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

Phoenix Sky Harbor · ECMWF IFS HRES · lead day 8

KPHX · ifs_hres · lead 8

Target day = initialization date + 8 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
tmax00Zbilinear30d17 1 QC5.09 [2.92, 7.56]4.57-3.44 [-7.03, 1.02]6.82 [3.70, 9.07]18% [0%, 30%]29%41%+0.01-0.042026-08-09 → 2026-08-30
tmax00Zbilinear90d17 1 QC5.09 [2.82, 8.02]4.57-3.44 [-7.91, 2.04]6.82 [3.64, 9.24]18% [0%, 33%]29%41%+0.01-0.042026-08-09 → 2026-08-30
tmax00Zbilinear365d17 1 QC5.09 [2.84, 8.13]4.57-3.44 [-7.90, 2.06]6.82 [3.58, 9.24]18% [0%, 30%]29%41%+0.01-0.042026-08-09 → 2026-08-30
tmax00Zbilinearall17 1 QC5.09 [2.66, 7.91]4.57-3.44 [-7.79, 2.41]6.82 [3.43, 9.23]18% [0%, 33%]29%41%+0.01-0.042026-08-09 → 2026-08-30
tmax00Znearest30d17 1 QC5.08 [2.99, 7.45]4.53-3.37 [-6.94, 1.09]6.74 [3.71, 8.91]18% [0%, 30%]29%41%+0.01-0.032026-08-09 → 2026-08-30
tmax00Znearest90d17 1 QC5.08 [2.89, 7.91]4.53-3.37 [-7.80, 2.12]6.74 [3.67, 9.09]18% [0%, 33%]29%41%+0.01-0.032026-08-09 → 2026-08-30
tmax00Znearest365d17 1 QC5.08 [2.93, 8.03]4.53-3.37 [-7.79, 2.13]6.74 [3.62, 9.08]18% [0%, 30%]29%41%+0.01-0.032026-08-09 → 2026-08-30
tmax00Znearestall17 1 QC5.08 [2.72, 7.80]4.53-3.37 [-7.70, 2.46]6.74 [3.45, 9.07]18% [0%, 33%]29%41%+0.01-0.032026-08-09 → 2026-08-30
tmax12Zbilinear30d17 1 QC3.78 [2.74, 4.62]3.08-2.18 [-3.87, 0.60]4.26 [2.96, 5.02]0% [0%, 0%]18%47%+0.26+0.302026-08-09 → 2026-08-30
tmax12Zbilinear90d17 1 QC3.78 [2.65, 4.64]3.08-2.18 [-3.84, 1.39]4.26 [2.90, 5.05]0% [0%, 0%]18%47%+0.26+0.302026-08-09 → 2026-08-30
tmax12Zbilinear365d17 1 QC3.78 [2.64, 4.61]3.08-2.18 [-3.80, 1.19]4.26 [2.87, 5.04]0% [0%, 0%]18%47%+0.26+0.302026-08-09 → 2026-08-30
tmax12Zbilinearall17 1 QC3.78 [2.65, 4.66]3.08-2.18 [-3.90, 1.42]4.26 [2.89, 5.07]0% [0%, 0%]18%47%+0.26+0.302026-08-09 → 2026-08-30
tmax12Znearest30d17 1 QC3.75 [2.79, 4.51]3.01-2.04 [-3.70, 0.66]4.14 [3.03, 4.80]0% [0%, 0%]18%41%+0.27+0.312026-08-09 → 2026-08-30
tmax12Znearest90d17 1 QC3.75 [2.72, 4.54]3.01-2.04 [-3.86, 1.42]4.14 [2.99, 4.84]0% [0%, 0%]18%41%+0.27+0.312026-08-09 → 2026-08-30
tmax12Znearest365d17 1 QC3.75 [2.70, 4.49]3.01-2.04 [-3.87, 1.27]4.14 [2.95, 4.85]0% [0%, 0%]18%41%+0.27+0.312026-08-09 → 2026-08-30
tmax12Znearestall17 1 QC3.75 [2.72, 4.55]3.01-2.04 [-3.86, 1.48]4.14 [2.96, 4.86]0% [0%, 0%]18%41%+0.27+0.312026-08-09 → 2026-08-30
tmin00Zbilinear30d17 1 QC3.02 [2.42, 3.97]3.02+0.54 [-0.38, 2.29]3.70 [2.75, 4.65]24% [0%, 39%]41%47%+0.44+0.462026-08-09 → 2026-08-30
tmin00Zbilinear90d17 1 QC3.02 [2.42, 4.00]3.02+0.54 [-0.35, 3.89]3.70 [2.79, 4.65]24% [0%, 40%]41%47%+0.44+0.462026-08-09 → 2026-08-30
tmin00Zbilinear365d17 1 QC3.02 [2.36, 4.00]3.02+0.54 [-0.39, 4.00]3.70 [2.68, 4.70]24% [0%, 42%]41%47%+0.44+0.462026-08-09 → 2026-08-30
tmin00Zbilinearall17 1 QC3.02 [2.33, 4.04]3.02+0.54 [-0.47, 3.91]3.70 [2.65, 4.78]24% [0%, 40%]41%47%+0.44+0.462026-08-09 → 2026-08-30
tmin00Znearest30d17 1 QC3.30 [2.47, 4.45]3.13+1.31 [0.38, 3.04]4.05 [3.01, 5.04]24% [0%, 35%]35%53%+0.38+0.442026-08-09 → 2026-08-30
tmin00Znearest90d17 1 QC3.30 [2.47, 4.67]3.13+1.31 [0.42, 4.64]4.05 [3.01, 5.07]24% [0%, 33%]35%53%+0.38+0.442026-08-09 → 2026-08-30
tmin00Znearest365d17 1 QC3.30 [2.39, 4.67]3.13+1.31 [0.36, 4.67]4.05 [2.93, 5.13]24% [0%, 36%]35%53%+0.38+0.442026-08-09 → 2026-08-30
tmin00Znearestall17 1 QC3.30 [2.39, 4.67]3.13+1.31 [0.26, 4.67]4.05 [2.94, 5.18]24% [0%, 38%]35%53%+0.38+0.442026-08-09 → 2026-08-30
tmin12Zbilinear30d17 1 QC4.26 [3.10, 5.43]4.19+1.12 [-1.18, 3.53]5.65 [3.32, 7.27]18% [0%, 31%]29%35%+0.20+0.252026-08-09 → 2026-08-30
tmin12Zbilinear90d17 1 QC4.26 [3.04, 5.51]4.19+1.12 [-1.31, 3.76]5.65 [3.04, 7.33]18% [0%, 31%]29%35%+0.20+0.252026-08-09 → 2026-08-30
tmin12Zbilinear365d17 1 QC4.26 [3.00, 5.63]4.19+1.12 [-1.31, 3.82]5.65 [3.04, 7.46]18% [0%, 33%]29%35%+0.20+0.252026-08-09 → 2026-08-30
tmin12Zbilinearall17 1 QC4.26 [3.04, 5.51]4.19+1.12 [-1.45, 3.77]5.65 [3.04, 7.30]18% [0%, 33%]29%35%+0.20+0.252026-08-09 → 2026-08-30
tmin12Znearest30d17 1 QC4.47 [3.35, 5.68]4.29+1.79 [-0.43, 4.48]5.77 [3.70, 7.40]18% [0%, 31%]24%41%+0.16+0.232026-08-09 → 2026-08-30
tmin12Znearest90d17 1 QC4.47 [3.33, 5.80]4.29+1.79 [-0.56, 4.55]5.77 [3.68, 7.55]18% [0%, 31%]24%41%+0.16+0.232026-08-09 → 2026-08-30
tmin12Znearest365d17 1 QC4.47 [3.29, 5.90]4.29+1.79 [-0.55, 4.55]5.77 [3.64, 7.55]18% [0%, 33%]24%41%+0.16+0.232026-08-09 → 2026-08-30
tmin12Znearestall17 1 QC4.47 [3.31, 5.87]4.29+1.79 [-0.77, 4.55]5.77 [3.69, 7.51]18% [0%, 33%]24%41%+0.16+0.232026-08-09 → 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 8, 00Z bilinear tmax+20+100-10-202026-08-09: -8.97 °F2026-08-15: +0.79 °F2026-08-16: -1.07 °F2026-08-17: -3.3 °F2026-08-18: -5.33 °F2026-08-19: -14.55 °F2026-08-20: -16.23 °F2026-08-21: -8.18 °F2026-08-22: -4.73 °F2026-08-23: -1.92 °F2026-08-24: +0.36 °F2026-08-25: -4.95 °F2026-08-26: -3.22 °F2026-08-27: +0.51 °F2026-08-28: +2.77 °F2026-08-29: +2.25 °F2026-08-30: +7.35 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+7.35
2026-08-29+2.25
2026-08-28+2.77
2026-08-27+0.51
2026-08-26-3.22
2026-08-25-4.95
2026-08-24+0.36
2026-08-23-1.92
2026-08-22-4.73
2026-08-21-8.18
2026-08-20-16.23
2026-08-19-14.55
2026-08-18-5.33
2026-08-17-3.30
2026-08-16-1.07
2026-08-15+0.79
2026-08-14—
2026-08-13—
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09-8.97

