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

San Francisco Intl · ECMWF IFS HRES · lead day 5

KSFO · ifs_hres · lead 5

Target day = initialization date + 5 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
tmax00Zbilinear30d18 1 QC6.20 [4.86, 7.35]2.86-6.20 [-7.35, -4.86]7.15 [5.49, 8.29]0% [0%, 0%]11%22%-0.57+0.292026-08-06 → 2026-08-30
tmax00Zbilinear90d18 1 QC6.20 [4.81, 7.28]2.86-6.20 [-7.28, -4.81]7.15 [5.40, 8.25]0% [0%, 0%]11%22%-0.57+0.292026-08-06 → 2026-08-30
tmax00Zbilinear365d18 1 QC6.20 [4.79, 7.46]2.86-6.20 [-7.46, -4.79]7.15 [5.39, 8.41]0% [0%, 0%]11%22%-0.57+0.292026-08-06 → 2026-08-30
tmax00Zbilinearall18 1 QC6.20 [4.78, 7.51]2.86-6.20 [-7.51, -4.78]7.15 [5.44, 8.43]0% [0%, 0%]11%22%-0.57+0.292026-08-06 → 2026-08-30
tmax00Znearest30d18 1 QC3.64 [2.67, 4.25]3.77-1.19 [-2.52, 0.97]4.45 [3.44, 5.07]22% [6%, 46%]39%44%+0.08+0.062026-08-06 → 2026-08-30
tmax00Znearest90d18 1 QC3.64 [2.15, 4.33]3.77-1.19 [-2.55, 1.16]4.45 [2.77, 5.09]22% [5%, 63%]39%44%+0.08+0.062026-08-06 → 2026-08-30
tmax00Znearest365d18 1 QC3.64 [2.27, 4.40]3.77-1.19 [-2.76, 1.15]4.45 [2.89, 5.14]22% [0%, 67%]39%44%+0.08+0.062026-08-06 → 2026-08-30
tmax00Znearestall18 1 QC3.64 [2.25, 4.30]3.77-1.19 [-2.82, 1.17]4.45 [2.99, 5.12]22% [0%, 59%]39%44%+0.08+0.062026-08-06 → 2026-08-30
tmax12Zbilinear30d20 1 QC6.22 [5.01, 7.36]2.33-6.22 [-7.36, -5.01]6.90 [5.32, 8.11]0% [0%, 0%]5%10%-0.64+0.392026-08-06 → 2026-08-30
tmax12Zbilinear90d20 1 QC6.22 [4.97, 7.34]2.33-6.22 [-7.34, -4.97]6.90 [5.32, 8.08]0% [0%, 0%]5%10%-0.64+0.392026-08-06 → 2026-08-30
tmax12Zbilinear365d20 1 QC6.22 [4.86, 7.52]2.33-6.22 [-7.52, -4.86]6.90 [5.20, 8.30]0% [0%, 0%]5%10%-0.64+0.392026-08-06 → 2026-08-30
tmax12Zbilinearall20 1 QC6.22 [4.91, 7.50]2.33-6.22 [-7.50, -4.91]6.90 [5.20, 8.27]0% [0%, 0%]5%10%-0.64+0.392026-08-06 → 2026-08-30
tmax12Znearest30d20 1 QC2.64 [1.86, 3.48]2.72-1.07 [-2.10, 0.62]3.32 [2.35, 4.05]35% [19%, 54%]40%65%+0.30+0.292026-08-06 → 2026-08-30
tmax12Znearest90d20 1 QC2.64 [1.60, 3.56]2.72-1.07 [-2.11, 0.98]3.32 [2.05, 4.13]35% [17%, 59%]40%65%+0.30+0.292026-08-06 → 2026-08-30
tmax12Znearest365d20 1 QC2.64 [1.62, 3.66]2.72-1.07 [-2.31, 0.98]3.32 [2.06, 4.18]35% [14%, 62%]40%65%+0.30+0.292026-08-06 → 2026-08-30
tmax12Znearestall20 1 QC2.64 [1.73, 3.55]2.72-1.07 [-2.32, 0.99]3.32 [2.06, 4.14]35% [15%, 57%]40%65%+0.30+0.292026-08-06 → 2026-08-30
tmin00Zbilinear30d18 1 QC0.64 [0.38, 0.82]0.61-0.21 [-0.50, 0.05]0.81 [0.50, 0.95]83% [74%, 100%]100%100%+0.45+0.492026-08-06 → 2026-08-30
tmin00Zbilinear90d18 1 QC0.64 [0.35, 0.82]0.61-0.21 [-0.57, 0.06]0.81 [0.49, 0.96]83% [75%, 100%]100%100%+0.45+0.492026-08-06 → 2026-08-30
tmin00Zbilinear365d18 1 QC0.64 [0.34, 0.84]0.61-0.21 [-0.57, 0.10]0.81 [0.48, 0.98]83% [71%, 100%]100%100%+0.45+0.492026-08-06 → 2026-08-30
tmin00Zbilinearall18 1 QC0.64 [0.35, 0.84]0.61-0.21 [-0.63, 0.09]0.81 [0.46, 0.97]83% [73%, 100%]100%100%+0.45+0.492026-08-06 → 2026-08-30
tmin00Znearest30d18 1 QC0.98 [0.63, 1.28]0.93-0.31 [-0.76, -0.00]1.25 [0.74, 1.57]67% [50%, 87%]89%100%+0.16+0.222026-08-06 → 2026-08-30
tmin00Znearest90d18 1 QC0.98 [0.46, 1.35]0.93-0.31 [-0.82, 0.02]1.25 [0.53, 1.64]67% [44%, 100%]89%100%+0.16+0.222026-08-06 → 2026-08-30
tmin00Znearest365d18 1 QC0.98 [0.46, 1.38]0.93-0.31 [-0.83, 0.02]1.25 [0.51, 1.68]67% [44%, 100%]89%100%+0.16+0.222026-08-06 → 2026-08-30
tmin00Znearestall18 1 QC0.98 [0.50, 1.32]0.93-0.31 [-0.85, 0.04]1.25 [0.56, 1.64]67% [44%, 100%]89%100%+0.16+0.222026-08-06 → 2026-08-30
tmin12Zbilinear30d20 1 QC0.80 [0.59, 0.99]0.79-0.07 [-0.51, 0.25]0.99 [0.67, 1.22]75% [61%, 93%]90%100%+0.36+0.392026-08-06 → 2026-08-30
tmin12Zbilinear90d20 1 QC0.80 [0.59, 0.99]0.79-0.07 [-0.60, 0.22]0.99 [0.60, 1.23]75% [61%, 100%]90%100%+0.36+0.392026-08-06 → 2026-08-30
tmin12Zbilinear365d20 1 QC0.80 [0.58, 1.00]0.79-0.07 [-0.60, 0.29]0.99 [0.60, 1.25]75% [60%, 100%]90%100%+0.36+0.392026-08-06 → 2026-08-30
tmin12Zbilinearall20 1 QC0.80 [0.57, 1.03]0.79-0.07 [-0.63, 0.23]0.99 [0.60, 1.26]75% [57%, 100%]90%100%+0.36+0.392026-08-06 → 2026-08-30
tmin12Znearest30d20 1 QC1.07 [0.74, 1.33]1.06-0.22 [-0.74, 0.06]1.27 [0.81, 1.55]60% [38%, 89%]85%100%+0.14+0.182026-08-06 → 2026-08-30
tmin12Znearest90d20 1 QC1.07 [0.58, 1.36]1.06-0.22 [-0.82, 0.04]1.27 [0.61, 1.61]60% [38%, 100%]85%100%+0.14+0.182026-08-06 → 2026-08-30
tmin12Znearest365d20 1 QC1.07 [0.60, 1.40]1.06-0.22 [-0.82, 0.08]1.27 [0.63, 1.62]60% [33%, 100%]85%100%+0.14+0.182026-08-06 → 2026-08-30
tmin12Znearestall20 1 QC1.07 [0.58, 1.41]1.06-0.22 [-0.92, 0.06]1.27 [0.61, 1.62]60% [33%, 100%]85%100%+0.14+0.182026-08-06 → 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 KSFO, lead day 5, 00Z bilinear tmax+20+100-10-202026-08-06: -6.44 °F2026-08-12: -6.35 °F2026-08-13: -2.01 °F2026-08-14: -1.98 °F2026-08-16: -6.97 °F2026-08-17: -9.33 °F2026-08-19: -3.37 °F2026-08-20: -4.77 °F2026-08-21: -4.69 °F2026-08-22: -2.98 °F2026-08-23: -14.02 °F2026-08-24: -9.33 °F2026-08-25: -3.86 °F2026-08-26: -13.13 °F2026-08-27: -5.08 °F2026-08-28: -1.35 °F2026-08-29: -6.56 °F2026-08-30: -9.37 °F2026-08-062026-08-30°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 (25 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-9.37
2026-08-29-6.56
2026-08-28-1.35
2026-08-27-5.08
2026-08-26-13.13
2026-08-25-3.86
2026-08-24-9.33
2026-08-23-14.02
2026-08-22-2.98
2026-08-21-4.69
2026-08-20-4.77
2026-08-19-3.37
2026-08-18—
2026-08-17-9.33
2026-08-16-6.97
2026-08-15—
2026-08-14-1.98
2026-08-13-2.01
2026-08-12-6.35
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06-6.44

