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

Philadelphia Intl · ECMWF AIFS Single · lead day 3

KPHL · 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
tmax00Zbilinear30d27 1 QC2.44 [1.92, 3.05]1.70-2.06 [-2.83, -1.55]2.90 [2.41, 3.47]26% [12%, 40%]37%67%+0.28+0.502026-08-04 → 2026-08-30
tmax00Zbilinear90d27 1 QC2.44 [1.84, 3.15]1.70-2.06 [-2.90, -1.51]2.90 [2.30, 3.56]26% [10%, 41%]37%67%+0.28+0.502026-08-04 → 2026-08-30
tmax00Zbilinear365d27 1 QC2.44 [1.80, 3.14]1.70-2.06 [-2.90, -1.48]2.90 [2.22, 3.52]26% [11%, 43%]37%67%+0.28+0.502026-08-04 → 2026-08-30
tmax00Zbilinearall27 1 QC2.44 [1.82, 3.25]1.70-2.06 [-3.04, -1.48]2.90 [2.25, 3.66]26% [9%, 42%]37%67%+0.28+0.502026-08-04 → 2026-08-30
tmax00Znearest30d27 1 QC2.15 [1.77, 2.61]1.72-1.37 [-2.11, -0.88]2.48 [1.99, 2.99]19% [9%, 27%]44%74%+0.37+0.492026-08-04 → 2026-08-30
tmax00Znearest90d27 1 QC2.15 [1.69, 2.70]1.72-1.37 [-2.25, -0.81]2.48 [1.90, 3.10]19% [8%, 29%]44%74%+0.37+0.492026-08-04 → 2026-08-30
tmax00Znearest365d27 1 QC2.15 [1.60, 2.68]1.72-1.37 [-2.18, -0.79]2.48 [1.82, 3.04]19% [8%, 29%]44%74%+0.37+0.492026-08-04 → 2026-08-30
tmax00Znearestall27 1 QC2.15 [1.64, 2.75]1.72-1.37 [-2.36, -0.83]2.48 [1.85, 3.13]19% [7%, 29%]44%74%+0.37+0.492026-08-04 → 2026-08-30
tmax12Zbilinear30d27 1 QC2.67 [2.31, 3.14]1.69-2.30 [-2.99, -1.69]3.13 [2.71, 3.61]15% [4%, 30%]37%63%+0.22+0.502026-08-04 → 2026-08-30
tmax12Zbilinear90d27 1 QC2.67 [2.29, 3.24]1.69-2.30 [-3.09, -1.52]3.13 [2.63, 3.68]15% [0%, 29%]37%63%+0.22+0.502026-08-04 → 2026-08-30
tmax12Zbilinear365d27 1 QC2.67 [2.22, 3.26]1.69-2.30 [-3.18, -1.47]3.13 [2.50, 3.69]15% [0%, 30%]37%63%+0.22+0.502026-08-04 → 2026-08-30
tmax12Zbilinearall27 1 QC2.67 [2.22, 3.38]1.69-2.30 [-3.23, -1.50]3.13 [2.54, 3.80]15% [0%, 29%]37%63%+0.22+0.502026-08-04 → 2026-08-30
tmax12Znearest30d27 1 QC2.30 [1.95, 2.71]1.74-1.61 [-2.39, -0.95]2.70 [2.29, 3.15]22% [8%, 34%]41%74%+0.32+0.492026-08-04 → 2026-08-30
tmax12Znearest90d27 1 QC2.30 [1.93, 2.81]1.74-1.61 [-2.50, -0.81]2.70 [2.22, 3.23]22% [7%, 35%]41%74%+0.32+0.492026-08-04 → 2026-08-30
tmax12Znearest365d27 1 QC2.30 [1.92, 2.80]1.74-1.61 [-2.59, -0.76]2.70 [2.10, 3.23]22% [5%, 36%]41%74%+0.32+0.492026-08-04 → 2026-08-30
tmax12Znearestall27 1 QC2.30 [1.91, 2.93]1.74-1.61 [-2.65, -0.76]2.70 [2.15, 3.31]22% [0%, 36%]41%74%+0.32+0.492026-08-04 → 2026-08-30
tmin00Zbilinear30d27 1 QC2.17 [1.45, 2.92]2.15+0.33 [-0.30, 1.06]2.54 [1.67, 3.20]22% [11%, 35%]48%78%+0.38+0.372026-08-04 → 2026-08-30
tmin00Zbilinear90d27 1 QC2.17 [1.39, 2.95]2.15+0.33 [-0.37, 1.15]2.54 [1.62, 3.21]22% [11%, 36%]48%78%+0.38+0.372026-08-04 → 2026-08-30
tmin00Zbilinear365d27 1 QC2.17 [1.39, 2.99]2.15+0.33 [-0.32, 1.23]2.54 [1.61, 3.29]22% [10%, 36%]48%78%+0.38+0.372026-08-04 → 2026-08-30
tmin00Zbilinearall27 1 QC2.17 [1.38, 2.99]2.15+0.33 [-0.35, 1.06]2.54 [1.61, 3.26]22% [11%, 38%]48%78%+0.38+0.372026-08-04 → 2026-08-30
tmin00Znearest30d27 1 QC2.29 [1.61, 2.98]2.19+0.86 [0.30, 1.62]2.66 [1.80, 3.38]11% [3%, 21%]52%78%+0.35+0.362026-08-04 → 2026-08-30
tmin00Znearest90d27 1 QC2.29 [1.52, 3.05]2.19+0.86 [0.23, 1.64]2.66 [1.70, 3.40]11% [0%, 23%]52%78%+0.35+0.362026-08-04 → 2026-08-30
tmin00Znearest365d27 1 QC2.29 [1.57, 3.11]2.19+0.86 [0.28, 1.74]2.66 [1.74, 3.46]11% [0%, 23%]52%78%+0.35+0.362026-08-04 → 2026-08-30
tmin00Znearestall27 1 QC2.29 [1.53, 3.07]2.19+0.86 [0.23, 1.57]2.66 [1.70, 3.41]11% [0%, 22%]52%78%+0.35+0.362026-08-04 → 2026-08-30
