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

New York Central Park · NCEP GFS · lead day 6

KNYC · gfs · lead 6

Target day = initialization date + 6 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
tmax00Zbilinear30d24 1 QC4.45 [3.29, 6.12]3.27+3.63 [1.51, 5.97]5.37 [4.00, 6.92]8% [0%, 16%]29%42%-0.21+0.042026-08-07 → 2026-08-30
tmax00Zbilinear90d24 1 QC4.45 [3.26, 6.39]3.27+3.63 [1.60, 6.22]5.37 [3.97, 7.18]8% [0%, 15%]29%42%-0.21+0.042026-08-07 → 2026-08-30
tmax00Zbilinear365d24 1 QC4.45 [3.18, 6.39]3.27+3.63 [1.26, 6.31]5.37 [3.83, 7.16]8% [0%, 15%]29%42%-0.21+0.042026-08-07 → 2026-08-30
tmax00Zbilinearall24 1 QC4.45 [3.19, 6.44]3.27+3.63 [1.27, 6.43]5.37 [3.93, 7.27]8% [0%, 15%]29%42%-0.21+0.042026-08-07 → 2026-08-30
tmax00Znearest30d24 1 QC4.58 [3.38, 6.26]3.26+3.84 [1.78, 6.14]5.52 [4.11, 7.07]8% [0%, 16%]29%38%-0.25+0.042026-08-07 → 2026-08-30
tmax00Znearest90d24 1 QC4.58 [3.36, 6.56]3.26+3.84 [1.86, 6.42]5.52 [4.13, 7.37]8% [0%, 15%]29%38%-0.25+0.042026-08-07 → 2026-08-30
tmax00Znearest365d24 1 QC4.58 [3.28, 6.50]3.26+3.84 [1.53, 6.44]5.52 [3.94, 7.31]8% [0%, 15%]29%38%-0.25+0.042026-08-07 → 2026-08-30
tmax00Znearestall24 1 QC4.58 [3.29, 6.62]3.26+3.84 [1.53, 6.60]5.52 [4.00, 7.45]8% [0%, 15%]29%38%-0.25+0.042026-08-07 → 2026-08-30
tmax12Zbilinear30d24 1 QC4.13 [3.07, 5.58]3.48+2.35 [0.20, 5.25]5.05 [3.82, 6.27]12% [4%, 21%]33%46%-0.13-0.022026-08-07 → 2026-08-30
tmax12Zbilinear90d24 1 QC4.13 [3.04, 5.83]3.48+2.35 [-0.05, 5.83]5.05 [3.79, 6.48]12% [0%, 23%]33%46%-0.13-0.022026-08-07 → 2026-08-30
tmax12Zbilinear365d24 1 QC4.13 [2.91, 5.85]3.48+2.35 [-0.30, 5.84]5.05 [3.62, 6.52]12% [0%, 24%]33%46%-0.13-0.022026-08-07 → 2026-08-30
tmax12Zbilinearall24 1 QC4.13 [3.01, 5.92]3.48+2.35 [-0.13, 5.92]5.05 [3.77, 6.47]12% [0%, 22%]33%46%-0.13-0.022026-08-07 → 2026-08-30
tmax12Znearest30d24 1 QC4.23 [3.18, 5.70]3.44+2.59 [0.47, 5.41]5.11 [3.85, 6.37]8% [0%, 21%]25%46%-0.15-0.012026-08-07 → 2026-08-30
tmax12Znearest90d24 1 QC4.23 [3.09, 5.96]3.44+2.59 [0.28, 5.96]5.11 [3.78, 6.66]8% [0%, 22%]25%46%-0.15-0.012026-08-07 → 2026-08-30
tmax12Znearest365d24 1 QC4.23 [3.00, 5.96]3.44+2.59 [0.01, 5.96]5.11 [3.64, 6.60]8% [0%, 23%]25%46%-0.15-0.012026-08-07 → 2026-08-30
tmax12Znearestall24 1 QC4.23 [3.16, 6.03]3.44+2.59 [0.15, 6.03]5.11 [3.81, 6.65]8% [0%, 22%]25%46%-0.15-0.012026-08-07 → 2026-08-30
tmin00Zbilinear30d24 1 QC5.58 [4.62, 6.64]2.91+5.05 [3.76, 6.50]6.43 [5.24, 7.51]12% [0%, 27%]12%17%-0.69+0.122026-08-07 → 2026-08-30
tmin00Zbilinear90d24 1 QC5.58 [4.58, 6.77]2.91+5.05 [3.84, 6.72]6.43 [5.12, 7.58]12% [0%, 26%]12%17%-0.69+0.122026-08-07 → 2026-08-30
tmin00Zbilinear365d24 1 QC5.58 [4.56, 6.82]2.91+5.05 [3.72, 6.73]6.43 [5.07, 7.62]12% [0%, 29%]12%17%-0.69+0.122026-08-07 → 2026-08-30
tmin00Zbilinearall24 1 QC5.58 [4.53, 6.78]2.91+5.05 [3.74, 6.78]6.43 [4.98, 7.65]12% [0%, 29%]12%17%-0.69+0.122026-08-07 → 2026-08-30
tmin00Znearest30d24 1 QC5.76 [4.81, 6.82]2.90+5.32 [4.04, 6.71]6.65 [5.45, 7.71]12% [0%, 27%]12%12%-0.75+0.132026-08-07 → 2026-08-30
tmin00Znearest90d24 1 QC5.76 [4.80, 6.98]2.90+5.32 [4.10, 6.91]6.65 [5.38, 7.78]12% [0%, 26%]12%12%-0.75+0.132026-08-07 → 2026-08-30
tmin00Znearest365d24 1 QC5.76 [4.77, 6.95]2.90+5.32 [3.99, 6.91]6.65 [5.33, 7.81]12% [0%, 29%]12%12%-0.75+0.132026-08-07 → 2026-08-30
tmin00Znearestall24 1 QC5.76 [4.75, 6.97]2.90+5.32 [4.02, 6.91]6.65 [5.26, 7.88]12% [0%, 29%]12%12%-0.75+0.132026-08-07 → 2026-08-30
tmin12Zbilinear30d24 1 QC5.61 [4.24, 7.44]3.03+5.12 [3.49, 7.35]6.45 [5.25, 7.69]4% [0%, 12%]12%29%-0.71+0.092026-08-07 → 2026-08-30
tmin12Zbilinear90d24 1 QC5.61 [4.18, 8.04]3.03+5.12 [3.45, 8.04]6.45 [5.09, 8.15]4% [0%, 11%]12%29%-0.71+0.092026-08-07 → 2026-08-30
tmin12Zbilinear365d24 1 QC5.61 [4.00, 7.86]3.03+5.12 [3.27, 7.86]6.45 [5.06, 7.98]4% [0%, 14%]12%29%-0.71+0.092026-08-07 → 2026-08-30
tmin12Zbilinearall24 1 QC5.61 [4.00, 7.97]3.03+5.12 [3.31, 7.97]6.45 [4.90, 8.08]4% [0%, 12%]12%29%-0.71+0.092026-08-07 → 2026-08-30
tmin12Znearest30d24 1 QC5.77 [4.35, 7.61]3.00+5.36 [3.75, 7.56]6.63 [5.39, 7.87]4% [0%, 12%]12%25%-0.75+0.102026-08-07 → 2026-08-30
tmin12Znearest90d24 1 QC5.77 [4.29, 8.20]3.00+5.36 [3.69, 8.20]6.63 [5.29, 8.35]4% [0%, 11%]12%25%-0.75+0.102026-08-07 → 2026-08-30
tmin12Znearest365d24 1 QC5.77 [4.05, 8.02]3.00+5.36 [3.53, 8.02]6.63 [5.16, 8.15]4% [0%, 14%]12%25%-0.75+0.102026-08-07 → 2026-08-30
tmin12Znearestall24 1 QC5.77 [4.11, 8.10]3.00+5.36 [3.55, 8.10]6.63 [5.06, 8.29]4% [0%, 12%]12%25%-0.75+0.102026-08-07 → 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 KNYC, lead day 6, 00Z bilinear tmax+20+100-10-202026-08-07: +4.26 °F2026-08-08: +8.54 °F2026-08-09: +6.36 °F2026-08-10: +11.63 °F2026-08-11: +8.07 °F2026-08-12: +0.48 °F2026-08-13: -1.87 °F2026-08-14: +4.09 °F2026-08-15: -4.27 °F2026-08-16: -2.32 °F2026-08-17: +1.05 °F2026-08-18: -1.39 °F2026-08-19: +3.97 °F2026-08-20: +7.34 °F2026-08-21: +5.42 °F2026-08-22: +1.33 °F2026-08-23: +7.35 °F2026-08-24: +2.38 °F2026-08-25: +5.15 °F2026-08-26: +0.52 °F2026-08-27: +1.75 °F2026-08-28: +2.96 °F2026-08-29: +4.52 °F2026-08-30: +9.67 °F2026-08-072026-08-30°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 (24 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+9.67
2026-08-29+4.52
2026-08-28+2.96
2026-08-27+1.75
2026-08-26+0.52
2026-08-25+5.15
2026-08-24+2.38
2026-08-23+7.35
2026-08-22+1.33
2026-08-21+5.42
2026-08-20+7.34
2026-08-19+3.97
2026-08-18-1.39
2026-08-17+1.05
2026-08-16-2.32
2026-08-15-4.27
2026-08-14+4.09
2026-08-13-1.87
2026-08-12+0.48
2026-08-11+8.07
2026-08-10+11.63
2026-08-09+6.36
2026-08-08+8.54
2026-08-07+4.26

