HeatCast-W34 Distributional Mesh GNN
HeatCast is a 4,637,891-parameter GraphCast-style mesh graph neural
network for probabilistic warm-season CONUS week-3--4 maximum-temperature
prediction.
Outputs
For every PRISM-grid land cell and lead from day 15 through day 28, HeatCast
produces a Gaussian conditional mean and state-dependent standard deviation.
It does not produce dynamically independent ensemble members.
Files
Each folds/foldN/ directory contains the selected best-monitor model weights
in Safetensors format and the checkpoint architecture metadata. Five
year-disjoint folds are provided.
Intended use
Research on retrospective CONUS MJJAS week-3--4 temperature prediction and
heat-exceedance calibration.
Important limitations
These are research hindcast models, not an operational warning system.
Training and evaluation target PRISM daily maximum temperature over CONUS.
Exact inference requires the HeatCast preprocessing inputs and normalization
conventions described in
MODEL_INPUTS.md.PRISM, ERA5, ECMWF ENS, and other external datasets are not distributed here.
HeatCast weights provide mean and sigma. HeatCast-C probability calibration
and the HeatCast-plus-ENS stack require additional fold-safe calibration and
ECMWF ENS artifacts.
Performance outside CONUS, May through September, or the historical record
has not been established.
Architecture
The model uses grid-to-mesh encoding, an icosahedral multimesh message-passing
processor, multi-lead tube attention, mesh-to-grid decoding, and a
distributional head trained using Gaussian CRPS.
License
MIT for the distributed HeatCast code and weights. External datasets retain
their original terms and licenses.