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

Phoenix Sky Harbor · ECMWF AIFS Single · lead day 2

KPHX · aifs_single · lead 2

Target day = initialization date + 2 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
tmax00Zbilinear30d28 1 QC3.49 [2.43, 4.59]2.16-3.27 [-4.44, -2.08]4.42 [3.05, 5.75]14% [7%, 23%]29%50%+0.26+0.542026-08-03 → 2026-08-30
tmax00Zbilinear90d28 1 QC3.49 [2.18, 5.05]2.16-3.27 [-5.05, -1.72]4.42 [2.53, 6.24]14% [4%, 25%]29%50%+0.26+0.542026-08-03 → 2026-08-30
tmax00Zbilinear365d28 1 QC3.49 [2.10, 5.34]2.16-3.27 [-5.32, -1.66]4.42 [2.44, 6.48]14% [3%, 25%]29%50%+0.26+0.542026-08-03 → 2026-08-30
tmax00Zbilinearall28 1 QC3.49 [2.12, 5.18]2.16-3.27 [-5.07, -1.77]4.42 [2.53, 6.31]14% [0%, 25%]29%50%+0.26+0.542026-08-03 → 2026-08-30
tmax00Znearest30d28 1 QC3.45 [2.41, 4.57]2.15-3.26 [-4.43, -2.08]4.40 [3.02, 5.74]14% [7%, 23%]36%50%+0.27+0.552026-08-03 → 2026-08-30
tmax00Znearest90d28 1 QC3.45 [2.14, 5.04]2.15-3.26 [-5.04, -1.73]4.40 [2.52, 6.25]14% [4%, 25%]36%50%+0.27+0.552026-08-03 → 2026-08-30
tmax00Znearest365d28 1 QC3.45 [2.09, 5.34]2.15-3.26 [-5.31, -1.69]4.40 [2.41, 6.48]14% [3%, 25%]36%50%+0.27+0.552026-08-03 → 2026-08-30
tmax00Znearestall28 1 QC3.45 [2.11, 5.17]2.15-3.26 [-5.04, -1.79]4.40 [2.50, 6.31]14% [0%, 25%]36%50%+0.27+0.552026-08-03 → 2026-08-30
tmax12Zbilinear30d28 1 QC3.11 [2.26, 3.99]2.06-2.83 [-3.85, -1.82]3.93 [2.83, 4.96]18% [7%, 27%]39%68%+0.34+0.572026-08-03 → 2026-08-30
tmax12Zbilinear90d28 1 QC3.11 [2.19, 4.44]2.06-2.83 [-4.26, -1.54]3.93 [2.58, 5.31]18% [7%, 28%]39%68%+0.34+0.572026-08-03 → 2026-08-30
tmax12Zbilinear365d28 1 QC3.11 [2.14, 4.63]2.06-2.83 [-4.54, -1.46]3.93 [2.51, 5.58]18% [5%, 29%]39%68%+0.34+0.572026-08-03 → 2026-08-30
tmax12Zbilinearall28 1 QC3.11 [2.28, 4.37]2.06-2.83 [-4.31, -1.59]3.93 [2.65, 5.38]18% [6%, 29%]39%68%+0.34+0.572026-08-03 → 2026-08-30
tmax12Znearest30d28 1 QC3.07 [2.23, 3.94]2.05-2.80 [-3.78, -1.82]3.89 [2.79, 4.93]21% [8%, 36%]39%68%+0.35+0.572026-08-03 → 2026-08-30
tmax12Znearest90d28 1 QC3.07 [2.14, 4.35]2.05-2.80 [-4.22, -1.52]3.89 [2.53, 5.28]21% [8%, 36%]39%68%+0.35+0.572026-08-03 → 2026-08-30
tmax12Znearest365d28 1 QC3.07 [2.09, 4.57]2.05-2.80 [-4.51, -1.47]3.89 [2.47, 5.54]21% [6%, 36%]39%68%+0.35+0.572026-08-03 → 2026-08-30
tmax12Znearestall28 1 QC3.07 [2.24, 4.32]2.05-2.80 [-4.28, -1.59]3.89 [2.61, 5.36]21% [7%, 36%]39%68%+0.35+0.572026-08-03 → 2026-08-30
tmin00Zbilinear30d28 1 QC3.46 [2.39, 4.80]2.84-1.99 [-3.38, -0.60]4.29 [3.16, 5.45]18% [7%, 31%]39%50%+0.32+0.432026-08-03 → 2026-08-30
tmin00Zbilinear90d28 1 QC3.46 [2.10, 4.82]2.84-1.99 [-3.56, -0.51]4.29 [2.81, 5.46]18% [4%, 33%]39%50%+0.32+0.432026-08-03 → 2026-08-30
tmin00Zbilinear365d28 1 QC3.46 [2.09, 4.89]2.84-1.99 [-3.84, -0.37]4.29 [2.83, 5.46]18% [0%, 35%]39%50%+0.32+0.432026-08-03 → 2026-08-30
tmin00Zbilinearall28 1 QC3.46 [2.06, 4.82]2.84-1.99 [-3.70, -0.35]4.29 [2.79, 5.40]18% [0%, 33%]39%50%+0.32+0.432026-08-03 → 2026-08-30
tmin00Znearest30d28 1 QC3.51 [2.42, 4.86]2.91-2.05 [-3.47, -0.59]4.36 [3.22, 5.52]21% [7%, 38%]39%50%+0.31+0.422026-08-03 → 2026-08-30
tmin00Znearest90d28 1 QC3.51 [2.11, 4.92]2.91-2.05 [-3.62, -0.54]4.36 [2.84, 5.52]21% [4%, 41%]39%50%+0.31+0.422026-08-03 → 2026-08-30
tmin00Znearest365d28 1 QC3.51 [2.10, 4.99]2.91-2.05 [-3.94, -0.40]4.36 [2.86, 5.54]21% [0%, 42%]39%50%+0.31+0.422026-08-03 → 2026-08-30
tmin00Znearestall28 1 QC3.51 [2.08, 4.95]2.91-2.05 [-3.82, -0.38]4.36 [2.83, 5.46]21% [0%, 42%]39%50%+0.31+0.422026-08-03 → 2026-08-30
