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

Phoenix Sky Harbor · ECMWF IFS HRES · lead day 4

KPHX · 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 QC2.84 [2.35, 3.30]1.80-2.52 [-3.18, -1.83]3.31 [2.80, 3.81]20% [8%, 32%]40%60%+0.51+0.692026-08-05 → 2026-08-30
tmax00Zbilinear90d20 1 QC2.84 [2.22, 3.50]1.80-2.52 [-3.43, -1.59]3.31 [2.60, 4.05]20% [0%, 31%]40%60%+0.51+0.692026-08-05 → 2026-08-30
tmax00Zbilinear365d20 1 QC2.84 [2.19, 3.61]1.80-2.52 [-3.52, -1.55]3.31 [2.54, 4.10]20% [0%, 32%]40%60%+0.51+0.692026-08-05 → 2026-08-30
tmax00Zbilinearall20 1 QC2.84 [2.11, 3.57]1.80-2.52 [-3.48, -1.52]3.31 [2.52, 4.10]20% [0%, 31%]40%60%+0.51+0.692026-08-05 → 2026-08-30
tmax00Znearest30d20 1 QC2.70 [2.28, 3.18]1.81-2.33 [-3.00, -1.74]3.17 [2.72, 3.75]20% [8%, 32%]45%60%+0.53+0.692026-08-05 → 2026-08-30
tmax00Znearest90d20 1 QC2.70 [2.16, 3.37]1.81-2.33 [-3.19, -1.56]3.17 [2.47, 3.96]20% [0%, 31%]45%60%+0.53+0.692026-08-05 → 2026-08-30
tmax00Znearest365d20 1 QC2.70 [2.16, 3.47]1.81-2.33 [-3.23, -1.55]3.17 [2.47, 4.05]20% [0%, 32%]45%60%+0.53+0.692026-08-05 → 2026-08-30
tmax00Znearestall20 1 QC2.70 [2.10, 3.46]1.81-2.33 [-3.31, -1.55]3.17 [2.44, 4.11]20% [0%, 31%]45%60%+0.53+0.692026-08-05 → 2026-08-30
tmax12Zbilinear30d21 1 QC3.17 [2.42, 4.18]1.53-3.12 [-4.13, -2.39]3.69 [2.69, 4.63]14% [0%, 25%]24%52%+0.44+0.732026-08-05 → 2026-08-30
tmax12Zbilinear90d21 1 QC3.17 [2.34, 4.39]1.53-3.12 [-4.34, -2.30]3.69 [2.59, 4.80]14% [0%, 25%]24%52%+0.44+0.732026-08-05 → 2026-08-30
tmax12Zbilinear365d21 1 QC3.17 [2.30, 4.44]1.53-3.12 [-4.43, -2.25]3.69 [2.56, 4.89]14% [0%, 25%]24%52%+0.44+0.732026-08-05 → 2026-08-30
tmax12Zbilinearall21 1 QC3.17 [2.34, 4.51]1.53-3.12 [-4.47, -2.29]3.69 [2.56, 4.92]14% [0%, 26%]24%52%+0.44+0.732026-08-05 → 2026-08-30
tmax12Znearest30d21 1 QC3.14 [2.40, 4.10]1.50-3.03 [-4.04, -2.32]3.63 [2.66, 4.57]14% [0%, 25%]29%52%+0.44+0.742026-08-05 → 2026-08-30
tmax12Znearest90d21 1 QC3.14 [2.33, 4.29]1.50-3.03 [-4.25, -2.23]3.63 [2.59, 4.71]14% [0%, 25%]29%52%+0.44+0.742026-08-05 → 2026-08-30
tmax12Znearest365d21 1 QC3.14 [2.32, 4.41]1.50-3.03 [-4.34, -2.20]3.63 [2.57, 4.81]14% [0%, 25%]29%52%+0.44+0.742026-08-05 → 2026-08-30
tmax12Znearestall21 1 QC3.14 [2.35, 4.44]1.50-3.03 [-4.42, -2.24]3.63 [2.58, 4.81]14% [0%, 26%]29%52%+0.44+0.742026-08-05 → 2026-08-30
tmin00Zbilinear30d20 1 QC3.71 [2.49, 4.87]3.72+1.41 [-0.86, 3.47]4.84 [2.99, 6.23]20% [8%, 30%]40%55%+0.39+0.392026-08-05 → 2026-08-30
tmin00Zbilinear90d20 1 QC3.71 [2.29, 4.92]3.72+1.41 [-1.21, 3.76]4.84 [2.72, 6.26]20% [0%, 29%]40%55%+0.39+0.392026-08-05 → 2026-08-30
tmin00Zbilinear365d20 1 QC3.71 [2.35, 4.91]3.72+1.41 [-1.27, 3.73]4.84 [2.75, 6.26]20% [0%, 30%]40%55%+0.39+0.392026-08-05 → 2026-08-30
tmin00Zbilinearall20 1 QC3.71 [2.29, 4.86]3.72+1.41 [-1.42, 3.84]4.84 [2.72, 6.24]20% [0%, 31%]40%55%+0.39+0.392026-08-05 → 2026-08-30
tmin00Znearest30d20 1 QC3.78 [2.45, 5.07]3.66+2.21 [-0.12, 4.25]5.01 [3.09, 6.41]30% [17%, 50%]35%60%+0.38+0.402026-08-05 → 2026-08-30
tmin00Znearest90d20 1 QC3.78 [2.22, 5.14]3.66+2.21 [-0.76, 4.50]5.01 [2.63, 6.50]30% [14%, 60%]35%60%+0.38+0.402026-08-05 → 2026-08-30
