Raw model output on the native 0.25° grid — no MOS, no bias correction, no post-processing. Scores understate operational forecast quality. Read the fairness statement →

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

San Diego Lindbergh · NCEP GFS · lead day 7

KSAN · gfs · lead 7

Target day = initialization date + 7 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, gfs-0p25, 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 QC3.72 [2.42, 5.10]2.49-3.43 [-4.97, -1.89]4.57 [3.07, 5.88]13% [0%, 23%]35%43%+0.00+0.282026-08-08 → 2026-08-30
tmax00Zbilinear90d23 1 QC3.72 [2.36, 5.25]2.49-3.43 [-5.14, -1.78]4.57 [2.94, 5.89]13% [0%, 24%]35%43%+0.00+0.282026-08-08 → 2026-08-30
tmax00Zbilinear365d23 1 QC3.72 [2.27, 5.38]2.49-3.43 [-5.30, -1.76]4.57 [2.82, 6.02]13% [0%, 24%]35%43%+0.00+0.282026-08-08 → 2026-08-30
tmax00Zbilinearall23 1 QC3.72 [2.20, 5.40]2.49-3.43 [-5.31, -1.71]4.57 [2.74, 6.09]13% [0%, 25%]35%43%+0.00+0.282026-08-08 → 2026-08-30
tmax00Znearest30d23 1 QC5.79 [3.97, 7.59]2.41-5.79 [-7.59, -3.97]6.52 [4.61, 8.14]0% [0%, 0%]9%22%-0.55+0.302026-08-08 → 2026-08-30
tmax00Znearest90d23 1 QC5.79 [3.90, 7.67]2.41-5.79 [-7.67, -3.90]6.52 [4.51, 8.24]0% [0%, 0%]9%22%-0.55+0.302026-08-08 → 2026-08-30
tmax00Znearest365d23 1 QC5.79 [3.79, 7.88]2.41-5.79 [-7.88, -3.79]6.52 [4.41, 8.42]0% [0%, 0%]9%22%-0.55+0.302026-08-08 → 2026-08-30
tmax00Znearestall23 1 QC5.79 [3.71, 7.84]2.41-5.79 [-7.84, -3.71]6.52 [4.25, 8.42]0% [0%, 0%]9%22%-0.55+0.302026-08-08 → 2026-08-30
tmax12Zbilinear30d23 1 QC3.52 [2.27, 4.87]2.08-3.44 [-4.81, -2.17]4.34 [2.85, 5.56]17% [0%, 28%]35%48%+0.06+0.402026-08-08 → 2026-08-30
tmax12Zbilinear90d23 1 QC3.52 [2.24, 4.95]2.08-3.44 [-4.93, -2.11]4.34 [2.77, 5.66]17% [0%, 29%]35%48%+0.06+0.402026-08-08 → 2026-08-30
tmax12Zbilinear365d23 1 QC3.52 [2.09, 5.01]2.08-3.44 [-4.95, -1.98]4.34 [2.71, 5.76]17% [0%, 29%]35%48%+0.06+0.402026-08-08 → 2026-08-30
tmax12Zbilinearall23 1 QC3.52 [2.08, 5.01]2.08-3.44 [-4.93, -1.96]4.34 [2.63, 5.78]17% [0%, 29%]35%48%+0.06+0.402026-08-08 → 2026-08-30
tmax12Znearest30d23 1 QC5.88 [4.31, 7.55]2.22-5.88 [-7.55, -4.31]6.46 [4.63, 8.06]0% [0%, 0%]4%13%-0.57+0.362026-08-08 → 2026-08-30
tmax12Znearest90d23 1 QC5.88 [4.25, 7.73]2.22-5.88 [-7.73, -4.25]6.46 [4.54, 8.19]0% [0%, 0%]4%13%-0.57+0.362026-08-08 → 2026-08-30
tmax12Znearest365d23 1 QC5.88 [4.17, 7.81]2.22-5.88 [-7.81, -4.17]6.46 [4.48, 8.28]0% [0%, 0%]4%13%-0.57+0.362026-08-08 → 2026-08-30
tmax12Znearestall23 1 QC5.88 [4.13, 7.79]2.22-5.88 [-7.79, -4.13]6.46 [4.43, 8.26]0% [0%, 0%]4%13%-0.57+0.362026-08-08 → 2026-08-30
tmin00Zbilinear30d23 1 QC2.34 [1.49, 3.10]1.38+2.34 [1.48, 3.10]2.88 [1.87, 3.67]30% [13%, 50%]52%65%-0.42+0.152026-08-08 → 2026-08-30
tmin00Zbilinear90d23 1 QC2.34 [1.36, 3.14]1.38+2.34 [1.36, 3.14]2.88 [1.70, 3.73]30% [13%, 55%]52%65%-0.42+0.152026-08-08 → 2026-08-30
tmin00Zbilinear365d23 1 QC2.34 [1.36, 3.28]1.38+2.34 [1.36, 3.28]2.88 [1.56, 3.87]30% [12%, 52%]52%65%-0.42+0.152026-08-08 → 2026-08-30
tmin00Zbilinearall23 1 QC2.34 [1.36, 3.27]1.38+2.34 [1.36, 3.26]2.88 [1.56, 3.89]30% [11%, 53%]52%65%-0.42+0.152026-08-08 → 2026-08-30
tmin00Znearest30d23 1 QC1.81 [1.06, 2.38]1.29+1.54 [0.57, 2.31]2.23 [1.30, 2.80]30% [14%, 55%]65%83%-0.09+0.202026-08-08 → 2026-08-30
tmin00Znearest90d23 1 QC1.81 [0.98, 2.41]1.29+1.54 [0.43, 2.31]2.23 [1.21, 2.86]30% [14%, 62%]65%83%-0.09+0.202026-08-08 → 2026-08-30
tmin00Znearest365d23 1 QC1.81 [0.99, 2.47]1.29+1.54 [0.40, 2.43]2.23 [1.20, 2.92]30% [14%, 60%]65%83%-0.09+0.202026-08-08 → 2026-08-30
