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

Boston Logan · ECMWF AIFS Single · lead day 2

KBOS · aifs_single · 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, 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
tmax00Zbilinear30d27 1 QC3.39 [2.75, 4.08]2.55-2.92 [-3.84, -2.14]4.16 [3.37, 4.86]15% [7%, 22%]33%52%+0.45+0.572026-08-03 → 2026-08-30
tmax00Zbilinear90d27 1 QC3.39 [2.80, 4.15]2.55-2.92 [-3.99, -2.11]4.16 [3.39, 4.90]15% [6%, 23%]33%52%+0.45+0.572026-08-03 → 2026-08-30
tmax00Zbilinear365d27 1 QC3.39 [2.71, 4.18]2.55-2.92 [-4.05, -1.99]4.16 [3.31, 4.89]15% [6%, 22%]33%52%+0.45+0.572026-08-03 → 2026-08-30
tmax00Zbilinearall27 1 QC3.39 [2.73, 4.19]2.55-2.92 [-4.00, -2.04]4.16 [3.31, 4.95]15% [6%, 22%]33%52%+0.45+0.572026-08-03 → 2026-08-30
tmax00Znearest30d27 1 QC3.38 [2.68, 4.16]2.52-2.92 [-3.90, -2.11]4.16 [3.33, 4.93]15% [7%, 22%]37%52%+0.46+0.582026-08-03 → 2026-08-30
tmax00Znearest90d27 1 QC3.38 [2.71, 4.28]2.52-2.92 [-4.06, -2.11]4.16 [3.33, 4.96]15% [6%, 23%]37%52%+0.46+0.582026-08-03 → 2026-08-30
tmax00Znearest365d27 1 QC3.38 [2.61, 4.28]2.52-2.92 [-4.10, -1.98]4.16 [3.25, 4.98]15% [6%, 22%]37%52%+0.46+0.582026-08-03 → 2026-08-30
tmax00Znearestall27 1 QC3.38 [2.66, 4.28]2.52-2.92 [-4.09, -2.03]4.16 [3.26, 5.00]15% [6%, 22%]37%52%+0.46+0.582026-08-03 → 2026-08-30
tmax12Zbilinear30d27 1 QC3.44 [2.96, 3.92]2.50-2.96 [-3.80, -2.16]4.15 [3.65, 4.60]22% [13%, 32%]33%44%+0.46+0.592026-08-03 → 2026-08-30
tmax12Zbilinear90d27 1 QC3.44 [3.01, 4.02]2.50-2.96 [-3.89, -2.15]4.15 [3.69, 4.61]22% [12%, 33%]33%44%+0.46+0.592026-08-03 → 2026-08-30
tmax12Zbilinear365d27 1 QC3.44 [2.92, 4.01]2.50-2.96 [-3.98, -2.01]4.15 [3.65, 4.61]22% [12%, 35%]33%44%+0.46+0.592026-08-03 → 2026-08-30
tmax12Zbilinearall27 1 QC3.44 [2.97, 4.04]2.50-2.96 [-3.96, -2.09]4.15 [3.63, 4.65]22% [11%, 33%]33%44%+0.46+0.592026-08-03 → 2026-08-30
tmax12Znearest30d27 1 QC3.41 [2.89, 3.95]2.52-2.95 [-3.83, -2.15]4.13 [3.60, 4.62]22% [13%, 32%]33%44%+0.46+0.592026-08-03 → 2026-08-30
tmax12Znearest90d27 1 QC3.41 [2.96, 4.05]2.52-2.95 [-3.98, -2.15]4.13 [3.65, 4.65]22% [12%, 33%]33%44%+0.46+0.592026-08-03 → 2026-08-30
tmax12Znearest365d27 1 QC3.41 [2.86, 4.05]2.52-2.95 [-4.01, -2.02]4.13 [3.58, 4.68]22% [12%, 35%]33%44%+0.46+0.592026-08-03 → 2026-08-30
tmax12Znearestall27 1 QC3.41 [2.91, 4.09]2.52-2.95 [-4.03, -2.06]4.13 [3.56, 4.69]22% [11%, 33%]33%44%+0.46+0.592026-08-03 → 2026-08-30
tmin00Zbilinear30d27 1 QC1.35 [0.87, 1.96]1.35+0.03 [-0.66, 0.89]1.83 [1.10, 2.43]52% [38%, 65%]81%85%+0.49+0.492026-08-03 → 2026-08-30
tmin00Zbilinear90d27 1 QC1.35 [0.83, 2.02]1.35+0.03 [-0.86, 0.98]1.83 [1.01, 2.51]52% [36%, 67%]81%85%+0.49+0.492026-08-03 → 2026-08-30
tmin00Zbilinear365d27 1 QC1.35 [0.84, 2.11]1.35+0.03 [-1.09, 1.11]1.83 [1.00, 2.59]52% [35%, 65%]81%85%+0.49+0.492026-08-03 → 2026-08-30
