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

Boston Logan · ECMWF IFS HRES · lead day 4

KBOS · ifs_hres · 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, 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
tmax00Zbilinear30d19 1 QC3.81 [2.89, 4.95]3.84-0.51 [-2.32, 0.57]4.54 [3.34, 5.73]11% [0%, 30%]21%53%+0.45+0.442026-08-05 → 2026-08-30
tmax00Zbilinear90d19 1 QC3.81 [2.84, 5.51]3.84-0.51 [-2.86, 0.62]4.54 [3.30, 6.27]11% [0%, 33%]21%53%+0.45+0.442026-08-05 → 2026-08-30
tmax00Zbilinear365d19 1 QC3.81 [2.78, 5.40]3.84-0.51 [-2.82, 0.76]4.54 [3.28, 6.09]11% [0%, 38%]21%53%+0.45+0.442026-08-05 → 2026-08-30
tmax00Zbilinearall19 1 QC3.81 [2.79, 5.17]3.84-0.51 [-2.85, 0.61]4.54 [3.30, 5.93]11% [0%, 38%]21%53%+0.45+0.442026-08-05 → 2026-08-30
tmax00Znearest30d19 1 QC3.67 [2.99, 4.42]3.68-0.17 [-1.69, 1.04]4.24 [3.36, 5.04]5% [0%, 14%]16%47%+0.47+0.462026-08-05 → 2026-08-30
tmax00Znearest90d19 1 QC3.67 [2.90, 4.65]3.68-0.17 [-2.04, 1.00]4.24 [3.36, 5.19]5% [0%, 14%]16%47%+0.47+0.462026-08-05 → 2026-08-30
tmax00Znearest365d19 1 QC3.67 [2.92, 4.68]3.68-0.17 [-2.05, 1.32]4.24 [3.38, 5.19]5% [0%, 15%]16%47%+0.47+0.462026-08-05 → 2026-08-30
tmax00Znearestall19 1 QC3.67 [2.90, 4.56]3.68-0.17 [-1.98, 1.13]4.24 [3.38, 5.17]5% [0%, 14%]16%47%+0.47+0.462026-08-05 → 2026-08-30
tmax12Zbilinear30d20 1 QC3.67 [2.71, 4.49]3.63-0.41 [-2.52, 0.62]4.38 [3.37, 5.18]15% [0%, 38%]35%45%+0.49+0.482026-08-05 → 2026-08-30
tmax12Zbilinear90d20 1 QC3.67 [2.48, 4.69]3.63-0.41 [-3.32, 0.60]4.38 [3.05, 5.38]15% [0%, 50%]35%45%+0.49+0.482026-08-05 → 2026-08-30
tmax12Zbilinear365d20 1 QC3.67 [2.38, 4.76]3.63-0.41 [-3.28, 0.67]4.38 [2.94, 5.41]15% [0%, 50%]35%45%+0.49+0.482026-08-05 → 2026-08-30
tmax12Zbilinearall20 1 QC3.67 [2.48, 4.72]3.63-0.41 [-3.05, 0.63]4.38 [3.06, 5.40]15% [0%, 50%]35%45%+0.49+0.482026-08-05 → 2026-08-30
tmax12Znearest30d20 1 QC3.58 [2.48, 4.34]3.58-0.05 [-2.01, 1.06]4.36 [3.22, 5.03]25% [7%, 44%]30%45%+0.51+0.492026-08-05 → 2026-08-30
tmax12Znearest90d20 1 QC3.58 [2.07, 4.46]3.58-0.05 [-2.63, 1.02]4.36 [2.70, 5.08]25% [0%, 50%]30%45%+0.51+0.492026-08-05 → 2026-08-30
tmax12Znearest365d20 1 QC3.58 [1.92, 4.43]3.58-0.05 [-2.55, 1.12]4.36 [2.62, 5.04]25% [0%, 50%]30%45%+0.51+0.492026-08-05 → 2026-08-30
tmax12Znearestall20 1 QC3.58 [1.93, 4.45]3.58-0.05 [-2.57, 1.06]4.36 [2.64, 5.08]25% [0%, 53%]30%45%+0.51+0.492026-08-05 → 2026-08-30
tmin00Zbilinear30d19 1 QC2.23 [1.47, 2.70]1.96+1.73 [0.67, 2.25]2.92 [2.16, 3.40]37% [17%, 62%]58%68%-0.01+0.012026-08-05 → 2026-08-30
tmin00Zbilinear90d19 1 QC2.23 [1.14, 2.84]1.96+1.73 [0.43, 2.23]2.92 [1.89, 3.49]37% [14%, 71%]58%68%-0.01+0.012026-08-05 → 2026-08-30
tmin00Zbilinear365d19 1 QC2.23 [1.15, 2.83]1.96+1.73 [0.26, 2.25]2.92 [1.47, 3.57]37% [14%, 71%]58%68%-0.01+0.012026-08-05 → 2026-08-30
tmin00Zbilinearall19 1 QC2.23 [1.02, 2.83]1.96+1.73 [0.24, 2.29]2.92 [1.43, 3.57]37% [14%, 67%]58%68%-0.01+0.012026-08-05 → 2026-08-30
tmin00Znearest30d19 1 QC2.36 [1.55, 2.87]2.18+1.71 [0.51, 2.30]3.05 [2.28, 3.53]37% [17%, 62%]47%68%-0.07-0.112026-08-05 → 2026-08-30
tmin00Znearest90d19 1 QC2.36 [1.18, 2.98]2.18+1.71 [0.22, 2.28]3.05 [1.99, 3.65]37% [14%, 71%]47%68%-0.07-0.112026-08-05 → 2026-08-30
tmin00Znearest365d19 1 QC2.36 [1.12, 2.98]2.18+1.71 [-0.02, 2.31]3.05 [1.56, 3.70]37% [14%, 71%]47%68%-0.07-0.112026-08-05 → 2026-08-30
tmin00Znearestall19 1 QC2.36 [1.00, 2.98]2.18+1.71 [-0.13, 2.33]3.05 [1.47, 3.69]37% [14%, 67%]47%68%-0.07-0.112026-08-05 → 2026-08-30
tmin12Zbilinear30d20 1 QC1.80 [0.78, 2.49]1.74+1.23 [0.25, 1.86]2.38 [0.84, 3.03]40% [21%, 67%]70%75%+0.28+0.212026-08-05 → 2026-08-30
tmin12Zbilinear90d20 1 QC1.80 [0.65, 2.53]1.74+1.23 [-0.06, 1.92]2.38 [0.70, 3.06]40% [20%, 80%]70%75%+0.28+0.212026-08-05 → 2026-08-30
tmin12Zbilinear365d20 1 QC1.80 [0.65, 2.57]1.74+1.23 [-0.00, 1.97]2.38 [0.70, 3.09]40% [20%, 75%]70%75%+0.28+0.212026-08-05 → 2026-08-30
tmin12Zbilinearall20 1 QC1.80 [0.67, 2.57]1.74+1.23 [-0.06, 1.96]2.38 [0.70, 3.08]40% [20%, 75%]70%75%+0.28+0.212026-08-05 → 2026-08-30
tmin12Znearest30d20 1 QC1.85 [0.95, 2.44]1.75+1.24 [0.25, 1.91]2.40 [1.06, 2.98]30% [17%, 55%]70%75%+0.26+0.212026-08-05 → 2026-08-30
tmin12Znearest90d20 1 QC1.85 [0.75, 2.47]1.75+1.24 [-0.00, 1.96]2.40 [0.83, 2.99]30% [14%, 67%]70%75%+0.26+0.212026-08-05 → 2026-08-30
tmin12Znearest365d20 1 QC1.85 [0.75, 2.50]1.75+1.24 [-0.02, 1.97]2.40 [0.86, 3.02]30% [14%, 60%]70%75%+0.26+0.212026-08-05 → 2026-08-30
tmin12Znearestall20 1 QC1.85 [0.76, 2.51]1.75+1.24 [-0.01, 1.96]2.40 [0.86, 3.05]30% [14%, 67%]70%75%+0.26+0.212026-08-05 → 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 IFS HRES at KBOS, lead day 4, 00Z bilinear tmax+10+50-5-102026-08-05: -8.18 °F2026-08-11: +2.55 °F2026-08-12: +1.88 °F2026-08-13: -5.8 °F2026-08-14: +3.86 °F2026-08-16: +1.5 °F2026-08-17: -2.32 °F2026-08-18: +2.4 °F2026-08-19: -4.87 °F2026-08-20: -9.65 °F2026-08-21: +7.48 °F2026-08-22: +2.34 °F2026-08-23: +3.16 °F2026-08-24: -2.53 °F2026-08-25: -4.34 °F2026-08-26: +0.65 °F2026-08-27: -2.82 °F2026-08-29: +5.53 °F2026-08-30: -0.61 °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
2026-08-30-0.61
2026-08-29+5.53
2026-08-28—
2026-08-27-2.82
2026-08-26+0.65
2026-08-25-4.34
2026-08-24-2.53
2026-08-23+3.16
2026-08-22+2.34
2026-08-21+7.48
2026-08-20-9.65
2026-08-19-4.87
2026-08-18+2.40
2026-08-17-2.32
2026-08-16+1.50
2026-08-15—
2026-08-14+3.86
2026-08-13-5.80
2026-08-12+1.88
2026-08-11+2.55
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05-8.18

