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

Austin Bergstrom · ECMWF AIFS Single · lead day 4

KAUS · aifs_single · lead 4

Target day = initialization date + 4 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, 1 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
tmax00Zbilinear30d26 1 QC4.87 [4.21, 5.43]1.05-4.87 [-5.43, -4.21]5.05 [4.44, 5.55]0% [0%, 0%]4%8%-1.48+0.472026-08-05 → 2026-08-30
tmax00Zbilinear90d26 1 QC4.87 [4.12, 5.51]1.05-4.87 [-5.51, -4.12]5.05 [4.34, 5.62]0% [0%, 0%]4%8%-1.48+0.472026-08-05 → 2026-08-30
tmax00Zbilinear365d26 1 QC4.87 [3.93, 5.51]1.05-4.87 [-5.51, -3.93]5.05 [4.16, 5.62]0% [0%, 0%]4%8%-1.48+0.472026-08-05 → 2026-08-30
tmax00Zbilinearall26 1 QC4.87 [4.04, 5.51]1.05-4.87 [-5.51, -4.04]5.05 [4.25, 5.62]0% [0%, 0%]4%8%-1.48+0.472026-08-05 → 2026-08-30
tmax00Znearest30d26 1 QC5.01 [4.33, 5.55]1.02-5.01 [-5.55, -4.33]5.17 [4.55, 5.65]0% [0%, 0%]4%8%-1.55+0.482026-08-05 → 2026-08-30
tmax00Znearest90d26 1 QC5.01 [4.27, 5.64]1.02-5.01 [-5.64, -4.27]5.17 [4.47, 5.75]0% [0%, 0%]4%8%-1.55+0.482026-08-05 → 2026-08-30
tmax00Znearest365d26 1 QC5.01 [4.06, 5.64]1.02-5.01 [-5.64, -4.06]5.17 [4.28, 5.74]0% [0%, 0%]4%8%-1.55+0.482026-08-05 → 2026-08-30
tmax00Znearestall26 1 QC5.01 [4.21, 5.64]1.02-5.01 [-5.64, -4.21]5.17 [4.34, 5.76]0% [0%, 0%]4%8%-1.55+0.482026-08-05 → 2026-08-30
tmax12Zbilinear30d26 1 QC5.39 [4.80, 5.81]0.98-5.39 [-5.81, -4.80]5.52 [5.00, 5.89]0% [0%, 0%]0%4%-1.75+0.512026-08-05 → 2026-08-30
tmax12Zbilinear90d26 1 QC5.39 [4.71, 5.87]0.98-5.39 [-5.87, -4.71]5.52 [4.90, 5.94]0% [0%, 0%]0%4%-1.75+0.512026-08-05 → 2026-08-30
tmax12Zbilinear365d26 1 QC5.39 [4.61, 5.87]0.98-5.39 [-5.87, -4.61]5.52 [4.81, 5.94]0% [0%, 0%]0%4%-1.75+0.512026-08-05 → 2026-08-30
tmax12Zbilinearall26 1 QC5.39 [4.63, 5.88]0.98-5.39 [-5.88, -4.63]5.52 [4.81, 5.93]0% [0%, 0%]0%4%-1.75+0.512026-08-05 → 2026-08-30
tmax12Znearest30d26 1 QC5.53 [4.96, 5.92]0.95-5.53 [-5.92, -4.96]5.65 [5.15, 5.98]0% [0%, 0%]0%4%-1.82+0.522026-08-05 → 2026-08-30
tmax12Znearest90d26 1 QC5.53 [4.85, 5.98]0.95-5.53 [-5.98, -4.85]5.65 [5.05, 6.04]0% [0%, 0%]0%4%-1.82+0.522026-08-05 → 2026-08-30
tmax12Znearest365d26 1 QC5.53 [4.77, 5.98]0.95-5.53 [-5.98, -4.77]5.65 [4.97, 6.04]0% [0%, 0%]0%4%-1.82+0.522026-08-05 → 2026-08-30
tmax12Znearestall26 1 QC5.53 [4.78, 5.98]0.95-5.53 [-5.98, -4.78]5.65 [4.96, 6.04]0% [0%, 0%]0%4%-1.82+0.522026-08-05 → 2026-08-30
tmin00Zbilinear30d26 1 QC3.14 [2.24, 3.84]1.41+3.04 [2.01, 3.84]3.52 [2.72, 4.11]8% [0%, 21%]31%54%+0.02+0.562026-08-05 → 2026-08-30
tmin00Zbilinear90d26 1 QC3.14 [2.19, 3.97]1.41+3.04 [1.97, 3.97]3.52 [2.66, 4.21]8% [0%, 22%]31%54%+0.02+0.562026-08-05 → 2026-08-30
tmin00Zbilinear365d26 1 QC3.14 [2.12, 4.03]1.41+3.04 [1.85, 4.03]3.52 [2.59, 4.27]8% [0%, 22%]31%54%+0.02+0.562026-08-05 → 2026-08-30
tmin00Zbilinearall26 1 QC3.14 [2.07, 4.02]1.41+3.04 [1.82, 4.02]3.52 [2.53, 4.25]8% [0%, 22%]31%54%+0.02+0.562026-08-05 → 2026-08-30
tmin00Znearest30d26 1 QC2.99 [2.12, 3.71]1.42+2.86 [1.80, 3.71]3.38 [2.57, 4.00]8% [0%, 21%]31%58%+0.06+0.562026-08-05 → 2026-08-30
tmin00Znearest90d26 1 QC2.99 [2.06, 3.83]1.42+2.86 [1.74, 3.83]3.38 [2.50, 4.10]8% [0%, 22%]31%58%+0.06+0.562026-08-05 → 2026-08-30
tmin00Znearest365d26 1 QC2.99 [2.01, 3.90]1.42+2.86 [1.63, 3.90]3.38 [2.44, 4.15]8% [0%, 22%]31%58%+0.06+0.562026-08-05 → 2026-08-30
tmin00Znearestall26 1 QC2.99 [1.97, 3.91]1.42+2.86 [1.60, 3.91]3.38 [2.38, 4.15]8% [0%, 22%]31%58%+0.06+0.562026-08-05 → 2026-08-30
