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

Boston Logan · ECMWF AIFS Single · lead day 3

KBOS · aifs_single · lead 3

Target day = initialization date + 3 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
tmax00Zbilinear30d26 1 QC4.06 [3.34, 4.80]3.37-2.43 [-4.17, -0.90]4.72 [3.88, 5.43]12% [3%, 21%]27%42%+0.34+0.452026-08-04 → 2026-08-30
tmax00Zbilinear90d26 1 QC4.06 [3.26, 4.95]3.37-2.43 [-4.54, -0.78]4.72 [3.85, 5.57]12% [0%, 21%]27%42%+0.34+0.452026-08-04 → 2026-08-30
tmax00Zbilinear365d26 1 QC4.06 [3.14, 4.98]3.37-2.43 [-4.45, -0.57]4.72 [3.68, 5.60]12% [0%, 22%]27%42%+0.34+0.452026-08-04 → 2026-08-30
tmax00Zbilinearall26 1 QC4.06 [3.17, 5.01]3.37-2.43 [-4.53, -0.75]4.72 [3.66, 5.63]12% [0%, 21%]27%42%+0.34+0.452026-08-04 → 2026-08-30
tmax00Znearest30d26 1 QC4.03 [3.26, 4.81]3.33-2.45 [-4.24, -0.91]4.71 [3.82, 5.47]12% [3%, 21%]27%38%+0.34+0.462026-08-04 → 2026-08-30
tmax00Znearest90d26 1 QC4.03 [3.19, 5.00]3.33-2.45 [-4.65, -0.80]4.71 [3.79, 5.63]12% [0%, 21%]27%38%+0.34+0.462026-08-04 → 2026-08-30
tmax00Znearest365d26 1 QC4.03 [3.06, 5.02]3.33-2.45 [-4.53, -0.57]4.71 [3.62, 5.63]12% [0%, 22%]27%38%+0.34+0.462026-08-04 → 2026-08-30
tmax00Znearestall26 1 QC4.03 [3.10, 5.06]3.33-2.45 [-4.61, -0.75]4.71 [3.59, 5.65]12% [0%, 21%]27%38%+0.34+0.462026-08-04 → 2026-08-30
tmax12Zbilinear30d26 1 QC4.04 [3.19, 4.86]3.24-2.98 [-4.38, -1.77]4.84 [3.85, 5.62]15% [8%, 24%]27%46%+0.34+0.482026-08-04 → 2026-08-30
tmax12Zbilinear90d26 1 QC4.04 [3.27, 5.05]3.24-2.98 [-4.73, -1.71]4.84 [3.88, 5.81]15% [6%, 25%]27%46%+0.34+0.482026-08-04 → 2026-08-30
tmax12Zbilinear365d26 1 QC4.04 [3.09, 5.02]3.24-2.98 [-4.66, -1.48]4.84 [3.65, 5.74]15% [0%, 25%]27%46%+0.34+0.482026-08-04 → 2026-08-30
tmax12Zbilinearall26 1 QC4.04 [3.12, 5.15]3.24-2.98 [-4.75, -1.62]4.84 [3.73, 5.80]15% [3%, 25%]27%46%+0.34+0.482026-08-04 → 2026-08-30
tmax12Znearest30d26 1 QC3.99 [3.10, 4.89]3.22-2.97 [-4.42, -1.77]4.81 [3.76, 5.63]15% [8%, 24%]27%50%+0.35+0.482026-08-04 → 2026-08-30
tmax12Znearest90d26 1 QC3.99 [3.16, 5.07]3.22-2.97 [-4.78, -1.71]4.81 [3.81, 5.82]15% [6%, 25%]27%50%+0.35+0.482026-08-04 → 2026-08-30
tmax12Znearest365d26 1 QC3.99 [2.98, 5.06]3.22-2.97 [-4.71, -1.50]4.81 [3.60, 5.77]15% [0%, 25%]27%50%+0.35+0.482026-08-04 → 2026-08-30
tmax12Znearestall26 1 QC3.99 [3.02, 5.14]3.22-2.97 [-4.82, -1.65]4.81 [3.66, 5.83]15% [3%, 25%]27%50%+0.35+0.482026-08-04 → 2026-08-30
tmin00Zbilinear30d26 1 QC1.59 [1.19, 2.03]1.59+0.00 [-0.82, 0.97]1.95 [1.43, 2.45]38% [20%, 58%]73%81%+0.41+0.412026-08-04 → 2026-08-30
tmin00Zbilinear90d26 1 QC1.59 [1.15, 2.04]1.59+0.00 [-1.00, 1.06]1.95 [1.39, 2.44]38% [19%, 60%]73%81%+0.41+0.412026-08-04 → 2026-08-30
tmin00Zbilinear365d26 1 QC1.59 [1.19, 2.15]1.59+0.00 [-1.13, 1.17]1.95 [1.40, 2.58]38% [19%, 60%]73%81%+0.41+0.412026-08-04 → 2026-08-30
tmin00Zbilinearall26 1 QC1.59 [1.16, 2.15]1.59+0.00 [-1.13, 1.02]1.95 [1.39, 2.57]38% [17%, 60%]73%81%+0.41+0.412026-08-04 → 2026-08-30
tmin00Znearest30d26 1 QC1.54 [1.08, 2.05]1.58+0.28 [-0.54, 1.27]1.95 [1.36, 2.51]46% [27%, 64%]73%85%+0.43+0.412026-08-04 → 2026-08-30
tmin00Znearest90d26 1 QC1.54 [1.04, 2.09]1.58+0.28 [-0.70, 1.38]1.95 [1.27, 2.53]46% [24%, 67%]73%85%+0.43+0.412026-08-04 → 2026-08-30
tmin00Znearest365d26 1 QC1.54 [1.07, 2.17]1.58+0.28 [-0.83, 1.47]1.95 [1.31, 2.62]46% [22%, 67%]73%85%+0.43+0.412026-08-04 → 2026-08-30
tmin00Znearestall26 1 QC1.54 [1.05, 2.15]1.58+0.28 [-0.83, 1.36]1.95 [1.30, 2.57]46% [20%, 67%]73%85%+0.43+0.412026-08-04 → 2026-08-30
tmin12Zbilinear30d26 1 QC1.47 [1.01, 2.05]1.45-0.10 [-0.88, 0.81]1.98 [1.22, 2.62]46% [31%, 58%]81%85%+0.45+0.462026-08-04 → 2026-08-30
tmin12Zbilinear90d26 1 QC1.47 [0.93, 2.14]1.45-0.10 [-1.06, 0.85]1.98 [1.07, 2.77]46% [29%, 58%]81%85%+0.45+0.462026-08-04 → 2026-08-30
tmin12Zbilinear365d26 1 QC1.47 [0.91, 2.18]1.45-0.10 [-1.19, 0.99]1.98 [1.04, 2.78]46% [29%, 59%]81%85%+0.45+0.462026-08-04 → 2026-08-30
tmin12Zbilinearall26 1 QC1.47 [0.93, 2.19]1.45-0.10 [-1.16, 0.85]1.98 [1.05, 2.76]46% [27%, 57%]81%85%+0.45+0.462026-08-04 → 2026-08-30
tmin12Znearest30d26 1 QC1.41 [0.91, 2.03]1.44+0.17 [-0.63, 1.08]1.95 [1.19, 2.61]54% [38%, 64%]77%85%+0.48+0.472026-08-04 → 2026-08-30
tmin12Znearest90d26 1 QC1.41 [0.84, 2.12]1.44+0.17 [-0.76, 1.13]1.95 [1.04, 2.71]54% [38%, 64%]77%85%+0.48+0.472026-08-04 → 2026-08-30
tmin12Znearest365d26 1 QC1.41 [0.85, 2.19]1.44+0.17 [-0.80, 1.29]1.95 [1.04, 2.78]54% [36%, 64%]77%85%+0.48+0.472026-08-04 → 2026-08-30
tmin12Znearestall26 1 QC1.41 [0.84, 2.13]1.44+0.17 [-0.86, 1.15]1.95 [1.04, 2.74]54% [33%, 64%]77%85%+0.48+0.472026-08-04 → 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 3, 00Z bilinear tmax+10+50-5-102026-08-04: -5.55 °F2026-08-05: -7.97 °F2026-08-06: -1.29 °F2026-08-07: -7.38 °F2026-08-08: -6.92 °F2026-08-09: -2.94 °F2026-08-10: -0.72 °F2026-08-11: -3.3 °F2026-08-12: -1.62 °F2026-08-13: -4.01 °F2026-08-14: -5.51 °F2026-08-15: +1.32 °F2026-08-16: -2.94 °F2026-08-17: +4.39 °F2026-08-18: +2.89 °F2026-08-19: -8.75 °F2026-08-20: -3.15 °F2026-08-21: +5.98 °F2026-08-22: +0.94 °F2026-08-23: +3.87 °F2026-08-24: -6.81 °F2026-08-25: -6.11 °F2026-08-26: -0.46 °F2026-08-27: -6.55 °F2026-08-29: +1.69 °F2026-08-30: -2.37 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.37
2026-08-29+1.69
2026-08-28—
2026-08-27-6.55
2026-08-26-0.46
2026-08-25-6.11
2026-08-24-6.81
2026-08-23+3.87
2026-08-22+0.94
2026-08-21+5.98
2026-08-20-3.15
2026-08-19-8.75
2026-08-18+2.89
2026-08-17+4.39
2026-08-16-2.94
2026-08-15+1.32
2026-08-14-5.51
2026-08-13-4.01
2026-08-12-1.62
2026-08-11-3.30
2026-08-10-0.72
2026-08-09-2.94
2026-08-08-6.92
2026-08-07-7.38
2026-08-06-1.29
2026-08-05-7.97
2026-08-04-5.55