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KBOS, lead day 4-10 to -9 °F: 1 day-9 to -8 °F: 1 day-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 1 day-5 to -4 °F: 2 days-4 to -3 °F: 0 days-3 to -2 °F: 3 days-2 to -1 °F: 0 days-1 to 0 °F: 1 day0 to 1 °F: 1 day1 to 2 °F: 2 days2 to 3 °F: 3 days3 to 4 °F: 2 days4 to 5 °F: 0 days5 to 6 °F: 1 day6 to 7 °F: 0 days7 to 8 °F: 1 day8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2.82 · P90 |e| 7.62 °F-100+10 °Fn = 19 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
-10.00-9.001
-9.00-8.001
-8.00-7.000
-7.00-6.000
-6.00-5.001
-5.00-4.002
-4.00-3.000
-3.00-2.003
-2.00-1.000
-1.00+0.001
+0.00+1.001
+1.00+2.002
+2.00+3.003
+3.00+4.002
+4.00+5.000
+5.00+6.001
+6.00+7.000
+7.00+8.001
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08193.81 -0.51

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-05 → 2026-08-30 19
ECMWF IFS HRES2026-08-05 → 2026-08-30 19
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 20

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 19 -0.70 [-1.70, 0.40] no
NCEP GFS 19 -0.87 [-3.14, 0.64] no
GraphCast (IFS init) 18 -0.83 [-1.84, 1.38] no
Persistence (baseline) 19 -3.13 [-5.29, 0.74] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KBOS (Boston Logan), model ifs_hres, 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/KBOS/model/ifs_hres/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