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

Boston Logan · ECMWF AIFS Single · lead day 1

KBOS · aifs_single · lead 1

Target day = initialization date + 1 day. 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
tmax00Zbilinear30d28 1 QC3.38 [2.92, 3.82]2.54-2.75 [-3.54, -1.96]4.04 [3.53, 4.48]21% [13%, 31%]25%46%+0.31+0.512026-08-02 → 2026-08-30
tmax00Zbilinear90d28 1 QC3.38 [2.98, 3.86]2.54-2.75 [-3.62, -1.94]4.04 [3.57, 4.50]21% [11%, 33%]25%46%+0.31+0.512026-08-02 → 2026-08-30
tmax00Zbilinear365d28 1 QC3.38 [2.87, 3.84]2.54-2.75 [-3.68, -1.82]4.04 [3.49, 4.48]21% [11%, 33%]25%46%+0.31+0.512026-08-02 → 2026-08-30
tmax00Zbilinearall28 1 QC3.38 [2.91, 3.94]2.54-2.75 [-3.65, -1.92]4.04 [3.49, 4.52]21% [10%, 32%]25%46%+0.31+0.512026-08-02 → 2026-08-30
tmax00Znearest30d28 1 QC3.36 [2.87, 3.85]2.51-2.75 [-3.58, -1.95]4.02 [3.47, 4.49]21% [13%, 31%]32%50%+0.31+0.522026-08-02 → 2026-08-30
tmax00Znearest90d28 1 QC3.36 [2.92, 3.91]2.51-2.75 [-3.70, -1.95]4.02 [3.51, 4.49]21% [11%, 33%]32%50%+0.31+0.522026-08-02 → 2026-08-30
tmax00Znearest365d28 1 QC3.36 [2.82, 3.90]2.51-2.75 [-3.74, -1.83]4.02 [3.40, 4.48]21% [11%, 33%]32%50%+0.31+0.522026-08-02 → 2026-08-30
tmax00Znearestall28 1 QC3.36 [2.86, 3.97]2.51-2.75 [-3.72, -1.90]4.02 [3.43, 4.52]21% [10%, 32%]32%50%+0.31+0.522026-08-02 → 2026-08-30
tmax12Zbilinear30d28 1 QC3.23 [2.78, 3.68]2.47-2.57 [-3.32, -1.79]3.86 [3.35, 4.30]21% [13%, 31%]32%46%+0.33+0.522026-08-02 → 2026-08-30
tmax12Zbilinear90d28 1 QC3.23 [2.76, 3.71]2.47-2.57 [-3.42, -1.77]3.86 [3.32, 4.30]21% [11%, 33%]32%46%+0.33+0.522026-08-02 → 2026-08-30
tmax12Zbilinear365d28 1 QC3.23 [2.69, 3.73]2.47-2.57 [-3.46, -1.70]3.86 [3.27, 4.33]21% [11%, 33%]32%46%+0.33+0.522026-08-02 → 2026-08-30
tmax12Zbilinearall28 1 QC3.23 [2.72, 3.77]2.47-2.57 [-3.46, -1.74]3.86 [3.28, 4.34]21% [10%, 32%]32%46%+0.33+0.522026-08-02 → 2026-08-30
tmax12Znearest30d28 1 QC3.22 [2.72, 3.70]2.44-2.55 [-3.35, -1.75]3.83 [3.31, 4.28]21% [13%, 31%]32%46%+0.33+0.522026-08-02 → 2026-08-30
tmax12Znearest90d28 1 QC3.22 [2.69, 3.74]2.44-2.55 [-3.47, -1.72]3.83 [3.28, 4.29]21% [11%, 33%]32%46%+0.33+0.522026-08-02 → 2026-08-30
tmax12Znearest365d28 1 QC3.22 [2.60, 3.73]2.44-2.55 [-3.49, -1.67]3.83 [3.23, 4.31]21% [11%, 33%]32%46%+0.33+0.522026-08-02 → 2026-08-30
tmax12Znearestall28 1 QC3.22 [2.67, 3.77]2.44-2.55 [-3.49, -1.71]3.83 [3.23, 4.32]21% [10%, 32%]32%46%+0.33+0.522026-08-02 → 2026-08-30
tmin00Zbilinear30d28 1 QC1.22 [0.88, 1.63]1.22-0.03 [-0.69, 0.77]1.66 [1.11, 2.12]57% [43%, 71%]79%93%+0.33+0.342026-08-02 → 2026-08-30
tmin00Zbilinear90d28 1 QC1.22 [0.84, 1.69]1.22-0.03 [-0.96, 0.88]1.66 [1.05, 2.26]57% [43%, 73%]79%93%+0.33+0.342026-08-02 → 2026-08-30
tmin00Zbilinear365d28 1 QC1.22 [0.84, 1.72]1.22-0.03 [-1.18, 0.93]1.66 [1.06, 2.30]57% [43%, 73%]79%93%+0.33+0.342026-08-02 → 2026-08-30
tmin00Zbilinearall28 1 QC1.22 [0.84, 1.73]1.22-0.03 [-1.03, 0.82]1.66 [1.04, 2.28]57% [43%, 74%]79%93%+0.33+0.342026-08-02 → 2026-08-30
