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CastCheck methodology v0.2 · data through 2026-08-30

Las Vegas Harry Reid · NCEP GFS · lead day 6

KLAS · gfs · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d24 2 QC5.23 [3.65, 6.30]4.64-3.15 [-5.62, -0.04]6.43 [4.91, 7.44]17% [6%, 33%]21%38%+0.34+0.402026-08-07 → 2026-08-30
tmax00Zbilinear90d24 2 QC5.23 [3.01, 6.34]4.64-3.15 [-5.89, 0.32]6.43 [4.22, 7.43]17% [0%, 38%]21%38%+0.34+0.402026-08-07 → 2026-08-30
tmax00Zbilinear365d24 2 QC5.23 [3.03, 6.40]4.64-3.15 [-5.96, 0.65]6.43 [4.34, 7.56]17% [0%, 38%]21%38%+0.34+0.402026-08-07 → 2026-08-30
tmax00Zbilinearall24 2 QC5.23 [2.90, 6.37]4.64-3.15 [-5.90, 0.38]6.43 [4.22, 7.57]17% [0%, 40%]21%38%+0.34+0.402026-08-07 → 2026-08-30
tmax00Znearest30d24 2 QC5.94 [3.94, 7.43]4.29-4.73 [-7.22, -1.64]7.12 [4.77, 8.62]8% [0%, 19%]21%29%+0.25+0.442026-08-07 → 2026-08-30
tmax00Znearest90d24 2 QC5.94 [3.55, 7.59]4.29-4.73 [-7.38, -1.26]7.12 [4.37, 8.75]8% [0%, 20%]21%29%+0.25+0.442026-08-07 → 2026-08-30
tmax00Znearest365d24 2 QC5.94 [3.40, 7.69]4.29-4.73 [-7.51, -1.01]7.12 [4.27, 8.80]8% [0%, 20%]21%29%+0.25+0.442026-08-07 → 2026-08-30
tmax00Znearestall24 2 QC5.94 [3.40, 7.51]4.29-4.73 [-7.32, -1.27]7.12 [4.16, 8.75]8% [0%, 20%]21%29%+0.25+0.442026-08-07 → 2026-08-30
tmax12Zbilinear30d24 2 QC5.61 [2.99, 7.85]4.87-4.17 [-7.63, -0.22]7.25 [3.55, 9.60]4% [0%, 14%]17%46%+0.29+0.372026-08-07 → 2026-08-30
tmax12Zbilinear90d24 2 QC5.61 [2.58, 7.93]4.87-4.17 [-7.82, 0.28]7.25 [2.73, 9.67]4% [0%, 17%]17%46%+0.29+0.372026-08-07 → 2026-08-30
tmax12Zbilinear365d24 2 QC5.61 [2.57, 8.12]4.87-4.17 [-8.12, 0.38]7.25 [2.72, 10.03]4% [0%, 17%]17%46%+0.29+0.372026-08-07 → 2026-08-30
tmax12Zbilinearall24 2 QC5.61 [2.47, 8.38]4.87-4.17 [-8.38, 0.30]7.25 [2.64, 10.11]4% [0%, 17%]17%46%+0.29+0.372026-08-07 → 2026-08-30
tmax12Znearest30d24 2 QC6.49 [3.30, 9.39]4.82-5.81 [-9.28, -1.81]8.26 [4.27, 10.90]12% [0%, 33%]21%25%+0.18+0.372026-08-07 → 2026-08-30
tmax12Znearest90d24 2 QC6.49 [2.99, 9.58]4.82-5.81 [-9.52, -1.30]8.26 [3.42, 10.99]12% [0%, 33%]21%25%+0.18+0.372026-08-07 → 2026-08-30
tmax12Znearest365d24 2 QC6.49 [2.84, 9.77]4.82-5.81 [-9.77, -1.24]8.26 [3.32, 11.41]12% [0%, 35%]21%25%+0.18+0.372026-08-07 → 2026-08-30
tmax12Znearestall24 2 QC6.49 [2.98, 10.00]4.82-5.81 [-10.00, -1.27]8.26 [3.41, 11.45]12% [0%, 35%]21%25%+0.18+0.372026-08-07 → 2026-08-30
tmin00Zbilinear30d24 2 QC3.81 [2.38, 5.57]3.86+0.15 [-2.67, 3.55]4.96 [3.03, 6.71]21% [5%, 33%]33%58%+0.49+0.472026-08-07 → 2026-08-30
tmin00Zbilinear90d24 2 QC3.81 [2.29, 5.65]3.86+0.15 [-3.09, 3.59]4.96 [2.84, 6.76]21% [0%, 35%]33%58%+0.49+0.472026-08-07 → 2026-08-30
tmin00Zbilinear365d24 2 QC3.81 [2.14, 5.84]3.86+0.15 [-3.06, 3.84]4.96 [2.57, 6.91]21% [0%, 38%]33%58%+0.49+0.472026-08-07 → 2026-08-30
tmin00Zbilinearall24 2 QC3.81 [2.25, 5.84]3.86+0.15 [-3.09, 3.88]4.96 [2.75, 6.84]21% [0%, 37%]33%58%+0.49+0.472026-08-07 → 2026-08-30
tmin00Znearest30d24 2 QC3.80 [2.60, 5.20]3.62-0.56 [-3.14, 2.64]4.64 [3.15, 6.04]12% [3%, 23%]25%38%+0.49+0.512026-08-07 → 2026-08-30
tmin00Znearest90d24 2 QC3.80 [2.47, 5.32]3.62-0.56 [-3.51, 2.65]4.64 [3.05, 6.04]12% [0%, 25%]25%38%+0.49+0.512026-08-07 → 2026-08-30
tmin00Znearest365d24 2 QC3.80 [2.33, 5.41]3.62-0.56 [-3.46, 2.84]4.64 [2.82, 6.17]12% [0%, 26%]25%38%+0.49+0.512026-08-07 → 2026-08-30
tmin00Znearestall24 2 QC3.80 [2.52, 5.47]3.62-0.56 [-3.48, 2.85]4.64 [3.11, 6.18]12% [0%, 25%]25%38%+0.49+0.512026-08-07 → 2026-08-30
tmin12Zbilinear30d24 2 QC4.06 [2.68, 5.65]4.06-0.05 [-2.98, 3.24]4.96 [3.49, 6.33]17% [4%, 32%]33%46%+0.45+0.442026-08-07 → 2026-08-30
tmin12Zbilinear90d24 2 QC4.06 [2.65, 5.78]4.06-0.05 [-3.42, 3.38]4.96 [3.42, 6.35]17% [0%, 36%]33%46%+0.45+0.442026-08-07 → 2026-08-30
tmin12Zbilinear365d24 2 QC4.06 [2.38, 5.88]4.06-0.05 [-3.46, 3.52]4.96 [3.13, 6.45]17% [0%, 38%]33%46%+0.45+0.442026-08-07 → 2026-08-30
tmin12Zbilinearall24 2 QC4.06 [2.58, 6.05]4.06-0.05 [-3.51, 3.63]4.96 [3.36, 6.49]17% [0%, 33%]33%46%+0.45+0.442026-08-07 → 2026-08-30
tmin12Znearest30d24 2 QC4.28 [2.95, 5.65]4.19-0.94 [-3.87, 2.43]5.23 [4.02, 6.19]25% [6%, 43%]25%42%+0.42+0.432026-08-07 → 2026-08-30
tmin12Znearest90d24 2 QC4.28 [2.92, 5.93]4.19-0.94 [-4.36, 2.48]5.23 [3.93, 6.29]25% [0%, 44%]25%42%+0.42+0.432026-08-07 → 2026-08-30
tmin12Znearest365d24 2 QC4.28 [2.59, 5.89]4.19-0.94 [-4.38, 2.58]5.23 [3.67, 6.27]25% [0%, 50%]25%42%+0.42+0.432026-08-07 → 2026-08-30
tmin12Znearestall24 2 QC4.28 [2.87, 5.95]4.19-0.94 [-4.53, 2.69]5.23 [3.89, 6.31]25% [0%, 44%]25%42%+0.42+0.432026-08-07 → 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 6, 00Z bilinear tmax+20+100-10-202026-08-07: -2.56 °F2026-08-08: -10.9 °F2026-08-09: -1.61 °F2026-08-10: +2.14 °F2026-08-11: +5.27 °F2026-08-12: +3.5 °F2026-08-13: +10.8 °F2026-08-14: +0.21 °F2026-08-15: +2.3 °F2026-08-16: -12.88 °F2026-08-17: -9.63 °F2026-08-18: -5.39 °F2026-08-19: -8.13 °F2026-08-20: -4.17 °F2026-08-21: +0.48 °F2026-08-22: -5.71 °F2026-08-23: -6.86 °F2026-08-24: -10.98 °F2026-08-25: -6.9 °F2026-08-26: -5.76 °F2026-08-27: -6.21 °F2026-08-28: -2.18 °F2026-08-29: -0.72 °F2026-08-30: +0.2 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+0.20
2026-08-29-0.72
2026-08-28-2.18
2026-08-27-6.21
2026-08-26-5.76
2026-08-25-6.90
2026-08-24-10.98
2026-08-23-6.86
2026-08-22-5.71
2026-08-21+0.48
2026-08-20-4.17
2026-08-19-8.13
2026-08-18-5.39
2026-08-17-9.63
2026-08-16-12.88
2026-08-15+2.30
2026-08-14+0.21
2026-08-13+10.80
2026-08-12+3.50
2026-08-11+5.27
2026-08-10+2.14
2026-08-09-1.61
2026-08-08-10.90
2026-08-07-2.56

