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

San Francisco Intl · ECMWF IFS HRES · lead day 2

KSFO · ifs_hres · lead 2

Target day = initialization date + 2 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
tmax00Zbilinear30d23 1 QC5.98 [5.06, 7.19]2.82-5.98 [-7.19, -5.06]6.88 [6.09, 7.96]9% [0%, 21%]17%22%-0.48+0.312026-08-03 → 2026-08-30
tmax00Zbilinear90d23 1 QC5.98 [5.15, 7.32]2.82-5.98 [-7.32, -5.15]6.88 [6.16, 8.02]9% [0%, 22%]17%22%-0.48+0.312026-08-03 → 2026-08-30
tmax00Zbilinear365d23 1 QC5.98 [5.02, 7.15]2.82-5.98 [-7.15, -5.02]6.88 [6.04, 7.95]9% [0%, 25%]17%22%-0.48+0.312026-08-03 → 2026-08-30
tmax00Zbilinearall23 1 QC5.98 [5.06, 7.89]2.82-5.98 [-7.89, -5.06]6.88 [6.10, 8.38]9% [0%, 21%]17%22%-0.48+0.312026-08-03 → 2026-08-30
tmax00Znearest30d23 1 QC3.27 [2.49, 4.35]3.26-0.12 [-1.68, 1.96]4.08 [3.01, 5.37]17% [8%, 31%]43%61%+0.19+0.202026-08-03 → 2026-08-30
tmax00Znearest90d23 1 QC3.27 [2.29, 4.58]3.26-0.12 [-1.69, 2.30]4.08 [2.89, 5.52]17% [7%, 39%]43%61%+0.19+0.202026-08-03 → 2026-08-30
tmax00Znearest365d23 1 QC3.27 [2.18, 4.58]3.26-0.12 [-1.74, 2.16]4.08 [2.75, 5.56]17% [5%, 36%]43%61%+0.19+0.202026-08-03 → 2026-08-30
tmax00Znearestall23 1 QC3.27 [2.22, 4.60]3.26-0.12 [-1.89, 2.30]4.08 [2.78, 5.60]17% [6%, 40%]43%61%+0.19+0.202026-08-03 → 2026-08-30
tmax12Zbilinear30d22 1 QC6.16 [5.36, 7.54]2.66-6.16 [-7.54, -5.36]7.00 [6.11, 8.32]9% [0%, 24%]9%14%-0.54+0.342026-08-03 → 2026-08-30
tmax12Zbilinear90d22 1 QC6.16 [5.40, 7.70]2.66-6.16 [-7.70, -5.40]7.00 [6.07, 8.48]9% [0%, 25%]9%14%-0.54+0.342026-08-03 → 2026-08-30
tmax12Zbilinear365d22 1 QC6.16 [5.28, 7.71]2.66-6.16 [-7.71, -5.28]7.00 [5.98, 8.33]9% [0%, 27%]9%14%-0.54+0.342026-08-03 → 2026-08-30
tmax12Zbilinearall22 1 QC6.16 [5.34, 8.00]2.66-6.16 [-8.00, -5.34]7.00 [6.10, 8.67]9% [0%, 25%]9%14%-0.54+0.342026-08-03 → 2026-08-30
tmax12Znearest30d22 1 QC3.23 [2.71, 3.85]3.20-0.34 [-1.68, 0.99]3.85 [3.23, 4.63]9% [0%, 20%]36%50%+0.19+0.212026-08-03 → 2026-08-30
tmax12Znearest90d22 1 QC3.23 [2.58, 3.94]3.20-0.34 [-1.74, 1.06]3.85 [3.05, 4.71]9% [0%, 22%]36%50%+0.19+0.212026-08-03 → 2026-08-30
tmax12Znearest365d22 1 QC3.23 [2.56, 3.97]3.20-0.34 [-1.82, 1.02]3.85 [3.04, 4.68]9% [0%, 21%]36%50%+0.19+0.212026-08-03 → 2026-08-30
tmax12Znearestall22 1 QC3.23 [2.52, 3.90]3.20-0.34 [-1.99, 1.00]3.85 [3.04, 4.70]9% [0%, 22%]36%50%+0.19+0.212026-08-03 → 2026-08-30
tmin00Zbilinear30d23 1 QC0.95 [0.65, 1.36]0.95-0.08 [-0.61, 0.34]1.17 [0.86, 1.52]57% [28%, 76%]91%100%+0.22+0.222026-08-03 → 2026-08-30
tmin00Zbilinear90d23 1 QC0.95 [0.68, 1.48]0.95-0.08 [-0.80, 0.34]1.17 [0.88, 1.61]57% [19%, 74%]91%100%+0.22+0.222026-08-03 → 2026-08-30
tmin00Zbilinear365d23 1 QC0.95 [0.64, 1.49]0.95-0.08 [-0.69, 0.36]1.17 [0.85, 1.60]57% [17%, 77%]91%100%+0.22+0.222026-08-03 → 2026-08-30
tmin00Zbilinearall23 1 QC0.95 [0.65, 1.48]0.95-0.08 [-0.85, 0.33]1.17 [0.87, 1.62]57% [20%, 74%]91%100%+0.22+0.222026-08-03 → 2026-08-30
tmin00Znearest30d23 1 QC1.22 [0.91, 1.65]1.22+0.04 [-0.54, 0.50]1.46 [1.14, 1.82]43% [17%, 62%]70%100%-0.00-0.002026-08-03 → 2026-08-30
tmin00Znearest90d23 1 QC1.22 [0.93, 1.77]1.22+0.04 [-0.70, 0.50]1.46 [1.15, 1.89]43% [6%, 61%]70%100%-0.00-0.002026-08-03 → 2026-08-30
tmin00Znearest365d23 1 QC1.22 [0.91, 1.78]1.22+0.04 [-0.63, 0.54]1.46 [1.12, 1.92]43% [0%, 62%]70%100%-0.00-0.002026-08-03 → 2026-08-30
tmin00Znearestall23 1 QC1.22 [0.91, 1.82]1.22+0.04 [-0.82, 0.50]1.46 [1.13, 1.92]43% [0%, 63%]70%100%-0.00-0.002026-08-03 → 2026-08-30
