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 1

KLAS · aifs_single · lead 1

Target day = initialization date + 1 day. 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
tmax00Zbilinear30d29 2 QC4.47 [3.99, 4.93]1.78-4.34 [-4.77, -3.86]5.02 [4.20, 5.87]7% [0%, 17%]10%24%-0.42+0.442026-08-02 → 2026-08-30
tmax00Zbilinear90d29 2 QC4.47 [3.95, 4.92]1.78-4.34 [-4.79, -3.81]5.02 [4.13, 5.84]7% [0%, 18%]10%24%-0.42+0.442026-08-02 → 2026-08-30
tmax00Zbilinear365d29 2 QC4.47 [3.95, 4.95]1.78-4.34 [-4.80, -3.80]5.02 [4.12, 5.96]7% [0%, 19%]10%24%-0.42+0.442026-08-02 → 2026-08-30
tmax00Zbilinearall29 2 QC4.47 [3.93, 4.95]1.78-4.34 [-4.83, -3.85]5.02 [4.11, 5.91]7% [0%, 18%]10%24%-0.42+0.442026-08-02 → 2026-08-30
tmax00Znearest30d29 2 QC5.44 [4.99, 5.86]1.73-5.37 [-5.83, -4.84]5.91 [5.24, 6.54]3% [0%, 10%]7%14%-0.73+0.452026-08-02 → 2026-08-30
tmax00Znearest90d29 2 QC5.44 [4.92, 5.85]1.73-5.37 [-5.83, -4.79]5.91 [5.18, 6.55]3% [0%, 10%]7%14%-0.73+0.452026-08-02 → 2026-08-30
tmax00Znearest365d29 2 QC5.44 [4.91, 5.85]1.73-5.37 [-5.82, -4.78]5.91 [5.17, 6.64]3% [0%, 11%]7%14%-0.73+0.452026-08-02 → 2026-08-30
tmax00Znearestall29 2 QC5.44 [4.96, 5.89]1.73-5.37 [-5.86, -4.84]5.91 [5.23, 6.59]3% [0%, 10%]7%14%-0.73+0.452026-08-02 → 2026-08-30
tmax12Zbilinear30d29 2 QC4.94 [4.14, 5.77]1.66-4.69 [-5.39, -3.95]5.31 [4.29, 6.27]0% [0%, 0%]0%10%-0.58+0.472026-08-02 → 2026-08-30
tmax12Zbilinear90d29 2 QC4.94 [4.08, 5.76]1.66-4.69 [-5.40, -3.90]5.31 [4.23, 6.26]0% [0%, 0%]0%10%-0.58+0.472026-08-02 → 2026-08-30
tmax12Zbilinear365d29 2 QC4.94 [4.04, 5.81]1.66-4.69 [-5.48, -3.87]5.31 [4.16, 6.37]0% [0%, 0%]0%10%-0.58+0.472026-08-02 → 2026-08-30
tmax12Zbilinearall29 2 QC4.94 [3.93, 5.78]1.66-4.69 [-5.48, -3.87]5.31 [4.08, 6.28]0% [0%, 0%]0%10%-0.58+0.472026-08-02 → 2026-08-30
tmax12Znearest30d29 2 QC5.92 [5.21, 6.59]1.63-5.73 [-6.43, -4.99]6.22 [5.38, 7.00]0% [0%, 0%]0%3%-0.89+0.482026-08-02 → 2026-08-30
tmax12Znearest90d29 2 QC5.92 [5.15, 6.59]1.63-5.73 [-6.46, -4.89]6.22 [5.27, 7.01]0% [0%, 0%]0%3%-0.89+0.482026-08-02 → 2026-08-30
tmax12Znearest365d29 2 QC5.92 [5.09, 6.64]1.63-5.73 [-6.53, -4.95]6.22 [5.23, 7.10]0% [0%, 0%]0%3%-0.89+0.482026-08-02 → 2026-08-30
tmax12Znearestall29 2 QC5.92 [5.14, 6.68]1.63-5.73 [-6.54, -4.94]6.22 [5.25, 7.07]0% [0%, 0%]0%3%-0.89+0.482026-08-02 → 2026-08-30
tmin00Zbilinear30d29 2 QC5.34 [3.46, 6.77]1.99-5.29 [-6.77, -3.33]5.91 [4.56, 6.88]17% [0%, 45%]17%17%-1.24+0.162026-08-02 → 2026-08-30
tmin00Zbilinear90d29 2 QC5.34 [3.57, 6.84]1.99-5.29 [-6.84, -3.44]5.91 [4.63, 6.94]17% [0%, 44%]17%17%-1.24+0.162026-08-02 → 2026-08-30
tmin00Zbilinear365d29 2 QC5.34 [3.37, 6.85]1.99-5.29 [-6.85, -3.27]5.91 [4.44, 6.94]17% [0%, 48%]17%17%-1.24+0.162026-08-02 → 2026-08-30
tmin00Zbilinearall29 2 QC5.34 [3.56, 6.99]1.99-5.29 [-6.99, -3.43]5.91 [4.59, 7.09]17% [0%, 46%]17%17%-1.24+0.162026-08-02 → 2026-08-30
