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

Boston Logan · ECMWF AIFS Single · lead day 5

KBOS · aifs_single · lead 5

Target day = initialization date + 5 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
tmax00Zbilinear30d24 1 QC4.63 [3.77, 5.42]4.12-2.29 [-4.09, -0.67]5.46 [4.54, 6.22]17% [7%, 33%]25%29%+0.33+0.382026-08-06 → 2026-08-30
tmax00Zbilinear90d24 1 QC4.63 [3.74, 5.50]4.12-2.29 [-4.18, -0.62]5.46 [4.44, 6.29]17% [5%, 38%]25%29%+0.33+0.382026-08-06 → 2026-08-30
tmax00Zbilinear365d24 1 QC4.63 [3.58, 5.51]4.12-2.29 [-4.30, -0.27]5.46 [4.29, 6.27]17% [5%, 40%]25%29%+0.33+0.382026-08-06 → 2026-08-30
tmax00Zbilinearall24 1 QC4.63 [3.55, 5.58]4.12-2.29 [-4.21, -0.53]5.46 [4.21, 6.30]17% [5%, 40%]25%29%+0.33+0.382026-08-06 → 2026-08-30
tmax00Znearest30d24 1 QC4.66 [3.75, 5.50]4.12-2.30 [-4.12, -0.69]5.48 [4.50, 6.27]8% [0%, 17%]25%33%+0.32+0.382026-08-06 → 2026-08-30
tmax00Znearest90d24 1 QC4.66 [3.73, 5.59]4.12-2.30 [-4.23, -0.63]5.48 [4.43, 6.35]8% [0%, 16%]25%33%+0.32+0.382026-08-06 → 2026-08-30
tmax00Znearest365d24 1 QC4.66 [3.63, 5.58]4.12-2.30 [-4.34, -0.25]5.48 [4.25, 6.33]8% [0%, 17%]25%33%+0.32+0.382026-08-06 → 2026-08-30
tmax00Znearestall24 1 QC4.66 [3.56, 5.66]4.12-2.30 [-4.28, -0.51]5.48 [4.18, 6.35]8% [0%, 16%]25%33%+0.32+0.382026-08-06 → 2026-08-30
tmax12Zbilinear30d23 1 QC4.29 [3.62, 4.95]3.75-2.21 [-4.14, -0.44]4.94 [4.20, 5.55]13% [0%, 33%]17%39%+0.39+0.452026-08-06 → 2026-08-30
tmax12Zbilinear90d23 1 QC4.29 [3.62, 4.98]3.75-2.21 [-4.40, -0.45]4.94 [4.24, 5.58]13% [0%, 40%]17%39%+0.39+0.452026-08-06 → 2026-08-30
tmax12Zbilinear365d23 1 QC4.29 [3.54, 4.99]3.75-2.21 [-4.51, -0.09]4.94 [4.16, 5.57]13% [0%, 40%]17%39%+0.39+0.452026-08-06 → 2026-08-30
tmax12Zbilinearall23 1 QC4.29 [3.52, 5.02]3.75-2.21 [-4.45, -0.32]4.94 [4.13, 5.58]13% [0%, 40%]17%39%+0.39+0.452026-08-06 → 2026-08-30
tmax12Znearest30d23 1 QC4.25 [3.55, 4.93]3.73-2.20 [-4.21, -0.45]4.91 [4.13, 5.56]9% [0%, 25%]22%39%+0.40+0.462026-08-06 → 2026-08-30
tmax12Znearest90d23 1 QC4.25 [3.54, 4.99]3.73-2.20 [-4.53, -0.43]4.91 [4.17, 5.59]9% [0%, 29%]22%39%+0.40+0.462026-08-06 → 2026-08-30
tmax12Znearest365d23 1 QC4.25 [3.45, 4.97]3.73-2.20 [-4.61, -0.07]4.91 [4.07, 5.59]9% [0%, 33%]22%39%+0.40+0.462026-08-06 → 2026-08-30
tmax12Znearestall23 1 QC4.25 [3.47, 5.03]3.73-2.20 [-4.55, -0.33]4.91 [4.07, 5.61]9% [0%, 29%]22%39%+0.40+0.462026-08-06 → 2026-08-30
tmin00Zbilinear30d24 1 QC1.86 [0.89, 2.67]1.84-0.09 [-1.10, 1.04]2.45 [1.30, 3.14]38% [14%, 67%]62%75%+0.44+0.432026-08-06 → 2026-08-30
tmin00Zbilinear90d24 1 QC1.86 [0.71, 2.71]1.84-0.09 [-1.22, 1.13]2.45 [1.04, 3.19]38% [14%, 71%]62%75%+0.44+0.432026-08-06 → 2026-08-30
tmin00Zbilinear365d24 1 QC1.86 [0.77, 2.79]1.84-0.09 [-1.31, 1.29]2.45 [1.13, 3.26]38% [12%, 71%]62%75%+0.44+0.432026-08-06 → 2026-08-30
tmin00Zbilinearall24 1 QC1.86 [0.74, 2.70]1.84-0.09 [-1.33, 1.06]2.45 [1.05, 3.18]38% [12%, 71%]62%75%+0.44+0.432026-08-06 → 2026-08-30
tmin00Znearest30d24 1 QC1.79 [0.83, 2.61]1.82+0.18 [-0.88, 1.34]2.40 [1.18, 3.16]38% [14%, 67%]67%79%+0.46+0.432026-08-06 → 2026-08-30
tmin00Znearest90d24 1 QC1.79 [0.69, 2.65]1.82+0.18 [-0.95, 1.44]2.40 [0.94, 3.20]38% [12%, 71%]67%79%+0.46+0.432026-08-06 → 2026-08-30
tmin00Znearest365d24 1 QC1.79 [0.74, 2.75]1.82+0.18 [-0.98, 1.64]2.40 [0.98, 3.31]38% [12%, 70%]67%79%+0.46+0.432026-08-06 → 2026-08-30
tmin00Znearestall24 1 QC1.79 [0.70, 2.67]1.82+0.18 [-1.03, 1.37]2.40 [0.92, 3.18]38% [12%, 70%]67%79%+0.46+0.432026-08-06 → 2026-08-30
tmin12Zbilinear30d23 1 QC1.87 [1.41, 2.31]1.80-0.40 [-1.50, 0.57]2.20 [1.74, 2.59]30% [10%, 50%]52%78%+0.43+0.422026-08-06 → 2026-08-30
tmin12Zbilinear90d23 1 QC1.87 [1.30, 2.40]1.80-0.40 [-1.65, 0.61]2.20 [1.58, 2.67]30% [0%, 52%]52%78%+0.43+0.422026-08-06 → 2026-08-30
tmin12Zbilinear365d23 1 QC1.87 [1.32, 2.44]1.80-0.40 [-1.71, 0.78]2.20 [1.59, 2.71]30% [0%, 52%]52%78%+0.43+0.422026-08-06 → 2026-08-30
tmin12Zbilinearall23 1 QC1.87 [1.33, 2.46]1.80-0.40 [-1.79, 0.60]2.20 [1.60, 2.76]30% [0%, 53%]52%78%+0.43+0.422026-08-06 → 2026-08-30
tmin12Znearest30d23 1 QC1.86 [1.41, 2.27]1.84-0.12 [-1.27, 0.89]2.17 [1.66, 2.54]26% [7%, 43%]61%78%+0.44+0.412026-08-06 → 2026-08-30
tmin12Znearest90d23 1 QC1.86 [1.30, 2.36]1.84-0.12 [-1.44, 0.94]2.17 [1.52, 2.61]26% [0%, 46%]61%78%+0.44+0.412026-08-06 → 2026-08-30
tmin12Znearest365d23 1 QC1.86 [1.29, 2.40]1.84-0.12 [-1.44, 1.13]2.17 [1.50, 2.64]26% [0%, 46%]61%78%+0.44+0.412026-08-06 → 2026-08-30
tmin12Znearestall23 1 QC1.86 [1.29, 2.40]1.84-0.12 [-1.58, 0.91]2.17 [1.50, 2.64]26% [0%, 46%]61%78%+0.44+0.412026-08-06 → 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 5, 00Z bilinear tmax+20+100-10-202026-08-06: -0.96 °F2026-08-07: -6.03 °F2026-08-08: -10.47 °F2026-08-09: -3.3 °F2026-08-10: +2.25 °F2026-08-11: -6 °F2026-08-12: -3.67 °F2026-08-13: -3.23 °F2026-08-14: -5.98 °F2026-08-15: +1.34 °F2026-08-16: -1.75 °F2026-08-17: +7.29 °F2026-08-18: -0.24 °F2026-08-19: -10.41 °F2026-08-20: -5.15 °F2026-08-21: +8.15 °F2026-08-22: +3.02 °F2026-08-23: +5.34 °F2026-08-24: -7.51 °F2026-08-25: -5.78 °F2026-08-26: +0.64 °F2026-08-27: -6.39 °F2026-08-29: -0.87 °F2026-08-30: -5.31 °F2026-08-062026-08-30°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 (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-5.31
2026-08-29-0.87
2026-08-28—
2026-08-27-6.39
2026-08-26+0.64
2026-08-25-5.78
2026-08-24-7.51
2026-08-23+5.34
2026-08-22+3.02
2026-08-21+8.15
2026-08-20-5.15
2026-08-19-10.41
2026-08-18-0.24
2026-08-17+7.29
2026-08-16-1.75
2026-08-15+1.34
2026-08-14-5.98
2026-08-13-3.23
2026-08-12-3.67
2026-08-11-6.00
2026-08-10+2.25
2026-08-09-3.30
2026-08-08-10.47
2026-08-07-6.03
2026-08-06-0.96

