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

San Diego Lindbergh · ECMWF IFS HRES · lead day 4

KSAN · ifs_hres · lead 4

Target day = initialization date + 4 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
tmax00Zbilinear30d20 1 QC5.69 [4.63, 6.71]1.75-5.66 [-6.70, -4.58]6.19 [5.04, 7.11]5% [0%, 14%]10%10%-0.81+0.432026-08-05 → 2026-08-30
tmax00Zbilinear90d20 1 QC5.69 [4.54, 6.75]1.75-5.66 [-6.73, -4.50]6.19 [4.95, 7.12]5% [0%, 14%]10%10%-0.81+0.432026-08-05 → 2026-08-30
tmax00Zbilinear365d20 1 QC5.69 [4.54, 6.77]1.75-5.66 [-6.77, -4.47]6.19 [4.95, 7.22]5% [0%, 14%]10%10%-0.81+0.432026-08-05 → 2026-08-30
tmax00Zbilinearall20 1 QC5.69 [4.54, 6.87]1.75-5.66 [-6.87, -4.52]6.19 [4.93, 7.22]5% [0%, 14%]10%10%-0.81+0.432026-08-05 → 2026-08-30
tmax00Znearest30d20 1 QC9.44 [7.71, 10.76]2.08-9.44 [-10.76, -7.71]9.81 [7.83, 11.15]0% [0%, 0%]0%0%-2.00+0.322026-08-05 → 2026-08-30
tmax00Znearest90d20 1 QC9.44 [7.70, 10.80]2.08-9.44 [-10.80, -7.70]9.81 [7.79, 11.16]0% [0%, 0%]0%0%-2.00+0.322026-08-05 → 2026-08-30
tmax00Znearest365d20 1 QC9.44 [7.65, 10.94]2.08-9.44 [-10.94, -7.65]9.81 [7.74, 11.33]0% [0%, 0%]0%0%-2.00+0.322026-08-05 → 2026-08-30
tmax00Znearestall20 1 QC9.44 [7.60, 11.00]2.08-9.44 [-11.00, -7.60]9.81 [7.69, 11.34]0% [0%, 0%]0%0%-2.00+0.322026-08-05 → 2026-08-30
tmax12Zbilinear30d21 1 QC5.67 [4.82, 6.59]1.81-5.61 [-6.59, -4.74]6.10 [5.09, 6.94]5% [0%, 14%]5%10%-0.80+0.422026-08-05 → 2026-08-30
tmax12Zbilinear90d21 1 QC5.67 [4.71, 6.57]1.81-5.61 [-6.55, -4.55]6.10 [4.98, 6.98]5% [0%, 14%]5%10%-0.80+0.422026-08-05 → 2026-08-30
tmax12Zbilinear365d21 1 QC5.67 [4.58, 6.71]1.81-5.61 [-6.71, -4.54]6.10 [4.95, 7.03]5% [0%, 14%]5%10%-0.80+0.422026-08-05 → 2026-08-30
tmax12Zbilinearall21 1 QC5.67 [4.62, 6.77]1.81-5.61 [-6.77, -4.51]6.10 [4.84, 7.11]5% [0%, 14%]5%10%-0.80+0.422026-08-05 → 2026-08-30
tmax12Znearest30d21 1 QC9.28 [7.57, 10.62]2.10-9.28 [-10.62, -7.57]9.66 [7.70, 11.00]0% [0%, 0%]0%0%-1.95+0.322026-08-05 → 2026-08-30
tmax12Znearest90d21 1 QC9.28 [7.42, 10.65]2.10-9.28 [-10.65, -7.42]9.66 [7.54, 11.04]0% [0%, 0%]0%0%-1.95+0.322026-08-05 → 2026-08-30
tmax12Znearest365d21 1 QC9.28 [7.45, 10.77]2.10-9.28 [-10.77, -7.45]9.66 [7.57, 11.13]0% [0%, 0%]0%0%-1.95+0.322026-08-05 → 2026-08-30
tmax12Znearestall21 1 QC9.28 [7.38, 10.76]2.10-9.28 [-10.76, -7.38]9.66 [7.42, 11.12]0% [0%, 0%]0%0%-1.95+0.322026-08-05 → 2026-08-30
tmin00Zbilinear30d20 1 QC1.35 [0.98, 1.72]1.27-0.77 [-1.27, -0.24]1.63 [1.34, 1.87]45% [23%, 67%]65%100%-0.13-0.062026-08-05 → 2026-08-30
tmin00Zbilinear90d20 1 QC1.35 [0.93, 1.80]1.27-0.77 [-1.40, -0.04]1.63 [1.27, 1.89]45% [18%, 71%]65%100%-0.13-0.062026-08-05 → 2026-08-30
tmin00Zbilinear365d20 1 QC1.35 [0.91, 1.83]1.27-0.77 [-1.43, -0.07]1.63 [1.28, 1.90]45% [17%, 71%]65%100%-0.13-0.062026-08-05 → 2026-08-30
tmin00Zbilinearall20 1 QC1.35 [0.90, 1.84]1.27-0.77 [-1.45, 0.01]1.63 [1.24, 1.91]45% [17%, 72%]65%100%-0.13-0.062026-08-05 → 2026-08-30
tmin00Znearest30d20 1 QC1.23 [0.93, 1.59]1.19-0.75 [-1.18, -0.32]1.55 [1.12, 1.95]50% [22%, 65%]85%95%-0.03+0.002026-08-05 → 2026-08-30
tmin00Znearest90d20 1 QC1.23 [0.96, 1.67]1.19-0.75 [-1.27, -0.16]1.55 [1.09, 2.00]50% [0%, 65%]85%95%-0.03+0.002026-08-05 → 2026-08-30
tmin00Znearest365d20 1 QC1.23 [0.95, 1.69]1.19-0.75 [-1.34, -0.14]1.55 [1.08, 2.02]50% [0%, 67%]85%95%-0.03+0.002026-08-05 → 2026-08-30
