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

Trenton Mercer · ECMWF IFS HRES · lead day 2

KTTN · ifs_hres · 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, ifs-gpid161, 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
tmax00Zbilinear30d22 1 QC2.44 [1.79, 3.15]2.45+0.10 [-1.66, 1.81]3.16 [2.35, 3.92]41% [23%, 58%]50%59%-0.03-0.122026-08-03 → 2026-08-30
tmax00Zbilinear90d22 1 QC2.44 [1.75, 3.29]2.45+0.10 [-2.06, 1.96]3.16 [2.30, 3.96]41% [18%, 58%]50%59%-0.03-0.122026-08-03 → 2026-08-30
tmax00Zbilinear365d22 1 QC2.44 [1.71, 3.27]2.45+0.10 [-2.13, 2.08]3.16 [2.19, 3.97]41% [20%, 58%]50%59%-0.03-0.122026-08-03 → 2026-08-30
tmax00Zbilinearall22 1 QC2.44 [1.74, 3.31]2.45+0.10 [-2.22, 2.03]3.16 [2.24, 3.96]41% [14%, 58%]50%59%-0.03-0.122026-08-03 → 2026-08-30
tmax00Znearest30d22 1 QC2.30 [1.63, 3.02]2.31+0.18 [-1.50, 1.89]3.02 [2.26, 3.75]36% [18%, 57%]50%64%+0.03-0.052026-08-03 → 2026-08-30
tmax00Znearest90d22 1 QC2.30 [1.60, 3.17]2.31+0.18 [-1.90, 1.97]3.02 [2.20, 3.77]36% [14%, 57%]50%64%+0.03-0.052026-08-03 → 2026-08-30
tmax00Znearest365d22 1 QC2.30 [1.53, 3.15]2.31+0.18 [-1.97, 2.19]3.02 [2.10, 3.78]36% [13%, 58%]50%64%+0.03-0.052026-08-03 → 2026-08-30
tmax00Znearestall22 1 QC2.30 [1.58, 3.17]2.31+0.18 [-2.04, 2.09]3.02 [2.18, 3.79]36% [12%, 56%]50%64%+0.03-0.052026-08-03 → 2026-08-30
tmax12Zbilinear30d22 1 QC2.83 [2.36, 3.30]2.84-0.75 [-2.48, 0.91]3.85 [2.83, 4.71]32% [10%, 48%]50%64%-0.20-0.292026-08-03 → 2026-08-30
tmax12Zbilinear90d22 1 QC2.83 [2.27, 3.40]2.84-0.75 [-2.92, 1.01]3.85 [2.82, 4.75]32% [0%, 50%]50%64%-0.20-0.292026-08-03 → 2026-08-30
tmax12Zbilinear365d22 1 QC2.83 [2.22, 3.38]2.84-0.75 [-3.02, 1.18]3.85 [2.72, 4.88]32% [0%, 54%]50%64%-0.20-0.292026-08-03 → 2026-08-30
tmax12Zbilinearall22 1 QC2.83 [2.20, 3.38]2.84-0.75 [-3.12, 1.02]3.85 [2.63, 4.79]32% [0%, 52%]50%64%-0.20-0.292026-08-03 → 2026-08-30
tmax12Znearest30d22 1 QC2.84 [2.34, 3.29]2.83-0.55 [-2.37, 1.26]3.87 [2.95, 4.60]36% [20%, 50%]45%59%-0.20-0.292026-08-03 → 2026-08-30
tmax12Znearest90d22 1 QC2.84 [2.31, 3.34]2.83-0.55 [-2.78, 1.32]3.87 [2.92, 4.66]36% [17%, 53%]45%59%-0.20-0.292026-08-03 → 2026-08-30
tmax12Znearest365d22 1 QC2.84 [2.25, 3.35]2.83-0.55 [-2.88, 1.54]3.87 [2.86, 4.70]36% [17%, 57%]45%59%-0.20-0.292026-08-03 → 2026-08-30
tmax12Znearestall22 1 QC2.84 [2.23, 3.36]2.83-0.55 [-3.15, 1.34]3.87 [2.76, 4.66]36% [14%, 54%]45%59%-0.20-0.292026-08-03 → 2026-08-30
tmin00Zbilinear30d22 1 QC4.34 [3.58, 5.25]2.07+4.34 [3.58, 5.25]4.99 [4.32, 5.74]14% [0%, 25%]18%32%-0.21+0.432026-08-03 → 2026-08-30
tmin00Zbilinear90d22 1 QC4.34 [3.54, 5.43]2.07+4.34 [3.54, 5.43]4.99 [4.27, 5.90]14% [0%, 25%]18%32%-0.21+0.432026-08-03 → 2026-08-30
tmin00Zbilinear365d22 1 QC4.34 [3.53, 5.50]2.07+4.34 [3.53, 5.50]4.99 [4.23, 5.95]14% [0%, 26%]18%32%-0.21+0.432026-08-03 → 2026-08-30
tmin00Zbilinearall22 1 QC4.34 [3.52, 5.41]2.07+4.34 [3.52, 5.41]4.99 [4.24, 5.89]14% [0%, 25%]18%32%-0.21+0.432026-08-03 → 2026-08-30
tmin00Znearest30d22 1 QC4.57 [3.85, 5.46]2.07+4.57 [3.85, 5.46]5.19 [4.53, 5.94]14% [0%, 25%]18%32%-0.27+0.432026-08-03 → 2026-08-30
tmin00Znearest90d22 1 QC4.57 [3.81, 5.61]2.07+4.57 [3.81, 5.61]5.19 [4.48, 6.10]14% [0%, 25%]18%32%-0.27+0.432026-08-03 → 2026-08-30
tmin00Znearest365d22 1 QC4.57 [3.79, 5.66]2.07+4.57 [3.79, 5.66]5.19 [4.42, 6.16]14% [0%, 26%]18%32%-0.27+0.432026-08-03 → 2026-08-30
tmin00Znearestall22 1 QC4.57 [3.79, 5.59]2.07+4.57 [3.79, 5.59]5.19 [4.42, 6.09]14% [0%, 25%]18%32%-0.27+0.432026-08-03 → 2026-08-30
tmin12Zbilinear30d22 1 QC4.04 [3.59, 4.65]1.61+3.86 [3.17, 4.64]4.37 [3.93, 4.88]0% [0%, 0%]9%27%-0.11+0.562026-08-03 → 2026-08-30
tmin12Zbilinear90d22 1 QC4.04 [3.57, 4.82]1.61+3.86 [3.16, 4.82]4.37 [3.89, 4.98]0% [0%, 0%]9%27%-0.11+0.562026-08-03 → 2026-08-30
tmin12Zbilinear365d22 1 QC4.04 [3.56, 4.75]1.61+3.86 [3.07, 4.75]4.37 [3.87, 4.96]0% [0%, 0%]9%27%-0.11+0.562026-08-03 → 2026-08-30
tmin12Zbilinearall22 1 QC4.04 [3.56, 4.99]1.61+3.86 [3.10, 4.99]4.37 [3.85, 5.13]0% [0%, 0%]9%27%-0.11+0.562026-08-03 → 2026-08-30
tmin12Znearest30d22 1 QC4.31 [3.83, 4.95]1.63+4.17 [3.52, 4.95]4.65 [4.18, 5.19]0% [0%, 0%]9%32%-0.19+0.562026-08-03 → 2026-08-30
tmin12Znearest90d22 1 QC4.31 [3.83, 5.10]1.63+4.17 [3.47, 5.10]4.65 [4.17, 5.22]0% [0%, 0%]9%32%-0.19+0.562026-08-03 → 2026-08-30
tmin12Znearest365d22 1 QC4.31 [3.82, 5.07]1.63+4.17 [3.45, 5.07]4.65 [4.15, 5.25]0% [0%, 0%]9%32%-0.19+0.562026-08-03 → 2026-08-30
tmin12Znearestall22 1 QC4.31 [3.79, 5.26]1.63+4.17 [3.44, 5.26]4.65 [4.11, 5.40]0% [0%, 0%]9%32%-0.19+0.562026-08-03 → 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 IFS HRES at KTTN, lead day 2, 00Z bilinear tmax+10+50-5-102026-08-03: -3.68 °F2026-08-08: -3.57 °F2026-08-09: -0.87 °F2026-08-11: +3.89 °F2026-08-13: -0.17 °F2026-08-14: +2.72 °F2026-08-15: +3.41 °F2026-08-16: +8.04 °F2026-08-17: +2.6 °F2026-08-18: -0.46 °F2026-08-19: -0.87 °F2026-08-20: -4.81 °F2026-08-21: -1.35 °F2026-08-22: -5.73 °F2026-08-23: -0.43 °F2026-08-24: -3.04 °F2026-08-25: +0.35 °F2026-08-26: +0.8 °F2026-08-27: +0.6 °F2026-08-28: -0.79 °F2026-08-29: +3.85 °F2026-08-30: +1.69 °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+1.69
2026-08-29+3.85
2026-08-28-0.79
2026-08-27+0.60
2026-08-26+0.80
2026-08-25+0.35
2026-08-24-3.04
2026-08-23-0.43
2026-08-22-5.73
2026-08-21-1.35
2026-08-20-4.81
2026-08-19-0.87
2026-08-18-0.46
2026-08-17+2.60
2026-08-16+8.04
2026-08-15+3.41
2026-08-14+2.72
2026-08-13-0.17
2026-08-12—
2026-08-11+3.89
2026-08-10—
2026-08-09-0.87
2026-08-08-3.57
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03-3.68

