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 · ECMWF AIFS Single · lead day 2

KLAS · aifs_single · 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, aifs-single-gpid5, 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 QC4.95 [4.36, 5.51]2.00-4.82 [-5.37, -4.25]5.53 [4.60, 6.46]4% [0%, 10%]7%14%-0.21+0.502026-08-03 → 2026-08-30
tmax00Zbilinear90d28 2 QC4.95 [4.32, 5.55]2.00-4.82 [-5.42, -4.21]5.53 [4.56, 6.45]4% [0%, 11%]7%14%-0.21+0.502026-08-03 → 2026-08-30
tmax00Zbilinear365d28 2 QC4.95 [4.36, 5.56]2.00-4.82 [-5.42, -4.24]5.53 [4.57, 6.59]4% [0%, 11%]7%14%-0.21+0.502026-08-03 → 2026-08-30
tmax00Zbilinearall28 2 QC4.95 [4.21, 5.63]2.00-4.82 [-5.48, -4.16]5.53 [4.43, 6.54]4% [0%, 11%]7%14%-0.21+0.502026-08-03 → 2026-08-30
tmax00Znearest30d28 2 QC5.88 [5.35, 6.44]1.95-5.86 [-6.43, -5.32]6.44 [5.63, 7.24]7% [0%, 20%]7%7%-0.43+0.512026-08-03 → 2026-08-30
tmax00Znearest90d28 2 QC5.88 [5.27, 6.51]1.95-5.86 [-6.50, -5.23]6.44 [5.63, 7.25]7% [0%, 19%]7%7%-0.43+0.512026-08-03 → 2026-08-30
tmax00Znearest365d28 2 QC5.88 [5.27, 6.46]1.95-5.86 [-6.46, -5.25]6.44 [5.61, 7.39]7% [0%, 20%]7%7%-0.43+0.512026-08-03 → 2026-08-30
tmax00Znearestall28 2 QC5.88 [5.29, 6.53]1.95-5.86 [-6.52, -5.27]6.44 [5.54, 7.33]7% [0%, 20%]7%7%-0.43+0.512026-08-03 → 2026-08-30
tmax12Zbilinear30d28 2 QC4.80 [4.20, 5.45]2.03-4.64 [-5.21, -4.08]5.53 [4.38, 6.69]7% [0%, 17%]14%18%-0.17+0.492026-08-03 → 2026-08-30
tmax12Zbilinear90d28 2 QC4.80 [4.17, 5.47]2.03-4.64 [-5.31, -4.01]5.53 [4.31, 6.73]7% [0%, 19%]14%18%-0.17+0.492026-08-03 → 2026-08-30
tmax12Zbilinear365d28 2 QC4.80 [4.17, 5.53]2.03-4.64 [-5.33, -4.05]5.53 [4.32, 6.86]7% [0%, 20%]14%18%-0.17+0.492026-08-03 → 2026-08-30
tmax12Zbilinearall28 2 QC4.80 [4.11, 5.52]2.03-4.64 [-5.36, -4.02]5.53 [4.25, 6.74]7% [0%, 19%]14%18%-0.17+0.492026-08-03 → 2026-08-30
tmax12Znearest30d28 2 QC5.77 [5.24, 6.34]1.99-5.69 [-6.27, -5.12]6.40 [5.44, 7.41]0% [0%, 0%]11%14%-0.41+0.502026-08-03 → 2026-08-30
tmax12Znearest90d28 2 QC5.77 [5.17, 6.41]1.99-5.69 [-6.35, -5.06]6.40 [5.39, 7.42]0% [0%, 0%]11%14%-0.41+0.502026-08-03 → 2026-08-30
tmax12Znearest365d28 2 QC5.77 [5.20, 6.44]1.99-5.69 [-6.37, -5.08]6.40 [5.37, 7.55]0% [0%, 0%]11%14%-0.41+0.502026-08-03 → 2026-08-30
tmax12Znearestall28 2 QC5.77 [5.23, 6.43]1.99-5.69 [-6.42, -5.11]6.40 [5.38, 7.44]0% [0%, 0%]11%14%-0.41+0.502026-08-03 → 2026-08-30
tmin00Zbilinear30d28 2 QC5.29 [3.65, 6.61]2.25-5.01 [-6.61, -2.93]5.84 [4.54, 6.80]14% [0%, 36%]14%18%-0.37+0.422026-08-03 → 2026-08-30
tmin00Zbilinear90d28 2 QC5.29 [3.76, 6.70]2.25-5.01 [-6.70, -2.99]5.84 [4.56, 6.88]14% [0%, 35%]14%18%-0.37+0.422026-08-03 → 2026-08-30
tmin00Zbilinear365d28 2 QC5.29 [3.57, 6.66]2.25-5.01 [-6.66, -2.74]5.84 [4.36, 6.85]14% [0%, 39%]14%18%-0.37+0.422026-08-03 → 2026-08-30
tmin00Zbilinearall28 2 QC5.29 [3.65, 6.76]2.25-5.01 [-6.76, -2.97]5.84 [4.47, 6.93]14% [0%, 36%]14%18%-0.37+0.422026-08-03 → 2026-08-30
tmin00Znearest30d28 2 QC6.05 [4.15, 7.61]2.25-5.89 [-7.61, -3.73]6.63 [5.05, 7.77]7% [0%, 20%]14%18%-0.57+0.422026-08-03 → 2026-08-30
tmin00Znearest90d28 2 QC6.05 [4.24, 7.74]2.25-5.89 [-7.74, -3.79]6.63 [5.17, 7.88]7% [0%, 20%]14%18%-0.57+0.422026-08-03 → 2026-08-30
tmin00Znearest365d28 2 QC6.05 [4.02, 7.72]2.25-5.89 [-7.72, -3.61]6.63 [5.01, 7.85]7% [0%, 21%]14%18%-0.57+0.422026-08-03 → 2026-08-30
tmin00Znearestall28 2 QC6.05 [4.19, 7.91]2.25-5.89 [-7.91, -3.71]6.63 [5.15, 8.01]7% [0%, 21%]14%18%-0.57+0.422026-08-03 → 2026-08-30
