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 2

KSAN · gfs · 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, 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
tmax00Zbilinear30d28 1 QC2.82 [2.07, 3.57]1.33-2.78 [-3.57, -1.97]3.33 [2.44, 4.22]14% [3%, 31%]29%61%-0.24+0.412026-08-03 → 2026-08-30
tmax00Zbilinear90d28 1 QC2.82 [1.92, 3.58]1.33-2.78 [-3.56, -1.76]3.33 [2.27, 4.18]14% [0%, 33%]29%61%-0.24+0.412026-08-03 → 2026-08-30
tmax00Zbilinear365d28 1 QC2.82 [1.89, 3.69]1.33-2.78 [-3.68, -1.75]3.33 [2.22, 4.37]14% [0%, 33%]29%61%-0.24+0.412026-08-03 → 2026-08-30
tmax00Zbilinearall28 1 QC2.82 [1.84, 3.67]1.33-2.78 [-3.67, -1.71]3.33 [2.29, 4.32]14% [0%, 39%]29%61%-0.24+0.412026-08-03 → 2026-08-30
tmax00Znearest30d28 1 QC5.14 [4.30, 6.02]1.24-5.14 [-6.02, -4.30]5.48 [4.57, 6.50]0% [0%, 0%]4%11%-1.25+0.452026-08-03 → 2026-08-30
tmax00Znearest90d28 1 QC5.14 [4.12, 5.99]1.24-5.14 [-5.99, -4.12]5.48 [4.35, 6.50]0% [0%, 0%]4%11%-1.25+0.452026-08-03 → 2026-08-30
tmax00Znearest365d28 1 QC5.14 [4.11, 6.12]1.24-5.14 [-6.12, -4.11]5.48 [4.35, 6.67]0% [0%, 0%]4%11%-1.25+0.452026-08-03 → 2026-08-30
tmax00Znearestall28 1 QC5.14 [4.07, 6.10]1.24-5.14 [-6.10, -4.07]5.48 [4.33, 6.61]0% [0%, 0%]4%11%-1.25+0.452026-08-03 → 2026-08-30
tmax12Zbilinear30d28 1 QC2.98 [2.27, 3.69]1.49-2.91 [-3.68, -2.13]3.57 [2.66, 4.52]18% [7%, 35%]32%61%-0.30+0.342026-08-03 → 2026-08-30
tmax12Zbilinear90d28 1 QC2.98 [2.17, 3.67]1.49-2.91 [-3.65, -2.04]3.57 [2.56, 4.50]18% [7%, 40%]32%61%-0.30+0.342026-08-03 → 2026-08-30
tmax12Zbilinear365d28 1 QC2.98 [2.10, 3.80]1.49-2.91 [-3.80, -1.92]3.57 [2.49, 4.69]18% [5%, 40%]32%61%-0.30+0.342026-08-03 → 2026-08-30
tmax12Zbilinearall28 1 QC2.98 [2.09, 3.77]1.49-2.91 [-3.77, -1.92]3.57 [2.55, 4.61]18% [5%, 42%]32%61%-0.30+0.342026-08-03 → 2026-08-30
tmax12Znearest30d28 1 QC5.27 [4.53, 6.20]1.36-5.27 [-6.20, -4.53]5.67 [4.76, 6.81]0% [0%, 0%]0%7%-1.31+0.402026-08-03 → 2026-08-30
tmax12Znearest90d28 1 QC5.27 [4.39, 6.16]1.36-5.27 [-6.16, -4.39]5.67 [4.59, 6.82]0% [0%, 0%]0%7%-1.31+0.402026-08-03 → 2026-08-30
tmax12Znearest365d28 1 QC5.27 [4.35, 6.33]1.36-5.27 [-6.33, -4.35]5.67 [4.54, 7.03]0% [0%, 0%]0%7%-1.31+0.402026-08-03 → 2026-08-30
tmax12Znearestall28 1 QC5.27 [4.33, 6.26]1.36-5.27 [-6.26, -4.33]5.67 [4.53, 6.93]0% [0%, 0%]0%7%-1.31+0.402026-08-03 → 2026-08-30
tmin00Zbilinear30d28 1 QC2.54 [1.87, 3.25]1.23+2.39 [1.48, 3.23]2.87 [2.13, 3.55]11% [0%, 23%]32%64%-1.63-0.212026-08-03 → 2026-08-30
tmin00Zbilinear90d28 1 QC2.54 [1.84, 3.27]1.23+2.39 [1.42, 3.26]2.87 [2.10, 3.59]11% [0%, 24%]32%64%-1.63-0.212026-08-03 → 2026-08-30
tmin00Zbilinear365d28 1 QC2.54 [1.73, 3.33]1.23+2.39 [1.31, 3.33]2.87 [2.02, 3.61]11% [0%, 27%]32%64%-1.63-0.212026-08-03 → 2026-08-30
tmin00Zbilinearall28 1 QC2.54 [1.74, 3.38]1.23+2.39 [1.36, 3.38]2.87 [2.01, 3.66]11% [0%, 26%]32%64%-1.63-0.212026-08-03 → 2026-08-30