tmin00Znearest365d20 1 QC3.78 [2.20, 5.12]3.66+2.21 [-0.81, 4.45]5.01 [2.67, 6.49]30% [14%, 60%]35%60%+0.38+0.402026-08-05 → 2026-08-30
tmin00Znearestall20 1 QC3.78 [2.19, 5.15]3.66+2.21 [-0.81, 4.53]5.01 [2.62, 6.45]30% [13%, 57%]35%60%+0.38+0.402026-08-05 → 2026-08-30
tmin12Zbilinear30d21 1 QC3.34 [2.40, 4.31]3.39+0.88 [-1.09, 2.87]4.44 [2.80, 5.92]24% [8%, 42%]38%57%+0.43+0.432026-08-05 → 2026-08-30
tmin12Zbilinear90d21 1 QC3.34 [2.26, 4.37]3.39+0.88 [-1.38, 3.12]4.44 [2.68, 5.99]24% [7%, 50%]38%57%+0.43+0.432026-08-05 → 2026-08-30
tmin12Zbilinear365d21 1 QC3.34 [2.24, 4.37]3.39+0.88 [-1.46, 3.24]4.44 [2.68, 5.94]24% [0%, 50%]38%57%+0.43+0.432026-08-05 → 2026-08-30
tmin12Zbilinearall21 1 QC3.34 [2.22, 4.45]3.39+0.88 [-1.53, 3.30]4.44 [2.64, 5.94]24% [6%, 50%]38%57%+0.43+0.432026-08-05 → 2026-08-30
tmin12Znearest30d21 1 QC3.36 [2.20, 4.51]3.36+1.58 [-0.36, 3.56]4.64 [2.75, 6.22]29% [12%, 48%]38%57%+0.43+0.432026-08-05 → 2026-08-30
tmin12Znearest90d21 1 QC3.36 [1.96, 4.61]3.36+1.58 [-0.58, 3.77]4.64 [2.47, 6.40]29% [9%, 56%]38%57%+0.43+0.432026-08-05 → 2026-08-30
tmin12Znearest365d21 1 QC3.36 [2.09, 4.58]3.36+1.58 [-0.61, 3.86]4.64 [2.55, 6.31]29% [8%, 55%]38%57%+0.43+0.432026-08-05 → 2026-08-30
tmin12Znearestall21 1 QC3.36 [1.99, 4.63]3.36+1.58 [-0.66, 3.93]4.64 [2.46, 6.36]29% [9%, 50%]38%57%+0.43+0.432026-08-05 → 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 KPHX, lead day 4, 00Z bilinear tmax+10+50-5-102026-08-05: -1.36 °F2026-08-11: -2.75 °F2026-08-12: -2.96 °F2026-08-13: -4.72 °F2026-08-14: +0.4 °F2026-08-16: -4.66 °F2026-08-17: -1.34 °F2026-08-18: -4 °F2026-08-19: -4.3 °F2026-08-20: -2.4 °F2026-08-21: -0.91 °F2026-08-22: -4.73 °F2026-08-23: -3.75 °F2026-08-24: +1.93 °F2026-08-25: -1.86 °F2026-08-26: -2.15 °F2026-08-27: +0.8 °F2026-08-28: -0.33 °F2026-08-29: -5.51 °F2026-08-30: -5.86 °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
2026-08-30-5.86
2026-08-29-5.51
2026-08-28-0.33
2026-08-27+0.80
2026-08-26-2.15
2026-08-25-1.86
2026-08-24+1.93
2026-08-23-3.75
2026-08-22-4.73
2026-08-21-0.91
2026-08-20-2.40
2026-08-19-4.30
2026-08-18-4.00
2026-08-17-1.34
2026-08-16-4.66
2026-08-15—
2026-08-14+0.40
2026-08-13-4.72
2026-08-12-2.96
2026-08-11-2.75
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05-1.36

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KPHX, lead day 4-10 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: 2 days-5 to -4 °F: 4 days-4 to -3 °F: 2 days-3 to -2 °F: 4 days-2 to -1 °F: 3 days-1 to 0 °F: 2 days0 to 1 °F: 2 days1 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| 2.58 · P90 |e| 4.81 °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
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.002
-5.00-4.004
-4.00-3.002
-3.00-2.004
-2.00-1.003
-1.00+0.002
+0.00+1.002
+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
2026-08202.84 -2.52

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 -1.17 [-3.77, 0.84] no
NCEP GFS 20 -0.79 [-1.96, 0.34] no
GraphCast (IFS init) 19 -1.69 [-3.24, 0.28] no
Persistence (baseline) 20 -2.91 [-7.03, -0.43] yes

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KPHX (Phoenix Sky Harbor), 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/KPHX/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