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

All stations (mean of daily station errors) · ECMWF AIFS Single · lead day 7

ALL · aifs_single · lead 7

Target day = initialization date + 7 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
tmax00Zbilinear30d23 2 QC4.38 [4.00, 4.76]0.83-3.92 [-4.33, -3.48]5.49 [5.01, 5.93]13% [12%, 16%]27%40%-0.05+0.402026-08-08 → 2026-08-30
tmax00Zbilinear90d23 2 QC4.38 [3.93, 4.78]0.83-3.92 [-4.38, -3.41]5.49 [4.91, 5.96]13% [12%, 17%]27%40%-0.05+0.402026-08-08 → 2026-08-30
tmax00Zbilinear365d23 2 QC4.38 [3.94, 4.80]0.83-3.92 [-4.39, -3.40]5.49 [4.91, 5.97]13% [12%, 17%]27%40%-0.05+0.402026-08-08 → 2026-08-30
tmax00Zbilinearall23 2 QC4.38 [3.91, 4.82]0.83-3.92 [-4.39, -3.38]5.49 [4.84, 6.01]13% [11%, 17%]27%40%-0.05+0.402026-08-08 → 2026-08-30
tmax00Znearest30d23 2 QC4.39 [4.00, 4.79]0.82-3.87 [-4.27, -3.44]5.54 [5.05, 5.98]15% [13%, 18%]26%40%-0.05+0.412026-08-08 → 2026-08-30
tmax00Znearest90d23 2 QC4.39 [3.96, 4.81]0.82-3.87 [-4.32, -3.40]5.54 [4.96, 6.01]15% [13%, 18%]26%40%-0.05+0.412026-08-08 → 2026-08-30
tmax00Znearest365d23 2 QC4.39 [3.92, 4.84]0.82-3.87 [-4.32, -3.37]5.54 [4.95, 6.03]15% [13%, 18%]26%40%-0.05+0.412026-08-08 → 2026-08-30
tmax00Znearestall23 2 QC4.39 [3.90, 4.86]0.82-3.87 [-4.33, -3.38]5.54 [4.94, 6.06]15% [13%, 18%]26%40%-0.05+0.412026-08-08 → 2026-08-30
tmax12Zbilinear30d23 2 QC4.33 [4.07, 4.59]0.61-3.83 [-4.14, -3.55]5.33 [5.05, 5.59]12% [10%, 14%]25%38%-0.03+0.562026-08-08 → 2026-08-30
tmax12Zbilinear90d23 2 QC4.33 [4.06, 4.63]0.61-3.83 [-4.15, -3.54]5.33 [5.04, 5.62]12% [10%, 14%]25%38%-0.03+0.562026-08-08 → 2026-08-30
tmax12Zbilinear365d23 2 QC4.33 [4.03, 4.63]0.61-3.83 [-4.18, -3.52]5.33 [5.00, 5.63]12% [10%, 14%]25%38%-0.03+0.562026-08-08 → 2026-08-30
tmax12Zbilinearall23 2 QC4.33 [4.04, 4.63]0.61-3.83 [-4.17, -3.52]5.33 [5.01, 5.64]12% [10%, 14%]25%38%-0.03+0.562026-08-08 → 2026-08-30
tmax12Znearest30d23 2 QC4.35 [4.05, 4.65]0.62-3.77 [-4.09, -3.48]5.37 [5.06, 5.66]13% [11%, 15%]26%39%-0.04+0.562026-08-08 → 2026-08-30
tmax12Znearest90d23 2 QC4.35 [4.03, 4.69]0.62-3.77 [-4.14, -3.47]5.37 [5.04, 5.70]13% [11%, 15%]26%39%-0.04+0.562026-08-08 → 2026-08-30
tmax12Znearest365d23 2 QC4.35 [4.00, 4.69]0.62-3.77 [-4.16, -3.45]5.37 [4.99, 5.71]13% [10%, 15%]26%39%-0.04+0.562026-08-08 → 2026-08-30
tmax12Znearestall23 2 QC4.35 [4.01, 4.69]0.62-3.77 [-4.14, -3.46]5.37 [4.97, 5.72]13% [10%, 15%]26%39%-0.04+0.562026-08-08 → 2026-08-30
tmin00Zbilinear30d23 2 QC2.74 [2.44, 2.99]0.56+0.36 [0.02, 0.71]3.58 [3.17, 3.87]25% [22%, 28%]47%65%+0.25+0.532026-08-08 → 2026-08-30
tmin00Zbilinear90d23 2 QC2.74 [2.40, 3.01]0.56+0.36 [-0.04, 0.75]3.58 [3.13, 3.89]25% [22%, 28%]47%65%+0.25+0.532026-08-08 → 2026-08-30
tmin00Zbilinear365d23 2 QC2.74 [2.39, 3.03]0.56+0.36 [-0.04, 0.77]3.58 [3.10, 3.89]25% [22%, 28%]47%65%+0.25+0.532026-08-08 → 2026-08-30
tmin00Zbilinearall23 2 QC2.74 [2.37, 3.01]0.56+0.36 [-0.06, 0.71]3.58 [3.09, 3.89]25% [22%, 28%]47%65%+0.25+0.532026-08-08 → 2026-08-30
tmin00Znearest30d23 2 QC2.83 [2.50, 3.11]0.57+0.34 [-0.02, 0.70]3.72 [3.26, 4.04]25% [22%, 29%]46%64%+0.23+0.522026-08-08 → 2026-08-30
tmin00Znearest90d23 2 QC2.83 [2.46, 3.12]0.57+0.34 [-0.07, 0.73]3.72 [3.22, 4.05]25% [22%, 29%]46%64%+0.23+0.522026-08-08 → 2026-08-30
tmin00Znearest365d23 2 QC2.83 [2.44, 3.15]0.57+0.34 [-0.08, 0.77]3.72 [3.19, 4.05]25% [22%, 29%]46%64%+0.23+0.522026-08-08 → 2026-08-30
