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

Philadelphia Intl · ECMWF AIFS Single · lead day 6

KPHL · aifs_single · lead 6

Target day = initialization date + 6 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 QC3.25 [2.51, 3.81]2.23-2.88 [-3.59, -1.94]3.93 [3.05, 4.52]21% [8%, 35%]38%50%+0.06+0.352026-08-07 → 2026-08-30
tmax00Zbilinear90d24 1 QC3.25 [2.31, 3.83]2.23-2.88 [-3.67, -1.81]3.93 [2.82, 4.55]21% [9%, 38%]38%50%+0.06+0.352026-08-07 → 2026-08-30
tmax00Zbilinear365d24 1 QC3.25 [2.33, 3.84]2.23-2.88 [-3.62, -1.80]3.93 [2.90, 4.61]21% [8%, 37%]38%50%+0.06+0.352026-08-07 → 2026-08-30
tmax00Zbilinearall24 1 QC3.25 [2.36, 3.83]2.23-2.88 [-3.67, -1.89]3.93 [2.91, 4.57]21% [6%, 36%]38%50%+0.06+0.352026-08-07 → 2026-08-30
tmax00Znearest30d24 1 QC2.89 [2.27, 3.41]2.25-2.27 [-2.96, -1.36]3.52 [2.66, 4.13]25% [12%, 36%]38%54%+0.16+0.342026-08-07 → 2026-08-30
tmax00Znearest90d24 1 QC2.89 [2.15, 3.46]2.25-2.27 [-3.06, -1.22]3.52 [2.50, 4.18]25% [11%, 36%]38%54%+0.16+0.342026-08-07 → 2026-08-30
tmax00Znearest365d24 1 QC2.89 [2.16, 3.49]2.25-2.27 [-3.00, -1.21]3.52 [2.54, 4.26]25% [11%, 40%]38%54%+0.16+0.342026-08-07 → 2026-08-30
tmax00Znearestall24 1 QC2.89 [2.20, 3.49]2.25-2.27 [-3.02, -1.29]3.52 [2.52, 4.20]25% [11%, 39%]38%54%+0.16+0.342026-08-07 → 2026-08-30
tmax12Zbilinear30d24 1 QC3.42 [2.37, 4.25]2.43-2.63 [-3.38, -1.87]4.32 [2.83, 5.20]12% [4%, 21%]33%58%+0.01+0.292026-08-07 → 2026-08-30
tmax12Zbilinear90d24 1 QC3.42 [2.22, 4.28]2.43-2.63 [-3.43, -1.76]4.32 [2.55, 5.23]12% [4%, 22%]33%58%+0.01+0.292026-08-07 → 2026-08-30
tmax12Zbilinear365d24 1 QC3.42 [2.12, 4.38]2.43-2.63 [-3.46, -1.77]4.32 [2.50, 5.33]12% [0%, 22%]33%58%+0.01+0.292026-08-07 → 2026-08-30
tmax12Zbilinearall24 1 QC3.42 [2.10, 4.32]2.43-2.63 [-3.40, -1.79]4.32 [2.49, 5.23]12% [0%, 20%]33%58%+0.01+0.292026-08-07 → 2026-08-30
tmax12Znearest30d24 1 QC3.00 [2.04, 3.74]2.41-1.99 [-2.69, -1.26]3.90 [2.49, 4.71]21% [7%, 33%]42%58%+0.13+0.292026-08-07 → 2026-08-30
tmax12Znearest90d24 1 QC3.00 [1.91, 3.79]2.41-1.99 [-2.72, -1.20]3.90 [2.17, 4.76]21% [6%, 35%]42%58%+0.13+0.292026-08-07 → 2026-08-30
tmax12Znearest365d24 1 QC3.00 [1.84, 3.85]2.41-1.99 [-2.78, -1.21]3.90 [2.14, 4.84]21% [5%, 36%]42%58%+0.13+0.292026-08-07 → 2026-08-30
tmax12Znearestall24 1 QC3.00 [1.80, 3.81]2.41-1.99 [-2.71, -1.20]3.90 [2.10, 4.81]21% [0%, 38%]42%58%+0.13+0.292026-08-07 → 2026-08-30
tmin00Zbilinear30d24 1 QC3.05 [2.25, 3.93]3.04-0.07 [-1.37, 1.26]3.54 [2.60, 4.45]17% [4%, 31%]33%50%+0.11+0.062026-08-07 → 2026-08-30
tmin00Zbilinear90d24 1 QC3.05 [2.24, 4.00]3.04-0.07 [-1.37, 1.55]3.54 [2.60, 4.50]17% [3%, 32%]33%50%+0.11+0.062026-08-07 → 2026-08-30
tmin00Zbilinear365d24 1 QC3.05 [2.24, 4.23]3.04-0.07 [-1.46, 1.49]3.54 [2.59, 4.69]17% [0%, 33%]33%50%+0.11+0.062026-08-07 → 2026-08-30
tmin00Zbilinearall24 1 QC3.05 [2.25, 4.05]3.04-0.07 [-1.54, 1.49]3.54 [2.61, 4.54]17% [0%, 31%]33%50%+0.11+0.062026-08-07 → 2026-08-30
tmin00Znearest30d24 1 QC2.95 [2.17, 3.85]3.01+0.48 [-0.76, 1.77]3.54 [2.63, 4.42]21% [12%, 31%]38%46%+0.14+0.072026-08-07 → 2026-08-30
tmin00Znearest90d24 1 QC2.95 [2.16, 3.94]3.01+0.48 [-0.75, 2.06]3.54 [2.64, 4.50]21% [11%, 30%]38%46%+0.14+0.072026-08-07 → 2026-08-30
tmin00Znearest365d24 1 QC2.95 [2.14, 4.15]3.01+0.48 [-0.84, 1.98]3.54 [2.58, 4.65]21% [11%, 30%]38%46%+0.14+0.072026-08-07 → 2026-08-30
tmin00Znearestall24 1 QC2.95 [2.12, 3.99]3.01+0.48 [-0.88, 1.97]3.54 [2.58, 4.48]21% [9%, 31%]38%46%+0.14+0.072026-08-07 → 2026-08-30