tmin00Znearest30d28 1 QC1.18 [0.77, 1.63]1.21+0.20 [-0.48, 1.01]1.67 [1.10, 2.14]57% [43%, 72%]82%89%+0.36+0.352026-08-02 → 2026-08-30
tmin00Znearest90d28 1 QC1.18 [0.73, 1.72]1.21+0.20 [-0.73, 1.09]1.67 [1.04, 2.27]57% [43%, 72%]82%89%+0.36+0.352026-08-02 → 2026-08-30
tmin00Znearest365d28 1 QC1.18 [0.71, 1.77]1.21+0.20 [-0.87, 1.15]1.67 [0.99, 2.32]57% [43%, 74%]82%89%+0.36+0.352026-08-02 → 2026-08-30
tmin00Znearestall28 1 QC1.18 [0.72, 1.72]1.21+0.20 [-0.74, 1.10]1.67 [0.97, 2.28]57% [42%, 73%]82%89%+0.36+0.352026-08-02 → 2026-08-30
tmin12Zbilinear30d28 1 QC1.23 [0.88, 1.62]1.21-0.08 [-0.79, 0.75]1.63 [1.10, 2.08]61% [41%, 79%]82%89%+0.34+0.352026-08-02 → 2026-08-30
tmin12Zbilinear90d28 1 QC1.23 [0.85, 1.69]1.21-0.08 [-1.09, 0.82]1.63 [1.05, 2.23]61% [41%, 79%]82%89%+0.34+0.352026-08-02 → 2026-08-30
tmin12Zbilinear365d28 1 QC1.23 [0.84, 1.72]1.21-0.08 [-1.24, 0.90]1.63 [1.02, 2.25]61% [40%, 82%]82%89%+0.34+0.352026-08-02 → 2026-08-30
tmin12Zbilinearall28 1 QC1.23 [0.84, 1.73]1.21-0.08 [-1.14, 0.83]1.63 [1.01, 2.23]61% [41%, 79%]82%89%+0.34+0.352026-08-02 → 2026-08-30
tmin12Znearest30d28 1 QC1.17 [0.82, 1.57]1.19+0.16 [-0.56, 1.02]1.63 [1.08, 2.11]57% [41%, 73%]82%86%+0.37+0.362026-08-02 → 2026-08-30
tmin12Znearest90d28 1 QC1.17 [0.81, 1.63]1.19+0.16 [-0.81, 1.08]1.63 [1.02, 2.19]57% [40%, 74%]82%86%+0.37+0.362026-08-02 → 2026-08-30
tmin12Znearest365d28 1 QC1.17 [0.79, 1.69]1.19+0.16 [-0.94, 1.17]1.63 [0.99, 2.24]57% [40%, 75%]82%86%+0.37+0.362026-08-02 → 2026-08-30
tmin12Znearestall28 1 QC1.17 [0.80, 1.64]1.19+0.16 [-0.86, 1.11]1.63 [1.00, 2.21]57% [41%, 75%]82%86%+0.37+0.362026-08-02 → 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 1, 00Z bilinear tmax+10+50-5-102026-08-02: -4.52 °F2026-08-03: -2.26 °F2026-08-04: -5.05 °F2026-08-05: -4.87 °F2026-08-06: -0.25 °F2026-08-07: -5.77 °F2026-08-08: -6.53 °F2026-08-09: -2.46 °F2026-08-10: +0.16 °F2026-08-11: -3.98 °F2026-08-12: -2.02 °F2026-08-13: -4.71 °F2026-08-14: -4.13 °F2026-08-15: +1.7 °F2026-08-16: -2.66 °F2026-08-17: -2.11 °F2026-08-18: +0.03 °F2026-08-19: -7.93 °F2026-08-20: -3.64 °F2026-08-21: +3.05 °F2026-08-22: +0.65 °F2026-08-23: +2.19 °F2026-08-24: -7.23 °F2026-08-25: -5.35 °F2026-08-26: +0.1 °F2026-08-27: -5.69 °F2026-08-29: +0.96 °F2026-08-30: -4.55 °F2026-08-022026-08-30°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 (29 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.55
2026-08-29+0.96
2026-08-28—
2026-08-27-5.69
2026-08-26+0.10
2026-08-25-5.35
2026-08-24-7.23
2026-08-23+2.19
2026-08-22+0.65
2026-08-21+3.05
2026-08-20-3.64
2026-08-19-7.93
2026-08-18+0.03
2026-08-17-2.11
2026-08-16-2.66
2026-08-15+1.70
2026-08-14-4.13
2026-08-13-4.71
2026-08-12-2.02
2026-08-11-3.98
2026-08-10+0.16
2026-08-09-2.46
2026-08-08-6.53
2026-08-07-5.77
2026-08-06-0.25
2026-08-05-4.87
2026-08-04-5.05
2026-08-03-2.26
2026-08-02-4.52

