---
license: cc-by-4.0
pretty_name: CastCheck — U.S. station-level temperature forecast verification
tags:
  - weather
  - forecast-verification
  - climate
  - time-series
  - ecmwf
  - gfs
  - graphcast
  - pangu-weather
  - aifs
size_categories:
  - 1M<n<10M
---

# CastCheck — daily station-level verification of public weather forecasts

Independent, automated verification of **raw** 2 m temperature forecasts from operational NWP
(ECMWF IFS HRES, NCEP GFS) and AI models (ECMWF AIFS Single; NOAA/CIRA operational runs of GraphCast,
Pangu-Weather, FourCastNet v2 and Aurora from both GFS and IFS initial conditions) at 23
U.S. first-order stations — 22 major airports plus New York Central Park. The headline metric is the instantaneous 2 m temperature at 00/06/12/18 UTC
against the ASOS observation at the same instants; daily extremes are published as secondary
variables, both like-for-like and against the NWS Daily Climate Report (CLI).

- Site and permanent links: https://castcheck.zifanzhang.com
- Methodology v0.3.1: https://castcheck.zifanzhang.com/methodology/
- Code: https://github.com/ZzZTripleZzZ/castcheck
- Archived: https://doi.org/10.5281/zenodo.22212363
- Updated daily by an automated pipeline. Last push: 2026-10-19 17:35 UTC

## Fairness statement
These are raw model outputs at 0.25°, without MOS, bias correction, or downscaling. They are not
equivalent to the post-processed products end users receive, and scores here understate operational
forecast quality. Every model is sampled at the same four instants, and the headline metric compares
those samples with observations at the same instants, so no part of it depends on a model's own
diurnal amplitude. The extremes verified against the CLI report (`tmax_cli`, `tmin_cli`) carry a
sampling penalty whose size does differ between models, so they are secondary and are never used to
rank (see methodology §2.3).

## Files (schema v0.3)
- `data/forecast_values/model_id=*/year_month=*.parquet` — extracted station values (long format)
- `data/truth_instant/year=*.parquet` — observed 2 m temperature at 00/06/12/18 UTC, with QC flags
- `data/truth_daily/year=*.parquet` — NWS CLI/CF6/observation truth with first-final policy and QC flags
- `data/daily_forecasts/model_id=*/year=*.parquet` — derived sampled/native daily extremes per lead day
- `data/scores/latest.parquet`, `data/scores/pairwise_latest.parquet` — published aggregates with bootstrap CIs

```python
from datasets import load_dataset
ds = load_dataset("castcheck/temperature-verification", data_files="data/scores/latest.parquet")
```

## Sources and licences
ECMWF Open Data (CC-BY-4.0) · NOAA/NCEP GFS (public domain) · NOAA/CIRA AIWP (open data; cite
the AIWP BAMS paper) · NWS climate reports (public domain) · Iowa Environmental Mesonet AFOS archive.
ECMWF data is © ECMWF, licensed under CC-BY-4.0 and used unmodified apart from interpolation to the
station; ECMWF does not endorse this work. This dataset is released under CC-BY-4.0; please cite as
*CastCheck, methodology v0.3.1, doi:10.5281/zenodo.22212363,
https://castcheck.zifanzhang.com (accessed YYYY-MM-DD)*.

## Models
- `ifs_hres` — ECMWF IFS HRES
- `aifs_single` — ECMWF AIFS Single
- `gfs` — NCEP GFS
- `graphcast_ifs` — GraphCast (IFS initial conditions)
- `graphcast_gfs` — GraphCast (GFS initial conditions)
- `pangu_ifs` — Pangu-Weather (IFS initial conditions)
- `pangu_gfs` — Pangu-Weather (GFS initial conditions)
- `fourcastnet_ifs` — FourCastNet v2 (IFS initial conditions)
- `fourcastnet_gfs` — FourCastNet v2 (GFS initial conditions)
- `aurora_ifs` — Aurora (IFS initial conditions)
- `aurora_gfs` — Aurora (GFS initial conditions)

## Stations
- `KNYC` New York Central Park (40.783, -73.967, 46.9 m)
- `KEWR` Newark Liberty (40.682, -74.169, 4.9 m)
- `KPHL` Philadelphia Intl (39.873, -75.227, 2.1 m)
- `KTTN` Trenton Mercer (40.276, -74.816, 64.0 m)
- `KBOS` Boston Logan (42.361, -71.011, 6.1 m)
- `KDCA` Washington Reagan (38.848, -77.034, 4.0 m)
- `KATL` Atlanta Hartsfield (33.640, -84.427, 313.0 m)
- `KMIA` Miami Intl (25.791, -80.316, 3.0 m)
- `KORD` Chicago O'Hare (41.980, -87.904, 203.0 m)
- `KMSP` Minneapolis-St Paul (44.883, -93.229, 256.0 m)
- `KDFW` Dallas-Fort Worth (32.897, -97.022, 164.9 m)
- `KIAH` Houston Bush (29.984, -95.361, 27.1 m)
- `KAUS` Austin Bergstrom (30.183, -97.680, 148.1 m)
- `KSAT` San Antonio Intl (29.533, -98.464, 246.0 m)
- `KMSY` New Orleans Intl (29.993, -90.251, 0.9 m)
- `KOKC` Oklahoma City (35.389, -97.600, 394.1 m)
- `KDEN` Denver Intl (39.847, -104.656, 1647.1 m)
- `KPHX` Phoenix Sky Harbor (33.428, -112.003, 339.9 m)
- `KLAS` Las Vegas Harry Reid (36.072, -115.163, 664.5 m)
- `KLAX` Los Angeles Intl (33.938, -118.389, 38.1 m)
- `KSAN` San Diego Lindbergh (32.734, -117.183, 4.0 m)
- `KSFO` San Francisco Intl (37.620, -122.366, 3.0 m)
- `KSEA` Seattle-Tacoma (47.445, -122.314, 130.1 m)