tmin00Znearest30d28 1 QC1.87 [1.45, 2.32]1.06+1.67 [0.97, 2.28]2.16 [1.65, 2.61]25% [10%, 40%]61%82%-0.94-0.042026-08-03 → 2026-08-30
tmin00Znearest90d28 1 QC1.87 [1.41, 2.33]1.06+1.67 [0.95, 2.30]2.16 [1.62, 2.61]25% [9%, 41%]61%82%-0.94-0.042026-08-03 → 2026-08-30
tmin00Znearest365d28 1 QC1.87 [1.35, 2.37]1.06+1.67 [0.82, 2.35]2.16 [1.54, 2.65]25% [7%, 43%]61%82%-0.94-0.042026-08-03 → 2026-08-30
tmin00Znearestall28 1 QC1.87 [1.36, 2.41]1.06+1.67 [0.86, 2.41]2.16 [1.57, 2.69]25% [5%, 43%]61%82%-0.94-0.042026-08-03 → 2026-08-30
tmin12Zbilinear30d28 1 QC2.39 [1.71, 3.14]1.20+2.23 [1.29, 3.12]2.75 [1.99, 3.49]18% [7%, 32%]32%75%-1.48-0.182026-08-03 → 2026-08-30
tmin12Zbilinear90d28 1 QC2.39 [1.68, 3.17]1.20+2.23 [1.26, 3.15]2.75 [1.96, 3.50]18% [4%, 34%]32%75%-1.48-0.182026-08-03 → 2026-08-30
tmin12Zbilinear365d28 1 QC2.39 [1.62, 3.22]1.20+2.23 [1.18, 3.22]2.75 [1.91, 3.54]18% [0%, 36%]32%75%-1.48-0.182026-08-03 → 2026-08-30
tmin12Zbilinearall28 1 QC2.39 [1.62, 3.32]1.20+2.23 [1.19, 3.32]2.75 [1.90, 3.60]18% [0%, 36%]32%75%-1.48-0.182026-08-03 → 2026-08-30
tmin12Znearest30d28 1 QC1.75 [1.34, 2.22]1.05+1.53 [0.82, 2.16]2.06 [1.52, 2.54]32% [20%, 46%]68%82%-0.81-0.032026-08-03 → 2026-08-30
tmin12Znearest90d28 1 QC1.75 [1.30, 2.23]1.05+1.53 [0.82, 2.19]2.06 [1.50, 2.55]32% [19%, 46%]68%82%-0.81-0.032026-08-03 → 2026-08-30
tmin12Znearest365d28 1 QC1.75 [1.28, 2.26]1.05+1.53 [0.69, 2.23]2.06 [1.47, 2.58]32% [18%, 48%]68%82%-0.81-0.032026-08-03 → 2026-08-30
tmin12Znearestall28 1 QC1.75 [1.27, 2.31]1.05+1.53 [0.73, 2.29]2.06 [1.47, 2.63]32% [18%, 48%]68%82%-0.81-0.032026-08-03 → 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 NCEP GFS at KSAN, lead day 2, 00Z bilinear tmax+10+50-5-102026-08-03: +0.29 °F2026-08-04: +0.27 °F2026-08-05: -2.54 °F2026-08-06: -2.95 °F2026-08-07: -2.32 °F2026-08-08: -1.27 °F2026-08-09: -2.52 °F2026-08-10: -3.03 °F2026-08-11: -3.04 °F2026-08-12: -3.62 °F2026-08-13: -4.57 °F2026-08-14: -4.13 °F2026-08-15: -3.41 °F2026-08-16: -1.94 °F2026-08-17: -2.03 °F2026-08-18: -1.32 °F2026-08-19: -0.77 °F2026-08-20: -2.44 °F2026-08-21: -3.47 °F2026-08-22: -2.66 °F2026-08-23: -5.28 °F2026-08-24: -2.8 °F2026-08-25: -2.04 °F2026-08-26: -8.3 °F2026-08-27: -4.62 °F2026-08-28: -0.02 °F2026-08-29: -5.64 °F2026-08-30: -1.77 °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
2026-08-30-1.77
2026-08-29-5.64
2026-08-28-0.02
2026-08-27-4.62
2026-08-26-8.30
2026-08-25-2.04
2026-08-24-2.80
2026-08-23-5.28
2026-08-22-2.66
2026-08-21-3.47
2026-08-20-2.44
2026-08-19-0.77
2026-08-18-1.32
2026-08-17-2.03
2026-08-16-1.94
2026-08-15-3.41
2026-08-14-4.13
2026-08-13-4.57
2026-08-12-3.62
2026-08-11-3.04
2026-08-10-3.03
2026-08-09-2.52
2026-08-08-1.27
2026-08-07-2.32
2026-08-06-2.95
2026-08-05-2.54
2026-08-04+0.27
2026-08-03+0.29