tmin00Znearest30d29 2 QC6.20 [4.14, 7.85]2.07-6.20 [-7.85, -4.14]6.78 [5.20, 7.97]14% [0%, 35%]17%17%-1.61+0.132026-08-02 → 2026-08-30
tmin00Znearest90d29 2 QC6.20 [4.25, 7.98]2.07-6.20 [-7.98, -4.25]6.78 [5.33, 8.09]14% [0%, 34%]17%17%-1.61+0.132026-08-02 → 2026-08-30
tmin00Znearest365d29 2 QC6.20 [4.03, 7.96]2.07-6.20 [-7.96, -4.03]6.78 [5.09, 8.06]14% [0%, 38%]17%17%-1.61+0.132026-08-02 → 2026-08-30
tmin00Znearestall29 2 QC6.20 [4.20, 8.18]2.07-6.20 [-8.18, -4.20]6.78 [5.24, 8.28]14% [0%, 36%]17%17%-1.61+0.132026-08-02 → 2026-08-30
tmin12Zbilinear30d29 2 QC5.05 [3.53, 6.24]1.73-4.98 [-6.24, -3.33]5.49 [4.34, 6.34]14% [0%, 37%]17%17%-1.12+0.272026-08-02 → 2026-08-30
tmin12Zbilinear90d29 2 QC5.05 [3.58, 6.36]1.73-4.98 [-6.36, -3.41]5.49 [4.38, 6.45]14% [0%, 37%]17%17%-1.12+0.272026-08-02 → 2026-08-30
tmin12Zbilinear365d29 2 QC5.05 [3.40, 6.36]1.73-4.98 [-6.36, -3.24]5.49 [4.18, 6.45]14% [0%, 39%]17%17%-1.12+0.272026-08-02 → 2026-08-30
tmin12Zbilinearall29 2 QC5.05 [3.56, 6.49]1.73-4.98 [-6.49, -3.37]5.49 [4.30, 6.56]14% [0%, 37%]17%17%-1.12+0.272026-08-02 → 2026-08-30
tmin12Znearest30d29 2 QC5.91 [4.16, 7.32]1.81-5.89 [-7.32, -4.12]6.38 [5.01, 7.45]7% [0%, 20%]14%17%-1.49+0.242026-08-02 → 2026-08-30
tmin12Znearest90d29 2 QC5.91 [4.26, 7.49]1.81-5.89 [-7.49, -4.20]6.38 [5.12, 7.62]7% [0%, 19%]14%17%-1.49+0.242026-08-02 → 2026-08-30
tmin12Znearest365d29 2 QC5.91 [4.08, 7.49]1.81-5.89 [-7.49, -4.01]6.38 [4.86, 7.60]7% [0%, 21%]14%17%-1.49+0.242026-08-02 → 2026-08-30
tmin12Znearestall29 2 QC5.91 [4.19, 7.66]1.81-5.89 [-7.66, -4.14]6.38 [5.06, 7.77]7% [0%, 21%]14%17%-1.49+0.242026-08-02 → 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 1, 00Z bilinear tmax+20+100-10-202026-08-02: -2.88 °F2026-08-03: -3.53 °F2026-08-04: -3.43 °F2026-08-05: -5.81 °F2026-08-06: -2.02 °F2026-08-07: -5.12 °F2026-08-08: -6.76 °F2026-08-09: -4.22 °F2026-08-10: -0.97 °F2026-08-11: -6.3 °F2026-08-12: -8.31 °F2026-08-13: -0.33 °F2026-08-14: -12.31 °F2026-08-15: +1.91 °F2026-08-16: -2.28 °F2026-08-17: -5.32 °F2026-08-18: -5.02 °F2026-08-19: -3.83 °F2026-08-20: -3.97 °F2026-08-21: -3.5 °F2026-08-22: -3.81 °F2026-08-23: -5.53 °F2026-08-24: -4.82 °F2026-08-25: -4.35 °F2026-08-26: -3.74 °F2026-08-27: -5.6 °F2026-08-28: -4.96 °F2026-08-29: -6.25 °F2026-08-30: -2.72 °F2026-08-022026-08-30°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 (29 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.72
2026-08-29-6.25
2026-08-28-4.96
2026-08-27-5.60
2026-08-26-3.74
2026-08-25-4.35
2026-08-24-4.82
2026-08-23-5.53
2026-08-22-3.81
2026-08-21-3.50
2026-08-20-3.97
2026-08-19-3.83
2026-08-18-5.02
2026-08-17-5.32
2026-08-16-2.28
2026-08-15+1.91
2026-08-14-12.31
2026-08-13-0.33
2026-08-12-8.31
2026-08-11-6.30
2026-08-10-0.97
2026-08-09-4.22
2026-08-08-6.76
2026-08-07-5.12
2026-08-06-2.02
2026-08-05-5.81
2026-08-04-3.43
2026-08-03-3.53
2026-08-02-2.88

