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

Phoenix Sky Harbor · ECMWF AIFS Single · lead day 1

KPHX · 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 QC3.15 [2.36, 4.00]2.08-2.90 [-3.82, -1.95]3.96 [2.88, 4.99]14% [7%, 23%]45%62%+0.01+0.342026-08-02 → 2026-08-30
tmax00Zbilinear90d29 1 QC3.15 [2.27, 4.40]2.08-2.90 [-4.34, -1.74]3.96 [2.69, 5.41]14% [5%, 22%]45%62%+0.01+0.342026-08-02 → 2026-08-30
tmax00Zbilinear365d29 1 QC3.15 [2.20, 4.63]2.08-2.90 [-4.50, -1.69]3.96 [2.63, 5.65]14% [4%, 24%]45%62%+0.01+0.342026-08-02 → 2026-08-30
tmax00Zbilinearall29 1 QC3.15 [2.29, 4.44]2.08-2.90 [-4.33, -1.77]3.96 [2.72, 5.44]14% [4%, 22%]45%62%+0.01+0.342026-08-02 → 2026-08-30
tmax00Znearest30d29 1 QC3.11 [2.32, 3.96]2.06-2.89 [-3.81, -1.96]3.93 [2.85, 4.98]10% [3%, 17%]45%62%+0.02+0.352026-08-02 → 2026-08-30
tmax00Znearest90d29 1 QC3.11 [2.24, 4.37]2.06-2.89 [-4.34, -1.76]3.93 [2.67, 5.40]10% [3%, 17%]45%62%+0.02+0.352026-08-02 → 2026-08-30
tmax00Znearest365d29 1 QC3.11 [2.17, 4.61]2.06-2.89 [-4.51, -1.72]3.93 [2.59, 5.63]10% [0%, 17%]45%62%+0.02+0.352026-08-02 → 2026-08-30
tmax00Znearestall29 1 QC3.11 [2.27, 4.41]2.06-2.89 [-4.30, -1.81]3.93 [2.71, 5.44]10% [0%, 17%]45%62%+0.02+0.352026-08-02 → 2026-08-30
tmax12Zbilinear30d29 1 QC3.07 [2.31, 3.93]2.07-2.79 [-3.80, -1.79]3.90 [2.78, 4.92]17% [7%, 27%]45%66%+0.03+0.352026-08-02 → 2026-08-30
tmax12Zbilinear90d29 1 QC3.07 [2.20, 4.29]2.07-2.79 [-4.27, -1.60]3.90 [2.51, 5.34]17% [7%, 27%]45%66%+0.03+0.352026-08-02 → 2026-08-30
tmax12Zbilinear365d29 1 QC3.07 [2.16, 4.59]2.07-2.79 [-4.52, -1.58]3.90 [2.46, 5.62]17% [6%, 29%]45%66%+0.03+0.352026-08-02 → 2026-08-30
tmax12Zbilinearall29 1 QC3.07 [2.27, 4.40]2.07-2.79 [-4.28, -1.69]3.90 [2.58, 5.44]17% [6%, 29%]45%66%+0.03+0.352026-08-02 → 2026-08-30
tmax12Znearest30d29 1 QC3.03 [2.26, 3.91]2.05-2.76 [-3.78, -1.79]3.87 [2.75, 4.91]21% [10%, 31%]45%66%+0.05+0.352026-08-02 → 2026-08-30
tmax12Znearest90d29 1 QC3.03 [2.16, 4.24]2.05-2.76 [-4.24, -1.59]3.87 [2.47, 5.33]21% [9%, 32%]45%66%+0.05+0.352026-08-02 → 2026-08-30
tmax12Znearest365d29 1 QC3.03 [2.11, 4.56]2.05-2.76 [-4.49, -1.59]3.87 [2.44, 5.59]21% [7%, 32%]45%66%+0.05+0.352026-08-02 → 2026-08-30
tmax12Znearestall29 1 QC3.03 [2.23, 4.37]2.05-2.76 [-4.26, -1.70]3.87 [2.57, 5.42]21% [7%, 31%]45%66%+0.05+0.352026-08-02 → 2026-08-30
tmin00Zbilinear30d29 1 QC3.54 [2.52, 4.91]2.95-1.97 [-3.21, -0.63]4.29 [3.14, 5.51]14% [4%, 23%]34%45%-0.09+0.092026-08-02 → 2026-08-30
tmin00Zbilinear90d29 1 QC3.54 [2.34, 4.98]2.95-1.97 [-3.39, -0.57]4.29 [2.88, 5.57]14% [2%, 23%]34%45%-0.09+0.092026-08-02 → 2026-08-30
tmin00Zbilinear365d29 1 QC3.54 [2.29, 5.00]2.95-1.97 [-3.58, -0.49]4.29 [2.89, 5.55]14% [0%, 24%]34%45%-0.09+0.092026-08-02 → 2026-08-30
tmin00Zbilinearall29 1 QC3.54 [2.31, 4.89]2.95-1.97 [-3.62, -0.51]4.29 [2.82, 5.55]14% [0%, 25%]34%45%-0.09+0.092026-08-02 → 2026-08-30