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KPHX, lead day 8-20 to -18 °F: 0 days-18 to -16 °F: 1 day-16 to -14 °F: 1 day-14 to -12 °F: 0 days-12 to -10 °F: 0 days-10 to -8 °F: 2 days-8 to -6 °F: 0 days-6 to -4 °F: 3 days-4 to -2 °F: 2 days-2 to 0 °F: 2 days0 to 2 °F: 3 days2 to 4 °F: 2 days4 to 6 °F: 0 days6 to 8 °F: 1 day8 to 10 °F: 0 days10 to 12 °F: 0 days12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 3.3 · P90 |e| 11.2 °F-200+20 °Fn = 17 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
-20.00-18.000
-18.00-16.001
-16.00-14.001
-14.00-12.000
-12.00-10.000
-10.00-8.002
-8.00-6.000
-6.00-4.003
-4.00-2.002
-2.00+0.002
+0.00+2.003
+2.00+4.002
+4.00+6.000
+6.00+8.001
+8.00+10.000
+10.00+12.000
+12.00+14.000
+14.00+16.000
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08175.09 -3.44

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17
ECMWF IFS HRES2026-08-09 → 2026-08-30 17

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 17 -1.08 [-5.99, 3.88] no
NCEP GFS 17 -0.29 [-2.57, 2.29] no
GraphCast (IFS init) 17 -4.93 [-8.65, -0.26] yes
Persistence (baseline) 17 -0.03 [-1.87, 2.22] no

Cite this page

ShortCastCheck, KPHX ifs_hres lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KPHX/model/ifs_hres/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KPHX (Phoenix Sky Harbor), model ifs_hres, lead day 8. 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/8/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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