tmin00Zbilinearall27 1 QC1.35 [0.83, 2.07]1.35+0.03 [-1.04, 0.91]1.83 [0.99, 2.57]52% [35%, 66%]81%85%+0.49+0.492026-08-03 → 2026-08-30
tmin00Znearest30d27 1 QC1.35 [0.89, 1.89]1.34+0.28 [-0.42, 1.16]1.83 [1.09, 2.45]52% [32%, 71%]85%85%+0.49+0.492026-08-03 → 2026-08-30
tmin00Znearest90d27 1 QC1.35 [0.86, 1.97]1.34+0.28 [-0.59, 1.24]1.83 [1.00, 2.52]52% [30%, 73%]85%85%+0.49+0.492026-08-03 → 2026-08-30
tmin00Znearest365d27 1 QC1.35 [0.85, 2.09]1.34+0.28 [-0.77, 1.34]1.83 [0.99, 2.63]52% [29%, 76%]85%85%+0.49+0.492026-08-03 → 2026-08-30
tmin00Znearestall27 1 QC1.35 [0.85, 2.02]1.34+0.28 [-0.73, 1.21]1.83 [1.01, 2.57]52% [28%, 74%]85%85%+0.49+0.492026-08-03 → 2026-08-30
tmin12Zbilinear30d27 1 QC1.29 [0.85, 1.80]1.31+0.07 [-0.61, 0.84]1.81 [1.10, 2.40]59% [39%, 76%]81%85%+0.52+0.502026-08-03 → 2026-08-30
tmin12Zbilinear90d27 1 QC1.29 [0.85, 1.87]1.31+0.07 [-0.85, 0.91]1.81 [1.03, 2.55]59% [38%, 76%]81%85%+0.52+0.502026-08-03 → 2026-08-30
tmin12Zbilinear365d27 1 QC1.29 [0.83, 1.92]1.31+0.07 [-0.96, 1.03]1.81 [0.99, 2.56]59% [36%, 77%]81%85%+0.52+0.502026-08-03 → 2026-08-30
tmin12Zbilinearall27 1 QC1.29 [0.84, 1.89]1.31+0.07 [-0.93, 0.94]1.81 [0.99, 2.53]59% [33%, 77%]81%85%+0.52+0.502026-08-03 → 2026-08-30
tmin12Znearest30d27 1 QC1.24 [0.78, 1.79]1.29+0.32 [-0.39, 1.12]1.83 [1.12, 2.43]59% [41%, 73%]78%85%+0.54+0.512026-08-03 → 2026-08-30
tmin12Znearest90d27 1 QC1.24 [0.77, 1.87]1.29+0.32 [-0.60, 1.18]1.83 [1.03, 2.53]59% [40%, 73%]78%85%+0.54+0.512026-08-03 → 2026-08-30
tmin12Znearest365d27 1 QC1.24 [0.74, 1.92]1.29+0.32 [-0.71, 1.30]1.83 [0.99, 2.62]59% [40%, 75%]78%85%+0.54+0.512026-08-03 → 2026-08-30
tmin12Znearestall27 1 QC1.24 [0.75, 1.89]1.29+0.32 [-0.70, 1.21]1.83 [1.05, 2.57]59% [35%, 74%]78%85%+0.54+0.512026-08-03 → 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 AIFS Single at KBOS, lead day 2, 00Z bilinear tmax+10+50-5-102026-08-03: -2.56 °F2026-08-04: -5.7 °F2026-08-05: -6.29 °F2026-08-06: -0.53 °F2026-08-07: -7.41 °F2026-08-08: -6.8 °F2026-08-09: -2.1 °F2026-08-10: +0.07 °F2026-08-11: -3.68 °F2026-08-12: -2.78 °F2026-08-13: -4.48 °F2026-08-14: -3.68 °F2026-08-15: +1.23 °F2026-08-16: -2.19 °F2026-08-17: -1.65 °F2026-08-18: +0.25 °F2026-08-19: -7.46 °F2026-08-20: -4.25 °F2026-08-21: +2.14 °F2026-08-22: -1.05 °F2026-08-23: +1.2 °F2026-08-24: -7.95 °F2026-08-25: -5.31 °F2026-08-26: +0.08 °F2026-08-27: -5.64 °F2026-08-29: +1.36 °F2026-08-30: -3.7 °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
2026-08-30-3.70
2026-08-29+1.36
2026-08-28—
2026-08-27-5.64
2026-08-26+0.08
2026-08-25-5.31
2026-08-24-7.95
2026-08-23+1.20
2026-08-22-1.05
2026-08-21+2.14
2026-08-20-4.25
2026-08-19-7.46
2026-08-18+0.25
2026-08-17-1.65
2026-08-16-2.19
2026-08-15+1.23
2026-08-14-3.68
2026-08-13-4.48
2026-08-12-2.78
2026-08-11-3.68
2026-08-10+0.07
2026-08-09-2.10
2026-08-08-6.80
2026-08-07-7.41
2026-08-06-0.53
2026-08-05-6.29
2026-08-04-5.70
2026-08-03-2.56

