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

San Francisco Intl · ECMWF IFS HRES · lead day 7

KSFO · ifs_hres · lead 7

Target day = initialization date + 7 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 QC5.44 [3.31, 6.83]2.50-5.42 [-6.82, -3.30]6.24 [3.78, 7.62]6% [0%, 17%]6%28%-0.55+0.272026-08-08 → 2026-08-30
tmax00Zbilinear90d18 1 QC5.44 [2.31, 6.85]2.50-5.42 [-6.84, -2.31]6.24 [2.31, 7.63]6% [0%, 20%]6%28%-0.55+0.272026-08-08 → 2026-08-30
tmax00Zbilinear365d18 1 QC5.44 [2.33, 7.08]2.50-5.42 [-7.08, -2.33]6.24 [2.33, 7.79]6% [0%, 17%]6%28%-0.55+0.272026-08-08 → 2026-08-30
tmax00Zbilinearall18 1 QC5.44 [2.33, 7.10]2.50-5.42 [-7.08, -2.33]6.24 [2.33, 7.77]6% [0%, 17%]6%28%-0.55+0.272026-08-08 → 2026-08-30
tmax00Znearest30d18 1 QC2.94 [2.19, 4.09]2.90-0.38 [-2.02, 2.69]3.43 [2.64, 4.52]17% [0%, 31%]28%44%+0.16+0.162026-08-08 → 2026-08-30
tmax00Znearest90d18 1 QC2.94 [2.15, 4.69]2.90-0.38 [-2.01, 4.69]3.43 [2.53, 5.02]17% [0%, 33%]28%44%+0.16+0.162026-08-08 → 2026-08-30
tmax00Znearest365d18 1 QC2.94 [2.08, 4.40]2.90-0.38 [-2.28, 4.37]3.43 [2.47, 4.89]17% [0%, 33%]28%44%+0.16+0.162026-08-08 → 2026-08-30
tmax00Znearestall18 1 QC2.94 [2.13, 4.45]2.90-0.38 [-2.27, 4.01]3.43 [2.49, 4.88]17% [0%, 33%]28%44%+0.16+0.162026-08-08 → 2026-08-30
tmax12Zbilinear30d17 1 QC6.14 [3.88, 7.33]3.12-5.97 [-7.33, -3.29]7.03 [4.57, 8.23]6% [0%, 17%]12%24%-0.83+0.072026-08-08 → 2026-08-30
tmax12Zbilinear90d17 1 QC6.14 [2.50, 7.32]3.12-5.97 [-7.26, -1.25]7.03 [2.64, 8.23]6% [0%, 20%]12%24%-0.83+0.072026-08-08 → 2026-08-30
tmax12Zbilinear365d17 1 QC6.14 [2.75, 7.41]3.12-5.97 [-7.41, -1.61]7.03 [2.92, 8.30]6% [0%, 17%]12%24%-0.83+0.072026-08-08 → 2026-08-30
tmax12Zbilinearall17 1 QC6.14 [2.56, 7.54]3.12-5.97 [-7.52, -1.60]7.03 [2.83, 8.30]6% [0%, 17%]12%24%-0.83+0.072026-08-08 → 2026-08-30
tmax12Znearest30d17 1 QC3.90 [2.56, 6.49]3.74-0.83 [-2.62, 3.29]4.77 [3.06, 7.60]6% [0%, 18%]24%47%-0.16-0.122026-08-08 → 2026-08-30
tmax12Znearest90d17 1 QC3.90 [2.56, 7.96]3.74-0.83 [-2.56, 6.73]4.77 [3.01, 9.08]6% [0%, 18%]24%47%-0.16-0.122026-08-08 → 2026-08-30
tmax12Znearest365d17 1 QC3.90 [2.30, 8.10]3.74-0.83 [-2.91, 5.84]4.77 [2.69, 9.17]6% [0%, 18%]24%47%-0.16-0.122026-08-08 → 2026-08-30
tmax12Znearestall17 1 QC3.90 [2.31, 7.64]3.74-0.83 [-2.85, 5.59]4.77 [2.76, 8.62]6% [0%, 20%]24%47%-0.16-0.122026-08-08 → 2026-08-30
tmin00Zbilinear30d18 1 QC1.25 [0.80, 1.65]1.25-0.29 [-1.30, 0.65]1.61 [1.15, 1.90]50% [30%, 67%]72%94%-0.07-0.022026-08-08 → 2026-08-30
tmin00Zbilinear90d18 1 QC1.25 [0.73, 1.70]1.25-0.29 [-1.52, 0.64]1.61 [1.08, 1.88]50% [20%, 67%]72%94%-0.07-0.022026-08-08 → 2026-08-30
tmin00Zbilinear365d18 1 QC1.25 [0.71, 1.69]1.25-0.29 [-1.54, 0.75]1.61 [1.02, 1.88]50% [20%, 69%]72%94%-0.07-0.022026-08-08 → 2026-08-30
tmin00Zbilinearall18 1 QC1.25 [0.69, 1.72]1.25-0.29 [-1.60, 0.70]1.61 [0.99, 1.88]50% [19%, 70%]72%94%-0.07-0.022026-08-08 → 2026-08-30
tmin00Znearest30d18 1 QC1.60 [1.08, 2.13]1.41-0.76 [-1.74, 0.11]2.00 [1.40, 2.49]39% [22%, 60%]67%78%-0.37-0.152026-08-08 → 2026-08-30
tmin00Znearest90d18 1 QC1.60 [0.82, 2.22]1.41-0.76 [-1.81, 0.14]2.00 [0.82, 2.59]39% [20%, 75%]67%78%-0.37-0.152026-08-08 → 2026-08-30
tmin00Znearest365d18 1 QC1.60 [0.82, 2.17]1.41-0.76 [-1.83, 0.21]2.00 [0.82, 2.55]39% [20%, 70%]67%78%-0.37-0.152026-08-08 → 2026-08-30
