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 2

KLAS · gfs · lead 2

Target day = initialization date + 2 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
tmax00Zbilinear30d28 2 QC4.60 [3.24, 5.84]2.81-3.75 [-5.65, -1.61]5.30 [4.28, 6.14]7% [0%, 17%]25%29%-0.12+0.302026-08-03 → 2026-08-30
tmax00Zbilinear90d28 2 QC4.60 [3.01, 5.94]2.81-3.75 [-5.77, -1.54]5.30 [4.09, 6.16]7% [0%, 19%]25%29%-0.12+0.302026-08-03 → 2026-08-30
tmax00Zbilinear365d28 2 QC4.60 [3.02, 6.00]2.81-3.75 [-5.94, -1.41]5.30 [4.11, 6.20]7% [0%, 17%]25%29%-0.12+0.302026-08-03 → 2026-08-30
tmax00Zbilinearall28 2 QC4.60 [2.98, 6.03]2.81-3.75 [-6.02, -1.56]5.30 [3.93, 6.27]7% [0%, 17%]25%29%-0.12+0.302026-08-03 → 2026-08-30
tmax00Znearest30d28 2 QC6.05 [4.20, 7.74]2.87-5.59 [-7.66, -3.34]6.81 [5.14, 8.21]7% [0%, 17%]14%18%-0.47+0.282026-08-03 → 2026-08-30
tmax00Znearest90d28 2 QC6.05 [4.05, 7.93]2.87-5.59 [-7.85, -3.22]6.81 [4.90, 8.31]7% [0%, 19%]14%18%-0.47+0.282026-08-03 → 2026-08-30
tmax00Znearest365d28 2 QC6.05 [3.91, 8.02]2.87-5.59 [-8.02, -3.10]6.81 [4.84, 8.43]7% [0%, 20%]14%18%-0.47+0.282026-08-03 → 2026-08-30
tmax00Znearestall28 2 QC6.05 [3.95, 8.18]2.87-5.59 [-8.18, -3.30]6.81 [4.86, 8.62]7% [0%, 19%]14%18%-0.47+0.282026-08-03 → 2026-08-30
tmax12Zbilinear30d28 2 QC4.29 [3.25, 5.26]2.38-3.47 [-5.10, -1.66]4.71 [3.81, 5.39]11% [0%, 23%]18%25%-0.04+0.402026-08-03 → 2026-08-30
tmax12Zbilinear90d28 2 QC4.29 [3.09, 5.32]2.38-3.47 [-5.24, -1.52]4.71 [3.66, 5.44]11% [0%, 24%]18%25%-0.04+0.402026-08-03 → 2026-08-30
tmax12Zbilinear365d28 2 QC4.29 [3.05, 5.33]2.38-3.47 [-5.31, -1.37]4.71 [3.60, 5.45]11% [0%, 24%]18%25%-0.04+0.402026-08-03 → 2026-08-30
tmax12Zbilinearall28 2 QC4.29 [3.05, 5.32]2.38-3.47 [-5.29, -1.57]4.71 [3.63, 5.43]11% [0%, 24%]18%25%-0.04+0.402026-08-03 → 2026-08-30
tmax12Znearest30d28 2 QC5.80 [4.42, 7.04]2.42-5.30 [-6.97, -3.46]6.21 [4.98, 7.14]0% [0%, 0%]11%18%-0.41+0.392026-08-03 → 2026-08-30
tmax12Znearest90d28 2 QC5.80 [4.29, 7.17]2.42-5.30 [-7.14, -3.33]6.21 [4.85, 7.24]0% [0%, 0%]11%18%-0.41+0.392026-08-03 → 2026-08-30
tmax12Znearest365d28 2 QC5.80 [4.19, 7.21]2.42-5.30 [-7.21, -3.18]6.21 [4.78, 7.28]0% [0%, 0%]11%18%-0.41+0.392026-08-03 → 2026-08-30
tmax12Znearestall28 2 QC5.80 [4.16, 7.19]2.42-5.30 [-7.19, -3.28]6.21 [4.76, 7.27]0% [0%, 0%]11%18%-0.41+0.392026-08-03 → 2026-08-30
tmin00Zbilinear30d28 2 QC3.71 [2.80, 4.61]3.50-0.94 [-3.68, 2.15]4.32 [3.28, 5.27]4% [0%, 10%]29%50%+0.04+0.102026-08-03 → 2026-08-30
tmin00Zbilinear90d28 2 QC3.71 [2.74, 4.72]3.50-0.94 [-4.08, 2.05]4.32 [3.18, 5.27]4% [0%, 10%]29%50%+0.04+0.102026-08-03 → 2026-08-30
tmin00Zbilinear365d28 2 QC3.71 [2.64, 4.71]3.50-0.94 [-4.00, 2.47]4.32 [3.09, 5.33]4% [0%, 11%]29%50%+0.04+0.102026-08-03 → 2026-08-30
tmin00Zbilinearall28 2 QC3.71 [2.67, 4.76]3.50-0.94 [-4.40, 2.29]4.32 [3.12, 5.28]4% [0%, 11%]29%50%+0.04+0.102026-08-03 → 2026-08-30
tmin00Znearest30d28 2 QC3.77 [2.79, 4.63]3.41-1.62 [-4.28, 1.41]4.48 [3.55, 5.16]14% [4%, 24%]29%46%+0.02+0.122026-08-03 → 2026-08-30
tmin00Znearest90d28 2 QC3.77 [2.78, 4.83]3.41-1.62 [-4.73, 1.22]4.48 [3.51, 5.27]14% [0%, 23%]29%46%+0.02+0.122026-08-03 → 2026-08-30
tmin00Znearest365d28 2 QC3.77 [2.70, 4.84]3.41-1.62 [-4.69, 1.62]4.48 [3.42, 5.26]14% [0%, 24%]29%46%+0.02+0.122026-08-03 → 2026-08-30
tmin00Znearestall28 2 QC3.77 [2.76, 4.94]3.41-1.62 [-4.86, 1.54]4.48 [3.49, 5.33]14% [0%, 24%]29%46%+0.02+0.122026-08-03 → 2026-08-30
tmin12Zbilinear30d28 2 QC3.26 [2.43, 4.21]3.09-0.71 [-3.26, 2.08]3.81 [2.81, 4.78]11% [4%, 17%]29%50%+0.16+0.202026-08-03 → 2026-08-30
tmin12Zbilinear90d28 2 QC3.26 [2.35, 4.35]3.09-0.71 [-3.70, 1.95]3.81 [2.69, 4.79]11% [0%, 15%]29%50%+0.16+0.202026-08-03 → 2026-08-30
tmin12Zbilinear365d28 2 QC3.26 [2.22, 4.31]3.09-0.71 [-3.60, 2.39]3.81 [2.55, 4.85]11% [0%, 15%]29%50%+0.16+0.202026-08-03 → 2026-08-30
tmin12Zbilinearall28 2 QC3.26 [2.21, 4.44]3.09-0.71 [-4.01, 2.13]3.81 [2.55, 4.86]11% [0%, 15%]29%50%+0.16+0.202026-08-03 → 2026-08-30
tmin12Znearest30d28 2 QC3.18 [2.45, 4.02]2.78-1.34 [-3.65, 1.21]3.71 [2.93, 4.43]14% [4%, 23%]32%43%+0.17+0.282026-08-03 → 2026-08-30
tmin12Znearest90d28 2 QC3.18 [2.42, 4.18]2.78-1.34 [-4.08, 1.06]3.71 [2.86, 4.56]14% [0%, 24%]32%43%+0.17+0.282026-08-03 → 2026-08-30
tmin12Znearest365d28 2 QC3.18 [2.35, 4.14]2.78-1.34 [-3.96, 1.45]3.71 [2.73, 4.56]14% [0%, 23%]32%43%+0.17+0.282026-08-03 → 2026-08-30
tmin12Znearestall28 2 QC3.18 [2.39, 4.37]2.78-1.34 [-4.34, 1.33]3.71 [2.70, 4.67]14% [0%, 24%]32%43%+0.17+0.282026-08-03 → 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 2, 00Z bilinear tmax+20+100-10-202026-08-03: -3.35 °F2026-08-04: -3.87 °F2026-08-05: -4.84 °F2026-08-06: -0.06 °F2026-08-07: -1.32 °F2026-08-08: -10.43 °F2026-08-09: -1.78 °F2026-08-10: +1.2 °F2026-08-11: +0.19 °F2026-08-12: -1.62 °F2026-08-13: +2.21 °F2026-08-14: -1.95 °F2026-08-15: +8.3 °F2026-08-16: -5.97 °F2026-08-17: -5.99 °F2026-08-18: -6 °F2026-08-19: -5.62 °F2026-08-20: -5 °F2026-08-21: -5.91 °F2026-08-22: -5.58 °F2026-08-23: -6.7 °F2026-08-24: -6.92 °F2026-08-25: -9.86 °F2026-08-26: -3.91 °F2026-08-27: -6.28 °F2026-08-28: -4.46 °F2026-08-29: -5.73 °F2026-08-30: -3.81 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.81
2026-08-29-5.73
2026-08-28-4.46
2026-08-27-6.28
2026-08-26-3.91
2026-08-25-9.86
2026-08-24-6.92
2026-08-23-6.70
2026-08-22-5.58
2026-08-21-5.91
2026-08-20-5.00
2026-08-19-5.62
2026-08-18-6.00
2026-08-17-5.99
2026-08-16-5.97
2026-08-15+8.30
2026-08-14-1.95
2026-08-13+2.21
2026-08-12-1.62
2026-08-11+0.19
2026-08-10+1.20
2026-08-09-1.78
2026-08-08-10.43
2026-08-07-1.32
2026-08-06-0.06
2026-08-05-4.84
2026-08-04-3.87
2026-08-03-3.35

