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

Philadelphia Intl · ECMWF IFS HRES · lead day 4

KPHL · ifs_hres · lead 4

Target day = initialization date + 4 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, ifs-gpid161, 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
tmax00Zbilinear30d20 1 QC3.48 [2.57, 3.97]2.79-2.16 [-3.50, -0.19]4.20 [3.13, 4.74]15% [5%, 25%]35%50%+0.05+0.142026-08-05 → 2026-08-30
tmax00Zbilinear90d20 1 QC3.48 [2.00, 3.95]2.79-2.16 [-3.52, 0.57]4.20 [2.16, 4.71]15% [0%, 25%]35%50%+0.05+0.142026-08-05 → 2026-08-30
tmax00Zbilinear365d20 1 QC3.48 [2.02, 3.97]2.79-2.16 [-3.57, 0.28]4.20 [2.08, 4.74]15% [0%, 25%]35%50%+0.05+0.142026-08-05 → 2026-08-30
tmax00Zbilinearall20 1 QC3.48 [1.57, 3.93]2.79-2.16 [-3.61, 0.65]4.20 [1.57, 4.71]15% [0%, 25%]35%50%+0.05+0.142026-08-05 → 2026-08-30
tmax00Znearest30d20 1 QC3.38 [2.48, 3.89]2.51-2.04 [-3.19, -0.18]4.03 [2.94, 4.62]5% [0%, 18%]45%60%+0.07+0.232026-08-05 → 2026-08-30
tmax00Znearest90d20 1 QC3.38 [2.01, 3.89]2.51-2.04 [-3.22, 0.63]4.03 [2.31, 4.60]5% [0%, 22%]45%60%+0.07+0.232026-08-05 → 2026-08-30
tmax00Znearest365d20 1 QC3.38 [1.99, 3.93]2.51-2.04 [-3.25, 0.60]4.03 [2.16, 4.69]5% [0%, 23%]45%60%+0.07+0.232026-08-05 → 2026-08-30
tmax00Znearestall20 1 QC3.38 [1.71, 3.92]2.51-2.04 [-3.34, 0.87]4.03 [1.71, 4.60]5% [0%, 25%]45%60%+0.07+0.232026-08-05 → 2026-08-30
tmax12Zbilinear30d21 1 QC3.32 [2.00, 4.58]2.41-2.86 [-3.96, -1.41]4.19 [2.61, 5.54]19% [8%, 38%]29%57%+0.07+0.262026-08-05 → 2026-08-30
tmax12Zbilinear90d21 1 QC3.32 [1.51, 4.46]2.41-2.86 [-4.06, -0.79]4.19 [2.04, 5.52]19% [7%, 45%]29%57%+0.07+0.262026-08-05 → 2026-08-30
tmax12Zbilinear365d21 1 QC3.32 [1.74, 4.67]2.41-2.86 [-4.13, -0.99]4.19 [2.08, 5.62]19% [6%, 44%]29%57%+0.07+0.262026-08-05 → 2026-08-30
tmax12Zbilinearall21 1 QC3.32 [1.31, 4.57]2.41-2.86 [-4.02, -0.59]4.19 [1.57, 5.57]19% [6%, 42%]29%57%+0.07+0.262026-08-05 → 2026-08-30
tmax12Znearest30d21 1 QC3.48 [2.35, 4.55]2.57-2.67 [-3.97, -1.01]4.20 [2.75, 5.41]14% [4%, 33%]24%48%+0.02+0.212026-08-05 → 2026-08-30
tmax12Znearest90d21 1 QC3.48 [2.15, 4.58]2.57-2.67 [-4.00, -0.45]4.20 [2.51, 5.43]14% [4%, 43%]24%48%+0.02+0.212026-08-05 → 2026-08-30
tmax12Znearest365d21 1 QC3.48 [2.17, 4.73]2.57-2.67 [-4.15, -0.53]4.20 [2.33, 5.52]14% [0%, 40%]24%48%+0.02+0.212026-08-05 → 2026-08-30
tmax12Znearestall21 1 QC3.48 [1.81, 4.64]2.57-2.67 [-4.03, -0.13]4.20 [1.99, 5.47]14% [0%, 40%]24%48%+0.02+0.212026-08-05 → 2026-08-30
tmin00Zbilinear30d20 1 QC2.52 [1.93, 3.05]2.52+0.50 [-0.63, 1.50]2.86 [2.30, 3.27]10% [0%, 31%]35%75%+0.13+0.152026-08-05 → 2026-08-30
tmin00Zbilinear90d20 1 QC2.52 [1.72, 3.08]2.52+0.50 [-0.74, 1.62]2.86 [2.13, 3.28]10% [0%, 43%]35%75%+0.13+0.152026-08-05 → 2026-08-30
tmin00Zbilinear365d20 1 QC2.52 [1.68, 3.12]2.52+0.50 [-0.82, 1.60]2.86 [2.01, 3.31]10% [0%, 40%]35%75%+0.13+0.152026-08-05 → 2026-08-30
tmin00Zbilinearall20 1 QC2.52 [1.66, 3.11]2.52+0.50 [-0.75, 1.57]2.86 [2.02, 3.30]10% [0%, 40%]35%75%+0.13+0.152026-08-05 → 2026-08-30
tmin00Znearest30d20 1 QC2.65 [2.02, 3.20]2.65+0.42 [-0.75, 1.43]2.96 [2.38, 3.36]10% [0%, 31%]35%65%+0.09+0.112026-08-05 → 2026-08-30
tmin00Znearest90d20 1 QC2.65 [1.81, 3.21]2.65+0.42 [-0.84, 1.54]2.96 [2.20, 3.36]10% [0%, 43%]35%65%+0.09+0.112026-08-05 → 2026-08-30
tmin00Znearest365d20 1 QC2.65 [1.71, 3.26]2.65+0.42 [-0.94, 1.52]2.96 [2.11, 3.42]10% [0%, 40%]35%65%+0.09+0.112026-08-05 → 2026-08-30
tmin00Znearestall20 1 QC2.65 [1.74, 3.24]2.65+0.42 [-0.88, 1.63]2.96 [2.08, 3.40]10% [0%, 40%]35%65%+0.09+0.112026-08-05 → 2026-08-30