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KNYC, lead day 6-20 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: 0 days-10 to -8 °F: 0 days-8 to -6 °F: 0 days-6 to -4 °F: 1 day-4 to -2 °F: 1 day-2 to 0 °F: 2 days0 to 2 °F: 5 days2 to 4 °F: 3 days4 to 6 °F: 5 days6 to 8 °F: 3 days8 to 10 °F: 3 days10 to 12 °F: 1 day12 to 14 °F: 0 days14 to 16 °F: 0 days16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 4.17 · P90 |e| 8.4 °F-200+20 °Fn = 24 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
-12.00-10.000
-10.00-8.000
-8.00-6.000
-6.00-4.001
-4.00-2.001
-2.00+0.002
+0.00+2.005
+2.00+4.003
+4.00+6.005
+6.00+8.003
+8.00+10.003
+10.00+12.001
+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
2026-08244.45 +3.63

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24
NCEP GFS2026-08-07 → 2026-08-30 24

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 24 +2.16 [0.69, 4.45] yes
GraphCast (IFS init) 24 +2.07 [0.64, 4.37] yes
ECMWF IFS HRES 19 -0.03 [-1.72, 1.65] no
Persistence (baseline) 24 +0.78 [-0.62, 2.59] no

Cite this page

ShortCastCheck, KNYC gfs lead 6, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KNYC/model/gfs/lead/6/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KNYC (New York Central Park), model gfs, lead day 6. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KNYC/model/gfs/lead/6/

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