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

San Francisco Intl · ECMWF IFS HRES · lead day 0

KSFO · ifs_hres · lead 0

Target day = initialization date + 0 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
tmax00Zbilinear30d25 1 QC6.17 [5.39, 6.95]2.13-6.17 [-6.95, -5.39]6.74 [6.05, 7.37]0% [0%, 0%]12%24%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d25 1 QC6.17 [5.31, 6.98]2.13-6.17 [-6.98, -5.31]6.74 [5.88, 7.39]0% [0%, 0%]12%24%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d25 1 QC6.17 [5.24, 7.04]2.13-6.17 [-7.04, -5.24]6.74 [5.86, 7.42]0% [0%, 0%]12%24%——2026-08-01 → 2026-08-30
tmax00Zbilinearall25 1 QC6.17 [5.37, 7.05]2.13-6.17 [-7.05, -5.37]6.74 [5.89, 7.36]0% [0%, 0%]12%24%——2026-08-01 → 2026-08-30
tmax00Znearest30d25 1 QC2.51 [1.92, 3.17]2.41-0.38 [-1.53, 1.01]3.10 [2.29, 4.01]24% [14%, 36%]44%60%——2026-08-01 → 2026-08-30
tmax00Znearest90d25 1 QC2.51 [1.82, 3.33]2.41-0.38 [-1.59, 1.33]3.10 [2.16, 4.07]24% [11%, 38%]44%60%——2026-08-01 → 2026-08-30
tmax00Znearest365d25 1 QC2.51 [1.74, 3.35]2.41-0.38 [-1.71, 1.31]3.10 [2.04, 4.12]24% [11%, 38%]44%60%——2026-08-01 → 2026-08-30
tmax00Znearestall25 1 QC2.51 [1.84, 3.33]2.41-0.38 [-1.67, 1.31]3.10 [2.17, 4.11]24% [11%, 36%]44%60%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d25 1 QC0.78 [0.53, 1.11]0.77-0.17 [-0.53, 0.11]1.04 [0.75, 1.35]68% [50%, 82%]96%100%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d25 1 QC0.78 [0.57, 1.19]0.77-0.17 [-0.70, 0.18]1.04 [0.78, 1.43]68% [47%, 80%]96%100%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d25 1 QC0.78 [0.54, 1.15]0.77-0.17 [-0.68, 0.20]1.04 [0.76, 1.40]68% [50%, 81%]96%100%——2026-08-01 → 2026-08-30
tmin00Zbilinearall25 1 QC0.78 [0.54, 1.27]0.77-0.17 [-0.79, 0.16]1.04 [0.76, 1.53]68% [44%, 81%]96%100%——2026-08-01 → 2026-08-30
tmin00Znearest30d25 1 QC1.03 [0.72, 1.45]1.03-0.02 [-0.55, 0.37]1.34 [0.92, 1.76]56% [37%, 72%]88%100%——2026-08-01 → 2026-08-30
tmin00Znearest90d25 1 QC1.03 [0.76, 1.56]1.03-0.02 [-0.68, 0.38]1.34 [0.99, 1.85]56% [33%, 70%]88%100%——2026-08-01 → 2026-08-30
tmin00Znearest365d25 1 QC1.03 [0.73, 1.55]1.03-0.02 [-0.67, 0.41]1.34 [0.91, 1.83]56% [33%, 71%]88%100%——2026-08-01 → 2026-08-30
tmin00Znearestall25 1 QC1.03 [0.74, 1.65]1.03-0.02 [-0.90, 0.39]1.34 [0.93, 1.97]56% [31%, 71%]88%100%——2026-08-01 → 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 0, 00Z bilinear tmax+20+100-10-202026-08-01: -5.72 °F2026-08-06: -6.77 °F2026-08-08: -2.48 °F2026-08-09: -1.53 °F2026-08-10: -6.83 °F2026-08-11: -10.61 °F2026-08-12: -8.73 °F2026-08-13: -8.05 °F2026-08-14: -6.43 °F2026-08-15: -6.72 °F2026-08-16: -6.43 °F2026-08-17: -7.99 °F2026-08-18: -6.35 °F2026-08-19: -2.98 °F2026-08-20: -6.09 °F2026-08-21: -4.21 °F2026-08-22: -2.81 °F2026-08-23: -11.89 °F2026-08-24: -8.68 °F2026-08-25: -1.75 °F2026-08-26: -6.9 °F2026-08-27: -6.6 °F2026-08-28: -1.36 °F2026-08-29: -7.7 °F2026-08-30: -8.6 °F2026-08-012026-08-30°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 (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-8.60
2026-08-29-7.70
2026-08-28-1.36
2026-08-27-6.60
2026-08-26-6.90
2026-08-25-1.75
2026-08-24-8.68
2026-08-23-11.89
2026-08-22-2.81
2026-08-21-4.21
2026-08-20-6.09
2026-08-19-2.98
2026-08-18-6.35
2026-08-17-7.99
2026-08-16-6.43
2026-08-15-6.72
2026-08-14-6.43
2026-08-13-8.05
2026-08-12-8.73
2026-08-11-10.61
2026-08-10-6.83
2026-08-09-1.53
2026-08-08-2.48
2026-08-07—
2026-08-06-6.77
2026-08-05—
2026-08-04—
2026-08-03—
2026-08-02—
2026-08-01-5.72

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSFO, lead day 0-20 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: 4 days-8 to -6 °F: 11 days-6 to -4 °F: 2 days-4 to -2 °F: 3 days-2 to 0 °F: 3 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| 6.6 · P90 |e| 8.71 °F-200+20 °Fn = 25 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
-10.00-8.004
-8.00-6.0011
-6.00-4.002
-4.00-2.003
-2.00+0.003
+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
2026-08256.17 -6.17

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-01 → 2026-08-30 25
ECMWF IFS HRES2026-08-01 → 2026-08-30 25

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 25 +1.75 [1.23, 2.39] yes
Aurora (GFS init) 2 +0.46 [0.22, 0.71] yes
Aurora (IFS init) 3 +0.46 [0.03, 1.34] yes
FourCastNet v2 (GFS init) 2 +3.14 [2.97, 3.31] yes
FourCastNet v2 (IFS init) 3 +2.55 [-0.84, 4.64] no
NCEP GFS 25 +1.63 [0.85, 2.26] yes
GraphCast (GFS init) 2 +1.96 [1.31, 2.61] yes
GraphCast (IFS init) 23 +1.68 [0.96, 2.36] yes
Pangu-Weather (GFS init) 2 +0.86 [0.77, 0.94] yes
Pangu-Weather (IFS init) 3 +1.15 [0.42, 2.07] yes

Cite this page

ShortCastCheck, KSFO ifs_hres lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSFO/model/ifs_hres/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSFO (San Francisco Intl), model ifs_hres, lead day 0. 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/0/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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