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KBOS, lead day 2-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 3 days-7 to -6 °F: 2 days-6 to -5 °F: 3 days-5 to -4 °F: 2 days-4 to -3 °F: 3 days-3 to -2 °F: 4 days-2 to -1 °F: 2 days-1 to 0 °F: 1 day0 to 1 °F: 3 days1 to 2 °F: 3 days2 to 3 °F: 1 day3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2.78 · P90 |e| 7.05 °F-100+10 °Fn = 27 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
-8.00-7.003
-7.00-6.002
-6.00-5.003
-5.00-4.002
-4.00-3.003
-3.00-2.004
-2.00-1.002
-1.00+0.001
+0.00+1.003
+1.00+2.003
+2.00+3.001
+3.00+4.000
+4.00+5.000
+5.00+6.000
+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
2026-08273.39 -2.92

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-03 → 2026-08-30 27
ECMWF AIFS Single2026-08-03 → 2026-08-30 27
ECMWF AIFS Single2026-08-03 → 2026-08-30 27
ECMWF AIFS Single2026-08-03 → 2026-08-30 27

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
Aurora (IFS init) 1 -0.42 [-0.42, -0.42] yes
FourCastNet v2 (IFS init) 1 -2.39 [-2.39, -2.39] yes
NCEP GFS 27 +0.62 [-0.71, 1.70] no
GraphCast (IFS init) 26 +0.19 [-0.48, 1.11] no
ECMWF IFS HRES 21 +0.90 [0.04, 2.21] yes
Pangu-Weather (IFS init) 1 -0.14 [-0.14, -0.14] yes
Persistence (baseline) 26 -2.81 [-6.09, -0.17] yes

Cite this page

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

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