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 3

KLAS · 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, 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
tmax00Zbilinear30d27 2 QC4.69 [3.42, 5.91]2.87-3.69 [-5.64, -1.42]5.41 [4.16, 6.58]11% [0%, 26%]19%22%+0.11+0.452026-08-04 → 2026-08-30
tmax00Zbilinear90d27 2 QC4.69 [3.22, 6.08]2.87-3.69 [-5.99, -1.28]5.41 [3.99, 6.67]11% [0%, 27%]19%22%+0.11+0.452026-08-04 → 2026-08-30
tmax00Zbilinear365d27 2 QC4.69 [3.14, 6.13]2.87-3.69 [-6.09, -1.20]5.41 [3.85, 6.82]11% [0%, 28%]19%22%+0.11+0.452026-08-04 → 2026-08-30
tmax00Zbilinearall27 2 QC4.69 [3.17, 6.18]2.87-3.69 [-6.18, -1.30]5.41 [3.89, 6.87]11% [0%, 27%]19%22%+0.11+0.452026-08-04 → 2026-08-30
tmax00Znearest30d27 2 QC5.98 [4.26, 7.58]2.98-5.43 [-7.49, -3.08]6.69 [5.03, 8.10]4% [0%, 12%]11%22%-0.13+0.432026-08-04 → 2026-08-30
tmax00Znearest90d27 2 QC5.98 [4.01, 7.85]2.98-5.43 [-7.82, -2.99]6.69 [4.80, 8.27]4% [0%, 14%]11%22%-0.13+0.432026-08-04 → 2026-08-30
tmax00Znearest365d27 2 QC5.98 [3.89, 7.92]2.98-5.43 [-7.92, -2.87]6.69 [4.65, 8.36]4% [0%, 14%]11%22%-0.13+0.432026-08-04 → 2026-08-30
tmax00Znearestall27 2 QC5.98 [3.95, 7.98]2.98-5.43 [-7.98, -2.92]6.69 [4.65, 8.43]4% [0%, 14%]11%22%-0.13+0.432026-08-04 → 2026-08-30
tmax12Zbilinear30d27 2 QC4.38 [2.79, 5.87]2.83-3.43 [-5.70, -1.01]5.02 [3.54, 6.15]7% [0%, 17%]26%30%+0.17+0.462026-08-04 → 2026-08-30
tmax12Zbilinear90d27 2 QC4.38 [2.55, 6.05]2.83-3.43 [-6.03, -0.85]5.02 [3.05, 6.26]7% [0%, 18%]26%30%+0.17+0.462026-08-04 → 2026-08-30
tmax12Zbilinear365d27 2 QC4.38 [2.50, 6.14]2.83-3.43 [-6.13, -0.72]5.02 [3.04, 6.38]7% [0%, 18%]26%30%+0.17+0.462026-08-04 → 2026-08-30
tmax12Zbilinearall27 2 QC4.38 [2.47, 6.09]2.83-3.43 [-6.09, -0.84]5.02 [3.08, 6.34]7% [0%, 17%]26%30%+0.17+0.462026-08-04 → 2026-08-30
tmax12Znearest30d27 2 QC5.78 [3.89, 7.53]2.75-5.27 [-7.47, -2.95]6.40 [4.64, 7.75]11% [0%, 23%]11%19%-0.09+0.472026-08-04 → 2026-08-30
tmax12Znearest90d27 2 QC5.78 [3.69, 7.76]2.75-5.27 [-7.74, -2.85]6.40 [4.40, 7.94]11% [0%, 25%]11%19%-0.09+0.472026-08-04 → 2026-08-30
tmax12Znearest365d27 2 QC5.78 [3.58, 7.82]2.75-5.27 [-7.82, -2.67]6.40 [4.28, 8.03]11% [0%, 25%]11%19%-0.09+0.472026-08-04 → 2026-08-30
tmax12Znearestall27 2 QC5.78 [3.57, 7.88]2.75-5.27 [-7.88, -2.83]6.40 [4.25, 8.07]11% [0%, 26%]11%19%-0.09+0.472026-08-04 → 2026-08-30
tmin00Zbilinear30d27 2 QC3.39 [2.38, 4.81]3.34-0.12 [-2.83, 3.16]4.26 [2.73, 5.82]11% [0%, 24%]30%59%+0.29+0.302026-08-04 → 2026-08-30
tmin00Zbilinear90d27 2 QC3.39 [2.36, 4.87]3.34-0.12 [-3.09, 3.03]4.26 [2.74, 5.85]11% [0%, 24%]30%59%+0.29+0.302026-08-04 → 2026-08-30
tmin00Zbilinear365d27 2 QC3.39 [2.24, 5.01]3.34-0.12 [-3.11, 3.45]4.26 [2.61, 6.03]11% [0%, 27%]30%59%+0.29+0.302026-08-04 → 2026-08-30
tmin00Zbilinearall27 2 QC3.39 [2.24, 4.99]3.34-0.12 [-3.28, 3.25]4.26 [2.63, 5.93]11% [0%, 27%]30%59%+0.29+0.302026-08-04 → 2026-08-30
tmin00Znearest30d27 2 QC3.57 [2.72, 4.64]3.25-0.75 [-3.37, 2.50]4.26 [3.15, 5.47]11% [0%, 30%]22%48%+0.25+0.322026-08-04 → 2026-08-30
tmin00Znearest90d27 2 QC3.57 [2.72, 4.71]3.25-0.75 [-3.62, 2.29]4.26 [3.09, 5.50]11% [0%, 29%]22%48%+0.25+0.322026-08-04 → 2026-08-30
tmin00Znearest365d27 2 QC3.57 [2.58, 4.74]3.25-0.75 [-3.66, 2.77]4.26 [3.00, 5.61]11% [0%, 31%]22%48%+0.25+0.322026-08-04 → 2026-08-30
