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

Philadelphia Intl · ECMWF AIFS Single · lead day 1

KPHL · 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
tmax00Zbilinear30d29 1 QC2.41 [1.81, 3.36]1.46-2.28 [-3.33, -1.53]2.91 [2.25, 3.81]21% [7%, 33%]41%62%+0.25+0.552026-08-02 → 2026-08-30
tmax00Zbilinear90d29 1 QC2.41 [1.80, 3.46]1.46-2.28 [-3.41, -1.49]2.91 [2.25, 3.95]21% [6%, 33%]41%62%+0.25+0.552026-08-02 → 2026-08-30
tmax00Zbilinear365d29 1 QC2.41 [1.82, 3.46]1.46-2.28 [-3.42, -1.51]2.91 [2.25, 3.93]21% [6%, 33%]41%62%+0.25+0.552026-08-02 → 2026-08-30
tmax00Zbilinearall29 1 QC2.41 [1.82, 3.69]1.46-2.28 [-3.69, -1.46]2.91 [2.23, 4.09]21% [4%, 33%]41%62%+0.25+0.552026-08-02 → 2026-08-30
tmax00Znearest30d29 1 QC2.05 [1.53, 2.84]1.51-1.60 [-2.68, -0.76]2.46 [1.82, 3.27]24% [14%, 34%]59%76%+0.36+0.532026-08-02 → 2026-08-30
tmax00Znearest90d29 1 QC2.05 [1.55, 3.03]1.51-1.60 [-2.77, -0.71]2.46 [1.83, 3.44]24% [11%, 33%]59%76%+0.36+0.532026-08-02 → 2026-08-30
tmax00Znearest365d29 1 QC2.05 [1.52, 2.99]1.51-1.60 [-2.79, -0.71]2.46 [1.82, 3.42]24% [11%, 36%]59%76%+0.36+0.532026-08-02 → 2026-08-30
tmax00Znearestall29 1 QC2.05 [1.52, 3.15]1.51-1.60 [-3.04, -0.67]2.46 [1.80, 3.53]24% [9%, 36%]59%76%+0.36+0.532026-08-02 → 2026-08-30
tmax12Zbilinear30d29 1 QC2.19 [1.61, 3.00]1.28-2.09 [-2.96, -1.35]2.62 [1.95, 3.36]21% [10%, 33%]52%72%+0.32+0.602026-08-02 → 2026-08-30
tmax12Zbilinear90d29 1 QC2.19 [1.59, 3.08]1.28-2.09 [-3.08, -1.33]2.62 [1.92, 3.48]21% [8%, 33%]52%72%+0.32+0.602026-08-02 → 2026-08-30
tmax12Zbilinear365d29 1 QC2.19 [1.57, 3.07]1.28-2.09 [-3.07, -1.33]2.62 [1.93, 3.44]21% [7%, 33%]52%72%+0.32+0.602026-08-02 → 2026-08-30
tmax12Zbilinearall29 1 QC2.19 [1.55, 3.31]1.28-2.09 [-3.31, -1.26]2.62 [1.91, 3.67]21% [6%, 33%]52%72%+0.32+0.602026-08-02 → 2026-08-30
tmax12Znearest30d29 1 QC1.80 [1.31, 2.47]1.37-1.40 [-2.34, -0.55]2.20 [1.57, 2.84]34% [15%, 50%]66%79%+0.44+0.572026-08-02 → 2026-08-30
tmax12Znearest90d29 1 QC1.80 [1.32, 2.65]1.37-1.40 [-2.52, -0.51]2.20 [1.58, 2.97]34% [13%, 50%]66%79%+0.44+0.572026-08-02 → 2026-08-30
tmax12Znearest365d29 1 QC1.80 [1.29, 2.58]1.37-1.40 [-2.48, -0.49]2.20 [1.57, 2.95]34% [12%, 50%]66%79%+0.44+0.572026-08-02 → 2026-08-30
tmax12Znearestall29 1 QC1.80 [1.28, 2.70]1.37-1.40 [-2.68, -0.42]2.20 [1.56, 3.12]34% [10%, 50%]66%79%+0.44+0.572026-08-02 → 2026-08-30
tmin00Zbilinear30d29 1 QC1.60 [1.11, 2.13]1.60+0.01 [-0.44, 0.51]1.99 [1.46, 2.43]38% [21%, 55%]59%79%+0.42+0.422026-08-02 → 2026-08-30
tmin00Zbilinear90d29 1 QC1.60 [1.01, 2.13]1.60+0.01 [-0.48, 0.52]1.99 [1.33, 2.42]38% [20%, 57%]59%79%+0.42+0.422026-08-02 → 2026-08-30
tmin00Zbilinear365d29 1 QC1.60 [0.99, 2.17]1.60+0.01 [-0.51, 0.57]1.99 [1.23, 2.46]38% [19%, 57%]59%79%+0.42+0.422026-08-02 → 2026-08-30
tmin00Zbilinearall29 1 QC1.60 [1.02, 2.14]1.60+0.01 [-0.47, 0.48]1.99 [1.32, 2.44]38% [21%, 57%]59%79%+0.42+0.422026-08-02 → 2026-08-30
