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 8

KNYC · gfs · lead 8

Target day = initialization date + 8 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
tmax00Zbilinear30d22 1 QC3.67 [2.72, 4.87]3.40+1.72 [-0.11, 3.67]4.45 [3.35, 5.54]9% [0%, 21%]36%50%-0.08-0.032026-08-09 → 2026-08-30
tmax00Zbilinear90d22 1 QC3.67 [2.67, 5.24]3.40+1.72 [-0.09, 4.15]4.45 [3.31, 5.70]9% [0%, 25%]36%50%-0.08-0.032026-08-09 → 2026-08-30
tmax00Zbilinear365d22 1 QC3.67 [2.56, 5.04]3.40+1.72 [-0.32, 3.88]4.45 [3.26, 5.66]9% [0%, 25%]36%50%-0.08-0.032026-08-09 → 2026-08-30
tmax00Zbilinearall22 1 QC3.67 [2.49, 5.00]3.40+1.72 [-0.33, 4.18]4.45 [3.13, 5.65]9% [0%, 30%]36%50%-0.08-0.032026-08-09 → 2026-08-30
tmax00Znearest30d22 1 QC3.60 [2.62, 4.88]3.30+1.83 [0.04, 3.83]4.40 [3.24, 5.54]5% [0%, 12%]36%55%-0.06+0.012026-08-09 → 2026-08-30
tmax00Znearest90d22 1 QC3.60 [2.60, 5.18]3.30+1.83 [0.04, 4.25]4.40 [3.19, 5.74]5% [0%, 13%]36%55%-0.06+0.012026-08-09 → 2026-08-30
tmax00Znearest365d22 1 QC3.60 [2.52, 5.01]3.30+1.83 [-0.17, 4.00]4.40 [3.18, 5.66]5% [0%, 14%]36%55%-0.06+0.012026-08-09 → 2026-08-30
tmax00Znearestall22 1 QC3.60 [2.40, 5.02]3.30+1.83 [-0.17, 4.26]4.40 [3.04, 5.63]5% [0%, 14%]36%55%-0.06+0.012026-08-09 → 2026-08-30
tmax12Zbilinear30d22 1 QC4.30 [3.33, 5.84]3.35+3.05 [1.66, 5.10]5.18 [3.97, 6.59]9% [0%, 18%]18%41%-0.26-0.012026-08-09 → 2026-08-30
tmax12Zbilinear90d22 1 QC4.30 [3.38, 6.45]3.35+3.05 [1.63, 5.68]5.18 [4.01, 7.08]9% [0%, 17%]18%41%-0.26-0.012026-08-09 → 2026-08-30
tmax12Zbilinear365d22 1 QC4.30 [3.23, 6.34]3.35+3.05 [1.43, 5.67]5.18 [3.86, 7.04]9% [0%, 17%]18%41%-0.26-0.012026-08-09 → 2026-08-30
tmax12Zbilinearall22 1 QC4.30 [3.18, 7.01]3.35+3.05 [1.39, 6.11]5.18 [3.85, 7.56]9% [0%, 17%]18%41%-0.26-0.012026-08-09 → 2026-08-30
tmax12Znearest30d22 1 QC4.45 [3.50, 5.98]3.30+3.25 [1.89, 5.36]5.29 [4.08, 6.70]9% [0%, 18%]18%27%-0.31+0.002026-08-09 → 2026-08-30
tmax12Znearest90d22 1 QC4.45 [3.51, 6.79]3.30+3.25 [1.84, 5.97]5.29 [4.09, 7.33]9% [0%, 17%]18%27%-0.31+0.002026-08-09 → 2026-08-30
tmax12Znearest365d22 1 QC4.45 [3.40, 6.79]3.30+3.25 [1.68, 5.75]5.29 [4.01, 7.27]9% [0%, 17%]18%27%-0.31+0.002026-08-09 → 2026-08-30
tmax12Znearestall22 1 QC4.45 [3.37, 7.19]3.30+3.25 [1.67, 6.38]5.29 [3.99, 7.74]9% [0%, 17%]18%27%-0.31+0.002026-08-09 → 2026-08-30
tmin00Zbilinear30d22 1 QC5.12 [3.45, 6.83]3.08+4.73 [2.91, 6.57]6.08 [4.03, 7.75]5% [0%, 12%]18%27%-0.50+0.022026-08-09 → 2026-08-30
tmin00Zbilinear90d22 1 QC5.12 [3.41, 6.98]3.08+4.73 [2.86, 6.74]6.08 [4.00, 7.80]5% [0%, 14%]18%27%-0.50+0.022026-08-09 → 2026-08-30
tmin00Zbilinear365d22 1 QC5.12 [3.34, 7.05]3.08+4.73 [2.71, 6.93]6.08 [3.93, 7.88]5% [0%, 14%]18%27%-0.50+0.022026-08-09 → 2026-08-30
tmin00Zbilinearall22 1 QC5.12 [3.31, 7.33]3.08+4.73 [2.65, 7.17]6.08 [3.73, 8.06]5% [0%, 14%]18%27%-0.50+0.022026-08-09 → 2026-08-30
tmin00Znearest30d22 1 QC5.31 [3.60, 7.03]3.05+5.04 [3.24, 6.87]6.29 [4.24, 7.96]9% [0%, 22%]14%27%-0.56+0.032026-08-09 → 2026-08-30
tmin00Znearest90d22 1 QC5.31 [3.57, 7.22]3.05+5.04 [3.18, 7.02]6.29 [4.15, 8.03]9% [0%, 25%]14%27%-0.56+0.032026-08-09 → 2026-08-30
tmin00Znearest365d22 1 QC5.31 [3.49, 7.29]3.05+5.04 [3.02, 7.17]6.29 [4.05, 8.07]9% [0%, 25%]14%27%-0.56+0.032026-08-09 → 2026-08-30
tmin00Znearestall22 1 QC5.31 [3.43, 7.59]3.05+5.04 [2.97, 7.33]6.29 [3.99, 8.31]9% [0%, 30%]14%27%-0.56+0.032026-08-09 → 2026-08-30
tmin12Zbilinear30d22 1 QC5.58 [4.23, 7.10]3.67+5.01 [3.01, 7.01]6.79 [5.09, 8.43]14% [0%, 27%]18%27%-0.64-0.172026-08-09 → 2026-08-30
tmin12Zbilinear90d22 1 QC5.58 [4.11, 7.08]3.67+5.01 [2.87, 6.99]6.79 [4.90, 8.41]14% [0%, 28%]18%27%-0.64-0.172026-08-09 → 2026-08-30
tmin12Zbilinear365d22 1 QC5.58 [3.95, 7.23]3.67+5.01 [2.56, 7.14]6.79 [4.81, 8.51]14% [0%, 29%]18%27%-0.64-0.172026-08-09 → 2026-08-30
tmin12Zbilinearall22 1 QC5.58 [3.97, 7.79]3.67+5.01 [2.67, 7.79]6.79 [4.76, 8.51]14% [0%, 29%]18%27%-0.64-0.172026-08-09 → 2026-08-30
tmin12Znearest30d22 1 QC5.79 [4.38, 7.40]3.64+5.30 [3.26, 7.31]6.99 [5.23, 8.63]9% [0%, 23%]18%23%-0.70-0.162026-08-09 → 2026-08-30
tmin12Znearest90d22 1 QC5.79 [4.28, 7.31]3.64+5.30 [3.15, 7.30]6.99 [5.00, 8.62]9% [0%, 25%]18%23%-0.70-0.162026-08-09 → 2026-08-30
tmin12Znearest365d22 1 QC5.79 [4.10, 7.46]3.64+5.30 [2.83, 7.45]6.99 [4.91, 8.69]9% [0%, 27%]18%23%-0.70-0.162026-08-09 → 2026-08-30
tmin12Znearestall22 1 QC5.79 [4.08, 8.07]3.64+5.30 [2.95, 8.07]6.99 [4.88, 8.75]9% [0%, 29%]18%23%-0.70-0.162026-08-09 → 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 8, 00Z bilinear tmax+10+50-5-102026-08-09: +8.7 °F2026-08-10: +4.91 °F2026-08-11: +4.65 °F2026-08-12: -3.24 °F2026-08-13: -5.2 °F2026-08-14: +1.37 °F2026-08-15: -0.25 °F2026-08-16: +1.38 °F2026-08-17: -1.12 °F2026-08-18: -4.87 °F2026-08-19: -1.92 °F2026-08-20: +6.65 °F2026-08-21: +3.45 °F2026-08-22: +9.54 °F2026-08-23: +2.29 °F2026-08-24: +5.32 °F2026-08-25: +1.07 °F2026-08-26: -1.87 °F2026-08-27: +2.55 °F2026-08-28: -3 °F2026-08-29: +6.55 °F2026-08-30: +0.85 °F2026-08-092026-08-30°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 (22 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+0.85
2026-08-29+6.55
2026-08-28-3.00
2026-08-27+2.55
2026-08-26-1.87
2026-08-25+1.07
2026-08-24+5.32
2026-08-23+2.29
2026-08-22+9.54
2026-08-21+3.45
2026-08-20+6.65
2026-08-19-1.92
2026-08-18-4.87
2026-08-17-1.12
2026-08-16+1.38
2026-08-15-0.25
2026-08-14+1.37
2026-08-13-5.20
2026-08-12-3.24
2026-08-11+4.65
2026-08-10+4.91
2026-08-09+8.70