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KSAN, lead day 2-10 to -9 °F: 0 days-9 to -8 °F: 1 day-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 2 days-5 to -4 °F: 3 days-4 to -3 °F: 5 days-3 to -2 °F: 9 days-2 to -1 °F: 4 days-1 to 0 °F: 2 days0 to 1 °F: 2 days1 to 2 °F: 0 days2 to 3 °F: 0 days3 to 4 °F: 0 days4 to 5 °F: 0 days5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2.6 · P90 |e| 4.82 °F-100+10 °Fn = 28 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
-10.00-9.000
-9.00-8.001
-8.00-7.000
-7.00-6.000
-6.00-5.002
-5.00-4.003
-4.00-3.005
-3.00-2.009
-2.00-1.004
-1.00+0.002
+0.00+1.002
+1.00+2.000
+2.00+3.000
+3.00+4.000
+4.00+5.000
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08282.82 -2.78

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28
NCEP GFS2026-08-03 → 2026-08-30 28

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 28 -0.78 [-1.95, 0.35] no
Aurora (IFS init) 1 -2.08 [-2.08, -2.08] yes
FourCastNet v2 (IFS init) 1 +1.23 [1.23, 1.23] yes
GraphCast (IFS init) 26 -2.90 [-3.75, -2.02] yes
ECMWF IFS HRES 23 -2.85 [-3.69, -2.20] yes
Pangu-Weather (IFS init) 1 -3.08 [-3.08, -3.08] yes
Persistence (baseline) 28 +0.54 [-0.69, 1.24] no

Cite this page

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

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSAN (San Diego Lindbergh), model gfs, 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/KSAN/model/gfs/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