tmin00Znearestall20 1 QC1.23 [0.93, 1.70]1.19-0.75 [-1.31, -0.07]1.55 [1.08, 2.01]50% [0%, 65%]85%95%-0.03+0.002026-08-05 → 2026-08-30
tmin12Zbilinear30d21 1 QC1.26 [1.00, 1.61]1.11-0.84 [-1.32, -0.30]1.55 [1.25, 1.88]48% [27%, 66%]76%95%-0.02+0.122026-08-05 → 2026-08-30
tmin12Zbilinear90d21 1 QC1.26 [0.96, 1.69]1.11-0.84 [-1.41, -0.12]1.55 [1.19, 1.93]48% [23%, 69%]76%95%-0.02+0.122026-08-05 → 2026-08-30
tmin12Zbilinear365d21 1 QC1.26 [0.97, 1.72]1.11-0.84 [-1.48, -0.15]1.55 [1.20, 1.99]48% [20%, 72%]76%95%-0.02+0.122026-08-05 → 2026-08-30
tmin12Zbilinearall21 1 QC1.26 [0.96, 1.72]1.11-0.84 [-1.50, -0.07]1.55 [1.16, 1.99]48% [20%, 70%]76%95%-0.02+0.122026-08-05 → 2026-08-30
tmin12Znearest30d21 1 QC1.13 [0.88, 1.53]1.07-0.69 [-1.15, -0.25]1.39 [1.11, 1.69]52% [23%, 71%]86%100%+0.09+0.152026-08-05 → 2026-08-30
tmin12Znearest90d21 1 QC1.13 [0.89, 1.59]1.07-0.69 [-1.25, -0.07]1.39 [1.11, 1.76]52% [0%, 69%]86%100%+0.09+0.152026-08-05 → 2026-08-30
tmin12Znearest365d21 1 QC1.13 [0.87, 1.59]1.07-0.69 [-1.27, -0.07]1.39 [1.09, 1.79]52% [0%, 73%]86%100%+0.09+0.152026-08-05 → 2026-08-30
tmin12Znearestall21 1 QC1.13 [0.89, 1.58]1.07-0.69 [-1.23, -0.07]1.39 [1.11, 1.76]52% [0%, 71%]86%100%+0.09+0.152026-08-05 → 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 KSAN, lead day 4, 00Z bilinear tmax+20+100-10-202026-08-05: -5.13 °F2026-08-11: -5.91 °F2026-08-12: -6.03 °F2026-08-13: -4.43 °F2026-08-14: -4.6 °F2026-08-16: -4.29 °F2026-08-17: -5.45 °F2026-08-18: -5.95 °F2026-08-19: -4.84 °F2026-08-20: -7.73 °F2026-08-21: -7.37 °F2026-08-22: -7.27 °F2026-08-23: -10.46 °F2026-08-24: -5.09 °F2026-08-25: -5.55 °F2026-08-26: -11.07 °F2026-08-27: +0.35 °F2026-08-28: -1.19 °F2026-08-29: -6.6 °F2026-08-30: -4.57 °F2026-08-052026-08-30°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 (26 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-4.57
2026-08-29-6.60
2026-08-28-1.19
2026-08-27+0.35
2026-08-26-11.07
2026-08-25-5.55
2026-08-24-5.09
2026-08-23-10.46
2026-08-22-7.27
2026-08-21-7.37
2026-08-20-7.73
2026-08-19-4.84
2026-08-18-5.95
2026-08-17-5.45
2026-08-16-4.29
2026-08-15—
2026-08-14-4.60
2026-08-13-4.43
2026-08-12-6.03
2026-08-11-5.91
2026-08-10—
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05-5.13

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSAN, lead day 4-20 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: 0 days-8 to -6 °F: 5 days-6 to -4 °F: 11 days-4 to -2 °F: 0 days-2 to 0 °F: 1 day0 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| 5.5 · P90 |e| 8 °F-200+20 °Fn = 20 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
-10.00-8.000
-8.00-6.005
-6.00-4.0011
-4.00-2.000
-2.00+0.001
+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
2026-08205.69 -5.66

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 20
ECMWF IFS HRES2026-08-05 → 2026-08-30 21
ECMWF IFS HRES2026-08-05 → 2026-08-30 21

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 20 +2.37 [1.32, 3.33] yes
NCEP GFS 20 +2.71 [1.16, 4.20] yes
GraphCast (IFS init) 19 -0.07 [-2.39, 1.11] no
Persistence (baseline) 20 +2.54 [0.73, 3.94] yes

Cite this page

ShortCastCheck, KSAN ifs_hres lead 4, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSAN/model/ifs_hres/lead/4/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAN (San Diego Lindbergh), model ifs_hres, lead day 4. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KSAN/model/ifs_hres/lead/4/

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