tmin12Zbilinear30d27 1 QC2.06 [1.39, 2.75]2.10+0.33 [-0.41, 1.07]2.52 [1.77, 3.15]33% [17%, 54%]52%74%+0.42+0.392026-08-04 → 2026-08-30
tmin12Zbilinear90d27 1 QC2.06 [1.31, 2.76]2.10+0.33 [-0.58, 1.18]2.52 [1.66, 3.17]33% [17%, 59%]52%74%+0.42+0.392026-08-04 → 2026-08-30
tmin12Zbilinear365d27 1 QC2.06 [1.32, 2.84]2.10+0.33 [-0.50, 1.25]2.52 [1.64, 3.23]33% [14%, 58%]52%74%+0.42+0.392026-08-04 → 2026-08-30
tmin12Zbilinearall27 1 QC2.06 [1.26, 2.78]2.10+0.33 [-0.54, 1.13]2.52 [1.59, 3.17]33% [15%, 60%]52%74%+0.42+0.392026-08-04 → 2026-08-30
tmin12Znearest30d27 1 QC2.06 [1.38, 2.77]2.08+0.85 [0.16, 1.57]2.61 [1.85, 3.29]37% [26%, 50%]48%67%+0.41+0.392026-08-04 → 2026-08-30
tmin12Znearest90d27 1 QC2.06 [1.27, 2.80]2.08+0.85 [0.01, 1.66]2.61 [1.70, 3.30]37% [24%, 54%]48%67%+0.41+0.392026-08-04 → 2026-08-30
tmin12Znearest365d27 1 QC2.06 [1.27, 2.85]2.08+0.85 [0.11, 1.74]2.61 [1.66, 3.34]37% [22%, 50%]48%67%+0.41+0.392026-08-04 → 2026-08-30
tmin12Znearestall27 1 QC2.06 [1.23, 2.79]2.08+0.85 [0.06, 1.63]2.61 [1.62, 3.30]37% [24%, 54%]48%67%+0.41+0.392026-08-04 → 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 KPHL, lead day 3, 00Z bilinear tmax+10+50-5-102026-08-04: -4.75 °F2026-08-05: -2.96 °F2026-08-06: -3.47 °F2026-08-07: -5.88 °F2026-08-08: -0.78 °F2026-08-09: -2.22 °F2026-08-10: +1.28 °F2026-08-11: +2.53 °F2026-08-12: -4.33 °F2026-08-13: -1.96 °F2026-08-14: -4.27 °F2026-08-15: -4.58 °F2026-08-16: +0.07 °F2026-08-17: -0.23 °F2026-08-18: -2.43 °F2026-08-19: -3.58 °F2026-08-20: +0.26 °F2026-08-21: -2.56 °F2026-08-22: +0.77 °F2026-08-23: -2.3 °F2026-08-24: -3.75 °F2026-08-25: +0.21 °F2026-08-26: -2.94 °F2026-08-27: -3.2 °F2026-08-28: -2.66 °F2026-08-29: -0.24 °F2026-08-30: -1.66 °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
2026-08-30-1.66
2026-08-29-0.24
2026-08-28-2.66
2026-08-27-3.20
2026-08-26-2.94
2026-08-25+0.21
2026-08-24-3.75
2026-08-23-2.30
2026-08-22+0.77
2026-08-21-2.56
2026-08-20+0.26
2026-08-19-3.58
2026-08-18-2.43
2026-08-17-0.23
2026-08-16+0.07
2026-08-15-4.58
2026-08-14-4.27
2026-08-13-1.96
2026-08-12-4.33
2026-08-11+2.53
2026-08-10+1.28
2026-08-09-2.22
2026-08-08-0.78
2026-08-07-5.88
2026-08-06-3.47
2026-08-05-2.96
2026-08-04-4.75

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KPHL, lead day 3-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 1 day-5 to -4 °F: 4 days-4 to -3 °F: 4 days-3 to -2 °F: 7 days-2 to -1 °F: 2 days-1 to 0 °F: 3 days0 to 1 °F: 4 days1 to 2 °F: 1 day2 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| 2.53 · P90 |e| 4.43 °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
-8.00-7.000
-7.00-6.000
-6.00-5.001
-5.00-4.004
-4.00-3.004
-3.00-2.007
-2.00-1.002
-1.00+0.003
+0.00+1.004
+1.00+2.001
+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
2026-08272.44 -2.06

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 2026-08-30 27
ECMWF AIFS Single2026-08-04 → 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
NCEP GFS 27 -0.68 [-1.61, 0.29] no
GraphCast (IFS init) 25 -2.02 [-2.68, -1.60] yes
ECMWF IFS HRES 22 -0.99 [-1.93, -0.39] yes
Persistence (baseline) 27 -0.97 [-2.41, 0.29] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KPHL (Philadelphia Intl), 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/KPHL/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