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 9

KNYC · gfs · lead 9

Target day = initialization date + 9 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
tmax00Zbilinear30d21 1 QC5.21 [3.33, 7.36]5.13+2.84 [0.30, 5.83]6.53 [4.34, 8.27]10% [0%, 17%]24%48%-0.44-0.572026-08-10 → 2026-08-30
tmax00Zbilinear90d21 1 QC5.21 [3.21, 7.73]5.13+2.84 [0.05, 6.48]6.53 [4.16, 8.46]10% [0%, 17%]24%48%-0.44-0.572026-08-10 → 2026-08-30
tmax00Zbilinear365d21 1 QC5.21 [2.96, 7.47]5.13+2.84 [0.07, 6.01]6.53 [3.91, 8.43]10% [0%, 17%]24%48%-0.44-0.572026-08-10 → 2026-08-30
tmax00Zbilinearall21 1 QC5.21 [3.10, 7.52]5.13+2.84 [0.07, 6.23]6.53 [3.93, 8.46]10% [0%, 17%]24%48%-0.44-0.572026-08-10 → 2026-08-30
tmax00Znearest30d21 1 QC5.22 [3.35, 7.41]5.06+3.03 [0.43, 6.04]6.58 [4.40, 8.44]10% [0%, 17%]33%48%-0.44-0.552026-08-10 → 2026-08-30
tmax00Znearest90d21 1 QC5.22 [3.20, 7.85]5.06+3.03 [0.22, 6.74]6.58 [4.16, 8.55]10% [0%, 17%]33%48%-0.44-0.552026-08-10 → 2026-08-30
tmax00Znearest365d21 1 QC5.22 [2.98, 7.49]5.06+3.03 [0.23, 6.17]6.58 [3.84, 8.51]10% [0%, 17%]33%48%-0.44-0.552026-08-10 → 2026-08-30
tmax00Znearestall21 1 QC5.22 [3.11, 7.51]5.06+3.03 [0.24, 6.47]6.58 [3.91, 8.56]10% [0%, 17%]33%48%-0.44-0.552026-08-10 → 2026-08-30
tmax12Zbilinear30d21 1 QC5.07 [3.28, 7.08]4.90+2.67 [0.62, 5.34]7.09 [4.09, 9.80]14% [0%, 25%]33%38%-0.40-0.502026-08-10 → 2026-08-30
tmax12Zbilinear90d21 1 QC5.07 [3.26, 7.30]4.90+2.67 [0.57, 5.72]7.09 [3.99, 10.01]14% [0%, 26%]33%38%-0.40-0.502026-08-10 → 2026-08-30
tmax12Zbilinear365d21 1 QC5.07 [2.96, 7.32]4.90+2.67 [0.52, 5.87]7.09 [3.68, 10.19]14% [0%, 29%]33%38%-0.40-0.502026-08-10 → 2026-08-30
tmax12Zbilinearall21 1 QC5.07 [3.07, 7.38]4.90+2.67 [0.52, 6.18]7.09 [3.78, 10.25]14% [0%, 25%]33%38%-0.40-0.502026-08-10 → 2026-08-30
tmax12Znearest30d21 1 QC5.14 [3.48, 7.13]4.88+2.82 [0.86, 5.39]7.12 [4.15, 9.89]14% [0%, 25%]33%38%-0.42-0.502026-08-10 → 2026-08-30
tmax12Znearest90d21 1 QC5.14 [3.44, 7.30]4.88+2.82 [0.80, 5.81]7.12 [4.06, 10.08]14% [0%, 27%]33%38%-0.42-0.502026-08-10 → 2026-08-30
tmax12Znearest365d21 1 QC5.14 [3.15, 7.32]4.88+2.82 [0.73, 5.90]7.12 [3.74, 10.32]14% [0%, 29%]33%38%-0.42-0.502026-08-10 → 2026-08-30
tmax12Znearestall21 1 QC5.14 [3.25, 7.33]4.88+2.82 [0.76, 6.27]7.12 [3.87, 10.36]14% [0%, 27%]33%38%-0.42-0.502026-08-10 → 2026-08-30
tmin00Zbilinear30d21 1 QC5.32 [3.36, 7.31]3.60+4.64 [2.22, 7.11]6.35 [4.15, 8.04]5% [0%, 13%]24%29%-0.53-0.422026-08-10 → 2026-08-30
tmin00Zbilinear90d21 1 QC5.32 [3.17, 7.53]3.60+4.64 [2.16, 7.42]6.35 [3.70, 8.26]5% [0%, 15%]24%29%-0.53-0.422026-08-10 → 2026-08-30
tmin00Zbilinear365d21 1 QC5.32 [3.08, 7.61]3.60+4.64 [2.01, 7.51]6.35 [3.68, 8.27]5% [0%, 15%]24%29%-0.53-0.422026-08-10 → 2026-08-30
tmin00Zbilinearall21 1 QC5.32 [2.94, 8.11]3.60+4.64 [1.76, 8.11]6.35 [3.41, 8.56]5% [0%, 15%]24%29%-0.53-0.422026-08-10 → 2026-08-30
tmin00Znearest30d21 1 QC5.44 [3.43, 7.48]3.51+4.88 [2.53, 7.29]6.47 [4.28, 8.19]10% [0%, 21%]24%29%-0.56-0.382026-08-10 → 2026-08-30
tmin00Znearest90d21 1 QC5.44 [3.37, 7.72]3.51+4.88 [2.47, 7.58]6.47 [4.02, 8.39]10% [0%, 22%]24%29%-0.56-0.382026-08-10 → 2026-08-30
tmin00Znearest365d21 1 QC5.44 [3.29, 7.76]3.51+4.88 [2.28, 7.68]6.47 [3.86, 8.39]10% [0%, 21%]24%29%-0.56-0.382026-08-10 → 2026-08-30
tmin00Znearestall21 1 QC5.44 [3.13, 8.24]3.51+4.88 [2.07, 8.24]6.47 [3.68, 8.66]10% [0%, 22%]24%29%-0.56-0.382026-08-10 → 2026-08-30
tmin12Zbilinear30d21 1 QC4.52 [2.59, 6.45]3.52+4.41 [2.55, 6.39]6.07 [3.36, 7.99]19% [5%, 30%]38%52%-0.30-0.382026-08-10 → 2026-08-30
tmin12Zbilinear90d21 1 QC4.52 [2.49, 6.61]3.52+4.41 [2.47, 6.52]6.07 [3.10, 8.12]19% [0%, 30%]38%52%-0.30-0.382026-08-10 → 2026-08-30
tmin12Zbilinear365d21 1 QC4.52 [2.47, 6.71]3.52+4.41 [2.44, 6.66]6.07 [3.08, 8.20]19% [0%, 30%]38%52%-0.30-0.382026-08-10 → 2026-08-30
tmin12Zbilinearall21 1 QC4.52 [2.47, 7.16]3.52+4.41 [2.44, 7.16]6.07 [3.13, 8.33]19% [0%, 30%]38%52%-0.30-0.382026-08-10 → 2026-08-30
tmin12Znearest30d21 1 QC4.76 [2.85, 6.68]3.43+4.71 [2.85, 6.65]6.22 [3.58, 8.15]14% [0%, 28%]29%52%-0.37-0.352026-08-10 → 2026-08-30
tmin12Znearest90d21 1 QC4.76 [2.75, 6.87]3.43+4.71 [2.75, 6.81]6.22 [3.32, 8.26]14% [0%, 29%]29%52%-0.37-0.352026-08-10 → 2026-08-30
tmin12Znearest365d21 1 QC4.76 [2.75, 6.96]3.43+4.71 [2.75, 6.93]6.22 [3.31, 8.34]14% [0%, 29%]29%52%-0.37-0.352026-08-10 → 2026-08-30
tmin12Znearestall21 1 QC4.76 [2.76, 7.31]3.43+4.71 [2.76, 7.31]6.22 [3.30, 8.49]14% [0%, 29%]29%52%-0.37-0.352026-08-10 → 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 9, 00Z bilinear tmax+20+100-10-202026-08-10: +8.84 °F2026-08-11: +10.4 °F2026-08-12: +9.24 °F2026-08-13: -2.58 °F2026-08-14: -2.19 °F2026-08-15: +1.6 °F2026-08-16: +1.21 °F2026-08-17: -2.46 °F2026-08-18: -0.41 °F2026-08-19: -5.82 °F2026-08-20: +2.1 °F2026-08-21: -2.83 °F2026-08-22: +14.56 °F2026-08-23: +11.03 °F2026-08-24: +6.09 °F2026-08-25: +8.69 °F2026-08-26: -1.26 °F2026-08-27: +0.24 °F2026-08-28: -7.29 °F2026-08-29: +5.56 °F2026-08-30: +5.01 °F2026-08-102026-08-30°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 (21 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+5.01
2026-08-29+5.56
2026-08-28-7.29
2026-08-27+0.24
2026-08-26-1.26
2026-08-25+8.69
2026-08-24+6.09
2026-08-23+11.03
2026-08-22+14.56
2026-08-21-2.83
2026-08-20+2.10
2026-08-19-5.82
2026-08-18-0.41
2026-08-17-2.46
2026-08-16+1.21
2026-08-15+1.60
2026-08-14-2.19
2026-08-13-2.58
2026-08-12+9.24
2026-08-11+10.40
2026-08-10+8.84

