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

San Francisco Intl · ECMWF IFS HRES · lead day 1

KSFO · ifs_hres · 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, 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 QC6.71 [5.87, 8.13]2.29-6.71 [-8.13, -5.87]7.28 [6.41, 8.56]0% [0%, 0%]5%9%-1.05+0.312026-08-02 → 2026-08-30
tmax00Zbilinear90d22 1 QC6.71 [5.80, 9.04]2.29-6.71 [-9.04, -5.80]7.28 [6.35, 9.31]0% [0%, 0%]5%9%-1.05+0.312026-08-02 → 2026-08-30
tmax00Zbilinear365d22 1 QC6.71 [5.75, 8.69]2.29-6.71 [-8.69, -5.75]7.28 [6.25, 8.96]0% [0%, 0%]5%9%-1.05+0.312026-08-02 → 2026-08-30
tmax00Zbilinearall22 1 QC6.71 [5.83, 9.06]2.29-6.71 [-9.06, -5.83]7.28 [6.38, 9.29]0% [0%, 0%]5%9%-1.05+0.312026-08-02 → 2026-08-30
tmax00Znearest30d22 1 QC2.54 [2.02, 3.12]2.46-1.17 [-2.36, -0.32]2.95 [2.44, 3.43]18% [5%, 31%]36%73%+0.22+0.252026-08-02 → 2026-08-30
tmax00Znearest90d22 1 QC2.54 [1.95, 3.26]2.46-1.17 [-2.65, -0.28]2.95 [2.38, 3.55]18% [0%, 32%]36%73%+0.22+0.252026-08-02 → 2026-08-30
tmax00Znearest365d22 1 QC2.54 [1.92, 3.26]2.46-1.17 [-2.73, -0.25]2.95 [2.35, 3.58]18% [0%, 33%]36%73%+0.22+0.252026-08-02 → 2026-08-30
tmax00Znearestall22 1 QC2.54 [2.02, 3.39]2.46-1.17 [-2.79, -0.33]2.95 [2.39, 3.61]18% [0%, 30%]36%73%+0.22+0.252026-08-02 → 2026-08-30
tmax12Zbilinear30d24 1 QC6.17 [5.14, 7.39]2.50-6.17 [-7.39, -5.14]6.90 [5.94, 8.04]0% [0%, 0%]17%25%-0.92+0.232026-08-02 → 2026-08-30
tmax12Zbilinear90d24 1 QC6.17 [5.13, 7.79]2.50-6.17 [-7.79, -5.13]6.90 [5.93, 8.40]0% [0%, 0%]17%25%-0.92+0.232026-08-02 → 2026-08-30
tmax12Zbilinear365d24 1 QC6.17 [4.97, 7.57]2.50-6.17 [-7.57, -4.97]6.90 [5.80, 8.12]0% [0%, 0%]17%25%-0.92+0.232026-08-02 → 2026-08-30
tmax12Zbilinearall24 1 QC6.17 [5.09, 8.23]2.50-6.17 [-8.23, -5.09]6.90 [5.94, 8.51]0% [0%, 0%]17%25%-0.92+0.232026-08-02 → 2026-08-30
tmax12Znearest30d24 1 QC2.88 [2.14, 4.06]2.86-0.28 [-1.76, 1.48]3.54 [2.58, 4.91]17% [4%, 30%]29%62%+0.10+0.122026-08-02 → 2026-08-30
tmax12Znearest90d24 1 QC2.88 [2.07, 4.27]2.86-0.28 [-1.94, 1.78]3.54 [2.47, 5.19]17% [0%, 31%]29%62%+0.10+0.122026-08-02 → 2026-08-30
tmax12Znearest365d24 1 QC2.88 [2.02, 4.24]2.86-0.28 [-1.92, 1.87]3.54 [2.43, 5.10]17% [0%, 32%]29%62%+0.10+0.122026-08-02 → 2026-08-30
tmax12Znearestall24 1 QC2.88 [2.13, 4.27]2.86-0.28 [-2.18, 1.84]3.54 [2.49, 5.17]17% [0%, 29%]29%62%+0.10+0.122026-08-02 → 2026-08-30
tmin00Zbilinear30d22 1 QC0.87 [0.61, 1.32]0.88-0.13 [-0.68, 0.19]1.11 [0.80, 1.56]64% [44%, 77%]95%100%+0.13+0.122026-08-02 → 2026-08-30
tmin00Zbilinear90d22 1 QC0.87 [0.61, 1.45]0.88-0.13 [-1.03, 0.23]1.11 [0.81, 1.76]64% [40%, 77%]95%100%+0.13+0.122026-08-02 → 2026-08-30
tmin00Zbilinear365d22 1 QC0.87 [0.61, 1.43]0.88-0.13 [-0.87, 0.25]1.11 [0.80, 1.63]64% [44%, 77%]95%100%+0.13+0.122026-08-02 → 2026-08-30
tmin00Zbilinearall22 1 QC0.87 [0.60, 1.65]0.88-0.13 [-1.10, 0.23]1.11 [0.77, 1.84]64% [33%, 77%]95%100%+0.13+0.122026-08-02 → 2026-08-30
tmin00Znearest30d22 1 QC1.14 [0.75, 1.75]1.14-0.05 [-0.77, 0.37]1.49 [1.05, 2.01]55% [33%, 70%]77%95%-0.14-0.142026-08-02 → 2026-08-30
tmin00Znearest90d22 1 QC1.14 [0.78, 1.93]1.14-0.05 [-1.02, 0.38]1.49 [1.08, 2.18]55% [27%, 70%]77%95%-0.14-0.142026-08-02 → 2026-08-30
tmin00Znearest365d22 1 QC1.14 [0.75, 1.97]1.14-0.05 [-0.89, 0.41]1.49 [1.03, 2.18]55% [25%, 70%]77%95%-0.14-0.142026-08-02 → 2026-08-30
tmin00Znearestall22 1 QC1.14 [0.74, 2.25]1.14-0.05 [-1.12, 0.38]1.49 [1.02, 2.36]55% [20%, 70%]77%95%-0.14-0.142026-08-02 → 2026-08-30
tmin12Zbilinear30d24 1 QC0.87 [0.61, 1.29]0.88-0.05 [-0.54, 0.25]1.10 [0.76, 1.50]71% [50%, 86%]96%100%+0.13+0.122026-08-02 → 2026-08-30
tmin12Zbilinear90d24 1 QC0.87 [0.64, 1.38]0.88-0.05 [-0.77, 0.28]1.10 [0.80, 1.62]71% [50%, 86%]96%100%+0.13+0.122026-08-02 → 2026-08-30
tmin12Zbilinear365d24 1 QC0.87 [0.61, 1.31]0.88-0.05 [-0.68, 0.34]1.10 [0.74, 1.55]71% [50%, 88%]96%100%+0.13+0.122026-08-02 → 2026-08-30
tmin12Zbilinearall24 1 QC0.87 [0.61, 1.51]0.88-0.05 [-0.82, 0.29]1.10 [0.75, 1.71]71% [40%, 87%]96%100%+0.13+0.122026-08-02 → 2026-08-30
tmin12Znearest30d24 1 QC1.14 [0.81, 1.65]1.14-0.01 [-0.63, 0.37]1.46 [1.01, 1.93]50% [29%, 63%]79%96%-0.14-0.142026-08-02 → 2026-08-30
tmin12Znearest90d24 1 QC1.14 [0.84, 1.80]1.14-0.01 [-0.78, 0.35]1.46 [1.05, 2.01]50% [23%, 62%]79%96%-0.14-0.142026-08-02 → 2026-08-30
tmin12Znearest365d24 1 QC1.14 [0.82, 1.78]1.14-0.01 [-0.70, 0.40]1.46 [1.02, 1.98]50% [22%, 62%]79%96%-0.14-0.142026-08-02 → 2026-08-30
tmin12Znearestall24 1 QC1.14 [0.83, 1.98]1.14-0.01 [-0.96, 0.39]1.46 [1.01, 2.15]50% [20%, 63%]79%96%-0.14-0.142026-08-02 → 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 IFS HRES at KSFO, lead day 1, 00Z bilinear tmax+20+100-10-202026-08-02: -11.77 °F2026-08-10: -6.35 °F2026-08-11: -9.99 °F2026-08-12: -8.78 °F2026-08-13: -7.88 °F2026-08-14: -6.67 °F2026-08-15: -6.31 °F2026-08-16: -6.14 °F2026-08-17: -8.19 °F2026-08-18: -5.49 °F2026-08-19: -3.46 °F2026-08-20: -5.84 °F2026-08-21: -3.85 °F2026-08-22: -2.94 °F2026-08-23: -13.18 °F2026-08-24: -8.71 °F2026-08-25: -3.13 °F2026-08-26: -5.36 °F2026-08-27: -4.8 °F2026-08-28: -1.68 °F2026-08-29: -7.91 °F2026-08-30: -9.1 °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
2026-08-30-9.10
2026-08-29-7.91
2026-08-28-1.68
2026-08-27-4.80
2026-08-26-5.36
2026-08-25-3.13
2026-08-24-8.71
2026-08-23-13.18
2026-08-22-2.94
2026-08-21-3.85
2026-08-20-5.84
2026-08-19-3.46
2026-08-18-5.49
2026-08-17-8.19
2026-08-16-6.14
2026-08-15-6.31
2026-08-14-6.67
2026-08-13-7.88
2026-08-12-8.78
2026-08-11-9.99
2026-08-10-6.35
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03—
2026-08-02-11.77