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAS, lead day 6-20 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: 2 days-10 to -8 °F: 2 days-8 to -6 °F: 3 days-6 to -4 °F: 4 days-4 to -2 °F: 2 days-2 to 0 °F: 2 days0 to 2 °F: 3 days2 to 4 °F: 3 days4 to 6 °F: 1 day6 to 8 °F: 0 days8 to 10 °F: 0 days10 to 12 °F: 1 day12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 5.33 · P90 |e| 10.87 °F-200+20 °Fn = 24 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
-12.00-10.002
-10.00-8.002
-8.00-6.003
-6.00-4.004
-4.00-2.002
-2.00+0.002
+0.00+2.003
+2.00+4.003
+4.00+6.001
+6.00+8.000
+8.00+10.000
+10.00+12.001
+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
2026-08245.23 -3.15

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24

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 24 -1.84 [-3.29, -0.11] yes
GraphCast (IFS init) 24 -3.17 [-5.02, -1.58] yes
ECMWF IFS HRES 19 +1.45 [0.36, 2.57] yes
Persistence (baseline) 24 -2.65 [-6.04, 1.34] no

Cite this page

ShortCastCheck, KLAS gfs lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAS/model/gfs/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAS (Las Vegas Harry Reid), model gfs, lead day 6. 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/6/

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