tmin00Znearestall27 2 QC3.57 [2.60, 4.78]3.25-0.75 [-3.79, 2.56]4.26 [3.01, 5.59]11% [0%, 29%]22%48%+0.25+0.322026-08-04 → 2026-08-30
tmin12Zbilinear30d27 2 QC3.60 [2.40, 5.11]3.58-0.12 [-3.04, 3.16]4.39 [2.91, 5.89]15% [0%, 30%]30%48%+0.25+0.252026-08-04 → 2026-08-30
tmin12Zbilinear90d27 2 QC3.60 [2.40, 5.14]3.58-0.12 [-3.42, 3.08]4.39 [2.91, 5.95]15% [0%, 31%]30%48%+0.25+0.252026-08-04 → 2026-08-30
tmin12Zbilinear365d27 2 QC3.60 [2.29, 5.23]3.58-0.12 [-3.45, 3.57]4.39 [2.74, 6.01]15% [0%, 30%]30%48%+0.25+0.252026-08-04 → 2026-08-30
tmin12Zbilinearall27 2 QC3.60 [2.22, 5.30]3.58-0.12 [-3.69, 3.34]4.39 [2.69, 5.99]15% [0%, 33%]30%48%+0.25+0.252026-08-04 → 2026-08-30
tmin12Znearest30d27 2 QC3.63 [2.52, 4.83]3.46-0.81 [-3.59, 2.36]4.37 [3.21, 5.46]19% [5%, 33%]30%37%+0.24+0.282026-08-04 → 2026-08-30
tmin12Znearest90d27 2 QC3.63 [2.44, 4.88]3.46-0.81 [-3.99, 2.21]4.37 [3.12, 5.50]19% [3%, 33%]30%37%+0.24+0.282026-08-04 → 2026-08-30
tmin12Znearest365d27 2 QC3.63 [2.34, 4.96]3.46-0.81 [-4.03, 2.63]4.37 [2.91, 5.60]19% [0%, 33%]30%37%+0.24+0.282026-08-04 → 2026-08-30
tmin12Znearestall27 2 QC3.63 [2.30, 4.95]3.46-0.81 [-4.19, 2.49]4.37 [2.88, 5.57]19% [0%, 33%]30%37%+0.24+0.282026-08-04 → 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 KLAS, lead day 3, 00Z bilinear tmax+20+100-10-202026-08-04: -3.55 °F2026-08-05: -4.85 °F2026-08-06: +1.1 °F2026-08-07: -8.08 °F2026-08-08: -3.27 °F2026-08-09: -0.82 °F2026-08-10: +0.81 °F2026-08-11: -1.23 °F2026-08-12: -2.54 °F2026-08-13: +4.63 °F2026-08-14: -0.82 °F2026-08-15: +6.92 °F2026-08-16: -7.26 °F2026-08-17: -5.29 °F2026-08-18: -5.61 °F2026-08-19: -5.58 °F2026-08-20: -3.65 °F2026-08-21: -4.1 °F2026-08-22: -5.3 °F2026-08-23: -6.97 °F2026-08-24: -4.87 °F2026-08-25: -13.49 °F2026-08-26: -4.23 °F2026-08-27: -6.49 °F2026-08-28: -5.95 °F2026-08-29: -6.02 °F2026-08-30: -3.19 °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
2026-08-30-3.19
2026-08-29-6.02
2026-08-28-5.95
2026-08-27-6.49
2026-08-26-4.23
2026-08-25-13.49
2026-08-24-4.87
2026-08-23-6.97
2026-08-22-5.30
2026-08-21-4.10
2026-08-20-3.65
2026-08-19-5.58
2026-08-18-5.61
2026-08-17-5.29
2026-08-16-7.26
2026-08-15+6.92
2026-08-14-0.82
2026-08-13+4.63
2026-08-12-2.54
2026-08-11-1.23
2026-08-10+0.81
2026-08-09-0.82
2026-08-08-3.27
2026-08-07-8.08
2026-08-06+1.10
2026-08-05-4.85
2026-08-04-3.55

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAS, lead day 3-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 1 day-8 to -6 °F: 4 days-6 to -4 °F: 9 days-4 to -2 °F: 5 days-2 to 0 °F: 3 days0 to 2 °F: 2 days2 to 4 °F: 0 days4 to 6 °F: 1 day6 to 8 °F: 1 day8 to 10 °F: 0 days10 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| 4.85 · P90 |e| 7.08 °F-200+20 °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
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.001
-12.00-10.000
-10.00-8.001
-8.00-6.004
-6.00-4.009
-4.00-2.005
-2.00+0.003
+0.00+2.002
+2.00+4.000
+4.00+6.001
+6.00+8.001
+8.00+10.000
+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
2026-08274.69 -3.69

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 -0.38 [-2.04, 1.04] no
GraphCast (IFS init) 25 -1.24 [-2.44, 0.06] no
ECMWF IFS HRES 22 +1.47 [-0.51, 2.97] no
Persistence (baseline) 27 -0.61 [-4.41, 3.61] no

Cite this page

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

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