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSFO, lead day 1-20 to -18 °F: 0 days-18 to -16 °F: 0 days-16 to -14 °F: 0 days-14 to -12 °F: 1 day-12 to -10 °F: 1 day-10 to -8 °F: 5 days-8 to -6 °F: 6 days-6 to -4 °F: 4 days-4 to -2 °F: 4 days-2 to 0 °F: 1 day0 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| 6.33 · P90 |e| 9.9 °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
-16.00-14.000
-14.00-12.001
-12.00-10.001
-10.00-8.005
-8.00-6.006
-6.00-4.004
-4.00-2.004
-2.00+0.001
+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
2026-08226.71 -6.71

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-02 → 2026-08-30 22
ECMWF IFS HRES2026-08-02 → 2026-08-30 22
ECMWF IFS HRES2026-08-02 → 2026-08-30 24
ECMWF IFS HRES2026-08-02 → 2026-08-30 24

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 +1.74 [0.84, 2.49] yes
Aurora (GFS init) 1 +2.46 [2.46, 2.46] yes
Aurora (IFS init) 2 +0.18 [-0.43, 0.79] no
FourCastNet v2 (GFS init) 1 +7.69 [7.69, 7.69] yes
FourCastNet v2 (IFS init) 2 +6.06 [5.34, 6.77] yes
NCEP GFS 22 +1.48 [0.35, 2.19] yes
GraphCast (GFS init) 1 +4.46 [4.46, 4.46] yes
GraphCast (IFS init) 20 +1.58 [0.40, 2.67] yes
Pangu-Weather (GFS init) 1 +2.45 [2.45, 2.45] yes
Pangu-Weather (IFS init) 2 +1.80 [1.32, 2.28] yes
Persistence (baseline) 22 +3.43 [1.22, 5.77] yes

Cite this page

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

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