tmin00Znearest30d29 1 QC1.65 [1.12, 2.23]1.61+0.58 [0.18, 1.06]2.06 [1.48, 2.59]38% [20%, 59%]62%86%+0.40+0.422026-08-02 → 2026-08-30
tmin00Znearest90d29 1 QC1.65 [1.02, 2.24]1.61+0.58 [0.16, 1.05]2.06 [1.33, 2.58]38% [23%, 61%]62%86%+0.40+0.422026-08-02 → 2026-08-30
tmin00Znearest365d29 1 QC1.65 [1.00, 2.27]1.61+0.58 [0.13, 1.11]2.06 [1.24, 2.61]38% [21%, 64%]62%86%+0.40+0.422026-08-02 → 2026-08-30
tmin00Znearestall29 1 QC1.65 [1.02, 2.21]1.61+0.58 [0.13, 1.03]2.06 [1.29, 2.57]38% [22%, 62%]62%86%+0.40+0.422026-08-02 → 2026-08-30
tmin12Zbilinear30d29 1 QC1.48 [1.17, 1.85]1.50+0.21 [-0.27, 0.74]1.85 [1.51, 2.16]41% [23%, 59%]66%83%+0.46+0.462026-08-02 → 2026-08-30
tmin12Zbilinear90d29 1 QC1.48 [1.17, 1.84]1.50+0.21 [-0.36, 0.79]1.85 [1.46, 2.14]41% [22%, 60%]66%83%+0.46+0.462026-08-02 → 2026-08-30
tmin12Zbilinear365d29 1 QC1.48 [1.13, 1.86]1.50+0.21 [-0.41, 0.81]1.85 [1.42, 2.19]41% [21%, 62%]66%83%+0.46+0.462026-08-02 → 2026-08-30
tmin12Zbilinearall29 1 QC1.48 [1.15, 1.87]1.50+0.21 [-0.34, 0.71]1.85 [1.44, 2.19]41% [20%, 61%]66%83%+0.46+0.462026-08-02 → 2026-08-30
tmin12Znearest30d29 1 QC1.53 [1.20, 1.89]1.50+0.76 [0.32, 1.30]1.98 [1.55, 2.38]48% [37%, 60%]69%83%+0.45+0.462026-08-02 → 2026-08-30
tmin12Znearest90d29 1 QC1.53 [1.13, 1.87]1.50+0.76 [0.21, 1.32]1.98 [1.44, 2.38]48% [35%, 62%]69%83%+0.45+0.462026-08-02 → 2026-08-30
tmin12Znearest365d29 1 QC1.53 [1.08, 1.92]1.50+0.76 [0.20, 1.34]1.98 [1.40, 2.44]48% [36%, 62%]69%83%+0.45+0.462026-08-02 → 2026-08-30
tmin12Znearestall29 1 QC1.53 [1.12, 1.91]1.50+0.76 [0.23, 1.24]1.98 [1.43, 2.39]48% [35%, 62%]69%83%+0.45+0.462026-08-02 → 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 KPHL, lead day 1, 00Z bilinear tmax+10+50-5-102026-08-02: -4.53 °F2026-08-03: -6.51 °F2026-08-04: -4.92 °F2026-08-05: -2.96 °F2026-08-06: -2.37 °F2026-08-07: -3.31 °F2026-08-08: -0.02 °F2026-08-09: -0.09 °F2026-08-10: +0.85 °F2026-08-11: +1.04 °F2026-08-12: -4.24 °F2026-08-13: -1.37 °F2026-08-14: -2.16 °F2026-08-15: -3.32 °F2026-08-16: -0.12 °F2026-08-17: -1.59 °F2026-08-18: -0.02 °F2026-08-19: -3.38 °F2026-08-20: -3.78 °F2026-08-21: -4.19 °F2026-08-22: -1.44 °F2026-08-23: -2.03 °F2026-08-24: -1.94 °F2026-08-25: -0.5 °F2026-08-26: -2.04 °F2026-08-27: -2.29 °F2026-08-28: -3.05 °F2026-08-29: -1.62 °F2026-08-30: -4.25 °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
2026-08-30-4.25
2026-08-29-1.62
2026-08-28-3.05
2026-08-27-2.29
2026-08-26-2.04
2026-08-25-0.50
2026-08-24-1.94
2026-08-23-2.03
2026-08-22-1.44
2026-08-21-4.19
2026-08-20-3.78
2026-08-19-3.38
2026-08-18-0.02
2026-08-17-1.59
2026-08-16-0.12
2026-08-15-3.32
2026-08-14-2.16
2026-08-13-1.37
2026-08-12-4.24
2026-08-11+1.04
2026-08-10+0.85
2026-08-09-0.09
2026-08-08-0.02
2026-08-07-3.31
2026-08-06-2.37
2026-08-05-2.96
2026-08-04-4.92
2026-08-03-6.51
2026-08-02-4.53