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KNYC, lead day 9-20 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: 1 day-6 to -4 °F: 1 day-4 to -2 °F: 4 days-2 to 0 °F: 2 days0 to 2 °F: 3 days2 to 4 °F: 1 day4 to 6 °F: 2 days6 to 8 °F: 1 day8 to 10 °F: 3 days10 to 12 °F: 2 days12 to 14 °F: 0 days14 to 16 °F: 1 day16 to 18 °F: 0 days18 to 20 °F: 0 daysdashed: P50 |e| 5.01 · P90 |e| 10.4 °F-200+20 °Fn = 21 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
-8.00-6.001
-6.00-4.001
-4.00-2.004
-2.00+0.002
+0.00+2.003
+2.00+4.001
+4.00+6.002
+6.00+8.001
+8.00+10.003
+10.00+12.002
+12.00+14.000
+14.00+16.001
+16.00+18.000
+18.00+20.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08215.21 +2.84

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21
NCEP GFS2026-08-10 → 2026-08-30 21

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 21 +0.77 [-2.20, 4.10] no
GraphCast (IFS init) 21 +0.84 [-1.71, 4.60] no
ECMWF IFS HRES 16 +0.92 [-1.85, 5.09] no
Persistence (baseline) 21 +1.59 [-0.76, 5.21] no

Cite this page

ShortCastCheck, KNYC gfs lead 9, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KNYC/model/gfs/lead/9/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KNYC (New York Central Park), model gfs, lead day 9. 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/9/

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