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

Phoenix Sky Harbor · ECMWF AIFS Single · lead day 0

KPHX · aifs_single · lead 0

Target day = initialization date + 0 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
tmax00Zbilinear30d30 1 QC3.09 [2.34, 4.00]1.90-2.84 [-3.82, -1.94]3.91 [2.67, 5.18]10% [3%, 17%]40%67%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d30 1 QC3.09 [2.22, 4.59]1.90-2.84 [-4.46, -1.68]3.91 [2.50, 5.82]10% [0%, 19%]40%67%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d30 1 QC3.09 [2.20, 4.84]1.90-2.84 [-4.73, -1.68]3.91 [2.49, 6.14]10% [0%, 19%]40%67%——2026-08-01 → 2026-08-30
tmax00Zbilinearall30 1 QC3.09 [2.31, 4.66]1.90-2.84 [-4.57, -1.78]3.91 [2.62, 5.97]10% [0%, 19%]40%67%——2026-08-01 → 2026-08-30
tmax00Znearest30d30 1 QC3.06 [2.29, 4.02]1.91-2.83 [-3.85, -1.93]3.91 [2.64, 5.23]13% [3%, 23%]43%67%——2026-08-01 → 2026-08-30
tmax00Znearest90d30 1 QC3.06 [2.17, 4.62]1.91-2.83 [-4.48, -1.68]3.91 [2.47, 5.87]13% [0%, 26%]43%67%——2026-08-01 → 2026-08-30
tmax00Znearest365d30 1 QC3.06 [2.15, 4.87]1.91-2.83 [-4.76, -1.67]3.91 [2.48, 6.19]13% [0%, 25%]43%67%——2026-08-01 → 2026-08-30
tmax00Znearestall30 1 QC3.06 [2.25, 4.66]1.91-2.83 [-4.58, -1.77]3.91 [2.58, 6.06]13% [0%, 25%]43%67%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d30 1 QC3.73 [2.82, 4.88]2.97-2.29 [-3.39, -1.10]4.37 [3.46, 5.37]20% [7%, 33%]33%40%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d30 1 QC3.73 [2.76, 4.96]2.97-2.29 [-3.59, -1.13]4.37 [3.31, 5.42]20% [5%, 32%]33%40%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d30 1 QC3.73 [2.73, 4.99]2.97-2.29 [-3.73, -1.11]4.37 [3.32, 5.42]20% [4%, 33%]33%40%——2026-08-01 → 2026-08-30
tmin00Zbilinearall30 1 QC3.73 [2.75, 4.97]2.97-2.29 [-3.64, -0.96]4.37 [3.32, 5.44]20% [3%, 33%]33%40%——2026-08-01 → 2026-08-30
tmin00Znearest30d30 1 QC3.78 [2.84, 4.97]3.01-2.34 [-3.47, -1.13]4.42 [3.48, 5.45]20% [7%, 33%]33%40%——2026-08-01 → 2026-08-30
tmin00Znearest90d30 1 QC3.78 [2.79, 5.03]3.01-2.34 [-3.66, -1.16]4.42 [3.32, 5.48]20% [5%, 32%]33%40%——2026-08-01 → 2026-08-30
tmin00Znearest365d30 1 QC3.78 [2.75, 5.08]3.01-2.34 [-3.77, -1.12]4.42 [3.32, 5.51]20% [4%, 33%]33%40%——2026-08-01 → 2026-08-30
tmin00Znearestall30 1 QC3.78 [2.77, 5.06]3.01-2.34 [-3.72, -0.96]4.42 [3.31, 5.52]20% [3%, 33%]33%40%——2026-08-01 → 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 KPHX, lead day 0, 00Z bilinear tmax+20+100-10-202026-08-01: -1.06 °F2026-08-02: -2.77 °F2026-08-03: -4.19 °F2026-08-04: +1.96 °F2026-08-05: +0.6 °F2026-08-06: -3.27 °F2026-08-07: -2.35 °F2026-08-08: -2.89 °F2026-08-09: -1.66 °F2026-08-10: -0.9 °F2026-08-11: -1.03 °F2026-08-12: -5.58 °F2026-08-13: -5.89 °F2026-08-14: -3.98 °F2026-08-15: -2.21 °F2026-08-16: -1.67 °F2026-08-17: -1.48 °F2026-08-18: -2.65 °F2026-08-19: -1.66 °F2026-08-20: +1.2 °F2026-08-21: -2.22 °F2026-08-22: -3.93 °F2026-08-23: -5.49 °F2026-08-24: -0.56 °F2026-08-25: -2.53 °F2026-08-26: -2.96 °F2026-08-27: -1.61 °F2026-08-28: -4.86 °F2026-08-29: -7.24 °F2026-08-30: -12.28 °F2026-08-012026-08-30°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 (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-12.28
2026-08-29-7.24
2026-08-28-4.86
2026-08-27-1.61
2026-08-26-2.96
2026-08-25-2.53
2026-08-24-0.56
2026-08-23-5.49
2026-08-22-3.93
2026-08-21-2.22
2026-08-20+1.20
2026-08-19-1.66
2026-08-18-2.65
2026-08-17-1.48
2026-08-16-1.67
2026-08-15-2.21
2026-08-14-3.98
2026-08-13-5.89
2026-08-12-5.58
2026-08-11-1.03
2026-08-10-0.90
2026-08-09-1.66
2026-08-08-2.89
2026-08-07-2.35
2026-08-06-3.27
2026-08-05+0.60
2026-08-04+1.96
2026-08-03-4.19
2026-08-02-2.77
2026-08-01-1.06

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KPHX, lead day 0-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 0 days-8 to -6 °F: 1 day-6 to -4 °F: 5 days-4 to -2 °F: 11 days-2 to 0 °F: 9 days0 to 2 °F: 3 days2 to 4 °F: 0 days4 to 6 °F: 0 days6 to 8 °F: 0 days8 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| 2.44 · P90 |e| 5.61 °F-200+20 °Fn = 30 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
-18.00-16.000
-16.00-14.000
-14.00-12.001
-12.00-10.000
-10.00-8.000
-8.00-6.001
-6.00-4.005
-4.00-2.0011
-2.00+0.009
+0.00+2.003
+2.00+4.000
+4.00+6.000
+6.00+8.000
+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
2026-08303.09 -2.84

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-01 → 2026-08-30 30
ECMWF AIFS Single2026-08-01 → 2026-08-30 30

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) 2 -3.68 [-6.94, -0.42] yes
Aurora (IFS init) 3 +2.42 [1.28, 4.68] yes
FourCastNet v2 (GFS init) 2 -0.81 [-3.53, 1.92] no
FourCastNet v2 (IFS init) 3 +0.18 [-0.71, 1.97] no
NCEP GFS 30 +0.13 [-0.77, 1.01] no
GraphCast (GFS init) 2 -5.13 [-7.26, -3.00] yes
GraphCast (IFS init) 28 +0.26 [-0.39, 1.19] no
ECMWF IFS HRES 25 +1.14 [0.54, 1.72] yes
Pangu-Weather (GFS init) 2 +1.01 [-1.45, 3.47] no
Pangu-Weather (IFS init) 3 +2.03 [0.22, 5.65] yes

Cite this page

ShortCastCheck, KPHX aifs_single lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KPHX/model/aifs_single/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KPHX (Phoenix Sky Harbor), model aifs_single, lead day 0. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KPHX/model/aifs_single/lead/0/

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

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