tmin12Zbilinear30d28 2 QC5.10 [3.37, 6.48]2.12-5.01 [-6.48, -3.16]5.72 [4.51, 6.63]18% [0%, 46%]18%18%-0.32+0.452026-08-03 → 2026-08-30
tmin12Zbilinear90d28 2 QC5.10 [3.47, 6.54]2.12-5.01 [-6.54, -3.25]5.72 [4.58, 6.70]18% [0%, 45%]18%18%-0.32+0.452026-08-03 → 2026-08-30
tmin12Zbilinear365d28 2 QC5.10 [3.30, 6.55]2.12-5.01 [-6.55, -3.03]5.72 [4.42, 6.70]18% [0%, 50%]18%18%-0.32+0.452026-08-03 → 2026-08-30
tmin12Zbilinearall28 2 QC5.10 [3.41, 6.68]2.12-5.01 [-6.68, -3.16]5.72 [4.51, 6.82]18% [0%, 47%]18%18%-0.32+0.452026-08-03 → 2026-08-30
tmin12Znearest30d28 2 QC5.89 [3.93, 7.51]2.17-5.88 [-7.51, -3.92]6.54 [5.08, 7.67]18% [0%, 46%]18%18%-0.53+0.442026-08-03 → 2026-08-30
tmin12Znearest90d28 2 QC5.89 [4.03, 7.64]2.17-5.88 [-7.64, -4.02]6.54 [5.21, 7.82]18% [0%, 45%]18%18%-0.53+0.442026-08-03 → 2026-08-30
tmin12Znearest365d28 2 QC5.89 [3.79, 7.60]2.17-5.88 [-7.60, -3.78]6.54 [4.99, 7.75]18% [0%, 50%]18%18%-0.53+0.442026-08-03 → 2026-08-30
tmin12Znearestall28 2 QC5.89 [3.91, 7.85]2.17-5.88 [-7.85, -3.91]6.54 [5.18, 7.99]18% [0%, 47%]18%18%-0.53+0.442026-08-03 → 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 ECMWF AIFS Single at KLAS, lead day 2, 00Z bilinear tmax+20+100-10-202026-08-03: -3.54 °F2026-08-04: -3.33 °F2026-08-05: -5.34 °F2026-08-06: -2.36 °F2026-08-07: -4.2 °F2026-08-08: -8.74 °F2026-08-09: -6.15 °F2026-08-10: -2.33 °F2026-08-11: -7.63 °F2026-08-12: -9.19 °F2026-08-13: +0.57 °F2026-08-14: -12.57 °F2026-08-15: +1.26 °F2026-08-16: -3.24 °F2026-08-17: -4.41 °F2026-08-18: -5.5 °F2026-08-19: -4.06 °F2026-08-20: -5.94 °F2026-08-21: -6.12 °F2026-08-22: -3.66 °F2026-08-23: -6.95 °F2026-08-24: -4.93 °F2026-08-25: -3.31 °F2026-08-26: -3.74 °F2026-08-27: -5.62 °F2026-08-28: -4.27 °F2026-08-29: -6.04 °F2026-08-30: -3.64 °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
2026-08-30-3.64
2026-08-29-6.04
2026-08-28-4.27
2026-08-27-5.62
2026-08-26-3.74
2026-08-25-3.31
2026-08-24-4.93
2026-08-23-6.95
2026-08-22-3.66
2026-08-21-6.12
2026-08-20-5.94
2026-08-19-4.06
2026-08-18-5.50
2026-08-17-4.41
2026-08-16-3.24
2026-08-15+1.26
2026-08-14-12.57
2026-08-13+0.57
2026-08-12-9.19
2026-08-11-7.63
2026-08-10-2.33
2026-08-09-6.15
2026-08-08-8.74
2026-08-07-4.20
2026-08-06-2.36
2026-08-05-5.34
2026-08-04-3.33
2026-08-03-3.54

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single 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: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 2 days-8 to -6 °F: 5 days-6 to -4 °F: 9 days-4 to -2 °F: 9 days-2 to 0 °F: 0 days0 to 2 °F: 2 days2 to 4 °F: 0 days4 to 6 °F: 0 days6 to 8 °F: 0 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| 4.34 · P90 |e| 7.96 °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
-14.00-12.001
-12.00-10.000
-10.00-8.002
-8.00-6.005
-6.00-4.009
-4.00-2.009
-2.00+0.000
+0.00+2.002
+2.00+4.000
+4.00+6.000
+6.00+8.000
+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
2026-08284.95 -4.82

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF AIFS Single has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
Aurora (IFS init) 1 -0.28 [-0.28, -0.28] yes
FourCastNet v2 (IFS init) 1 -2.28 [-2.28, -2.28] yes
NCEP GFS 28 +0.35 [-1.22, 2.07] no
GraphCast (IFS init) 26 -0.69 [-1.05, -0.25] yes
ECMWF IFS HRES 23 +1.83 [1.04, 2.82] yes
Pangu-Weather (IFS init) 1 -1.87 [-1.87, -1.87] yes
Persistence (baseline) 28 +0.84 [-0.83, 2.39] no

Cite this page

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

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