.40-0.252026-08-02 → 2026-08-30
tmin12Zbilinear90d29 2 QC3.32 [2.03, 4.68]2.99-1.52 [-4.52, 1.02]3.99 [2.55, 5.04]21% [3%, 36%]31%48%-0.40-0.252026-08-02 → 2026-08-30
tmin12Zbilinear365d29 2 QC3.32 [1.94, 4.62]2.99-1.52 [-4.45, 1.50]3.99 [2.44, 5.02]21% [0%, 38%]31%48%-0.40-0.252026-08-02 → 2026-08-30
tmin12Zbilinearall29 2 QC3.32 [1.90, 4.63]2.99-1.52 [-4.46, 1.11]3.99 [2.41, 5.00]21% [0%, 38%]31%48%-0.40-0.252026-08-02 → 2026-08-30
tmin12Znearest30d29 2 QC3.40 [2.25, 4.60]2.77-2.14 [-4.42, 0.38]4.08 [2.95, 5.00]14% [0%, 30%]34%48%-0.43-0.162026-08-02 → 2026-08-30
tmin12Znearest90d29 2 QC3.40 [2.27, 4.86]2.77-2.14 [-4.78, 0.20]4.08 [2.90, 5.14]14% [0%, 30%]34%48%-0.43-0.162026-08-02 → 2026-08-30
tmin12Znearest365d29 2 QC3.40 [2.10, 4.79]2.77-2.14 [-4.78, 0.63]4.08 [2.70, 5.09]14% [0%, 30%]34%48%-0.43-0.162026-08-02 → 2026-08-30
tmin12Znearestall29 2 QC3.40 [2.17, 4.83]2.77-2.14 [-4.83, 0.27]4.08 [2.72, 5.10]14% [0%, 29%]34%48%-0.43-0.162026-08-02 → 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 KLAS, lead day 1, 00Z bilinear tmax+10+50-5-102026-08-02: -4.46 °F2026-08-03: -4.87 °F2026-08-04: -4.72 °F2026-08-05: -5.64 °F2026-08-06: -0.83 °F2026-08-07: -2.65 °F2026-08-08: -4.18 °F2026-08-09: -8.25 °F2026-08-10: +2.33 °F2026-08-11: -7.14 °F2026-08-12: -8.74 °F2026-08-13: +0.2 °F2026-08-14: -0.68 °F2026-08-15: +7.83 °F2026-08-16: -5.75 °F2026-08-17: -5.8 °F2026-08-18: -5.33 °F2026-08-19: -7.63 °F2026-08-20: -4.02 °F2026-08-21: -4.15 °F2026-08-22: -5.63 °F2026-08-23: -6.07 °F2026-08-24: -8.91 °F2026-08-25: -5.82 °F2026-08-26: -3.86 °F2026-08-27: -6.04 °F2026-08-28: -5.93 °F2026-08-29: -7.33 °F2026-08-30: -4.24 °F2026-08-022026-08-30°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 (29 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.24
2026-08-29-7.33
2026-08-28-5.93
2026-08-27-6.04
2026-08-26-3.86
2026-08-25-5.82
2026-08-24-8.91
2026-08-23-6.07
2026-08-22-5.63
2026-08-21-4.15
2026-08-20-4.02
2026-08-19-7.63
2026-08-18-5.33
2026-08-17-5.80
2026-08-16-5.75
2026-08-15+7.83
2026-08-14-0.68
2026-08-13+0.20
2026-08-12-8.74
2026-08-11-7.14
2026-08-10+2.33
2026-08-09-8.25
2026-08-08-4.18
2026-08-07-2.65
2026-08-06-0.83
2026-08-05-5.64
2026-08-04-4.72
2026-08-03-4.87
2026-08-02-4.46

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAS, lead day 1-10 to -9 °F: 0 days-9 to -8 °F: 3 days-8 to -7 °F: 3 days-7 to -6 °F: 2 days-6 to -5 °F: 7 days-5 to -4 °F: 7 days-4 to -3 °F: 1 day-3 to -2 °F: 1 day-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: 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: 1 day8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 5.63 · P90 |e| 7.91 °F-100+10 °Fn = 29 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
-9.00-8.003
-8.00-7.003
-7.00-6.002
-6.00-5.007
-5.00-4.007
-4.00-3.001
-3.00-2.001
-2.00-1.000
-1.00+0.002
+0.00+1.001
+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+8.001
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08295.14 -4.42

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-02 → 2026-08-30 29
NCEP GFS2026-08-02 → 2026-08-30 29
NCEP GFS2026-08-02 → 2026-08-30 29
NCEP GFS2026-08-02 → 2026-08-30 29

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 29 +0.67 [-0.06, 1.49] no
Aurora (GFS init) 1 -0.89 [-0.89, -0.89] yes
Aurora (IFS init) 2 +1.81 [1.61, 2.00] yes
FourCastNet v2 (GFS init) 1 -0.22 [-0.22, -0.22] yes
FourCastNet v2 (IFS init) 2 -0.29 [-1.95, 1.38] no
GraphCast (GFS init) 1 -3.40 [-3.40, -3.40] yes
GraphCast (IFS init) 27 +0.17 [-0.50, 0.91] no
ECMWF IFS HRES 22 +1.53 [0.25, 2.49] yes
Pangu-Weather (GFS init) 1 -0.65 [-0.65, -0.65] yes
Pangu-Weather (IFS init) 2 -0.02 [-0.29, 0.25] no
Persistence (baseline) 29 +2.00 [-0.14, 3.93] no

Cite this page

ShortCastCheck, KLAS gfs lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAS/model/gfs/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAS (Las Vegas Harry Reid), model gfs, lead day 1. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KLAS/model/gfs/lead/1/

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

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