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 7

KLAS · gfs · lead 7

Target day = initialization date + 7 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, 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
tmax00Zbilinear30d23 2 QC6.75 [4.28, 8.42]6.00-3.40 [-7.39, 1.34]8.23 [5.49, 9.89]9% [0%, 22%]17%30%+0.20+0.282026-08-08 → 2026-08-30
tmax00Zbilinear90d23 2 QC6.75 [3.46, 8.67]6.00-3.40 [-7.81, 1.93]8.23 [4.58, 10.01]9% [0%, 25%]17%30%+0.20+0.282026-08-08 → 2026-08-30
tmax00Zbilinear365d23 2 QC6.75 [3.44, 8.77]6.00-3.40 [-8.22, 2.14]8.23 [4.58, 10.16]9% [0%, 25%]17%30%+0.20+0.282026-08-08 → 2026-08-30
tmax00Zbilinearall23 2 QC6.75 [3.38, 8.73]6.00-3.40 [-8.63, 2.15]8.23 [4.55, 10.39]9% [0%, 25%]17%30%+0.20+0.282026-08-08 → 2026-08-30
tmax00Znearest30d23 2 QC7.66 [4.88, 9.58]5.89-5.16 [-9.10, -0.49]8.96 [6.05, 10.84]4% [0%, 17%]13%17%+0.09+0.292026-08-08 → 2026-08-30
tmax00Znearest90d23 2 QC7.66 [4.24, 9.89]5.89-5.16 [-9.49, 0.04]8.96 [5.36, 11.10]4% [0%, 20%]13%17%+0.09+0.292026-08-08 → 2026-08-30
tmax00Znearest365d23 2 QC7.66 [4.22, 9.93]5.89-5.16 [-9.78, 0.24]8.96 [5.33, 11.18]4% [0%, 20%]13%17%+0.09+0.292026-08-08 → 2026-08-30
tmax00Znearestall23 2 QC7.66 [4.08, 10.19]5.89-5.16 [-10.19, 0.34]8.96 [5.24, 11.52]4% [0%, 25%]13%17%+0.09+0.292026-08-08 → 2026-08-30
tmax12Zbilinear30d23 2 QC6.80 [3.40, 9.43]6.09-4.09 [-8.85, 1.04]9.00 [4.80, 11.73]17% [0%, 41%]22%30%+0.19+0.272026-08-08 → 2026-08-30
tmax12Zbilinear90d23 2 QC6.80 [2.31, 9.69]6.09-4.09 [-9.17, 1.63]9.00 [3.23, 12.04]17% [0%, 50%]22%30%+0.19+0.272026-08-08 → 2026-08-30
tmax12Zbilinear365d23 2 QC6.80 [2.43, 9.88]6.09-4.09 [-9.84, 1.66]9.00 [3.09, 12.47]17% [0%, 50%]22%30%+0.19+0.272026-08-08 → 2026-08-30
tmax12Zbilinearall23 2 QC6.80 [2.43, 10.07]6.09-4.09 [-10.07, 1.63]9.00 [2.91, 12.68]17% [0%, 50%]22%30%+0.19+0.272026-08-08 → 2026-08-30
tmax12Znearest30d23 2 QC7.75 [4.07, 10.87]6.02-5.94 [-10.55, -0.85]9.94 [5.37, 13.13]9% [0%, 22%]13%30%+0.08+0.282026-08-08 → 2026-08-30
tmax12Znearest90d23 2 QC7.75 [3.02, 11.17]6.02-5.94 [-10.96, -0.31]9.94 [3.57, 13.46]9% [0%, 24%]13%30%+0.08+0.282026-08-08 → 2026-08-30
tmax12Znearest365d23 2 QC7.75 [2.98, 11.62]6.02-5.94 [-11.62, -0.27]9.94 [3.49, 13.96]9% [0%, 25%]13%30%+0.08+0.282026-08-08 → 2026-08-30
tmax12Znearestall23 2 QC7.75 [2.91, 11.83]6.02-5.94 [-11.83, -0.30]9.94 [3.44, 14.18]9% [0%, 25%]13%30%+0.08+0.282026-08-08 → 2026-08-30
tmin00Zbilinear30d23 2 QC4.54 [2.65, 6.76]4.59+0.22 [-2.89, 4.08]6.00 [3.55, 8.23]22% [8%, 37%]35%39%+0.41+0.402026-08-08 → 2026-08-30
tmin00Zbilinear90d23 2 QC4.54 [2.49, 6.91]4.59+0.22 [-3.38, 3.95]6.00 [3.26, 8.29]22% [7%, 38%]35%39%+0.41+0.402026-08-08 → 2026-08-30
tmin00Zbilinear365d23 2 QC4.54 [2.28, 7.03]4.59+0.22 [-3.46, 4.30]6.00 [2.95, 8.49]22% [4%, 38%]35%39%+0.41+0.402026-08-08 → 2026-08-30
tmin00Zbilinearall23 2 QC4.54 [2.30, 7.25]4.59+0.22 [-3.22, 4.49]6.00 [3.07, 8.48]22% [6%, 40%]35%39%+0.41+0.402026-08-08 → 2026-08-30
tmin00Znearest30d23 2 QC4.79 [3.13, 6.61]4.64-0.64 [-3.57, 3.05]6.04 [4.11, 7.75]22% [4%, 44%]26%35%+0.38+0.392026-08-08 → 2026-08-30
tmin00Znearest90d23 2 QC4.79 [2.82, 6.71]4.64-0.64 [-4.04, 3.13]6.04 [3.70, 7.86]22% [0%, 50%]26%35%+0.38+0.392026-08-08 → 2026-08-30
tmin00Znearest365d23 2 QC4.79 [2.72, 6.85]4.64-0.64 [-4.14, 3.49]6.04 [3.64, 8.01]22% [0%, 50%]26%35%+0.38+0.392026-08-08 → 2026-08-30
tmin00Znearestall23 2 QC4.79 [2.64, 6.95]4.64-0.64 [-3.90, 3.57]6.04 [3.58, 8.03]22% [0%, 52%]26%35%+0.38+0.392026-08-08 → 2026-08-30
tmin12Zbilinear30d23 2 QC4.71 [3.16, 5.77]4.37-1.37 [-4.32, 2.22]5.76 [3.85, 6.71]13% [3%, 26%]26%35%+0.39+0.432026-08-08 → 2026-08-30
tmin12Zbilinear90d23 2 QC4.71 [2.92, 5.78]4.37-1.37 [-4.69, 2.26]5.76 [3.62, 6.73]13% [0%, 29%]26%35%+0.39+0.432026-08-08 → 2026-08-30
tmin12Zbilinear365d23 2 QC4.71 [2.96, 5.85]4.37-1.37 [-4.74, 2.51]5.76 [3.57, 6.77]13% [0%, 29%]26%35%+0.39+0.432026-08-08 → 2026-08-30
tmin12Zbilinearall23 2 QC4.71 [2.80, 5.95]4.37-1.37 [-4.82, 2.64]5.76 [3.43, 6.82]13% [0%, 33%]26%35%+0.39+0.432026-08-08 → 2026-08-30
tmin12Znearest30d23 2 QC5.25 [3.73, 6.44]4.42-2.38 [-5.40, 1.27]6.22 [4.50, 7.48]4% [0%, 17%]13%26%+0.32+0.422026-08-08 → 2026-08-30
tmin12Znearest90d23 2 QC5.25 [3.39, 6.45]4.42-2.38 [-5.74, 1.24]6.22 [4.15, 7.51]4% [0%, 20%]13%26%+0.32+0.422026-08-08 → 2026-08-30
tmin12Znearest365d23 2 QC5.25 [3.40, 6.55]4.42-2.38 [-5.93, 1.48]6.22 [4.09, 7.61]4% [0%, 20%]13%26%+0.32+0.422026-08-08 → 2026-08-30
tmin12Znearestall23 2 QC5.25 [3.20, 6.79]4.42-2.38 [-5.97, 1.69]6.22 [3.97, 7.74]4% [0%, 25%]13%26%+0.32+0.422026-08-08 → 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 7, 00Z bilinear tmax+20+100-10-202026-08-08: -7.67 °F2026-08-09: -2.2 °F2026-08-10: +0.23 °F2026-08-11: +4.48 °F2026-08-12: -1.37 °F2026-08-13: +12.1 °F2026-08-14: +7.19 °F2026-08-15: +11.54 °F2026-08-16: -7.26 °F2026-08-17: -9.43 °F2026-08-18: -8.92 °F2026-08-19: -7.27 °F2026-08-20: -6.07 °F2026-08-21: -2.27 °F2026-08-22: -1.7 °F2026-08-23: -13.23 °F2026-08-24: -15.17 °F2026-08-25: -16.9 °F2026-08-26: -5.08 °F2026-08-27: -9.39 °F2026-08-28: -2.65 °F2026-08-29: -0.18 °F2026-08-30: +3.03 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+3.03
2026-08-29-0.18
2026-08-28-2.65
2026-08-27-9.39
2026-08-26-5.08
2026-08-25-16.90
2026-08-24-15.17
2026-08-23-13.23
2026-08-22-1.70
2026-08-21-2.27
2026-08-20-6.07
2026-08-19-7.27
2026-08-18-8.92
2026-08-17-9.43
2026-08-16-7.26
2026-08-15+11.54
2026-08-14+7.19
2026-08-13+12.10
2026-08-12-1.37
2026-08-11+4.48
2026-08-10+0.23
2026-08-09-2.20
2026-08-08-7.67