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KNYC, lead day 8-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 0 days-6 to -5 °F: 1 day-5 to -4 °F: 1 day-4 to -3 °F: 1 day-3 to -2 °F: 1 day-2 to -1 °F: 3 days-1 to 0 °F: 1 day0 to 1 °F: 1 day1 to 2 °F: 3 days2 to 3 °F: 2 days3 to 4 °F: 1 day4 to 5 °F: 2 days5 to 6 °F: 1 day6 to 7 °F: 2 days7 to 8 °F: 0 days8 to 9 °F: 1 day9 to 10 °F: 1 daydashed: P50 |e| 3.12 · P90 |e| 6.64 °F-100+10 °Fn = 22 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
-9.00-8.000
-8.00-7.000
-7.00-6.000
-6.00-5.001
-5.00-4.001
-4.00-3.001
-3.00-2.001
-2.00-1.003
-1.00+0.001
+0.00+1.001
+1.00+2.003
+2.00+3.002
+3.00+4.001
+4.00+5.002
+5.00+6.001
+6.00+7.002
+7.00+8.000
+8.00+9.001
+9.00+10.001

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08223.67 +1.72

Availability

ModelScored period DaysCoverage
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22
NCEP GFS2026-08-09 → 2026-08-30 22

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 22 +1.33 [0.27, 3.15] yes
GraphCast (IFS init) 22 +0.15 [-1.18, 2.51] no
ECMWF IFS HRES 17 +0.18 [-2.24, 3.56] no
Persistence (baseline) 22 +0.26 [-1.34, 2.80] no

Cite this page

ShortCastCheck, KNYC gfs lead 8, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KNYC/model/gfs/lead/8/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KNYC (New York Central Park), model gfs, lead day 8. 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/8/

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