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KPHL, lead day 1-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-6 to -5 °F: 0 days-5 to -4 °F: 5 days-4 to -3 °F: 5 days-3 to -2 °F: 6 days-2 to -1 °F: 5 days-1 to 0 °F: 5 days0 to 1 °F: 1 day1 to 2 °F: 1 day2 to 3 °F: 0 days3 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| 2.16 · P90 |e| 4.31 °F-100+10 °Fn = 29 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
-7.00-6.001
-6.00-5.000
-5.00-4.005
-4.00-3.005
-3.00-2.006
-2.00-1.005
-1.00+0.005
+0.00+1.001
+1.00+2.001
+2.00+3.000
+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
2026-08292.41 -2.28

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29
ECMWF AIFS Single2026-08-02 → 2026-08-30 29

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 -2.26 [-2.26, -2.26] yes
Aurora (IFS init) 2 -1.25 [-1.92, -0.59] yes
FourCastNet v2 (GFS init) 1 -0.47 [-0.47, -0.47] yes
FourCastNet v2 (IFS init) 2 +0.23 [-1.00, 1.45] no
NCEP GFS 29 -0.47 [-1.44, 0.79] no
GraphCast (GFS init) 1 -2.10 [-2.10, -2.10] yes
GraphCast (IFS init) 27 -2.76 [-3.15, -2.42] yes
ECMWF IFS HRES 23 -2.01 [-2.90, -0.66] yes
Pangu-Weather (GFS init) 1 +1.72 [1.72, 1.72] yes
Pangu-Weather (IFS init) 2 +1.27 [0.94, 1.61] yes
Persistence (baseline) 29 -0.80 [-1.71, 0.57] no

Cite this page

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

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