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

San Francisco Intl · ECMWF IFS HRES · lead day 3

KSFO · ifs_hres · lead 3

Target day = initialization date + 3 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
tmax00Zbilinear30d22 1 QC6.33 [5.76, 7.21]2.47-6.33 [-7.21, -5.76]7.04 [6.29, 7.92]5% [0%, 14%]5%9%-1.05+0.202026-08-04 → 2026-08-30
tmax00Zbilinear90d22 1 QC6.33 [5.81, 7.32]2.47-6.33 [-7.32, -5.81]7.04 [6.29, 7.90]5% [0%, 17%]5%9%-1.05+0.202026-08-04 → 2026-08-30
tmax00Zbilinear365d22 1 QC6.33 [5.79, 7.50]2.47-6.33 [-7.50, -5.79]7.04 [6.19, 7.91]5% [0%, 15%]5%9%-1.05+0.202026-08-04 → 2026-08-30
tmax00Zbilinearall22 1 QC6.33 [5.79, 7.50]2.47-6.33 [-7.50, -5.79]7.04 [6.29, 8.00]5% [0%, 15%]5%9%-1.05+0.202026-08-04 → 2026-08-30
tmax00Znearest30d22 1 QC2.76 [2.03, 3.48]2.68-0.83 [-1.59, -0.00]3.44 [2.45, 4.20]18% [4%, 40%]41%73%+0.11+0.132026-08-04 → 2026-08-30
tmax00Znearest90d22 1 QC2.76 [1.77, 3.75]2.68-0.83 [-1.58, -0.00]3.44 [2.18, 4.42]18% [0%, 50%]41%73%+0.11+0.132026-08-04 → 2026-08-30
tmax00Znearest365d22 1 QC2.76 [1.80, 3.82]2.68-0.83 [-1.70, -0.01]3.44 [2.20, 4.48]18% [0%, 50%]41%73%+0.11+0.132026-08-04 → 2026-08-30
tmax00Znearestall22 1 QC2.76 [1.80, 3.72]2.68-0.83 [-1.68, -0.05]3.44 [2.21, 4.36]18% [0%, 50%]41%73%+0.11+0.132026-08-04 → 2026-08-30
tmax12Zbilinear30d22 1 QC6.50 [5.75, 7.52]2.50-6.50 [-7.52, -5.75]7.18 [6.38, 8.06]5% [0%, 14%]5%9%-1.10+0.192026-08-04 → 2026-08-30
tmax12Zbilinear90d22 1 QC6.50 [5.79, 7.67]2.50-6.50 [-7.67, -5.79]7.18 [6.34, 8.05]5% [0%, 17%]5%9%-1.10+0.192026-08-04 → 2026-08-30
tmax12Zbilinear365d22 1 QC6.50 [5.72, 7.67]2.50-6.50 [-7.67, -5.72]7.18 [6.23, 8.08]5% [0%, 15%]5%9%-1.10+0.192026-08-04 → 2026-08-30
tmax12Zbilinearall22 1 QC6.50 [5.79, 7.68]2.50-6.50 [-7.68, -5.79]7.18 [6.39, 8.14]5% [0%, 15%]5%9%-1.10+0.192026-08-04 → 2026-08-30
tmax12Znearest30d22 1 QC2.71 [1.75, 3.62]2.64-1.03 [-1.85, -0.38]3.37 [2.28, 4.16]23% [8%, 45%]41%64%+0.12+0.152026-08-04 → 2026-08-30
tmax12Znearest90d22 1 QC2.71 [1.52, 3.92]2.64-1.03 [-1.91, -0.32]3.37 [2.01, 4.35]23% [7%, 51%]41%64%+0.12+0.152026-08-04 → 2026-08-30
tmax12Znearest365d22 1 QC2.71 [1.54, 4.12]2.64-1.03 [-2.00, -0.28]3.37 [2.01, 4.45]23% [0%, 55%]41%64%+0.12+0.152026-08-04 → 2026-08-30
tmax12Znearestall22 1 QC2.71 [1.50, 3.92]2.64-1.03 [-1.93, -0.30]3.37 [2.07, 4.31]23% [6%, 50%]41%64%+0.12+0.152026-08-04 → 2026-08-30
tmin00Zbilinear30d22 1 QC0.91 [0.60, 1.37]0.91-0.08 [-0.76, 0.29]1.16 [0.79, 1.60]59% [26%, 85%]91%100%+0.17+0.172026-08-04 → 2026-08-30
tmin00Zbilinear90d22 1 QC0.91 [0.62, 1.48]0.91-0.08 [-1.04, 0.25]1.16 [0.80, 1.70]59% [22%, 83%]91%100%+0.17+0.172026-08-04 → 2026-08-30
tmin00Zbilinear365d22 1 QC0.91 [0.58, 1.49]0.91-0.08 [-1.07, 0.29]1.16 [0.74, 1.67]59% [21%, 86%]91%100%+0.17+0.172026-08-04 → 2026-08-30
tmin00Zbilinearall22 1 QC0.91 [0.60, 1.58]0.91-0.08 [-1.33, 0.26]1.16 [0.75, 1.77]59% [17%, 85%]91%100%+0.17+0.172026-08-04 → 2026-08-30
tmin00Znearest30d22 1 QC1.11 [0.80, 1.46]1.11+0.03 [-0.44, 0.52]1.45 [1.01, 1.77]55% [40%, 67%]82%95%-0.02-0.012026-08-04 → 2026-08-30
tmin00Znearest90d22 1 QC1.11 [0.73, 1.52]1.11+0.03 [-0.60, 0.50]1.45 [0.93, 1.85]55% [38%, 71%]82%95%-0.02-0.012026-08-04 → 2026-08-30
tmin00Znearest365d22 1 QC1.11 [0.69, 1.54]1.11+0.03 [-0.59, 0.53]1.45 [0.89, 1.84]55% [38%, 75%]82%95%-0.02-0.012026-08-04 → 2026-08-30