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KLAS, lead day 1-20 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: 3 days-6 to -4 °F: 10 days-4 to -2 °F: 11 days-2 to 0 °F: 2 days0 to 2 °F: 1 day2 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| 4.22 · P90 |e| 6.39 °F-200+20 °Fn = 29 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
-8.00-6.003
-6.00-4.0010
-4.00-2.0011
-2.00+0.002
+0.00+2.001
+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
2026-08294.47 -4.34

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29

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 (GFS init) 1 -2.41 [-2.41, -2.41] yes
Aurora (IFS init) 2 +0.51 [0.09, 0.93] yes
FourCastNet v2 (GFS init) 1 -1.74 [-1.74, -1.74] yes
FourCastNet v2 (IFS init) 2 -1.58 [-3.03, -0.14] yes
NCEP GFS 29 -0.67 [-1.49, 0.06] no
GraphCast (GFS init) 1 -4.92 [-4.92, -4.92] yes
GraphCast (IFS init) 27 -0.49 [-0.85, -0.20] yes
ECMWF IFS HRES 22 +0.66 [-0.05, 1.18] no
Pangu-Weather (GFS init) 1 -2.17 [-2.17, -2.17] yes
Pangu-Weather (IFS init) 2 -1.32 [-1.81, -0.83] yes
Persistence (baseline) 29 +1.33 [-0.37, 2.74] no

Cite this page

ShortCastCheck, KLAS aifs_single lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KLAS/model/aifs_single/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KLAS (Las Vegas Harry Reid), model aifs_single, lead day 1. 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/1/

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