tmin12Zbilinear30d22 1 QC0.87 [0.55, 1.29]0.88-0.03 [-0.48, 0.37]1.08 [0.78, 1.40]68% [42%, 85%]100%100%+0.29+0.292026-08-03 → 2026-08-30
tmin12Zbilinear90d22 1 QC0.87 [0.58, 1.39]0.88-0.03 [-0.65, 0.37]1.08 [0.80, 1.47]68% [35%, 85%]100%100%+0.29+0.292026-08-03 → 2026-08-30
tmin12Zbilinear365d22 1 QC0.87 [0.53, 1.38]0.88-0.03 [-0.56, 0.42]1.08 [0.77, 1.46]68% [37%, 86%]100%100%+0.29+0.292026-08-03 → 2026-08-30
tmin12Zbilinearall22 1 QC0.87 [0.55, 1.41]0.88-0.03 [-0.73, 0.38]1.08 [0.78, 1.48]68% [33%, 85%]100%100%+0.29+0.292026-08-03 → 2026-08-30
tmin12Znearest30d22 1 QC1.24 [0.96, 1.61]1.21+0.14 [-0.40, 0.59]1.45 [1.13, 1.76]45% [25%, 63%]77%100%-0.01+0.012026-08-03 → 2026-08-30
tmin12Znearest90d22 1 QC1.24 [0.99, 1.69]1.21+0.14 [-0.52, 0.62]1.45 [1.17, 1.81]45% [20%, 62%]77%100%-0.01+0.012026-08-03 → 2026-08-30
tmin12Znearest365d22 1 QC1.24 [0.94, 1.70]1.21+0.14 [-0.48, 0.65]1.45 [1.11, 1.85]45% [20%, 63%]77%100%-0.01+0.012026-08-03 → 2026-08-30
tmin12Znearestall22 1 QC1.24 [0.97, 1.69]1.21+0.14 [-0.69, 0.63]1.45 [1.13, 1.83]45% [20%, 63%]77%100%-0.01+0.012026-08-03 → 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 2, 00Z bilinear tmax+20+100-10-202026-08-03: -10.87 °F2026-08-08: -1.14 °F2026-08-09: -0.57 °F2026-08-10: -7 °F2026-08-11: -9.91 °F2026-08-13: -8.21 °F2026-08-14: -6.14 °F2026-08-15: -5.14 °F2026-08-16: -6.77 °F2026-08-17: -8.89 °F2026-08-18: -4.33 °F2026-08-19: -2.77 °F2026-08-20: -6.45 °F2026-08-21: -4.63 °F2026-08-22: -3.46 °F2026-08-23: -13.6 °F2026-08-24: -8.01 °F2026-08-25: -1.72 °F2026-08-26: -6.95 °F2026-08-27: -3.26 °F2026-08-28: -0.33 °F2026-08-29: -8.44 °F2026-08-30: -8.95 °F2026-08-032026-08-30°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 (28 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-8.95
2026-08-29-8.44
2026-08-28-0.33
2026-08-27-3.26
2026-08-26-6.95
2026-08-25-1.72
2026-08-24-8.01
2026-08-23-13.60
2026-08-22-3.46
2026-08-21-4.63
2026-08-20-6.45
2026-08-19-2.77
2026-08-18-4.33
2026-08-17-8.89
2026-08-16-6.77
2026-08-15-5.14
2026-08-14-6.14
2026-08-13-8.21
2026-08-12—
2026-08-11-9.91
2026-08-10-7.00
2026-08-09-0.57
2026-08-08-1.14
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04—
2026-08-03-10.87

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSFO, lead day 2-20 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: 6 days-8 to -6 °F: 5 days-6 to -4 °F: 3 days-4 to -2 °F: 3 days-2 to 0 °F: 4 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| 6.45 · P90 |e| 9.72 °F-200+20 °Fn = 23 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
-10.00-8.006
-8.00-6.005
-6.00-4.003
-4.00-2.003
-2.00+0.004
+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
2026-08235.98 -5.98

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-03 → 2026-08-30 23
ECMWF IFS HRES2026-08-03 → 2026-08-30 23
ECMWF IFS HRES2026-08-03 → 2026-08-30 22
ECMWF IFS HRES2026-08-03 → 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 23 +1.53 [0.87, 2.40] yes
Aurora (IFS init) 1 +0.61 [0.61, 0.61] yes
FourCastNet v2 (IFS init) 1 +7.33 [7.33, 7.33] yes
NCEP GFS 23 +1.24 [0.41, 2.15] yes
GraphCast (IFS init) 21 +1.11 [0.12, 2.35] yes
Pangu-Weather (IFS init) 1 +2.56 [2.56, 2.56] yes
Persistence (baseline) 23 +1.94 [-0.45, 4.10] no

Cite this page

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

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

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