tmin00Znearestall23 2 QC2.83 [2.42, 3.12]0.57+0.34 [-0.10, 0.70]3.72 [3.17, 4.05]25% [22%, 29%]46%64%+0.23+0.522026-08-08 → 2026-08-30
tmin12Zbilinear30d23 2 QC2.63 [2.42, 2.81]0.61+0.17 [-0.18, 0.49]3.40 [3.08, 3.65]27% [24%, 30%]48%66%+0.29+0.492026-08-08 → 2026-08-30
tmin12Zbilinear90d23 2 QC2.63 [2.40, 2.83]0.61+0.17 [-0.22, 0.52]3.40 [3.06, 3.68]27% [23%, 31%]48%66%+0.29+0.492026-08-08 → 2026-08-30
tmin12Zbilinear365d23 2 QC2.63 [2.39, 2.85]0.61+0.17 [-0.24, 0.54]3.40 [3.05, 3.68]27% [23%, 31%]48%66%+0.29+0.492026-08-08 → 2026-08-30
tmin12Zbilinearall23 2 QC2.63 [2.38, 2.83]0.61+0.17 [-0.28, 0.52]3.40 [3.03, 3.68]27% [23%, 31%]48%66%+0.29+0.492026-08-08 → 2026-08-30
tmin12Znearest30d23 2 QC2.70 [2.44, 2.92]0.62+0.15 [-0.20, 0.48]3.52 [3.17, 3.79]27% [25%, 29%]48%64%+0.26+0.482026-08-08 → 2026-08-30
tmin12Znearest90d23 2 QC2.70 [2.42, 2.94]0.62+0.15 [-0.25, 0.50]3.52 [3.14, 3.81]27% [25%, 29%]48%64%+0.26+0.482026-08-08 → 2026-08-30
tmin12Znearest365d23 2 QC2.70 [2.40, 2.96]0.62+0.15 [-0.29, 0.52]3.52 [3.12, 3.82]27% [24%, 29%]48%64%+0.26+0.482026-08-08 → 2026-08-30
tmin12Znearestall23 2 QC2.70 [2.39, 2.94]0.62+0.15 [-0.32, 0.50]3.52 [3.10, 3.82]27% [25%, 29%]48%64%+0.26+0.482026-08-08 → 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 ALL, lead day 7, 00Z bilinear tmax+10+50-5-102026-08-08: -4.65 °F2026-08-09: -4.84 °F2026-08-10: -3.03 °F2026-08-11: -4.48 °F2026-08-12: -5.68 °F2026-08-13: -4.01 °F2026-08-14: -3.69 °F2026-08-15: -3.24 °F2026-08-16: -2.65 °F2026-08-17: -2.65 °F2026-08-18: -2.93 °F2026-08-19: -5.34 °F2026-08-20: -2.74 °F2026-08-21: -3.55 °F2026-08-22: -3.97 °F2026-08-23: -4.66 °F2026-08-24: -6.18 °F2026-08-25: -4.06 °F2026-08-26: -3.49 °F2026-08-27: -4.81 °F2026-08-28: -3.55 °F2026-08-29: -3.34 °F2026-08-30: -2.59 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.59
2026-08-29-3.34
2026-08-28-3.55
2026-08-27-4.81
2026-08-26-3.49
2026-08-25-4.06
2026-08-24-6.18
2026-08-23-4.66
2026-08-22-3.97
2026-08-21-3.55
2026-08-20-2.74
2026-08-19-5.34
2026-08-18-2.93
2026-08-17-2.65
2026-08-16-2.65
2026-08-15-3.24
2026-08-14-3.69
2026-08-13-4.01
2026-08-12-5.68
2026-08-11-4.48
2026-08-10-3.03
2026-08-09-4.84
2026-08-08-4.65

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at ALL, lead day 7-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 2 days-5 to -4 °F: 7 days-4 to -3 °F: 8 days-3 to -2 °F: 5 days-2 to -1 °F: 0 days-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| 3.69 · P90 |e| 5.24 °F-100+10 °Fn = 23 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
-8.00-7.000
-7.00-6.001
-6.00-5.002
-5.00-4.007
-4.00-3.008
-3.00-2.005
-2.00-1.000
-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
2026-08233.92 -3.92

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-08 → 2026-08-30 23
ECMWF AIFS Single2026-08-08 → 2026-08-30 23
ECMWF AIFS Single2026-08-08 → 2026-08-30 23
ECMWF AIFS Single2026-08-08 → 2026-08-30 23

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 23 +0.46 [0.16, 0.86] yes
GraphCast (IFS init) 23 -1.50 [-1.97, -0.77] yes
ECMWF IFS HRES 18 +0.67 [0.16, 1.32] yes
Persistence (baseline) 23 +0.19 [-0.44, 0.74] no

Cite this page

ShortCastCheck, ALL aifs_single lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/ALL/model/aifs_single/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: ALL (All stations (mean of daily station errors)), model aifs_single, lead day 7. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/ALL/model/aifs_single/lead/7/

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