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KBOS, lead day 5-20 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: 4 days-6 to -4 °F: 4 days-4 to -2 °F: 3 days-2 to 0 °F: 4 days0 to 2 °F: 2 days2 to 4 °F: 2 days4 to 6 °F: 1 day6 to 8 °F: 1 day8 to 10 °F: 1 day10 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| 5.23 · P90 |e| 7.96 °F-200+20 °Fn = 24 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
-8.00-6.004
-6.00-4.004
-4.00-2.003
-2.00+0.004
+0.00+2.002
+2.00+4.002
+4.00+6.001
+6.00+8.001
+8.00+10.001
+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
2026-08244.63 -2.29

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-06 → 2026-08-30 24
ECMWF AIFS Single2026-08-06 → 2026-08-30 24
ECMWF AIFS Single2026-08-06 → 2026-08-30 23
ECMWF AIFS Single2026-08-06 → 2026-08-30 23

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 24 +0.42 [-1.01, 1.58] no
GraphCast (IFS init) 24 +0.46 [-0.84, 1.33] no
ECMWF IFS HRES 17 +0.70 [-2.73, 1.74] no
Persistence (baseline) 24 -2.25 [-3.77, -0.75] yes

Cite this page

ShortCastCheck, KBOS aifs_single lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KBOS/model/aifs_single/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KBOS (Boston Logan), model aifs_single, lead day 5. 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/5/

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

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