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

Boston Logan · ECMWF AIFS Single · lead day 7

KBOS · 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
tmax00Zbilinear30d22 1 QC4.87 [3.88, 6.06]4.14-3.12 [-5.52, -1.11]5.99 [4.82, 7.34]18% [8%, 28%]18%32%+0.31+0.422026-08-08 → 2026-08-30
tmax00Zbilinear90d22 1 QC4.87 [3.90, 6.14]4.14-3.12 [-5.88, -1.16]5.99 [4.89, 7.51]18% [7%, 27%]18%32%+0.31+0.422026-08-08 → 2026-08-30
tmax00Zbilinear365d22 1 QC4.87 [3.76, 6.11]4.14-3.12 [-5.97, -0.65]5.99 [4.74, 7.40]18% [6%, 29%]18%32%+0.31+0.422026-08-08 → 2026-08-30
tmax00Zbilinearall22 1 QC4.87 [3.85, 6.17]4.14-3.12 [-5.96, -0.79]5.99 [4.81, 7.38]18% [0%, 28%]18%32%+0.31+0.422026-08-08 → 2026-08-30
tmax00Znearest30d22 1 QC4.92 [3.91, 6.16]4.19-3.14 [-5.65, -1.09]6.05 [4.81, 7.49]18% [8%, 28%]18%36%+0.30+0.412026-08-08 → 2026-08-30
tmax00Znearest90d22 1 QC4.92 [3.92, 6.28]4.19-3.14 [-6.01, -1.15]6.05 [4.90, 7.67]18% [7%, 27%]18%36%+0.30+0.412026-08-08 → 2026-08-30
tmax00Znearest365d22 1 QC4.92 [3.77, 6.28]4.19-3.14 [-6.08, -0.65]6.05 [4.72, 7.53]18% [6%, 29%]18%36%+0.30+0.412026-08-08 → 2026-08-30
tmax00Znearestall22 1 QC4.92 [3.85, 6.39]4.19-3.14 [-6.08, -0.80]6.05 [4.82, 7.56]18% [0%, 28%]18%36%+0.30+0.412026-08-08 → 2026-08-30
tmax12Zbilinear30d22 1 QC4.46 [3.60, 5.67]3.90-3.08 [-4.73, -1.84]5.54 [4.45, 6.91]18% [4%, 33%]32%41%+0.37+0.452026-08-08 → 2026-08-30
tmax12Zbilinear90d22 1 QC4.46 [3.62, 5.83]3.90-3.08 [-5.01, -1.82]5.54 [4.43, 7.07]18% [0%, 35%]32%41%+0.37+0.452026-08-08 → 2026-08-30
tmax12Zbilinear365d22 1 QC4.46 [3.51, 5.83]3.90-3.08 [-5.09, -1.54]5.54 [4.31, 7.12]18% [0%, 36%]32%41%+0.37+0.452026-08-08 → 2026-08-30
tmax12Zbilinearall22 1 QC4.46 [3.59, 6.06]3.90-3.08 [-5.37, -1.65]5.54 [4.28, 7.18]18% [0%, 38%]32%41%+0.37+0.452026-08-08 → 2026-08-30
tmax12Znearest30d22 1 QC4.40 [3.54, 5.61]3.84-3.05 [-4.74, -1.82]5.49 [4.40, 6.84]23% [6%, 40%]32%41%+0.38+0.462026-08-08 → 2026-08-30
tmax12Znearest90d22 1 QC4.40 [3.55, 5.79]3.84-3.05 [-5.01, -1.77]5.49 [4.38, 7.01]23% [0%, 40%]32%41%+0.38+0.462026-08-08 → 2026-08-30
tmax12Znearest365d22 1 QC4.40 [3.42, 5.82]3.84-3.05 [-5.10, -1.55]5.49 [4.26, 7.03]23% [0%, 43%]32%41%+0.38+0.462026-08-08 → 2026-08-30
tmax12Znearestall22 1 QC4.40 [3.52, 6.04]3.84-3.05 [-5.41, -1.62]5.49 [4.23, 7.14]23% [0%, 40%]32%41%+0.38+0.462026-08-08 → 2026-08-30
tmin00Zbilinear30d22 1 QC2.35 [1.79, 2.83]2.30-0.26 [-1.51, 0.90]2.79 [2.18, 3.25]23% [12%, 33%]50%64%+0.39+0.362026-08-08 → 2026-08-30
tmin00Zbilinear90d22 1 QC2.35 [1.74, 2.87]2.30-0.26 [-1.78, 1.14]2.79 [2.09, 3.26]23% [12%, 33%]50%64%+0.39+0.362026-08-08 → 2026-08-30
tmin00Zbilinear365d22 1 QC2.35 [1.72, 2.93]2.30-0.26 [-1.89, 1.18]2.79 [2.08, 3.34]23% [9%, 33%]50%64%+0.39+0.362026-08-08 → 2026-08-30
tmin00Zbilinearall22 1 QC2.35 [1.71, 2.90]2.30-0.26 [-2.08, 0.91]2.79 [2.07, 3.29]23% [9%, 33%]50%64%+0.39+0.362026-08-08 → 2026-08-30
tmin00Znearest30d22 1 QC2.22 [1.62, 2.75]2.22-0.00 [-1.20, 1.13]2.70 [2.04, 3.20]27% [12%, 44%]50%64%+0.42+0.382026-08-08 → 2026-08-30
tmin00Znearest90d22 1 QC2.22 [1.58, 2.81]2.22-0.00 [-1.48, 1.35]2.70 [1.97, 3.24]27% [12%, 50%]50%64%+0.42+0.382026-08-08 → 2026-08-30
tmin00Znearest365d22 1 QC2.22 [1.52, 2.89]2.22-0.00 [-1.55, 1.43]2.70 [1.89, 3.29]27% [10%, 50%]50%64%+0.42+0.382026-08-08 → 2026-08-30
tmin00Znearestall22 1 QC2.22 [1.56, 2.85]2.22-0.00 [-1.77, 1.10]2.70 [1.93, 3.26]27% [12%, 50%]50%64%+0.42+0.382026-08-08 → 2026-08-30
tmin12Zbilinear30d22 1 QC2.09 [1.68, 2.61]2.10+0.06 [-1.12, 1.08]2.54 [2.07, 3.13]27% [14%, 41%]59%73%+0.45+0.422026-08-08 → 2026-08-30
tmin12Zbilinear90d22 1 QC2.09 [1.62, 2.64]2.10+0.06 [-1.44, 1.19]2.54 [1.98, 3.16]27% [13%, 44%]59%73%+0.45+0.422026-08-08 → 2026-08-30
tmin12Zbilinear365d22 1 QC2.09 [1.63, 2.80]2.10+0.06 [-1.52, 1.36]2.54 [1.99, 3.23]27% [14%, 44%]59%73%+0.45+0.422026-08-08 → 2026-08-30
tmin12Zbilinearall22 1 QC2.09 [1.61, 2.83]2.10+0.06 [-1.78, 1.18]2.54 [1.98, 3.37]27% [12%, 43%]59%73%+0.45+0.422026-08-08 → 2026-08-30
tmin12Znearest30d22 1 QC2.05 [1.58, 2.63]2.07+0.35 [-0.80, 1.35]2.50 [1.98, 3.05]27% [11%, 42%]55%77%+0.46+0.432026-08-08 → 2026-08-30
tmin12Znearest90d22 1 QC2.05 [1.53, 2.64]2.07+0.35 [-1.11, 1.45]2.50 [1.90, 3.06]27% [9%, 43%]55%77%+0.46+0.432026-08-08 → 2026-08-30
tmin12Znearest365d22 1 QC2.05 [1.53, 2.81]2.07+0.35 [-1.15, 1.60]2.50 [1.90, 3.20]27% [9%, 43%]55%77%+0.46+0.432026-08-08 → 2026-08-30
tmin12Znearestall22 1 QC2.05 [1.53, 2.78]2.07+0.35 [-1.40, 1.41]2.50 [1.90, 3.21]27% [0%, 44%]55%77%+0.46+0.432026-08-08 → 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 KBOS, lead day 7, 00Z bilinear tmax+20+100-10-202026-08-08: -8.95 °F2026-08-09: -3.47 °F2026-08-10: +0.45 °F2026-08-11: -14.95 °F2026-08-12: -4.38 °F2026-08-13: -4.79 °F2026-08-14: -5.6 °F2026-08-15: +2.21 °F2026-08-16: -3.05 °F2026-08-17: +0.45 °F2026-08-18: +0.87 °F2026-08-19: -9.89 °F2026-08-20: -2.41 °F2026-08-21: +6.22 °F2026-08-22: +4.02 °F2026-08-23: +5.04 °F2026-08-24: -8.02 °F2026-08-25: -5.96 °F2026-08-26: -0.18 °F2026-08-27: -6.63 °F2026-08-29: -2.4 °F2026-08-30: -7.24 °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
2026-08-30-7.24
2026-08-29-2.40
2026-08-28—
2026-08-27-6.63
2026-08-26-0.18
2026-08-25-5.96
2026-08-24-8.02
2026-08-23+5.04
2026-08-22+4.02
2026-08-21+6.22
2026-08-20-2.41
2026-08-19-9.89
2026-08-18+0.87
2026-08-17+0.45
2026-08-16-3.05
2026-08-15+2.21
2026-08-14-5.60
2026-08-13-4.79
2026-08-12-4.38
2026-08-11-14.95
2026-08-10+0.45
2026-08-09-3.47
2026-08-08-8.95