tmin12Zbilinear30d24 1 QC2.83 [1.78, 3.91]2.85-0.24 [-1.64, 1.25]3.41 [2.26, 4.33]29% [8%, 53%]33%50%+0.17+0.122026-08-07 → 2026-08-30
tmin12Zbilinear90d24 1 QC2.83 [1.66, 3.94]2.85-0.24 [-1.57, 1.50]3.41 [2.14, 4.37]29% [6%, 57%]33%50%+0.17+0.122026-08-07 → 2026-08-30
tmin12Zbilinear365d24 1 QC2.83 [1.68, 4.13]2.85-0.24 [-1.85, 1.38]3.41 [2.16, 4.44]29% [0%, 56%]33%50%+0.17+0.122026-08-07 → 2026-08-30
tmin12Zbilinearall24 1 QC2.83 [1.69, 3.97]2.85-0.24 [-1.72, 1.58]3.41 [2.16, 4.36]29% [0%, 55%]33%50%+0.17+0.122026-08-07 → 2026-08-30
tmin12Znearest30d24 1 QC2.84 [1.93, 3.81]2.80+0.29 [-1.05, 1.75]3.37 [2.41, 4.24]21% [7%, 36%]33%42%+0.17+0.142026-08-07 → 2026-08-30
tmin12Znearest90d24 1 QC2.84 [1.89, 3.89]2.80+0.29 [-0.98, 1.99]3.37 [2.36, 4.30]21% [0%, 38%]33%42%+0.17+0.142026-08-07 → 2026-08-30
tmin12Znearest365d24 1 QC2.84 [1.91, 4.06]2.80+0.29 [-1.24, 1.87]3.37 [2.37, 4.42]21% [0%, 38%]33%42%+0.17+0.142026-08-07 → 2026-08-30
tmin12Znearestall24 1 QC2.84 [1.92, 3.89]2.80+0.29 [-1.13, 2.08]3.37 [2.40, 4.26]21% [0%, 36%]33%42%+0.17+0.142026-08-07 → 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 6, 00Z bilinear tmax+10+50-5-102026-08-07: -3.7 °F2026-08-08: +0.76 °F2026-08-09: -1.58 °F2026-08-10: +0.96 °F2026-08-11: -1.5 °F2026-08-12: -5.73 °F2026-08-13: -2.98 °F2026-08-14: -3.44 °F2026-08-15: -5.36 °F2026-08-16: -2.66 °F2026-08-17: -1.42 °F2026-08-18: -5.23 °F2026-08-19: -5.07 °F2026-08-20: +0.07 °F2026-08-21: -8.79 °F2026-08-22: +2.37 °F2026-08-23: -1.31 °F2026-08-24: -5.38 °F2026-08-25: -0.85 °F2026-08-26: -3.65 °F2026-08-27: -6.53 °F2026-08-28: -4.41 °F2026-08-29: +0.22 °F2026-08-30: -3.99 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-3.99
2026-08-29+0.22
2026-08-28-4.41
2026-08-27-6.53
2026-08-26-3.65
2026-08-25-0.85
2026-08-24-5.38
2026-08-23-1.31
2026-08-22+2.37
2026-08-21-8.79
2026-08-20+0.07
2026-08-19-5.07
2026-08-18-5.23
2026-08-17-1.42
2026-08-16-2.66
2026-08-15-5.36
2026-08-14-3.44
2026-08-13-2.98
2026-08-12-5.73
2026-08-11-1.50
2026-08-10+0.96
2026-08-09-1.58
2026-08-08+0.76
2026-08-07-3.70

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KPHL, lead day 6-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 5 days-5 to -4 °F: 1 day-4 to -3 °F: 4 days-3 to -2 °F: 2 days-2 to -1 °F: 4 days-1 to 0 °F: 1 day0 to 1 °F: 4 days1 to 2 °F: 0 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| 3.21 · P90 |e| 5.62 °F-100+10 °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
-10.00-9.000
-9.00-8.001
-8.00-7.000
-7.00-6.001
-6.00-5.005
-5.00-4.001
-4.00-3.004
-3.00-2.002
-2.00-1.004
-1.00+0.001
+0.00+1.004
+1.00+2.000
+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
2026-08243.25 -2.88

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24
ECMWF AIFS Single2026-08-07 → 2026-08-30 24

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 -0.84 [-1.86, 0.95] no
GraphCast (IFS init) 24 -1.22 [-2.50, -0.11] yes
ECMWF IFS HRES 19 -0.99 [-3.43, 0.49] no
Persistence (baseline) 24 -0.21 [-0.98, 0.49] no

Cite this page

ShortCastCheck, KPHL aifs_single lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KPHL/model/aifs_single/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KPHL (Philadelphia Intl), model aifs_single, lead day 6. 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/6/

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