tmin12Zbilinear30d28 1 QC3.36 [2.39, 4.68]2.97-1.69 [-2.99, -0.32]4.18 [3.08, 5.32]25% [8%, 40%]39%50%+0.34+0.412026-08-03 → 2026-08-30
tmin12Zbilinear90d28 1 QC3.36 [2.20, 4.69]2.97-1.69 [-3.14, -0.19]4.18 [2.87, 5.38]25% [6%, 42%]39%50%+0.34+0.412026-08-03 → 2026-08-30
tmin12Zbilinear365d28 1 QC3.36 [2.15, 4.78]2.97-1.69 [-3.41, -0.16]4.18 [2.85, 5.35]25% [4%, 43%]39%50%+0.34+0.412026-08-03 → 2026-08-30
tmin12Zbilinearall28 1 QC3.36 [2.13, 4.60]2.97-1.69 [-3.37, -0.06]4.18 [2.79, 5.33]25% [3%, 43%]39%50%+0.34+0.412026-08-03 → 2026-08-30
tmin12Znearest30d28 1 QC3.42 [2.43, 4.76]3.04-1.73 [-3.07, -0.34]4.24 [3.13, 5.39]25% [8%, 40%]39%50%+0.33+0.392026-08-03 → 2026-08-30
tmin12Znearest90d28 1 QC3.42 [2.22, 4.77]3.04-1.73 [-3.22, -0.20]4.24 [2.89, 5.45]25% [6%, 42%]39%50%+0.33+0.392026-08-03 → 2026-08-30
tmin12Znearest365d28 1 QC3.42 [2.19, 4.85]3.04-1.73 [-3.49, -0.19]4.24 [2.87, 5.44]25% [4%, 43%]39%50%+0.33+0.392026-08-03 → 2026-08-30
tmin12Znearestall28 1 QC3.42 [2.16, 4.67]3.04-1.73 [-3.46, -0.10]4.24 [2.83, 5.39]25% [3%, 43%]39%50%+0.33+0.392026-08-03 → 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 2, 00Z bilinear tmax+20+100-10-202026-08-03: -3.36 °F2026-08-04: +1.22 °F2026-08-05: +0.53 °F2026-08-06: -1.31 °F2026-08-07: -2.51 °F2026-08-08: -3.36 °F2026-08-09: -2.32 °F2026-08-10: -2.13 °F2026-08-11: -2.06 °F2026-08-12: -8.87 °F2026-08-13: -4.51 °F2026-08-14: -4.17 °F2026-08-15: -4.03 °F2026-08-16: -1.29 °F2026-08-17: -0.81 °F2026-08-18: -2.82 °F2026-08-19: -0.51 °F2026-08-20: +1.23 °F2026-08-21: -3.39 °F2026-08-22: -5.26 °F2026-08-23: -7.63 °F2026-08-24: -2.37 °F2026-08-25: -3.36 °F2026-08-26: -3.58 °F2026-08-27: -0.46 °F2026-08-28: -3.85 °F2026-08-29: -9.7 °F2026-08-30: -10.97 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-10.97
2026-08-29-9.70
2026-08-28-3.85
2026-08-27-0.46
2026-08-26-3.58
2026-08-25-3.36
2026-08-24-2.37
2026-08-23-7.63
2026-08-22-5.26
2026-08-21-3.39
2026-08-20+1.23
2026-08-19-0.51
2026-08-18-2.82
2026-08-17-0.81
2026-08-16-1.29
2026-08-15-4.03
2026-08-14-4.17
2026-08-13-4.51
2026-08-12-8.87
2026-08-11-2.06
2026-08-10-2.13
2026-08-09-2.32
2026-08-08-3.36
2026-08-07-2.51
2026-08-06-1.31
2026-08-05+0.53
2026-08-04+1.22
2026-08-03-3.36

Error distribution

Distribution of the signed daily error in °F for ECMWF AIFS Single at KPHX, lead day 2-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 2 days-8 to -6 °F: 1 day-6 to -4 °F: 4 days-4 to -2 °F: 12 days-2 to 0 °F: 5 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| 3.09 · P90 |e| 8 °F-200+20 °Fn = 28 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
-14.00-12.000
-12.00-10.001
-10.00-8.002
-8.00-6.001
-6.00-4.004
-4.00-2.0012
-2.00+0.005
+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
2026-08283.49 -3.27

Availability

ModelScored period DaysCoverage
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28
ECMWF AIFS Single2026-08-03 → 2026-08-30 28

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 (IFS init) 1 +0.55 [0.55, 0.55] yes
FourCastNet v2 (IFS init) 1 -0.73 [-0.73, -0.73] yes
NCEP GFS 28 +0.73 [-0.66, 2.11] no
GraphCast (IFS init) 26 -0.25 [-0.95, 0.44] no
ECMWF IFS HRES 23 +0.83 [-0.59, 2.68] no
Pangu-Weather (IFS init) 1 +3.98 [3.98, 3.98] yes
Persistence (baseline) 28 -1.23 [-2.89, 0.88] no

Cite this page

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

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

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