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

Trenton Mercer · ECMWF AIFS Single · lead day 7

KTTN · 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, 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
tmax00Zbilinear30d23 1 QC1.59 [1.14, 1.89]1.64-0.32 [-1.10, 0.50]2.29 [1.68, 2.69]39% [20%, 63%]74%87%+0.56+0.512026-08-08 → 2026-08-30
tmax00Zbilinear90d23 1 QC1.59 [1.01, 1.86]1.64-0.32 [-1.12, 0.57]2.29 [1.45, 2.68]39% [18%, 70%]74%87%+0.56+0.512026-08-08 → 2026-08-30
tmax00Zbilinear365d23 1 QC1.59 [0.98, 1.89]1.64-0.32 [-1.14, 0.63]2.29 [1.43, 2.68]39% [14%, 70%]74%87%+0.56+0.512026-08-08 → 2026-08-30
tmax00Zbilinearall23 1 QC1.59 [0.99, 1.88]1.64-0.32 [-1.07, 0.56]2.29 [1.26, 2.68]39% [18%, 73%]74%87%+0.56+0.512026-08-08 → 2026-08-30
tmax00Znearest30d23 1 QC1.67 [1.18, 2.00]1.68-0.02 [-0.81, 0.80]2.30 [1.70, 2.68]39% [20%, 63%]70%87%+0.54+0.502026-08-08 → 2026-08-30
tmax00Znearest90d23 1 QC1.67 [1.06, 1.98]1.68-0.02 [-0.87, 0.89]2.30 [1.45, 2.67]39% [18%, 70%]70%87%+0.54+0.502026-08-08 → 2026-08-30
tmax00Znearest365d23 1 QC1.67 [1.01, 2.02]1.68-0.02 [-0.89, 0.95]2.30 [1.48, 2.67]39% [14%, 70%]70%87%+0.54+0.502026-08-08 → 2026-08-30
tmax00Znearestall23 1 QC1.67 [1.02, 2.00]1.68-0.02 [-0.83, 0.83]2.30 [1.27, 2.68]39% [18%, 73%]70%87%+0.54+0.502026-08-08 → 2026-08-30
tmax12Zbilinear30d23 1 QC1.44 [0.97, 1.76]1.41+0.34 [-0.20, 0.77]1.96 [1.36, 2.33]48% [29%, 69%]70%91%+0.61+0.582026-08-08 → 2026-08-30
tmax12Zbilinear90d23 1 QC1.44 [0.88, 1.76]1.41+0.34 [-0.20, 0.79]1.96 [1.21, 2.34]48% [29%, 75%]70%91%+0.61+0.582026-08-08 → 2026-08-30
tmax12Zbilinear365d23 1 QC1.44 [0.88, 1.80]1.41+0.34 [-0.23, 0.78]1.96 [1.20, 2.37]48% [27%, 75%]70%91%+0.61+0.582026-08-08 → 2026-08-30
tmax12Zbilinearall23 1 QC1.44 [0.84, 1.75]1.41+0.34 [-0.19, 0.80]1.96 [1.10, 2.36]48% [29%, 79%]70%91%+0.61+0.582026-08-08 → 2026-08-30
tmax12Znearest30d23 1 QC1.55 [1.11, 1.85]1.46+0.66 [0.06, 1.12]2.09 [1.55, 2.42]48% [29%, 69%]74%83%+0.58+0.572026-08-08 → 2026-08-30
tmax12Znearest90d23 1 QC1.55 [1.00, 1.86]1.46+0.66 [0.04, 1.16]2.09 [1.43, 2.44]48% [29%, 75%]74%83%+0.58+0.572026-08-08 → 2026-08-30
tmax12Znearest365d23 1 QC1.55 [0.98, 1.89]1.46+0.66 [0.02, 1.16]2.09 [1.42, 2.45]48% [27%, 75%]74%83%+0.58+0.572026-08-08 → 2026-08-30
tmax12Znearestall23 1 QC1.55 [0.96, 1.86]1.46+0.66 [0.06, 1.17]2.09 [1.35, 2.42]48% [29%, 79%]74%83%+0.58+0.572026-08-08 → 2026-08-30
tmin00Zbilinear30d23 1 QC4.46 [3.81, 5.37]1.98+4.40 [3.70, 5.37]5.01 [4.41, 5.70]13% [0%, 25%]17%22%-0.07+0.472026-08-08 → 2026-08-30
tmin00Zbilinear90d23 1 QC4.46 [3.80, 5.57]1.98+4.40 [3.69, 5.57]5.01 [4.39, 5.90]13% [0%, 25%]17%22%-0.07+0.472026-08-08 → 2026-08-30
tmin00Zbilinear365d23 1 QC4.46 [3.76, 5.52]1.98+4.40 [3.64, 5.52]5.01 [4.35, 5.84]13% [0%, 25%]17%22%-0.07+0.472026-08-08 → 2026-08-30
tmin00Zbilinearall23 1 QC4.46 [3.79, 5.60]1.98+4.40 [3.64, 5.60]5.01 [4.38, 5.94]13% [0%, 25%]17%22%-0.07+0.472026-08-08 → 2026-08-30
tmin00Znearest30d23 1 QC4.69 [4.02, 5.62]1.99+4.65 [3.94, 5.62]5.24 [4.62, 5.96]13% [0%, 25%]17%22%-0.12+0.472026-08-08 → 2026-08-30
tmin00Znearest90d23 1 QC4.69 [4.02, 5.84]1.99+4.65 [3.93, 5.84]5.24 [4.61, 6.16]13% [0%, 25%]17%22%-0.12+0.472026-08-08 → 2026-08-30
tmin00Znearest365d23 1 QC4.69 [3.97, 5.80]1.99+4.65 [3.89, 5.80]5.24 [4.58, 6.09]13% [0%, 25%]17%22%-0.12+0.472026-08-08 → 2026-08-30