tmin00Znearest30d29 1 QC3.61 [2.57, 4.99]3.02-2.04 [-3.32, -0.68]4.37 [3.20, 5.60]14% [4%, 23%]34%45%-0.11+0.072026-08-02 → 2026-08-30
tmin00Znearest90d29 1 QC3.61 [2.36, 5.10]3.02-2.04 [-3.48, -0.60]4.37 [2.90, 5.67]14% [2%, 23%]34%45%-0.11+0.072026-08-02 → 2026-08-30
tmin00Znearest365d29 1 QC3.61 [2.32, 5.10]3.02-2.04 [-3.70, -0.55]4.37 [2.90, 5.65]14% [0%, 24%]34%45%-0.11+0.072026-08-02 → 2026-08-30
tmin00Znearestall29 1 QC3.61 [2.33, 4.97]3.02-2.04 [-3.75, -0.52]4.37 [2.86, 5.61]14% [0%, 25%]34%45%-0.11+0.072026-08-02 → 2026-08-30
tmin12Zbilinear30d29 1 QC3.38 [2.37, 4.68]2.67-1.94 [-3.13, -0.69]4.12 [3.01, 5.29]17% [4%, 31%]34%48%-0.04+0.172026-08-02 → 2026-08-30
tmin12Zbilinear90d29 1 QC3.38 [2.23, 4.75]2.67-1.94 [-3.27, -0.67]4.12 [2.76, 5.36]17% [2%, 32%]34%48%-0.04+0.172026-08-02 → 2026-08-30
tmin12Zbilinear365d29 1 QC3.38 [2.16, 4.79]2.67-1.94 [-3.48, -0.62]4.12 [2.73, 5.33]17% [0%, 33%]34%48%-0.04+0.172026-08-02 → 2026-08-30
tmin12Zbilinearall29 1 QC3.38 [2.19, 4.73]2.67-1.94 [-3.50, -0.61]4.12 [2.70, 5.35]17% [0%, 33%]34%48%-0.04+0.172026-08-02 → 2026-08-30
tmin12Znearest30d29 1 QC3.43 [2.39, 4.76]2.73-1.97 [-3.18, -0.70]4.17 [3.02, 5.32]21% [7%, 37%]34%48%-0.06+0.162026-08-02 → 2026-08-30
tmin12Znearest90d29 1 QC3.43 [2.22, 4.83]2.73-1.97 [-3.33, -0.68]4.17 [2.76, 5.41]21% [2%, 38%]34%48%-0.06+0.162026-08-02 → 2026-08-30
tmin12Znearest365d29 1 QC3.43 [2.15, 4.86]2.73-1.97 [-3.56, -0.63]4.17 [2.74, 5.40]21% [0%, 38%]34%48%-0.06+0.162026-08-02 → 2026-08-30
tmin12Znearestall29 1 QC3.43 [2.18, 4.80]2.73-1.97 [-3.59, -0.60]4.17 [2.71, 5.44]21% [0%, 39%]34%48%-0.06+0.162026-08-02 → 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 KPHX, lead day 1, 00Z bilinear tmax+10+50-5-102026-08-02: -1.13 °F2026-08-03: -4.81 °F2026-08-04: +1.81 °F2026-08-05: +0.75 °F2026-08-06: -2.79 °F2026-08-07: -2.14 °F2026-08-08: -3.78 °F2026-08-09: -2.93 °F2026-08-10: -1.33 °F2026-08-11: -1.66 °F2026-08-12: -7.93 °F2026-08-13: -3.94 °F2026-08-14: -4.59 °F2026-08-15: -1.6 °F2026-08-16: -1.15 °F2026-08-17: -0.99 °F2026-08-18: -2.21 °F2026-08-19: -1.43 °F2026-08-20: +0.98 °F2026-08-21: -1.64 °F2026-08-22: -5.37 °F2026-08-23: -6.73 °F2026-08-24: -1.79 °F2026-08-25: -2.64 °F2026-08-26: -3.17 °F2026-08-27: -0.31 °F2026-08-28: -3.62 °F2026-08-29: -9.21 °F2026-08-30: -8.85 °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
2026-08-30-8.85
2026-08-29-9.21
2026-08-28-3.62
2026-08-27-0.31
2026-08-26-3.17
2026-08-25-2.64
2026-08-24-1.79
2026-08-23-6.73
2026-08-22-5.37
2026-08-21-1.64
2026-08-20+0.98
2026-08-19-1.43
2026-08-18-2.21
2026-08-17-0.99
2026-08-16-1.15
2026-08-15-1.60
2026-08-14-4.59
2026-08-13-3.94
2026-08-12-7.93
2026-08-11-1.66
2026-08-10-1.33
2026-08-09-2.93
2026-08-08-3.78
2026-08-07-2.14
2026-08-06-2.79
2026-08-05+0.75
2026-08-04+1.81
2026-08-03-4.81
2026-08-02-1.13

