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

Las Vegas Harry Reid · NCEP GFS · lead day 8

KLAS · gfs · lead 8

Target day = initialization date + 8 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
tmax00Zbilinear30d22 2 QC5.99 [4.18, 7.35]5.09-3.48 [-6.70, 0.92]6.85 [4.76, 8.20]5% [0%, 12%]18%23%+0.33+0.422026-08-09 → 2026-08-30
tmax00Zbilinear90d22 2 QC5.99 [3.73, 7.37]5.09-3.48 [-6.83, 1.41]6.85 [4.35, 8.25]5% [0%, 12%]18%23%+0.33+0.422026-08-09 → 2026-08-30
tmax00Zbilinear365d22 2 QC5.99 [3.86, 7.50]5.09-3.48 [-7.13, 1.42]6.85 [4.42, 8.39]5% [0%, 14%]18%23%+0.33+0.422026-08-09 → 2026-08-30
tmax00Zbilinearall22 2 QC5.99 [3.61, 7.43]5.09-3.48 [-7.05, 1.42]6.85 [4.24, 8.35]5% [0%, 14%]18%23%+0.33+0.422026-08-09 → 2026-08-30
tmax00Znearest30d22 2 QC6.87 [4.38, 8.81]5.00-5.26 [-8.46, -0.99]7.88 [5.26, 9.61]5% [0%, 16%]5%23%+0.23+0.432026-08-09 → 2026-08-30
tmax00Znearest90d22 2 QC6.87 [3.94, 8.92]5.00-5.26 [-8.61, -0.44]7.88 [4.64, 9.63]5% [0%, 20%]5%23%+0.23+0.432026-08-09 → 2026-08-30
tmax00Znearest365d22 2 QC6.87 [3.97, 8.96]5.00-5.26 [-8.95, -0.44]7.88 [4.65, 9.87]5% [0%, 18%]5%23%+0.23+0.432026-08-09 → 2026-08-30
tmax00Znearestall22 2 QC6.87 [3.98, 8.89]5.00-5.26 [-8.73, -0.44]7.88 [4.59, 9.78]5% [0%, 18%]5%23%+0.23+0.432026-08-09 → 2026-08-30
tmax12Zbilinear30d22 2 QC7.05 [4.04, 9.34]6.27-3.89 [-8.71, 2.00]8.63 [5.52, 10.56]9% [0%, 21%]18%32%+0.21+0.292026-08-09 → 2026-08-30
tmax12Zbilinear90d22 2 QC7.05 [3.26, 9.52]6.27-3.89 [-8.95, 2.74]8.63 [4.16, 10.73]9% [0%, 21%]18%32%+0.21+0.292026-08-09 → 2026-08-30
tmax12Zbilinear365d22 2 QC7.05 [3.61, 9.85]6.27-3.89 [-9.85, 2.79]8.63 [4.36, 10.95]9% [0%, 23%]18%32%+0.21+0.292026-08-09 → 2026-08-30
tmax12Zbilinearall22 2 QC7.05 [3.49, 9.97]6.27-3.89 [-9.97, 2.74]8.63 [4.17, 11.13]9% [0%, 23%]18%32%+0.21+0.292026-08-09 → 2026-08-30
tmax12Znearest30d22 2 QC7.82 [3.89, 10.88]6.21-5.72 [-10.52, 0.13]9.57 [5.42, 12.01]14% [0%, 35%]18%23%+0.13+0.292026-08-09 → 2026-08-30
tmax12Znearest90d22 2 QC7.82 [2.88, 11.07]6.21-5.72 [-10.68, 0.85]9.57 [4.08, 12.13]14% [0%, 43%]18%23%+0.13+0.292026-08-09 → 2026-08-30
tmax12Znearest365d22 2 QC7.82 [3.16, 11.54]6.21-5.72 [-11.54, 0.97]9.57 [4.13, 12.53]14% [0%, 42%]18%23%+0.13+0.292026-08-09 → 2026-08-30
tmax12Znearestall22 2 QC7.82 [3.19, 11.73]6.21-5.72 [-11.73, 0.91]9.57 [3.78, 12.66]14% [0%, 43%]18%23%+0.13+0.292026-08-09 → 2026-08-30
tmin00Zbilinear30d22 2 QC4.93 [3.02, 7.18]4.78-0.42 [-3.60, 3.70]5.96 [3.56, 8.12]14% [0%, 35%]18%32%+0.40+0.422026-08-09 → 2026-08-30
tmin00Zbilinear90d22 2 QC4.93 [2.88, 7.16]4.78-0.42 [-3.90, 3.69]5.96 [3.47, 8.10]14% [0%, 43%]18%32%+0.40+0.422026-08-09 → 2026-08-30
tmin00Zbilinear365d22 2 QC4.93 [2.75, 7.43]4.78-0.42 [-4.01, 4.11]5.96 [3.19, 8.32]14% [0%, 42%]18%32%+0.40+0.422026-08-09 → 2026-08-30
tmin00Zbilinearall22 2 QC4.93 [2.57, 7.49]4.78-0.42 [-3.87, 4.23]5.96 [3.18, 8.46]14% [0%, 50%]18%32%+0.40+0.422026-08-09 → 2026-08-30
tmin00Znearest30d22 2 QC5.30 [3.60, 7.02]4.88-1.15 [-4.27, 3.01]6.11 [4.32, 7.79]9% [0%, 22%]14%23%+0.35+0.402026-08-09 → 2026-08-30
tmin00Znearest90d22 2 QC5.30 [3.43, 7.04]4.88-1.15 [-4.55, 2.99]6.11 [4.23, 7.75]9% [0%, 25%]14%23%+0.35+0.402026-08-09 → 2026-08-30
tmin00Znearest365d22 2 QC5.30 [3.40, 7.31]4.88-1.15 [-4.64, 3.53]6.11 [3.93, 8.07]9% [0%, 25%]14%23%+0.35+0.402026-08-09 → 2026-08-30
