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 · GraphCast (GFS init) · lead day 1

KNYC · graphcast_gfs · lead 1

Target day = initialization date + 1 day. 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, GRAP_v100, starting 2026-08-28 — 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
tmax00Zbilinear30d1 1 QC2.18 [2.18, 2.18]0.00-2.18 [-2.18, -2.18]2.18 [2.18, 2.18]0% [0%, 0%]0%100%-0.09—2026-08-30 → 2026-08-30
tmax00Zbilinear90d1 1 QC2.18 [2.18, 2.18]0.00-2.18 [-2.18, -2.18]2.18 [2.18, 2.18]0% [0%, 0%]0%100%-0.09—2026-08-30 → 2026-08-30
tmax00Zbilinear365d1 1 QC2.18 [2.18, 2.18]0.00-2.18 [-2.18, -2.18]2.18 [2.18, 2.18]0% [0%, 0%]0%100%-0.09—2026-08-30 → 2026-08-30
tmax00Zbilinearall1 1 QC2.18 [2.18, 2.18]0.00-2.18 [-2.18, -2.18]2.18 [2.18, 2.18]0% [0%, 0%]0%100%-0.09—2026-08-30 → 2026-08-30
tmax00Znearest30d1 1 QC2.05 [2.05, 2.05]0.00-2.05 [-2.05, -2.05]2.05 [2.05, 2.05]0% [0%, 0%]0%100%-0.02—2026-08-30 → 2026-08-30
tmax00Znearest90d1 1 QC2.05 [2.05, 2.05]0.00-2.05 [-2.05, -2.05]2.05 [2.05, 2.05]0% [0%, 0%]0%100%-0.02—2026-08-30 → 2026-08-30
tmax00Znearest365d1 1 QC2.05 [2.05, 2.05]0.00-2.05 [-2.05, -2.05]2.05 [2.05, 2.05]0% [0%, 0%]0%100%-0.02—2026-08-30 → 2026-08-30
tmax00Znearestall1 1 QC2.05 [2.05, 2.05]0.00-2.05 [-2.05, -2.05]2.05 [2.05, 2.05]0% [0%, 0%]0%100%-0.02—2026-08-30 → 2026-08-30
tmax12Zbilinear30d2 1 QC1.25 [0.93, 1.57]0.32-1.25 [-1.57, -0.93]1.29 [0.93, 1.57]50% [0%, 100%]100%100%+0.75+0.942026-08-29 → 2026-08-30
tmax12Zbilinear90d2 1 QC1.25 [0.93, 1.57]0.32-1.25 [-1.57, -0.93]1.29 [0.93, 1.57]50% [0%, 100%]100%100%+0.75+0.942026-08-29 → 2026-08-30
tmax12Zbilinear365d2 1 QC1.25 [0.93, 1.57]0.32-1.25 [-1.57, -0.93]1.29 [0.93, 1.57]50% [0%, 100%]100%100%+0.75+0.942026-08-29 → 2026-08-30
tmax12Zbilinearall2 1 QC1.25 [0.93, 1.57]0.32-1.25 [-1.57, -0.93]1.29 [0.93, 1.57]50% [0%, 100%]100%100%+0.75+0.942026-08-29 → 2026-08-30
tmax12Znearest30d2 1 QC1.01 [0.65, 1.36]0.35-1.01 [-1.36, -0.65]1.07 [0.65, 1.36]50% [0%, 100%]100%100%+0.80+0.932026-08-29 → 2026-08-30
tmax12Znearest90d2 1 QC1.01 [0.65, 1.36]0.35-1.01 [-1.36, -0.65]1.07 [0.65, 1.36]50% [0%, 100%]100%100%+0.80+0.932026-08-29 → 2026-08-30
tmax12Znearest365d2 1 QC1.01 [0.65, 1.36]0.35-1.01 [-1.36, -0.65]1.07 [0.65, 1.36]50% [0%, 100%]100%100%+0.80+0.932026-08-29 → 2026-08-30
tmax12Znearestall2 1 QC1.01 [0.65, 1.36]0.35-1.01 [-1.36, -0.65]1.07 [0.65, 1.36]50% [0%, 100%]100%100%+0.80+0.932026-08-29 → 2026-08-30
tmin00Zbilinear30d1 1 QC0.26 [0.26, 0.26]0.00+0.26 [0.26, 0.26]0.26 [0.26, 0.26]100% [100%, 100%]100%100%+0.91—2026-08-30 → 2026-08-30
tmin00Zbilinear90d1 1 QC0.26 [0.26, 0.26]0.00+0.26 [0.26, 0.26]0.26 [0.26, 0.26]100% [100%, 100%]100%100%+0.91—2026-08-30 → 2026-08-30
tmin00Zbilinear365d1 1 QC0.26 [0.26, 0.26]0.00+0.26 [0.26, 0.26]0.26 [0.26, 0.26]100% [100%, 100%]100%100%+0.91—2026-08-30 → 2026-08-30
tmin00Zbilinearall1 1 QC0.26 [0.26, 0.26]0.00+0.26 [0.26, 0.26]0.26 [0.26, 0.26]100% [100%, 100%]100%100%+0.91—2026-08-30 → 2026-08-30
tmin00Znearest30d1 1 QC0.42 [0.42, 0.42]0.00+0.42 [0.42, 0.42]0.42 [0.42, 0.42]100% [100%, 100%]100%100%+0.86—2026-08-30 → 2026-08-30
tmin00Znearest90d1 1 QC0.42 [0.42, 0.42]0.00+0.42 [0.42, 0.42]0.42 [0.42, 0.42]100% [100%, 100%]100%100%+0.86—2026-08-30 → 2026-08-30
tmin00Znearest365d1 1 QC0.42 [0.42, 0.42]0.00+0.42 [0.42, 0.42]0.42 [0.42, 0.42]100% [100%, 100%]100%100%+0.86—2026-08-30 → 2026-08-30
tmin00Znearestall1 1 QC0.42 [0.42, 0.42]0.00+0.42 [0.42, 0.42]0.42 [0.42, 0.42]100% [100%, 100%]100%100%+0.86—2026-08-30 → 2026-08-30
tmin12Zbilinear30d2 1 QC0.97 [0.83, 1.12]0.14+0.97 [0.83, 1.12]0.98 [0.83, 1.12]50% [0%, 100%]100%100%+0.72+0.962026-08-29 → 2026-08-30
tmin12Zbilinear90d2 1 QC0.97 [0.83, 1.12]0.14+0.97 [0.83, 1.12]0.98 [0.83, 1.12]50% [0%, 100%]100%100%+0.72+0.962026-08-29 → 2026-08-30
tmin12Zbilinear365d2 1 QC0.97 [0.83, 1.12]0.14+0.97 [0.83, 1.12]0.98 [0.83, 1.12]50% [0%, 100%]100%100%+0.72+0.962026-08-29 → 2026-08-30
tmin12Zbilinearall2 1 QC0.97 [0.83, 1.12]0.14+0.97 [0.83, 1.12]0.98 [0.83, 1.12]50% [0%, 100%]100%100%+0.72+0.962026-08-29 → 2026-08-30
tmin12Znearest30d2 1 QC1.17 [1.02, 1.31]0.14+1.17 [1.02, 1.31]1.18 [1.02, 1.31]0% [0%, 0%]100%100%+0.67+0.962026-08-29 → 2026-08-30
tmin12Znearest90d2 1 QC1.17 [1.02, 1.31]0.14+1.17 [1.02, 1.31]1.18 [1.02, 1.31]0% [0%, 0%]100%100%+0.67+0.962026-08-29 → 2026-08-30
tmin12Znearest365d2 1 QC1.17 [1.02, 1.31]0.14+1.17 [1.02, 1.31]1.18 [1.02, 1.31]0% [0%, 0%]100%100%+0.67+0.962026-08-29 → 2026-08-30
tmin12Znearestall2 1 QC1.17 [1.02, 1.31]0.14+1.17 [1.02, 1.31]1.18 [1.02, 1.31]0% [0%, 0%]100%100%+0.67+0.962026-08-29 → 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 GraphCast (GFS init) at KNYC, lead day 1, 00Z bilinear tmax+2.5+1.20-1.2-2.52026-08-30: -2.18 °F2026-08-30°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 (1 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.18

