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 2

KNYC · 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 QC4.14 [3.42, 4.91]3.17+2.47 [1.10, 4.00]4.66 [3.90, 5.39]11% [0%, 26%]18%36%-0.40-0.102026-08-03 → 2026-08-30
tmax00Zbilinear90d28 1 QC4.14 [3.30, 5.28]3.17+2.47 [0.83, 4.65]4.66 [3.72, 5.73]11% [0%, 28%]18%36%-0.40-0.102026-08-03 → 2026-08-30
tmax00Zbilinear365d28 1 QC4.14 [3.26, 5.27]3.17+2.47 [0.61, 4.85]4.66 [3.69, 5.73]11% [0%, 29%]18%36%-0.40-0.102026-08-03 → 2026-08-30
tmax00Zbilinearall28 1 QC4.14 [3.17, 5.25]3.17+2.47 [0.60, 4.58]4.66 [3.62, 5.70]11% [0%, 30%]18%36%-0.40-0.102026-08-03 → 2026-08-30
tmax00Znearest30d28 1 QC4.21 [3.46, 5.00]3.22+2.61 [1.20, 4.12]4.74 [3.96, 5.48]7% [0%, 23%]14%32%-0.42-0.122026-08-03 → 2026-08-30
tmax00Znearest90d28 1 QC4.21 [3.29, 5.36]3.22+2.61 [0.84, 4.74]4.74 [3.81, 5.88]7% [0%, 27%]14%32%-0.42-0.122026-08-03 → 2026-08-30
tmax00Znearest365d28 1 QC4.21 [3.23, 5.40]3.22+2.61 [0.73, 4.95]4.74 [3.72, 5.88]7% [0%, 25%]14%32%-0.42-0.122026-08-03 → 2026-08-30
tmax00Znearestall28 1 QC4.21 [3.16, 5.34]3.22+2.61 [0.70, 4.75]4.74 [3.63, 5.79]7% [0%, 29%]14%32%-0.42-0.122026-08-03 → 2026-08-30
tmax12Zbilinear30d28 1 QC3.77 [2.93, 4.66]2.60+2.79 [1.52, 4.07]4.31 [3.54, 5.06]7% [0%, 21%]21%32%-0.27+0.102026-08-03 → 2026-08-30
tmax12Zbilinear90d28 1 QC3.77 [2.90, 4.80]2.60+2.79 [1.31, 4.40]4.31 [3.42, 5.22]7% [0%, 23%]21%32%-0.27+0.102026-08-03 → 2026-08-30
tmax12Zbilinear365d28 1 QC3.77 [2.82, 4.79]2.60+2.79 [1.17, 4.63]4.31 [3.38, 5.25]7% [0%, 25%]21%32%-0.27+0.102026-08-03 → 2026-08-30
tmax12Zbilinearall28 1 QC3.77 [2.83, 4.82]2.60+2.79 [1.25, 4.58]4.31 [3.43, 5.23]7% [0%, 22%]21%32%-0.27+0.102026-08-03 → 2026-08-30
tmax12Znearest30d28 1 QC3.88 [3.03, 4.76]2.56+3.01 [1.79, 4.27]4.42 [3.61, 5.19]7% [0%, 21%]21%32%-0.31+0.112026-08-03 → 2026-08-30
tmax12Znearest90d28 1 QC3.88 [2.98, 4.95]2.56+3.01 [1.58, 4.60]4.42 [3.49, 5.39]7% [0%, 23%]21%32%-0.31+0.112026-08-03 → 2026-08-30
tmax12Znearest365d28 1 QC3.88 [2.94, 4.94]2.56+3.01 [1.44, 4.81]4.42 [3.44, 5.42]7% [0%, 25%]21%32%-0.31+0.112026-08-03 → 2026-08-30
tmax12Znearestall28 1 QC3.88 [2.97, 4.94]2.56+3.01 [1.51, 4.74]4.42 [3.45, 5.40]7% [0%, 22%]21%32%-0.31+0.112026-08-03 → 2026-08-30
tmin00Zbilinear30d28 1 QC4.46 [3.93, 4.94]1.67+4.46 [3.93, 4.94]4.95 [4.38, 5.43]7% [0%, 17%]18%18%-0.33+0.492026-08-03 → 2026-08-30
tmin00Zbilinear90d28 1 QC4.46 [3.87, 4.97]1.67+4.46 [3.87, 4.97]4.95 [4.36, 5.46]7% [0%, 17%]18%18%-0.33+0.492026-08-03 → 2026-08-30
tmin00Zbilinear365d28 1 QC4.46 [3.82, 4.99]1.67+4.46 [3.82, 4.99]4.95 [4.33, 5.46]7% [0%, 16%]18%18%-0.33+0.492026-08-03 → 2026-08-30
tmin00Zbilinearall28 1 QC4.46 [3.74, 4.98]1.67+4.46 [3.74, 4.98]4.95 [4.24, 5.44]7% [0%, 16%]18%18%-0.33+0.492026-08-03 → 2026-08-30
tmin00Znearest30d28 1 QC4.76 [4.18, 5.28]1.74+4.76 [4.18, 5.28]5.26 [4.65, 5.80]7% [0%, 17%]11%21%-0.42+0.472026-08-03 → 2026-08-30
tmin00Znearest90d28 1 QC4.76 [4.15, 5.34]1.74+4.76 [4.15, 5.34]5.26 [4.62, 5.83]7% [0%, 17%]11%21%-0.42+0.472026-08-03 → 2026-08-30
tmin00Znearest365d28 1 QC4.76 [4.08, 5.34]1.74+4.76 [4.08, 5.34]5.26 [4.62, 5.85]7% [0%, 16%]11%21%-0.42+0.472026-08-03 → 2026-08-30
tmin00Znearestall28 1 QC4.76 [4.02, 5.33]1.74+4.76 [4.02, 5.33]5.26 [4.53, 5.82]7% [0%, 16%]11%21%-0.42+0.472026-08-03 → 2026-08-30
tmin12Zbilinear30d28 1 QC4.52 [4.07, 4.98]1.67+4.52 [4.07, 4.98]5.01 [4.44, 5.51]4% [0%, 11%]11%25%-0.35+0.492026-08-03 → 2026-08-30
tmin12Zbilinear90d28 1 QC4.52 [3.95, 4.98]1.67+4.52 [3.95, 4.98]5.01 [4.32, 5.53]4% [0%, 10%]11%25%-0.35+0.492026-08-03 → 2026-08-30
tmin12Zbilinear365d28 1 QC4.52 [3.88, 4.98]1.67+4.52 [3.88, 4.98]5.01 [4.18, 5.56]4% [0%, 11%]11%25%-0.35+0.492026-08-03 → 2026-08-30
tmin12Zbilinearall28 1 QC4.52 [3.96, 4.99]1.67+4.52 [3.96, 4.99]5.01 [4.24, 5.54]4% [0%, 11%]11%25%-0.35+0.492026-08-03 → 2026-08-30
tmin12Znearest30d28 1 QC4.80 [4.34, 5.26]1.66+4.80 [4.34, 5.26]5.26 [4.67, 5.79]0% [0%, 0%]11%18%-0.43+0.492026-08-03 → 2026-08-30
tmin12Znearest90d28 1 QC4.80 [4.20, 5.25]1.66+4.80 [4.20, 5.25]5.26 [4.52, 5.81]0% [0%, 0%]11%18%-0.43+0.492026-08-03 → 2026-08-30
tmin12Znearest365d28 1 QC4.80 [4.14, 5.27]1.66+4.80 [4.14, 5.27]5.26 [4.40, 5.83]0% [0%, 0%]11%18%-0.43+0.492026-08-03 → 2026-08-30
tmin12Znearestall28 1 QC4.80 [4.23, 5.25]1.66+4.80 [4.23, 5.25]5.26 [4.46, 5.81]0% [0%, 0%]11%18%-0.43+0.492026-08-03 → 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 KNYC, lead day 2, 00Z bilinear tmax+10+50-5-102026-08-03: -4.33 °F2026-08-04: +0.89 °F2026-08-05: +0.82 °F2026-08-06: +3.8 °F2026-08-07: +4.68 °F2026-08-08: +5.02 °F2026-08-09: +6.53 °F2026-08-10: +8.27 °F2026-08-11: +4.83 °F2026-08-12: +3.16 °F2026-08-13: -6.29 °F2026-08-14: +2.87 °F2026-08-15: +0.86 °F2026-08-16: -1.51 °F2026-08-17: +5.09 °F2026-08-18: -2.31 °F2026-08-19: +5.85 °F2026-08-20: -5.36 °F2026-08-21: +5.36 °F2026-08-22: -3.54 °F2026-08-23: +2.91 °F2026-08-24: +2.08 °F2026-08-25: +1.53 °F2026-08-26: +2.57 °F2026-08-27: +5.68 °F2026-08-28: +3.6 °F2026-08-29: +8.1 °F2026-08-30: +8.01 °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+8.01
2026-08-29+8.10
2026-08-28+3.60
2026-08-27+5.68
2026-08-26+2.57
2026-08-25+1.53
2026-08-24+2.08
2026-08-23+2.91
2026-08-22-3.54
2026-08-21+5.36
2026-08-20-5.36
2026-08-19+5.85
2026-08-18-2.31
2026-08-17+5.09
2026-08-16-1.51
2026-08-15+0.86
2026-08-14+2.87
2026-08-13-6.29
2026-08-12+3.16
2026-08-11+4.83
2026-08-10+8.27
2026-08-09+6.53
2026-08-08+5.02
2026-08-07+4.68
2026-08-06+3.80
2026-08-05+0.82
2026-08-04+0.89
2026-08-03-4.33

