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

Boston Logan · ECMWF IFS HRES · lead day 6

KBOS · ifs_hres · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d18 1 QC4.76 [3.67, 6.51]4.69-0.66 [-3.80, 0.69]5.64 [3.99, 7.46]6% [0%, 19%]17%28%+0.34+0.282026-08-07 → 2026-08-30
tmax00Zbilinear90d18 1 QC4.76 [3.59, 7.44]4.69-0.66 [-6.55, 0.67]5.64 [3.76, 8.34]6% [0%, 20%]17%28%+0.34+0.282026-08-07 → 2026-08-30
tmax00Zbilinear365d18 1 QC4.76 [3.52, 6.80]4.69-0.66 [-6.57, 0.99]5.64 [3.65, 8.13]6% [0%, 25%]17%28%+0.34+0.282026-08-07 → 2026-08-30
tmax00Zbilinearall18 1 QC4.76 [3.58, 7.03]4.69-0.66 [-5.37, 0.88]5.64 [3.73, 8.00]6% [0%, 22%]17%28%+0.34+0.282026-08-07 → 2026-08-30
tmax00Znearest30d18 1 QC4.78 [3.77, 6.80]4.78-0.39 [-3.84, 1.00]5.72 [4.11, 8.00]11% [0%, 25%]17%22%+0.33+0.272026-08-07 → 2026-08-30
tmax00Znearest90d18 1 QC4.78 [3.70, 8.42]4.78-0.39 [-7.03, 1.08]5.72 [3.87, 9.39]11% [0%, 27%]17%22%+0.33+0.272026-08-07 → 2026-08-30
tmax00Znearest365d18 1 QC4.78 [3.63, 7.75]4.78-0.39 [-7.26, 1.38]5.72 [3.76, 9.22]11% [0%, 29%]17%22%+0.33+0.272026-08-07 → 2026-08-30
tmax00Znearestall18 1 QC4.78 [3.66, 7.65]4.78-0.39 [-5.82, 1.24]5.72 [3.82, 8.97]11% [0%, 29%]17%22%+0.33+0.272026-08-07 → 2026-08-30
tmax12Zbilinear30d18 1 QC3.36 [2.49, 5.18]3.31-0.94 [-4.10, 0.59]4.29 [3.23, 6.45]22% [5%, 38%]44%56%+0.53+0.492026-08-07 → 2026-08-30
tmax12Zbilinear90d18 1 QC3.36 [2.47, 6.73]3.31-0.94 [-6.14, 0.51]4.29 [3.13, 7.73]22% [0%, 40%]44%56%+0.53+0.492026-08-07 → 2026-08-30
tmax12Zbilinear365d18 1 QC3.36 [2.35, 6.68]3.31-0.94 [-6.27, 0.71]4.29 [3.04, 7.65]22% [0%, 40%]44%56%+0.53+0.492026-08-07 → 2026-08-30
tmax12Zbilinearall18 1 QC3.36 [2.40, 6.06]3.31-0.94 [-5.55, 0.75]4.29 [2.98, 7.44]22% [0%, 39%]44%56%+0.53+0.492026-08-07 → 2026-08-30
tmax12Znearest30d18 1 QC3.33 [2.52, 5.01]3.33-0.59 [-3.62, 0.93]4.22 [3.10, 6.33]17% [0%, 29%]44%56%+0.53+0.492026-08-07 → 2026-08-30
tmax12Znearest90d18 1 QC3.33 [2.43, 6.48]3.33-0.59 [-5.90, 0.92]4.22 [2.91, 7.58]17% [0%, 28%]44%56%+0.53+0.492026-08-07 → 2026-08-30
tmax12Znearest365d18 1 QC3.33 [2.36, 6.02]3.33-0.59 [-5.84, 1.05]4.22 [2.83, 7.33]17% [0%, 29%]44%56%+0.53+0.492026-08-07 → 2026-08-30
tmax12Znearestall18 1 QC3.33 [2.33, 5.95]3.33-0.59 [-5.08, 1.06]4.22 [2.79, 7.31]17% [0%, 29%]44%56%+0.53+0.492026-08-07 → 2026-08-30
tmin00Zbilinear30d18 1 QC2.58 [1.78, 3.27]2.46+1.06 [-0.63, 1.99]2.99 [2.08, 3.59]11% [0%, 27%]50%61%+0.26+0.232026-08-07 → 2026-08-30
tmin00Zbilinear90d18 1 QC2.58 [1.51, 3.38]2.46+1.06 [-1.07, 2.03]2.99 [1.65, 3.68]11% [0%, 29%]50%61%+0.26+0.232026-08-07 → 2026-08-30
tmin00Zbilinear365d18 1 QC2.58 [1.51, 3.40]2.46+1.06 [-1.22, 2.13]2.99 [1.56, 3.70]11% [0%, 30%]50%61%+0.26+0.232026-08-07 → 2026-08-30
tmin00Zbilinearall18 1 QC2.58 [1.51, 3.31]2.46+1.06 [-1.28, 1.97]2.99 [1.68, 3.64]11% [0%, 30%]50%61%+0.26+0.232026-08-07 → 2026-08-30
tmin00Znearest30d18 1 QC2.65 [1.75, 3.42]2.58+1.12 [-0.58, 2.09]3.15 [2.12, 3.83]17% [5%, 29%]50%61%+0.24+0.192026-08-07 → 2026-08-30
tmin00Znearest90d18 1 QC2.65 [1.36, 3.54]2.58+1.12 [-1.00, 2.15]3.15 [1.36, 3.92]17% [0%, 31%]50%61%+0.24+0.192026-08-07 → 2026-08-30
tmin00Znearest365d18 1 QC2.65 [1.36, 3.56]2.58+1.12 [-1.35, 2.25]3.15 [1.36, 3.94]17% [0%, 31%]50%61%+0.24+0.192026-08-07 → 2026-08-30
tmin00Znearestall18 1 QC2.65 [1.36, 3.48]2.58+1.12 [-1.32, 2.11]3.15 [1.40, 3.88]17% [0%, 30%]50%61%+0.24+0.192026-08-07 → 2026-08-30
tmin12Zbilinear30d18 1 QC2.09 [1.37, 2.60]2.12+0.86 [-0.52, 1.81]2.77 [1.94, 3.24]33% [22%, 63%]61%72%+0.40+0.342026-08-07 → 2026-08-30
tmin12Zbilinear90d18 1 QC2.09 [1.19, 2.60]2.12+0.86 [-0.57, 1.86]2.77 [1.69, 3.25]33% [22%, 81%]61%72%+0.40+0.342026-08-07 → 2026-08-30
tmin12Zbilinear365d18 1 QC2.09 [0.70, 2.64]2.12+0.86 [-0.61, 1.93]2.77 [0.70, 3.29]33% [21%, 100%]61%72%+0.40+0.342026-08-07 → 2026-08-30
tmin12Zbilinearall18 1 QC2.09 [0.70, 2.62]2.12+0.86 [-0.57, 1.79]2.77 [0.70, 3.27]33% [22%, 100%]61%72%+0.40+0.342026-08-07 → 2026-08-30
tmin12Znearest30d18 1 QC2.17 [1.28, 2.65]2.22+1.06 [-0.27, 1.94]2.91 [2.15, 3.32]39% [25%, 67%]56%72%+0.38+0.312026-08-07 → 2026-08-30
tmin12Znearest90d18 1 QC2.17 [0.99, 2.64]2.22+1.06 [-0.41, 2.06]2.91 [1.85, 3.33]39% [25%, 81%]56%72%+0.38+0.312026-08-07 → 2026-08-30
tmin12Znearest365d18 1 QC2.17 [0.38, 2.71]2.22+1.06 [-0.39, 2.10]2.91 [0.49, 3.37]39% [23%, 100%]56%72%+0.38+0.312026-08-07 → 2026-08-30
tmin12Znearestall18 1 QC2.17 [0.38, 2.68]2.22+1.06 [-0.30, 1.97]2.91 [0.48, 3.31]39% [25%, 100%]56%72%+0.38+0.312026-08-07 → 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 6, 00Z bilinear tmax+20+100-10-202026-08-07: -11 °F2026-08-13: +0.28 °F2026-08-14: -4.75 °F2026-08-15: +4.41 °F2026-08-16: -6.59 °F2026-08-17: +9.02 °F2026-08-18: -1.07 °F2026-08-19: -10.21 °F2026-08-20: -1.89 °F2026-08-21: +8.69 °F2026-08-22: +2.45 °F2026-08-23: +4.01 °F2026-08-24: -3.36 °F2026-08-25: -2.63 °F2026-08-26: +3.66 °F2026-08-27: -3.16 °F2026-08-29: +4.33 °F2026-08-30: -4.18 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.18
2026-08-29+4.33
2026-08-28—
2026-08-27-3.16
2026-08-26+3.66
2026-08-25-2.63
2026-08-24-3.36
2026-08-23+4.01
2026-08-22+2.45
2026-08-21+8.69
2026-08-20-1.89
2026-08-19-10.21
2026-08-18-1.07
2026-08-17+9.02
2026-08-16-6.59
2026-08-15+4.41
2026-08-14-4.75
2026-08-13+0.28
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07-11.00