Error distribution

Distribution of the signed daily error in °F for GraphCast (GFS init) at KNYC, lead day 1-2.5 to -2.25 °F: 0 days-2.25 to -2 °F: 1 day-2 to -1.75 °F: 0 days-1.75 to -1.5 °F: 0 days-1.5 to -1.25 °F: 0 days-1.25 to -1 °F: 0 days-1 to -0.75 °F: 0 days-0.75 to -0.5 °F: 0 days-0.5 to -0.25 °F: 0 days-0.25 to 0 °F: 0 days0 to 0.25 °F: 0 days0.25 to 0.5 °F: 0 days0.5 to 0.75 °F: 0 days0.75 to 1 °F: 0 days1 to 1.25 °F: 0 days1.25 to 1.5 °F: 0 days1.5 to 1.75 °F: 0 days1.75 to 2 °F: 0 days2 to 2.25 °F: 0 days2.25 to 2.5 °F: 0 daysdashed: P50 |e| 2.18 · P90 |e| 2.18 °F-2.50+2.5 °Fn = 1 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
-2.50-2.250
-2.25-2.001
-2.00-1.750
-1.75-1.500
-1.50-1.250
-1.25-1.000
-1.00-0.750
-0.75-0.500
-0.50-0.250
-0.25+0.000
+0.00+0.250
+0.25+0.500
+0.50+0.750
+0.75+1.000
+1.00+1.250
+1.25+1.500
+1.50+1.750
+1.75+2.000
+2.00+2.250
+2.25+2.500

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-0812.18 -2.18

Availability

ModelScored period DaysCoverage
GraphCast (GFS init)2026-08-30 → 2026-08-30 1
GraphCast (GFS init)2026-08-30 → 2026-08-30 1
GraphCast (GFS init)2026-08-29 → 2026-08-30 2
GraphCast (GFS init)2026-08-29 → 2026-08-30 2

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means GraphCast (GFS init) has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 1 +2.08 [2.08, 2.08] yes
Aurora (GFS init) 1 +1.94 [1.94, 1.94] yes
Aurora (IFS init) 1 +2.01 [2.01, 2.01] yes
FourCastNet v2 (GFS init) 1 +1.58 [1.58, 1.58] yes
FourCastNet v2 (IFS init) 1 +1.35 [1.35, 1.35] yes
NCEP GFS 1 -5.29 [-5.29, -5.29] yes
GraphCast (IFS init) 1 +0.41 [0.41, 0.41] yes
ECMWF IFS HRES 1 -3.25 [-3.25, -3.25] yes
Pangu-Weather (GFS init) 1 -2.26 [-2.26, -2.26] yes
Pangu-Weather (IFS init) 1 -1.72 [-1.72, -1.72] yes
Persistence (baseline) 1 +0.18 [0.18, 0.18] yes

Cite this page

ShortCastCheck, KNYC graphcast_gfs lead 1, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KNYC/model/graphcast_gfs/lead/1/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KNYC (New York Central Park), model graphcast_gfs, lead day 1. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KNYC/model/graphcast_gfs/lead/1/

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