tmin00Znearestall18 1 QC1.60 [0.82, 2.23]1.41-0.76 [-1.85, 0.18]2.00 [0.82, 2.57]39% [20%, 71%]67%78%-0.37-0.152026-08-08 → 2026-08-30
tmin12Zbilinear30d17 1 QC1.24 [0.83, 1.65]1.09-0.68 [-1.44, -0.02]1.43 [0.99, 1.83]41% [17%, 75%]88%100%-0.00+0.162026-08-08 → 2026-08-30
tmin12Zbilinear90d17 1 QC1.24 [0.81, 1.81]1.09-0.68 [-1.66, -0.00]1.43 [0.95, 1.95]41% [12%, 75%]88%100%-0.00+0.162026-08-08 → 2026-08-30
tmin12Zbilinear365d17 1 QC1.24 [0.75, 1.81]1.09-0.68 [-1.55, 0.09]1.43 [0.86, 1.93]41% [11%, 80%]88%100%-0.00+0.162026-08-08 → 2026-08-30
tmin12Zbilinearall17 1 QC1.24 [0.77, 1.78]1.09-0.68 [-1.62, 0.09]1.43 [0.91, 1.94]41% [11%, 80%]88%100%-0.00+0.162026-08-08 → 2026-08-30
tmin12Znearest30d17 1 QC1.47 [1.13, 1.81]1.14-0.94 [-1.69, -0.14]1.64 [1.19, 1.92]29% [10%, 48%]76%100%-0.19+0.112026-08-08 → 2026-08-30
tmin12Znearest90d17 1 QC1.47 [1.13, 1.87]1.14-0.94 [-1.85, -0.11]1.64 [1.18, 1.98]29% [0%, 50%]76%100%-0.19+0.112026-08-08 → 2026-08-30
tmin12Znearest365d17 1 QC1.47 [1.08, 1.86]1.14-0.94 [-1.85, -0.03]1.64 [1.14, 1.95]29% [0%, 50%]76%100%-0.19+0.112026-08-08 → 2026-08-30
tmin12Znearestall17 1 QC1.47 [1.09, 1.88]1.14-0.94 [-1.88, -0.03]1.64 [1.15, 1.95]29% [0%, 50%]76%100%-0.19+0.112026-08-08 → 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 7, 00Z bilinear tmax+20+100-10-202026-08-08: -2.25 °F2026-08-14: -2.35 °F2026-08-15: -2.31 °F2026-08-16: -4.21 °F2026-08-17: -7.91 °F2026-08-18: -4.82 °F2026-08-19: -2.66 °F2026-08-20: -4.36 °F2026-08-21: -5.71 °F2026-08-22: -6.54 °F2026-08-23: -11.58 °F2026-08-24: -8.67 °F2026-08-25: -4.94 °F2026-08-26: -10.63 °F2026-08-27: -9.44 °F2026-08-28: +0.15 °F2026-08-29: -3.91 °F2026-08-30: -5.44 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-5.44
2026-08-29-3.91
2026-08-28+0.15
2026-08-27-9.44
2026-08-26-10.63
2026-08-25-4.94
2026-08-24-8.67
2026-08-23-11.58
2026-08-22-6.54
2026-08-21-5.71
2026-08-20-4.36
2026-08-19-2.66
2026-08-18-4.82
2026-08-17-7.91
2026-08-16-4.21
2026-08-15-2.31
2026-08-14-2.35
2026-08-13—
2026-08-12—
2026-08-11—
2026-08-10—
2026-08-09—
2026-08-08-2.25

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSFO, lead day 7-20 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: 2 days-10 to -8 °F: 2 days-8 to -6 °F: 2 days-6 to -4 °F: 6 days-4 to -2 °F: 5 days-2 to 0 °F: 0 days0 to 2 °F: 1 day2 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| 4.88 · P90 |e| 9.8 °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
-16.00-14.000
-14.00-12.000
-12.00-10.002
-10.00-8.002
-8.00-6.002
-6.00-4.006
-4.00-2.005
-2.00+0.000
+0.00+2.001
+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
2026-08185.44 -5.42

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-08 → 2026-08-30 18
ECMWF IFS HRES2026-08-08 → 2026-08-30 18
ECMWF IFS HRES2026-08-08 → 2026-08-30 17
ECMWF IFS HRES2026-08-08 → 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 18 +0.54 [-1.53, 1.72] no
NCEP GFS 18 +1.11 [0.34, 1.58] yes
GraphCast (IFS init) 18 +0.30 [-1.51, 1.78] no
Persistence (baseline) 18 +1.94 [-2.22, 3.37] no

Cite this page

ShortCastCheck, KSFO ifs_hres lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSFO/model/ifs_hres/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSFO (San Francisco Intl), model ifs_hres, lead day 7. 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/7/

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