tmin00Znearestall22 2 QC5.30 [3.11, 7.30]4.88-1.15 [-4.60, 3.59]6.11 [3.93, 8.09]9% [0%, 30%]14%23%+0.35+0.402026-08-09 → 2026-08-30
tmin12Zbilinear30d22 2 QC5.18 [3.53, 6.85]4.93-0.77 [-4.16, 3.45]6.34 [3.98, 7.92]5% [0%, 12%]14%27%+0.37+0.402026-08-09 → 2026-08-30
tmin12Zbilinear90d22 2 QC5.18 [3.21, 6.76]4.93-0.77 [-4.50, 3.59]6.34 [3.53, 7.87]5% [0%, 13%]14%27%+0.37+0.402026-08-09 → 2026-08-30
tmin12Zbilinear365d22 2 QC5.18 [3.13, 6.89]4.93-0.77 [-4.62, 3.77]6.34 [3.50, 7.93]5% [0%, 14%]14%27%+0.37+0.402026-08-09 → 2026-08-30
tmin12Zbilinearall22 2 QC5.18 [2.96, 6.96]4.93-0.77 [-4.62, 3.98]6.34 [3.11, 8.10]5% [0%, 14%]14%27%+0.37+0.402026-08-09 → 2026-08-30
tmin12Znearest30d22 2 QC5.54 [4.09, 6.68]4.98-1.67 [-5.06, 2.56]6.49 [4.48, 7.56]5% [0%, 12%]9%23%+0.32+0.392026-08-09 → 2026-08-30
tmin12Znearest90d22 2 QC5.54 [3.80, 6.63]4.98-1.67 [-5.46, 2.61]6.49 [4.04, 7.50]5% [0%, 13%]9%23%+0.32+0.392026-08-09 → 2026-08-30
tmin12Znearest365d22 2 QC5.54 [3.84, 6.65]4.98-1.67 [-5.49, 2.93]6.49 [4.08, 7.45]5% [0%, 14%]9%23%+0.32+0.392026-08-09 → 2026-08-30
tmin12Znearestall22 2 QC5.54 [3.48, 6.68]4.98-1.67 [-5.55, 3.09]6.49 [3.69, 7.50]5% [0%, 14%]9%23%+0.32+0.392026-08-09 → 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 8, 00Z bilinear tmax+20+100-10-202026-08-09: -6.57 °F2026-08-10: +1.3 °F2026-08-11: -1.73 °F2026-08-12: +4.45 °F2026-08-13: +7.23 °F2026-08-14: +4.28 °F2026-08-15: +6.14 °F2026-08-16: -0.63 °F2026-08-17: -11.46 °F2026-08-18: -8.63 °F2026-08-19: -13.29 °F2026-08-20: -9.07 °F2026-08-21: -4.06 °F2026-08-22: -2.64 °F2026-08-23: -7.49 °F2026-08-24: -7.22 °F2026-08-25: -10.46 °F2026-08-26: -7.39 °F2026-08-27: -7.32 °F2026-08-28: -4.8 °F2026-08-29: -1.46 °F2026-08-30: +4.28 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+4.28
2026-08-29-1.46
2026-08-28-4.80
2026-08-27-7.32
2026-08-26-7.39
2026-08-25-10.46
2026-08-24-7.22
2026-08-23-7.49
2026-08-22-2.64
2026-08-21-4.06
2026-08-20-9.07
2026-08-19-13.29
2026-08-18-8.63
2026-08-17-11.46
2026-08-16-0.63
2026-08-15+6.14
2026-08-14+4.28
2026-08-13+7.23
2026-08-12+4.45
2026-08-11-1.73
2026-08-10+1.30
2026-08-09-6.57

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAS, lead day 8-20 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: 5 days-6 to -4 °F: 2 days-4 to -2 °F: 1 day-2 to 0 °F: 3 days0 to 2 °F: 1 day2 to 4 °F: 0 days4 to 6 °F: 3 days6 to 8 °F: 2 days8 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| 6.35 · P90 |e| 10.32 °F-200+20 °Fn = 22 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
-8.00-6.005
-6.00-4.002
-4.00-2.001
-2.00+0.003
+0.00+2.001
+2.00+4.000
+4.00+6.003
+6.00+8.002
+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
2026-08225.99 -3.48

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22

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 22 -2.26 [-5.42, 1.43] no
GraphCast (IFS init) 22 -4.47 [-7.79, -1.58] yes
ECMWF IFS HRES 17 +0.34 [-1.75, 2.83] no
Persistence (baseline) 22 -2.96 [-7.49, 1.36] no

Cite this page

ShortCastCheck, KLAS gfs lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAS/model/gfs/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAS (Las Vegas Harry Reid), model gfs, lead day 8. 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/8/

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