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KPHX, lead day 1-10 to -9 °F: 1 day-9 to -8 °F: 1 day-8 to -7 °F: 1 day-7 to -6 °F: 1 day-6 to -5 °F: 1 day-5 to -4 °F: 2 days-4 to -3 °F: 4 days-3 to -2 °F: 5 days-2 to -1 °F: 8 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| 2.21 · P90 |e| 6.97 °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
-10.00-9.001
-9.00-8.001
-8.00-7.001
-7.00-6.001
-6.00-5.001
-5.00-4.002
-4.00-3.004
-3.00-2.005
-2.00-1.008
-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
2026-08293.15 -2.90

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 -5.73 [-5.73, -5.73] yes
Aurora (IFS init) 2 +0.67 [0.65, 0.70] yes
FourCastNet v2 (GFS init) 1 -3.79 [-3.79, -3.79] yes
FourCastNet v2 (IFS init) 2 -1.30 [-2.36, -0.25] yes
NCEP GFS 29 +0.24 [-0.98, 1.30] no
GraphCast (GFS init) 1 -5.05 [-5.05, -5.05] yes
GraphCast (IFS init) 27 -0.09 [-0.87, 0.56] no
ECMWF IFS HRES 22 +0.90 [0.04, 1.85] yes
Pangu-Weather (GFS init) 1 +1.43 [1.43, 1.43] yes
Pangu-Weather (IFS init) 2 +1.58 [0.17, 2.99] yes
Persistence (baseline) 29 -0.02 [-1.12, 1.30] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KPHX (Phoenix Sky Harbor), 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/KPHX/model/aifs_single/lead/1/

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