tmin00Znearestall23 1 QC1.81 [0.97, 2.49]1.29+1.54 [0.31, 2.38]2.23 [1.20, 2.91]30% [14%, 60%]65%83%-0.09+0.202026-08-08 → 2026-08-30
tmin12Zbilinear30d23 1 QC2.23 [1.64, 2.91]1.24+2.18 [1.54, 2.88]2.65 [1.91, 3.35]17% [9%, 27%]48%74%-0.35+0.242026-08-08 → 2026-08-30
tmin12Zbilinear90d23 1 QC2.23 [1.61, 2.99]1.24+2.18 [1.53, 2.96]2.65 [1.87, 3.42]17% [10%, 27%]48%74%-0.35+0.242026-08-08 → 2026-08-30
tmin12Zbilinear365d23 1 QC2.23 [1.58, 3.09]1.24+2.18 [1.50, 3.06]2.65 [1.86, 3.50]17% [8%, 29%]48%74%-0.35+0.242026-08-08 → 2026-08-30
tmin12Zbilinearall23 1 QC2.23 [1.57, 3.10]1.24+2.18 [1.49, 3.05]2.65 [1.82, 3.52]17% [8%, 29%]48%74%-0.35+0.242026-08-08 → 2026-08-30
tmin12Znearest30d23 1 QC1.63 [1.08, 2.20]1.19+1.45 [0.78, 2.11]2.01 [1.37, 2.55]43% [23%, 68%]61%87%+0.02+0.262026-08-08 → 2026-08-30
tmin12Znearest90d23 1 QC1.63 [1.01, 2.25]1.19+1.45 [0.66, 2.15]2.01 [1.27, 2.60]43% [22%, 71%]61%87%+0.02+0.262026-08-08 → 2026-08-30
tmin12Znearest365d23 1 QC1.63 [0.99, 2.33]1.19+1.45 [0.66, 2.22]2.01 [1.23, 2.65]43% [19%, 71%]61%87%+0.02+0.262026-08-08 → 2026-08-30
tmin12Znearestall23 1 QC1.63 [0.93, 2.30]1.19+1.45 [0.53, 2.20]2.01 [1.19, 2.60]43% [21%, 73%]61%87%+0.02+0.262026-08-08 → 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 NCEP GFS at KSAN, lead day 7, 00Z bilinear tmax+20+100-10-202026-08-08: -6.61 °F2026-08-09: -4.23 °F2026-08-10: -5.52 °F2026-08-11: -3.52 °F2026-08-12: -4.36 °F2026-08-13: +0.51 °F2026-08-14: +1.5 °F2026-08-15: -0.65 °F2026-08-16: -1.21 °F2026-08-17: -4.73 °F2026-08-18: -1.07 °F2026-08-19: -1.04 °F2026-08-20: -5.2 °F2026-08-21: -4.3 °F2026-08-22: +0.31 °F2026-08-23: -8.31 °F2026-08-24: -2.76 °F2026-08-25: -6.03 °F2026-08-26: -10.77 °F2026-08-27: -5.61 °F2026-08-28: -3.97 °F2026-08-29: -2.35 °F2026-08-30: +1.06 °F2026-08-082026-08-30°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 (23 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+1.06
2026-08-29-2.35
2026-08-28-3.97
2026-08-27-5.61
2026-08-26-10.77
2026-08-25-6.03
2026-08-24-2.76
2026-08-23-8.31
2026-08-22+0.31
2026-08-21-4.30
2026-08-20-5.20
2026-08-19-1.04
2026-08-18-1.07
2026-08-17-4.73
2026-08-16-1.21
2026-08-15-0.65
2026-08-14+1.50
2026-08-13+0.51
2026-08-12-4.36
2026-08-11-3.52
2026-08-10-5.52
2026-08-09-4.23
2026-08-08-6.61

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KSAN, lead day 7-20 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: 1 day-10 to -8 °F: 1 day-8 to -6 °F: 2 days-6 to -4 °F: 7 days-4 to -2 °F: 4 days-2 to 0 °F: 4 days0 to 2 °F: 4 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| 3.97 · P90 |e| 6.5 °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
-14.00-12.000
-12.00-10.001
-10.00-8.001
-8.00-6.002
-6.00-4.007
-4.00-2.004
-2.00+0.004
+0.00+2.004
+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
2026-08233.72 -3.43

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23
NCEP GFS2026-08-08 → 2026-08-30 23

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means NCEP GFS has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 23 +0.38 [-0.37, 1.47] no
GraphCast (IFS init) 23 -1.98 [-2.97, -0.89] yes
ECMWF IFS HRES 18 -1.73 [-3.33, 0.99] no
Persistence (baseline) 23 -0.02 [-1.18, 1.63] no

Cite this page

ShortCastCheck, KSAN gfs lead 7, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSAN/model/gfs/lead/7/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAN (San Diego Lindbergh), model gfs, lead day 7. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KSAN/model/gfs/lead/7/

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