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KBOS, lead day 7-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 1 day-14 to -12 °F: 0 days-12 to -10 °F: 0 days-10 to -8 °F: 3 days-8 to -6 °F: 2 days-6 to -4 °F: 4 days-4 to -2 °F: 4 days-2 to 0 °F: 1 day0 to 2 °F: 3 days2 to 4 °F: 1 day4 to 6 °F: 2 days6 to 8 °F: 1 day8 to 10 °F: 0 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| 4.59 · P90 |e| 8.86 °F-200+20 °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
-20.00-18.000
-18.00-16.000
-16.00-14.001
-14.00-12.000
-12.00-10.000
-10.00-8.003
-8.00-6.002
-6.00-4.004
-4.00-2.004
-2.00+0.001
+0.00+2.003
+2.00+4.001
+4.00+6.002
+6.00+8.001
+8.00+10.000
+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
2026-08224.87 -3.12

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-08 → 2026-08-30 22
ECMWF AIFS Single2026-08-08 → 2026-08-30 22
ECMWF AIFS Single2026-08-08 → 2026-08-30 22
ECMWF AIFS Single2026-08-08 → 2026-08-30 22

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 22 -0.62 [-2.24, 1.74] no
GraphCast (IFS init) 22 +0.35 [-1.34, 2.94] no
ECMWF IFS HRES 17 +0.29 [-0.92, 2.85] no
Persistence (baseline) 22 -2.17 [-4.53, 0.91] no

Cite this page

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

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