Error distribution

Distribution of the signed daily error in °F for NCEP GFS at KNYC, lead day 2-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 0 days-7 to -6 °F: 1 day-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: 1 day-1 to 0 °F: 0 days0 to 1 °F: 3 days1 to 2 °F: 1 day2 to 3 °F: 4 days3 to 4 °F: 3 days4 to 5 °F: 2 days5 to 6 °F: 5 days6 to 7 °F: 1 day7 to 8 °F: 0 days8 to 9 °F: 3 days9 to 10 °F: 0 daysdashed: P50 |e| 4.06 · P90 |e| 6.97 °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
-9.00-8.000
-8.00-7.000
-7.00-6.001
-6.00-5.001
-5.00-4.001
-4.00-3.001
-3.00-2.001
-2.00-1.001
-1.00+0.000
+0.00+1.003
+1.00+2.001
+2.00+3.004
+3.00+4.003
+4.00+5.002
+5.00+6.005
+6.00+7.001
+7.00+8.000
+8.00+9.003
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08284.14 +2.47

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 +2.24 [1.35, 3.42] yes
Aurora (IFS init) 1 +6.37 [6.37, 6.37] yes
FourCastNet v2 (IFS init) 1 +7.50 [7.50, 7.50] yes
GraphCast (IFS init) 26 +1.60 [0.47, 3.24] yes
ECMWF IFS HRES 22 +2.16 [1.42, 3.58] yes
Pangu-Weather (IFS init) 1 +4.18 [4.18, 4.18] yes
Persistence (baseline) 28 +1.17 [-0.10, 2.64] no

Cite this page

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

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