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KBOS, lead day 1-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 2 days-7 to -6 °F: 1 day-6 to -5 °F: 4 days-5 to -4 °F: 5 days-4 to -3 °F: 2 days-3 to -2 °F: 5 days-2 to -1 °F: 0 days-1 to 0 °F: 1 day0 to 1 °F: 5 days1 to 2 °F: 1 day2 to 3 °F: 1 day3 to 4 °F: 1 day4 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| 3.35 · P90 |e| 6 °F-100+10 °Fn = 28 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
-8.00-7.002
-7.00-6.001
-6.00-5.004
-5.00-4.005
-4.00-3.002
-3.00-2.005
-2.00-1.000
-1.00+0.001
+0.00+1.005
+1.00+2.001
+2.00+3.001
+3.00+4.001
+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
2026-08283.38 -2.75

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-02 → 2026-08-30 28
ECMWF AIFS Single2026-08-02 → 2026-08-30 28
ECMWF AIFS Single2026-08-02 → 2026-08-30 28
ECMWF AIFS Single2026-08-02 → 2026-08-30 28

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 (GFS init) 1 -1.00 [-1.00, -1.00] yes
Aurora (IFS init) 2 -0.26 [-0.34, -0.17] yes
FourCastNet v2 (GFS init) 1 -2.12 [-2.12, -2.12] yes
FourCastNet v2 (IFS init) 2 -2.03 [-2.55, -1.51] yes
NCEP GFS 28 +0.53 [-0.65, 1.54] no
GraphCast (GFS init) 1 -0.79 [-0.79, -0.79] yes
GraphCast (IFS init) 27 +0.40 [-0.04, 0.96] no
ECMWF IFS HRES 22 +0.77 [0.07, 1.87] yes
Pangu-Weather (GFS init) 1 +1.05 [1.05, 1.05] yes
Pangu-Weather (IFS init) 2 +0.12 [-1.14, 1.39] no
Persistence (baseline) 27 -1.53 [-2.95, -0.26] yes

Cite this page

ShortCastCheck, KBOS aifs_single lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KBOS/model/aifs_single/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KBOS (Boston Logan), model aifs_single, lead day 1. 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/1/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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