tmin12Zbilinear30d21 1 QC3.48 [2.59, 4.44]3.44-0.32 [-2.16, 0.93]3.82 [2.95, 4.63]5% [0%, 12%]24%43%-0.22-0.202026-08-05 → 2026-08-30
tmin12Zbilinear90d21 1 QC3.48 [2.55, 4.64]3.44-0.32 [-2.71, 1.33]3.82 [2.94, 4.81]5% [0%, 12%]24%43%-0.22-0.202026-08-05 → 2026-08-30
tmin12Zbilinear365d21 1 QC3.48 [2.50, 4.71]3.44-0.32 [-2.97, 1.37]3.82 [2.92, 4.81]5% [0%, 13%]24%43%-0.22-0.202026-08-05 → 2026-08-30
tmin12Zbilinearall21 1 QC3.48 [2.56, 4.74]3.44-0.32 [-2.92, 1.33]3.82 [2.95, 4.83]5% [0%, 13%]24%43%-0.22-0.202026-08-05 → 2026-08-30
tmin12Znearest30d21 1 QC3.57 [2.84, 4.48]3.52-0.35 [-2.03, 0.85]3.91 [3.15, 4.72]0% [0%, 0%]14%52%-0.25-0.232026-08-05 → 2026-08-30
tmin12Znearest90d21 1 QC3.57 [2.83, 4.72]3.52-0.35 [-2.53, 1.23]3.91 [3.13, 4.95]0% [0%, 0%]14%52%-0.25-0.232026-08-05 → 2026-08-30
tmin12Znearest365d21 1 QC3.57 [2.82, 4.79]3.52-0.35 [-2.93, 1.31]3.91 [3.12, 4.97]0% [0%, 0%]14%52%-0.25-0.232026-08-05 → 2026-08-30
tmin12Znearestall21 1 QC3.57 [2.85, 4.81]3.52-0.35 [-2.75, 1.22]3.91 [3.15, 5.01]0% [0%, 0%]14%52%-0.25-0.232026-08-05 → 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 IFS HRES at KPHL, lead day 4, 00Z bilinear tmax+10+50-5-102026-08-05: +1.57 °F2026-08-11: +2.5 °F2026-08-12: -3.09 °F2026-08-13: -4.95 °F2026-08-14: -0.8 °F2026-08-16: +7.74 °F2026-08-17: -2.37 °F2026-08-18: -2.73 °F2026-08-19: -0.45 °F2026-08-20: -8.83 °F2026-08-21: -1.86 °F2026-08-22: -3.97 °F2026-08-23: -4.71 °F2026-08-24: -5.46 °F2026-08-25: -0.64 °F2026-08-26: -4.38 °F2026-08-27: -4.95 °F2026-08-28: -6.25 °F2026-08-29: +1.4 °F2026-08-30: -1.01 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-1.01
2026-08-29+1.40
2026-08-28-6.25
2026-08-27-4.95
2026-08-26-4.38
2026-08-25-0.64
2026-08-24-5.46
2026-08-23-4.71
2026-08-22-3.97
2026-08-21-1.86
2026-08-20-8.83
2026-08-19-0.45
2026-08-18-2.73
2026-08-17-2.37
2026-08-16+7.74
2026-08-15—
2026-08-14-0.80
2026-08-13-4.95
2026-08-12-3.09
2026-08-11+2.50
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05+1.57

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KPHL, lead day 4-10 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: 1 day-5 to -4 °F: 4 days-4 to -3 °F: 2 days-3 to -2 °F: 2 days-2 to -1 °F: 2 days-1 to 0 °F: 3 days0 to 1 °F: 0 days1 to 2 °F: 2 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: 1 day8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2.91 · P90 |e| 6.4 °F-100+10 °Fn = 20 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
-6.00-5.001
-5.00-4.004
-4.00-3.002
-3.00-2.002
-2.00-1.002
-1.00+0.003
+0.00+1.000
+1.00+2.002
+2.00+3.001
+3.00+4.000
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.001
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08203.48 -2.16

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 21
ECMWF IFS HRES2026-08-05 → 2026-08-30 21

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF IFS HRES has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 20 +0.73 [-1.09, 1.43] no
NCEP GFS 20 -0.41 [-1.80, 0.83] no
GraphCast (IFS init) 19 -0.33 [-1.11, 0.82] no
Persistence (baseline) 20 -0.17 [-1.73, 0.49] no

Cite this page

ShortCastCheck, KPHL ifs_hres lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KPHL/model/ifs_hres/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KPHL (Philadelphia Intl), model ifs_hres, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KPHL/model/ifs_hres/lead/4/

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