tmin12Zbilinear30d26 1 QC2.98 [2.10, 3.72]1.46+2.83 [1.70, 3.72]3.37 [2.49, 4.03]8% [0%, 21%]31%54%+0.07+0.542026-08-05 → 2026-08-30
tmin12Zbilinear90d26 1 QC2.98 [2.06, 3.88]1.46+2.83 [1.68, 3.88]3.37 [2.44, 4.17]8% [0%, 22%]31%54%+0.07+0.542026-08-05 → 2026-08-30
tmin12Zbilinear365d26 1 QC2.98 [2.00, 3.96]1.46+2.83 [1.58, 3.96]3.37 [2.36, 4.23]8% [0%, 22%]31%54%+0.07+0.542026-08-05 → 2026-08-30
tmin12Zbilinearall26 1 QC2.98 [1.96, 3.92]1.46+2.83 [1.62, 3.92]3.37 [2.29, 4.21]8% [0%, 22%]31%54%+0.07+0.542026-08-05 → 2026-08-30
tmin12Znearest30d26 1 QC2.84 [1.98, 3.61]1.48+2.65 [1.48, 3.61]3.24 [2.35, 3.93]15% [0%, 37%]31%58%+0.11+0.542026-08-05 → 2026-08-30
tmin12Znearest90d26 1 QC2.84 [1.93, 3.79]1.48+2.65 [1.45, 3.79]3.24 [2.30, 4.07]15% [0%, 38%]31%58%+0.11+0.542026-08-05 → 2026-08-30
tmin12Znearest365d26 1 QC2.84 [1.88, 3.85]1.48+2.65 [1.34, 3.85]3.24 [2.22, 4.14]15% [0%, 40%]31%58%+0.11+0.542026-08-05 → 2026-08-30
tmin12Znearestall26 1 QC2.84 [1.84, 3.83]1.48+2.65 [1.36, 3.83]3.24 [2.15, 4.11]15% [0%, 40%]31%58%+0.11+0.542026-08-05 → 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 KAUS, lead day 4, 00Z bilinear tmax+10+50-5-102026-08-05: -4.04 °F2026-08-06: -6.46 °F2026-08-07: -6.99 °F2026-08-08: -6.07 °F2026-08-09: -6.08 °F2026-08-10: -5.39 °F2026-08-11: -4.75 °F2026-08-12: -3.66 °F2026-08-13: -4.83 °F2026-08-14: -3.91 °F2026-08-15: -5.88 °F2026-08-16: -4.18 °F2026-08-17: -6.48 °F2026-08-18: -4.6 °F2026-08-19: -4.13 °F2026-08-20: -4.71 °F2026-08-21: -5.1 °F2026-08-22: -7.42 °F2026-08-23: -5.17 °F2026-08-24: -4.82 °F2026-08-25: -3.79 °F2026-08-26: -2.38 °F2026-08-27: -6.19 °F2026-08-28: -3.96 °F2026-08-29: -1.83 °F2026-08-30: -3.88 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.88
2026-08-29-1.83
2026-08-28-3.96
2026-08-27-6.19
2026-08-26-2.38
2026-08-25-3.79
2026-08-24-4.82
2026-08-23-5.17
2026-08-22-7.42
2026-08-21-5.10
2026-08-20-4.71
2026-08-19-4.13
2026-08-18-4.60
2026-08-17-6.48
2026-08-16-4.18
2026-08-15-5.88
2026-08-14-3.91
2026-08-13-4.83
2026-08-12-3.66
2026-08-11-4.75
2026-08-10-5.39
2026-08-09-6.08
2026-08-08-6.07
2026-08-07-6.99
2026-08-06-6.46
2026-08-05-4.04

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KAUS, lead day 4-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 6 days-6 to -5 °F: 4 days-5 to -4 °F: 8 days-4 to -3 °F: 5 days-3 to -2 °F: 1 day-2 to -1 °F: 1 day-1 to 0 °F: 0 days0 to 1 °F: 0 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: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 4.78 · P90 |e| 6.47 °F-100+10 °Fn = 26 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
-10.00-9.000
-9.00-8.000
-8.00-7.001
-7.00-6.006
-6.00-5.004
-5.00-4.008
-4.00-3.005
-3.00-2.001
-2.00-1.001
-1.00+0.000
+0.00+1.000
+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+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08264.87 -4.87

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26
ECMWF AIFS Single2026-08-05 → 2026-08-30 26

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
NCEP GFS 26 +3.00 [1.35, 3.94] yes
GraphCast (IFS init) 25 -2.30 [-3.53, -0.43] yes
ECMWF IFS HRES 20 +0.66 [-0.43, 1.53] no
Persistence (baseline) 26 +2.91 [1.88, 3.67] yes

Cite this page

ShortCastCheck, KAUS aifs_single lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KAUS/model/aifs_single/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KAUS (Austin Bergstrom), model aifs_single, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KAUS/model/aifs_single/lead/4/

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