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAS, lead day 2-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 1 day-8 to -6 °F: 3 days-6 to -4 °F: 10 days-4 to -2 °F: 4 days-2 to 0 °F: 5 days0 to 2 °F: 2 days2 to 4 °F: 1 day4 to 6 °F: 0 days6 to 8 °F: 0 days8 to 10 °F: 1 day10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 4.92 · P90 |e| 7.33 °F-200+20 °Fn = 28 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
-18.00-16.000
-16.00-14.000
-14.00-12.000
-12.00-10.001
-10.00-8.001
-8.00-6.003
-6.00-4.0010
-4.00-2.004
-2.00+0.005
+0.00+2.002
+2.00+4.001
+4.00+6.000
+6.00+8.000
+8.00+10.001
+10.00+12.000
+12.00+14.000
+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
2026-08284.60 -3.75

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28

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 28 -0.35 [-2.07, 1.22] no
Aurora (IFS init) 1 -0.11 [-0.11, -0.11] yes
FourCastNet v2 (IFS init) 1 -2.11 [-2.11, -2.11] yes
GraphCast (IFS init) 26 -1.06 [-2.72, 0.54] no
ECMWF IFS HRES 23 +1.95 [0.33, 3.07] yes
Pangu-Weather (IFS init) 1 -1.70 [-1.70, -1.70] yes
Persistence (baseline) 28 +0.50 [-2.10, 3.31] no

Cite this page

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

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

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