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KBOS, lead day 6-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 2 days-10 to -8 °F: 0 days-8 to -6 °F: 1 day-6 to -4 °F: 2 days-4 to -2 °F: 3 days-2 to 0 °F: 2 days0 to 2 °F: 1 day2 to 4 °F: 2 days4 to 6 °F: 3 days6 to 8 °F: 0 days8 to 10 °F: 2 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 4.1 · P90 |e| 9.38 °F-200+20 °Fn = 18 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
-20.00-18.000
-18.00-16.000
-16.00-14.000
-14.00-12.000
-12.00-10.002
-10.00-8.000
-8.00-6.001
-6.00-4.002
-4.00-2.003
-2.00+0.002
+0.00+2.001
+2.00+4.002
+4.00+6.003
+6.00+8.000
+8.00+10.002
+10.00+12.000
+12.00+14.000
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08184.76 -0.66

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-07 → 2026-08-30 18
ECMWF IFS HRES2026-08-07 → 2026-08-30 18
ECMWF IFS HRES2026-08-07 → 2026-08-30 18
ECMWF IFS HRES2026-08-07 → 2026-08-30 18

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 18 +0.20 [-1.46, 2.61] no
NCEP GFS 18 -0.04 [-2.31, 4.13] no
GraphCast (IFS init) 18 +0.19 [-1.64, 3.51] no
Persistence (baseline) 18 -2.41 [-4.43, 2.00] no

Cite this page

ShortCastCheck, KBOS ifs_hres lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KBOS/model/ifs_hres/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KBOS (Boston Logan), model ifs_hres, lead day 6. 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/6/

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