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KTTN, lead day 2-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 1 day-5 to -4 °F: 1 day-4 to -3 °F: 3 days-3 to -2 °F: 0 days-2 to -1 °F: 1 day-1 to 0 °F: 6 days0 to 1 °F: 3 days1 to 2 °F: 1 day2 to 3 °F: 2 days3 to 4 °F: 3 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 1 day9 to 10 °F: 0 daysdashed: P50 |e| 2.15 · P90 |e| 4.72 °F-100+10 °Fn = 22 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
-7.00-6.000
-6.00-5.001
-5.00-4.001
-4.00-3.003
-3.00-2.000
-2.00-1.001
-1.00+0.006
+0.00+1.003
+1.00+2.001
+2.00+3.002
+3.00+4.003
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.001
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08222.44 +0.10

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-03 → 2026-08-30 22
ECMWF IFS HRES2026-08-03 → 2026-08-30 22
ECMWF IFS HRES2026-08-03 → 2026-08-30 22
ECMWF IFS HRES2026-08-03 → 2026-08-30 22

Compared with other models

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

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 22 -0.06 [-0.60, 0.36] no
Aurora (IFS init) 1 +1.38 [1.38, 1.38] yes
FourCastNet v2 (IFS init) 1 +0.62 [0.62, 0.62] yes
NCEP GFS 22 -0.88 [-3.25, 0.14] no
GraphCast (IFS init) 20 +0.10 [-0.56, 0.91] no
Pangu-Weather (IFS init) 1 -0.42 [-0.42, -0.42] yes
Persistence (baseline) 22 +0.08 [-0.46, 1.21] no

Cite this page

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

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