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

Las Vegas Harry Reid · NCEP GFS · lead day 0

KLAS · gfs · lead 0

Target day = initialization date + 0 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
tmax00Zbilinear30d30 2 QC5.08 [4.38, 5.71]1.89-4.52 [-5.47, -3.35]5.44 [4.79, 5.99]7% [0%, 17%]10%10%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d30 2 QC5.08 [4.29, 5.77]1.89-4.52 [-5.61, -3.31]5.44 [4.65, 6.02]7% [0%, 18%]10%10%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d30 2 QC5.08 [4.31, 5.82]1.89-4.52 [-5.73, -3.31]5.44 [4.68, 6.08]7% [0%, 19%]10%10%——2026-08-01 → 2026-08-30
tmax00Zbilinearall30 2 QC5.08 [4.30, 5.76]1.89-4.52 [-5.64, -3.38]5.44 [4.72, 6.05]7% [0%, 18%]10%10%——2026-08-01 → 2026-08-30
tmax00Znearest30d30 2 QC6.61 [5.47, 7.60]2.09-6.20 [-7.42, -4.79]6.96 [5.94, 7.80]0% [0%, 0%]7%7%——2026-08-01 → 2026-08-30
tmax00Znearest90d30 2 QC6.61 [5.34, 7.74]2.09-6.20 [-7.67, -4.74]6.96 [5.78, 7.89]0% [0%, 0%]7%7%——2026-08-01 → 2026-08-30
tmax00Znearest365d30 2 QC6.61 [5.34, 7.77]2.09-6.20 [-7.71, -4.71]6.96 [5.77, 7.94]0% [0%, 0%]7%7%——2026-08-01 → 2026-08-30
tmax00Znearestall30 2 QC6.61 [5.31, 7.71]2.09-6.20 [-7.63, -4.78]6.96 [5.77, 7.86]0% [0%, 0%]7%7%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d30 2 QC3.19 [2.14, 4.26]2.82-1.22 [-3.44, 1.47]3.93 [2.94, 4.81]20% [3%, 40%]40%47%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d30 2 QC3.19 [2.05, 4.28]2.82-1.22 [-3.70, 1.20]3.93 [2.77, 4.81]20% [3%, 41%]40%47%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d30 2 QC3.19 [1.87, 4.31]2.82-1.22 [-3.68, 1.69]3.93 [2.67, 4.85]20% [0%, 44%]40%47%——2026-08-01 → 2026-08-30
tmin00Zbilinearall30 2 QC3.19 [1.88, 4.26]2.82-1.22 [-3.71, 1.33]3.93 [2.69, 4.79]20% [3%, 44%]40%47%——2026-08-01 → 2026-08-30
tmin00Znearest30d30 2 QC3.59 [2.44, 4.68]2.88-2.00 [-4.12, 0.64]4.31 [3.23, 5.18]13% [3%, 27%]27%43%——2026-08-01 → 2026-08-30
tmin00Znearest90d30 2 QC3.59 [2.33, 4.83]2.88-2.00 [-4.39, 0.36]4.31 [3.08, 5.26]13% [0%, 30%]27%43%——2026-08-01 → 2026-08-30
tmin00Znearest365d30 2 QC3.59 [2.20, 4.91]2.88-2.00 [-4.34, 0.84]4.31 [2.92, 5.35]13% [0%, 31%]27%43%——2026-08-01 → 2026-08-30
tmin00Znearestall30 2 QC3.59 [2.20, 4.75]2.88-2.00 [-4.27, 0.42]4.31 [2.97, 5.27]13% [0%, 30%]27%43%——2026-08-01 → 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 0, 00Z bilinear tmax+10+50-5-102026-08-01: -4.61 °F2026-08-02: -4.4 °F2026-08-03: -5.24 °F2026-08-04: -4.9 °F2026-08-05: -5.13 °F2026-08-06: -1.97 °F2026-08-07: -3.38 °F2026-08-08: -6.55 °F2026-08-09: -4.77 °F2026-08-10: +0.94 °F2026-08-11: -4.02 °F2026-08-12: -8.7 °F2026-08-13: +0.16 °F2026-08-14: -3.4 °F2026-08-15: +7.24 °F2026-08-16: -6.4 °F2026-08-17: -4.95 °F2026-08-18: -9.32 °F2026-08-19: -5.14 °F2026-08-20: -4.55 °F2026-08-21: -4.88 °F2026-08-22: -5.07 °F2026-08-23: -6.16 °F2026-08-24: -5.14 °F2026-08-25: -6.42 °F2026-08-26: -4.15 °F2026-08-27: -7.4 °F2026-08-28: -7.23 °F2026-08-29: -6.27 °F2026-08-30: -3.8 °F2026-08-012026-08-30°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 (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.80
2026-08-29-6.27
2026-08-28-7.23
2026-08-27-7.40
2026-08-26-4.15
2026-08-25-6.42
2026-08-24-5.14
2026-08-23-6.16
2026-08-22-5.07
2026-08-21-4.88
2026-08-20-4.55
2026-08-19-5.14
2026-08-18-9.32
2026-08-17-4.95
2026-08-16-6.40
2026-08-15+7.24
2026-08-14-3.40
2026-08-13+0.16
2026-08-12-8.70
2026-08-11-4.02
2026-08-10+0.94
2026-08-09-4.77
2026-08-08-6.55
2026-08-07-3.38
2026-08-06-1.97
2026-08-05-5.13
2026-08-04-4.90
2026-08-03-5.24
2026-08-02-4.40
2026-08-01-4.61

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KLAS, lead day 0-10 to -9 °F: 1 day-9 to -8 °F: 1 day-8 to -7 °F: 2 days-7 to -6 °F: 5 days-6 to -5 °F: 5 days-5 to -4 °F: 9 days-4 to -3 °F: 3 days-3 to -2 °F: 0 days-2 to -1 °F: 1 day-1 to 0 °F: 0 days0 to 1 °F: 2 days1 to 2 °F: 0 days2 to 3 °F: 0 days3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 1 day8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 5.01 · P90 |e| 7.25 °F-100+10 °Fn = 30 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
-10.00-9.001
-9.00-8.001
-8.00-7.002
-7.00-6.005
-6.00-5.005
-5.00-4.009
-4.00-3.003
-3.00-2.000
-2.00-1.001
-1.00+0.000
+0.00+1.002
+1.00+2.000
+2.00+3.000
+3.00+4.000
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.001
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08305.08 -4.52

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-01 → 2026-08-30 30
NCEP GFS2026-08-01 → 2026-08-30 30

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 30 -0.01 [-1.26, 1.03] no
Aurora (GFS init) 2 -0.34 [-0.75, 0.06] no
Aurora (IFS init) 3 +1.80 [1.25, 2.42] yes
FourCastNet v2 (GFS init) 2 -0.22 [-0.74, 0.30] no
FourCastNet v2 (IFS init) 3 -0.16 [-1.55, 0.72] no
GraphCast (GFS init) 2 -2.91 [-3.07, -2.74] yes
GraphCast (IFS init) 28 -0.15 [-1.12, 0.81] no
ECMWF IFS HRES 25 +1.28 [0.52, 1.90] yes
Pangu-Weather (GFS init) 2 -0.12 [-0.46, 0.21] no
Pangu-Weather (IFS init) 3 +0.45 [0.18, 1.00] yes

Cite this page

ShortCastCheck, KLAS gfs lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAS/model/gfs/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAS (Las Vegas Harry Reid), model gfs, lead day 0. 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/0/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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