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KBOS, lead day 3-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 2 days-7 to -6 °F: 4 days-6 to -5 °F: 2 days-5 to -4 °F: 1 day-4 to -3 °F: 2 days-3 to -2 °F: 3 days-2 to -1 °F: 2 days-1 to 0 °F: 2 days0 to 1 °F: 1 day1 to 2 °F: 2 days2 to 3 °F: 1 day3 to 4 °F: 1 day4 to 5 °F: 1 day5 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| 3.59 · P90 |e| 7.15 °F-100+10 °Fn = 26 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
-9.00-8.001
-8.00-7.002
-7.00-6.004
-6.00-5.002
-5.00-4.001
-4.00-3.002
-3.00-2.003
-2.00-1.002
-1.00+0.002
+0.00+1.001
+1.00+2.002
+2.00+3.001
+3.00+4.001
+4.00+5.001
+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
2026-08264.06 -2.43

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-04 → 2026-08-30 26
ECMWF AIFS Single2026-08-04 → 2026-08-30 26
ECMWF AIFS Single2026-08-04 → 2026-08-30 26
ECMWF AIFS Single2026-08-04 → 2026-08-30 26

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 26 +0.22 [-1.18, 1.19] no
GraphCast (IFS init) 24 +0.84 [0.22, 1.31] yes
ECMWF IFS HRES 21 -0.06 [-0.86, 0.60] no
Persistence (baseline) 26 -2.06 [-4.39, 0.71] no

Cite this page

ShortCastCheck, KBOS aifs_single lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KBOS/model/aifs_single/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KBOS (Boston Logan), model aifs_single, lead day 3. 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/3/

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