tmin00Znearestall23 1 QC4.69 [4.02, 5.89]1.99+4.65 [3.91, 5.89]5.24 [4.59, 6.20]13% [0%, 25%]17%22%-0.12+0.472026-08-08 → 2026-08-30
tmin12Zbilinear30d23 1 QC4.24 [3.54, 5.04]1.86+4.02 [3.08, 5.02]4.75 [3.94, 5.51]9% [0%, 17%]13%30%-0.01+0.502026-08-08 → 2026-08-30
tmin12Zbilinear90d23 1 QC4.24 [3.54, 5.21]1.86+4.02 [3.04, 5.21]4.75 [3.99, 5.59]9% [0%, 15%]13%30%-0.01+0.502026-08-08 → 2026-08-30
tmin12Zbilinear365d23 1 QC4.24 [3.48, 5.16]1.86+4.02 [2.94, 5.16]4.75 [3.87, 5.59]9% [0%, 15%]13%30%-0.01+0.502026-08-08 → 2026-08-30
tmin12Zbilinearall23 1 QC4.24 [3.41, 5.14]1.86+4.02 [2.90, 5.14]4.75 [3.86, 5.53]9% [0%, 15%]13%30%-0.01+0.502026-08-08 → 2026-08-30
tmin12Znearest30d23 1 QC4.46 [3.72, 5.31]1.86+4.30 [3.38, 5.30]4.99 [4.18, 5.77]9% [0%, 17%]13%22%-0.07+0.502026-08-08 → 2026-08-30
tmin12Znearest90d23 1 QC4.46 [3.74, 5.51]1.86+4.30 [3.34, 5.51]4.99 [4.22, 5.85]9% [0%, 15%]13%22%-0.07+0.502026-08-08 → 2026-08-30
tmin12Znearest365d23 1 QC4.46 [3.65, 5.43]1.86+4.30 [3.25, 5.43]4.99 [4.10, 5.85]9% [0%, 15%]13%22%-0.07+0.502026-08-08 → 2026-08-30
tmin12Znearestall23 1 QC4.46 [3.57, 5.43]1.86+4.30 [3.21, 5.43]4.99 [4.08, 5.81]9% [0%, 15%]13%22%-0.07+0.502026-08-08 → 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 KTTN, lead day 7, 00Z bilinear tmax+10+50-5-102026-08-08: -1.47 °F2026-08-09: -0.02 °F2026-08-10: +2.01 °F2026-08-11: -0.28 °F2026-08-12: -6.46 °F2026-08-13: +0.48 °F2026-08-14: +1.24 °F2026-08-15: -1.33 °F2026-08-16: +1.01 °F2026-08-17: +1.99 °F2026-08-18: +1.26 °F2026-08-19: -2.23 °F2026-08-20: +5.03 °F2026-08-21: +0.06 °F2026-08-22: -1.09 °F2026-08-23: +0.41 °F2026-08-24: -1.83 °F2026-08-25: -2.4 °F2026-08-26: +0.44 °F2026-08-27: -4.61 °F2026-08-28: +0.14 °F2026-08-29: -0.27 °F2026-08-30: +0.56 °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+0.56
2026-08-29-0.27
2026-08-28+0.14
2026-08-27-4.61
2026-08-26+0.44
2026-08-25-2.40
2026-08-24-1.83
2026-08-23+0.41
2026-08-22-1.09
2026-08-21+0.06
2026-08-20+5.03
2026-08-19-2.23
2026-08-18+1.26
2026-08-17+1.99
2026-08-16+1.01
2026-08-15-1.33
2026-08-14+1.24
2026-08-13+0.48
2026-08-12-6.46
2026-08-11-0.28
2026-08-10+2.01
2026-08-09-0.02
2026-08-08-1.47

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KTTN, 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: 0 days-5 to -4 °F: 1 day-4 to -3 °F: 0 days-3 to -2 °F: 2 days-2 to -1 °F: 4 days-1 to 0 °F: 3 days0 to 1 °F: 6 days1 to 2 °F: 4 days2 to 3 °F: 1 day3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 1 day6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 1.24 · P90 |e| 4.17 °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
-6.00-5.000
-5.00-4.001
-4.00-3.000
-3.00-2.002
-2.00-1.004
-1.00+0.003
+0.00+1.006
+1.00+2.004
+2.00+3.001
+3.00+4.000
+4.00+5.000
+5.00+6.001
+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
2026-08231.59 -0.32

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 -1.70 [-2.81, -0.65] yes
GraphCast (IFS init) 23 -0.78 [-1.37, -0.29] yes
ECMWF IFS HRES 18 -1.22 [-3.50, -0.30] yes
Persistence (baseline) 23 -2.06 [-3.03, -0.76] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KTTN (Trenton Mercer), 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/KTTN/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