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSFO, lead day 5-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 1 day-14 to -12 °F: 1 day-12 to -10 °F: 0 days-10 to -8 °F: 3 days-8 to -6 °F: 4 days-6 to -4 °F: 3 days-4 to -2 °F: 4 days-2 to 0 °F: 2 days0 to 2 °F: 0 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| 5.72 · P90 |e| 10.5 °F-200+20 °Fn = 18 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
-16.00-14.001
-14.00-12.001
-12.00-10.000
-10.00-8.003
-8.00-6.004
-6.00-4.003
-4.00-2.004
-2.00+0.002
+0.00+2.000
+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
2026-08186.20 -6.20

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-06 → 2026-08-30 18
ECMWF IFS HRES2026-08-06 → 2026-08-30 18
ECMWF IFS HRES2026-08-06 → 2026-08-30 20
ECMWF IFS HRES2026-08-06 → 2026-08-30 20

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 18 +1.54 [-0.86, 2.72] no
NCEP GFS 18 +1.30 [0.17, 2.16] yes
GraphCast (IFS init) 18 +0.49 [-1.44, 1.31] no
Persistence (baseline) 18 +2.26 [0.79, 4.24] yes

Cite this page

ShortCastCheck, KSFO ifs_hres lead 5, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSFO/model/ifs_hres/lead/5/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSFO (San Francisco Intl), model ifs_hres, lead day 5. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KSFO/model/ifs_hres/lead/5/

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