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAS, lead day 7-20 to -18 °F: 0 days-18 to -16 °F: 1 day-16 to -14 °F: 1 day-14 to -12 °F: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 3 days-8 to -6 °F: 4 days-6 to -4 °F: 1 day-4 to -2 °F: 3 days-2 to 0 °F: 3 days0 to 2 °F: 1 day2 to 4 °F: 1 day4 to 6 °F: 1 day6 to 8 °F: 1 day8 to 10 °F: 0 days10 to 12 °F: 1 day12 to 14 °F: 1 day14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 7.19 · P90 |e| 13.01 °F-200+20 °Fn = 23 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
-18.00-16.001
-16.00-14.001
-14.00-12.001
-12.00-10.000
-10.00-8.003
-8.00-6.004
-6.00-4.001
-4.00-2.003
-2.00+0.003
+0.00+2.001
+2.00+4.001
+4.00+6.001
+6.00+8.001
+8.00+10.000
+10.00+12.001
+12.00+14.001
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08236.75 -3.40

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23

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 23 -0.28 [-2.98, 2.12] no
GraphCast (IFS init) 23 -2.16 [-5.95, 0.32] no
ECMWF IFS HRES 18 +2.82 [-0.05, 4.84] no
Persistence (baseline) 23 -1.68 [-5.31, 3.23] no

Cite this page

ShortCastCheck, KLAS gfs lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAS/model/gfs/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAS (Las Vegas Harry Reid), model gfs, lead day 7. 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/7/

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