tmin00Znearestall22 1 QC1.11 [0.66, 1.53]1.11+0.03 [-0.60, 0.50]1.45 [0.83, 1.81]55% [38%, 74%]82%95%-0.02-0.012026-08-04 → 2026-08-30
tmin12Zbilinear30d22 1 QC0.84 [0.61, 1.24]0.84-0.19 [-0.84, 0.12]1.06 [0.78, 1.48]68% [46%, 83%]91%100%+0.23+0.242026-08-04 → 2026-08-30
tmin12Zbilinear90d22 1 QC0.84 [0.65, 1.41]0.84-0.19 [-1.09, 0.09]1.06 [0.79, 1.62]68% [43%, 83%]91%100%+0.23+0.242026-08-04 → 2026-08-30
tmin12Zbilinear365d22 1 QC0.84 [0.61, 1.35]0.84-0.19 [-1.10, 0.12]1.06 [0.76, 1.57]68% [43%, 83%]91%100%+0.23+0.242026-08-04 → 2026-08-30
tmin12Zbilinearall22 1 QC0.84 [0.63, 1.44]0.84-0.19 [-1.32, 0.08]1.06 [0.77, 1.68]68% [33%, 83%]91%100%+0.23+0.242026-08-04 → 2026-08-30
tmin12Znearest30d22 1 QC1.00 [0.71, 1.40]1.00-0.07 [-0.58, 0.26]1.26 [0.89, 1.58]59% [32%, 83%]86%100%+0.08+0.092026-08-04 → 2026-08-30
tmin12Znearest90d22 1 QC1.00 [0.70, 1.50]1.00-0.07 [-0.74, 0.26]1.26 [0.83, 1.69]59% [23%, 87%]86%100%+0.08+0.092026-08-04 → 2026-08-30
tmin12Znearest365d22 1 QC1.00 [0.67, 1.59]1.00-0.07 [-0.68, 0.26]1.26 [0.81, 1.71]59% [21%, 88%]86%100%+0.08+0.092026-08-04 → 2026-08-30
tmin12Znearestall22 1 QC1.00 [0.64, 1.52]1.00-0.07 [-0.71, 0.25]1.26 [0.77, 1.71]59% [24%, 89%]86%100%+0.08+0.092026-08-04 → 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 3, 00Z bilinear tmax+20+100-10-202026-08-04: -7.5 °F2026-08-10: -6.53 °F2026-08-11: -10.55 °F2026-08-12: -5.22 °F2026-08-13: -3.55 °F2026-08-14: -5.21 °F2026-08-15: -5.03 °F2026-08-16: -6.63 °F2026-08-17: -9.24 °F2026-08-18: -6.7 °F2026-08-19: -3.17 °F2026-08-20: -5.41 °F2026-08-21: -3.77 °F2026-08-22: -3.92 °F2026-08-23: -14.3 °F2026-08-24: -8.7 °F2026-08-25: -2.97 °F2026-08-26: -9.24 °F2026-08-27: -4.17 °F2026-08-28: +0 °F2026-08-29: -7.91 °F2026-08-30: -9.43 °F2026-08-042026-08-30°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 (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-9.43
2026-08-29-7.91
2026-08-28+0.00
2026-08-27-4.17
2026-08-26-9.24
2026-08-25-2.97
2026-08-24-8.70
2026-08-23-14.30
2026-08-22-3.92
2026-08-21-3.77
2026-08-20-5.41
2026-08-19-3.17
2026-08-18-6.70
2026-08-17-9.24
2026-08-16-6.63
2026-08-15-5.03
2026-08-14-5.21
2026-08-13-3.55
2026-08-12-5.22
2026-08-11-10.55
2026-08-10-6.53
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04-7.50

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSFO, lead day 3-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 1 day-14 to -12 °F: 0 days-12 to -10 °F: 1 day-10 to -8 °F: 4 days-8 to -6 °F: 5 days-6 to -4 °F: 5 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| 5.97 · P90 |e| 9.41 °F-200+20 °Fn = 22 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
-14.00-12.000
-12.00-10.001
-10.00-8.004
-8.00-6.005
-6.00-4.005
-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
2026-08226.33 -6.33

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22

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 22 +1.55 [0.03, 2.76] yes
NCEP GFS 22 +1.18 [0.20, 2.43] yes
GraphCast (IFS init) 20 +0.54 [-1.21, 1.77] no
Persistence (baseline) 22 +3.23 [2.22, 4.50] yes

Cite this page

ShortCastCheck, KSFO ifs_hres lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSFO/model/ifs_hres/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSFO (San Francisco Intl), model ifs_hres, lead day 3. 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/3/

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